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. 2026 Jul 2;20(7):e0014450. doi: 10.1371/journal.pntd.0014450

Temporal and spatial patterns of Leprosy in Uganda, 2020–2024: A nationwide surveillance analysis

Gertrude Abbo 1,*, Richard Migisha 1, Emmanuel Mfitundinda 1, Lilian Bulage 1, Geofrey Amanya 2, Alex Mulindwa 2, Rose Kengonzi 2, Stavia Turyahabwe 2, Henry Luzze 2, Benon Kwesiga 1, Alex Riolexus Ario 1
Editor: Anil Fastenau3
PMCID: PMC13345463  PMID: 42391308

Abstract

Introduction

Despite sustained elimination efforts, leprosy transmission persists in Uganda. The World Health Organization’s Towards Zero Leprosy strategy targets zero infections and Grade 2 Disability (G2D) by 2030. Uganda’s National TB and Leprosy Strategic Plan aims to reduce child cases to <3% and G2D to <5%. We assessed temporal trends and spatial distribution of leprosy in Uganda from 2020–2024 to evaluate progress toward these targets.

Methods

We conducted a descriptive analysis using national surveillance data from the District Health Information System 2 (DHIS2). Newly diagnosed leprosy cases reported between 2020 and 2024 were analyzed by age, sex, clinical type, and disability grade. Incidence was calculated using annual mid-year population estimates from the Uganda Bureau of Statistics. Temporal trends were assessed using the Mann–Kendall test and Sen’s slope estimator. Spatial distribution of incidence, child cases, and G2D proportions was examined using QGIS at the regional and district levels.

Results

Between 2020 and 2024, Uganda reported 1,935 new leprosy cases, with an overall incidence of 8.8 per 1,000,000 population. Multibacillary disease accounted for 86% of cases, and 21% presented with Grade 2 Disability (G2D). Children aged ≤15 years comprised 14% of cases, consistently exceeding the national elimination target of 3%. No significant monotonic trend was observed in overall incidence (p = 0.89), child proportion (p = 0.069), or G2D proportion (p = 0.14). Spatial analysis demonstrated persistent concentration of high incidence in the West Nile region, with 9 of 13 districts bearing the highest disease burden. Elevated G2D proportions were observed intermittently in the Teso and Ankole regions.

Conclusion

Leprosy incidence in Uganda remained relatively stable from 2020 to 2024; however, persistently high proportions of multibacillary disease, child cases, and G2D indicate ongoing transmission and delayed diagnosis in specific regions. Targeted interventions, including strengthened contact tracing and active case detection in high-burden areas, are essential to accelerate progress toward national elimination goals.

Introduction

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, which primarily affects the skin, peripheral nerves, upper respiratory tract, and eyes. Delayed diagnosis and older age worsen the progression of physical deformities associated with the disease [1]. The disease has a lengthy and varied incubation period, typically averaging 5 years but potentially extending up to 20 years before symptoms appear [2]. Leprosy primarily spreads through direct or indirect contact between infected individuals and healthy people [3]. For treatment purposes, the World Health Organization (WHO) classifies patients into two categories: paucibacillary (PB), characterized by to five skin lesions, and multibacillary (MB), with six or more lesions. This classification guides appropriate treatment regimens and helps assess the risk of leprosy reactions and nerve damage [4].

Over 120 countries globally are leprosy endemic, with approximately 200,000 new cases reported annually [5]. The world officially achieved elimination of leprosy as a public health issue, defined as a prevalence of <1 per 10,000 population, in the year 2000, in line with the World Health Assembly Resolution 44.9, and in most countries by 2010 [6]. At the end of 2021, the global prevalence of leprosy was 16.9 per million population. By region, the highest prevalence was in Southeast Asia with 81,222 cases (39.4 per million), followed by the Americas with 25,053 cases (24.3 per million), Africa with 20,960 cases (18 per million), the Eastern Mediterranean with 4,206 cases (5.5 per million), and the Western Pacific with 2,360 cases (1.2 per million) [7].

Leprosy remains endemic in Uganda, with 40% of districts reporting at least one case to the National Tuberculosis and Leprosy Program (NTLP) as of 2016 [8]. In 2015/2016, 217 new cases were detected, 69% from the Northern region and 6% in children under 15, indicating ongoing transmission. By the financial year 2021/22, cases increased from 383 to 477, with the proportion of child cases slightly decreasing but still above the National Strategic Plan (NSP) targets [9]. The incidence of G2D also surged to 1.72 per million, over three times the NSP target [10].

Over the past 25 years, Uganda has made considerable progress in the fight against leprosy. The country achieved elimination of Leprosy as a public health problem in 1994 and has sustained this over the years. However, there has been a gradual increase of the number of cases registered in Uganda annually over the past five years, from 121 cases in 2017–388 cases reported in 2021. The number of new cases among children and those identified with major physical disabilities is high at 13% and 21.5%, respectively. The growing trend is due to the reinvigoration of leprosy control services and the ongoing transmission of leprosy in the community [11].

In 2021, the Ministry of Health launched the Community Awareness, Screening, Testing, and Treatment (CAST) Campaign to enhance case-finding for undiagnosed tuberculosis (TB) and leprosy cases, including those missed during the COVID-19 pandemic [12]. This initiative aimed to reduce community transmission and ultimately eliminate TB and leprosy in Uganda. In 2023, Uganda launched its Zero Leprosy Roadmap (2022–2030), a strategic framework designed to strengthen leprosy elimination efforts. Uganda’s National TB and Leprosy Strategic Plan 2020/21–2024/25 identified childhood leprosy and Grade 2 Disability (G2D) at diagnosis as key programme indicators. The plan aimed to reduce the proportion of newly diagnosed leprosy cases occurring among children from 8.6% in 2018 to <3% by 2024/25 and to reduce the proportion of patients presenting with G2D at diagnosis from 13.8% to <5% over the same period [10,13]. Persistently elevated childhood leprosy notifications may indicate sustained transmission, while a high proportion of G2D at diagnosis suggests delayed case detection. Assessing these indicators alongside temporal and spatial patterns of newly diagnosed cases is therefore important for identifying areas where intensified leprosy-control interventions are needed. We described the temporal and spatial patterns of newly diagnosed leprosy cases in Uganda from 2020 to 2024 and assessed progress against selected targets of the Uganda National TB and Leprosy Strategic Plan 2020/21–2024/25.

Methods

Ethics statement

Our study utilized routinely aggregated surveillance data with no personal identifiers in health facility quarterly reports, obtained from the DHIS2. The Uganda Public Health Fellowship Program is part of the National Rapid Response Team and has been granted permission to access and analyze surveillance data in the DHIS2 and other data, such as survey and field investigation data to inform decision-making in the control and prevention of outbreaks and public health programming. Additionally, the Ministry of Health has also granted the program permission to disseminate the information through scientific publications. We stored the abstracted dataset in a password-protected computer and only shared it with the investigation team. This activity was reviewed by the US CDC and was conducted consistent with applicable federal law and CDC policy. §§See, e.g., 45 C.F.R. part 46, 21 C.F.R. part 56; 42 U.S.C. § 241(d); 5 U.S.C. § 552a; 44 U.S.C. § 3501 et seq. All protocols were approved by the US CDC human subjects review board (The National Institute for Occupational Safety and Health Institutional Review Board) and the Uganda Ministry of Health, and were performed in accordance with the Declaration of Helsinki.

Study area and setting

Our study was conducted using data from across Uganda, which is administratively divided into 15 regions: North Central, Tooro, South Central, Acholi, Lango, Karamoja, Kigezi, Teso, Bugisu, Bukedi, Busoga, Bunyoro, Kampala City, Ankole, and West Nile. These regions are further subdivided into 146 districts. Uganda has 155 hospitals, comprising 2 National Referral Hospitals,14 Regional Referral Hospitals (RRHs), and 139 General Hospitals (GHs). Leprosy diagnosis and treatment are provided free of charge in Uganda. Suspected leprosy cases are first seen at lower-level health facilities such as Health Centers II, III, and IV, before referral to hospitals [14]. Currently, six health facilities serve as dedicated leprosy treatment centers: five General Hospitals and one Health Center III, two are located in Eastern Uganda, three in Northern Uganda, and one is situated in Western Uganda [8].

Case definitions and clinical classification

A “new leprosy case” was defined according to national guidelines as a patient newly diagnosed with leprosy during the reporting period who had not previously received multidrug therapy (MDT). Cases were identified through routine health facility reporting to the national District Health Information System (DHIS2).

Leprosy type was classified at the time of diagnosis using World Health Organization (WHO) operational criteria. Paucibacillary (PB) disease was defined as the presence of 1–5 skin lesions without detectable bacilli on slit-skin smear (where available), while multibacillary (MB) disease was defined as >5 skin lesions and/or positive slit-skin smear. In routine practice, classification was primarily based on clinical lesion count.

Disability grading was assessed at diagnosis using the WHO disability grading system. Grade 2 Disability (G2D) was defined as visible deformity or damage attributable to leprosy, including visible muscle weakness, clawing, foot drop, lagophthalmos, or severe visual impairment. Disability grading was performed by trained clinicians at the time of diagnosis and recorded in facility registers before initiation of treatment.

Study design and data source

This study was designed as a descriptive ecological analysis of routinely collected national leprosy surveillance data reported in the DHIS2 from 2020 to 2024. The DHIS2 is a computer-based national health information system where health data are reported weekly, monthly, quarterly, and annually. Because DHIS2 relies on routine reporting, data completeness and accuracy may vary across districts. We assessed reporting consistency by reviewing the completeness of quarterly submissions and cross-checking annual totals.

Since 2012, leprosy cases have been reported quarterly to the Ministry of Health from 5,299 health facilities across 15 administrative health regions. Each facility uses a standardized reporting form to document leprosy cases by week, month, and quarter, categorizing them as new cases, G2D cases, MB and paucibacillary PB cases, and by age group (≥15 years and <15 years). These data are submitted to the Ministry of Health through the monthly Health Management Information System (HMIS) Form 105 and the quarterly HMIS Form 106 in the DHIS2.

Study variables, data abstraction, and analysis

We collected data on leprosy cases categorized by age, sex, type of leprosy, and disability grade. Incidence was calculated by person (sex, age, and disability grade), place (districts), and time (cases reported by quarter). Leprosy incidence was defined as the number of new cases per 1,000,000 population per year. To determine the incidence of leprosy across different demographic groups and districts, we used the number of newly diagnosed cases as the numerator and the baseline population as the denominator. Annual mid-year population projections for 2020–2024 obtained from the Uganda Bureau of Statistics (UBOS) were used as denominators for incidence calculations [15]. Population estimates were disaggregated by sex (male/female), age group (<15 years and ≥15 years), district, and region. These denominators were used to calculate annual incidence rates per 1,000,000 population overall and by demographic subgroup. The denominator values used in the analysis are provided in S1 Table

We summarized national programme indicators annually to describe patterns over time and compare observed values with selected targets in Uganda’s National TB and Leprosy Strategic Plan 2020/21–2024/25. These annual indicators included the new-case detection rate, child-case proportion, child-case detection rate, proportion of newly diagnosed cases presenting with G2D, and G2D detection rate.

For temporal trend analysis, we used quarterly observations to provide sufficient time points and improve temporal resolution. The five-year study period yielded only five annual observations, which were insufficient for a robust monotonic trend assessment. Quarterly aggregation provided 20 observations from 2020 to 2024. We plotted quarterly new-case detection rates and programme indicators and assessed monotonic trends using the Mann–Kendall test. Sen’s slope estimator was used to quantify the magnitude and direction of change per quarter. Data analysis was conducted using R software. To assess recent programme performance, we compared the observed annual indicators with selected targets in Uganda’s National TB and Leprosy Strategic Plan 2020/21–2024/25. We used these comparisons to describe progress against national programme targets.

Results

Annual demographic and clinical characteristics of newly diagnosed leprosy cases, Uganda, 2020–2024

We identified a total of 1,935 leprosy cases from 2020 to 2024, of which 14% were children < 15 years of age, 55% were females, 86% were multi-bacillary, and 21% presented with Grade 2 Disability (G2D) (Table 1). The overall incidence was 8.8/1,000,000.

Table 1. Annual demographic and clinical characteristics of newly diagnosed leprosy cases, Uganda, 2020–2024.

Characteristic 2020

n (%)		 2021

n (%)		 2022

n (%)		 2023

n (%)		 2024

n (%)		 Total

n (%)
Total cases 238 468 591 344 294 1,935
Sex
 Male 126 (53) 217 (46) 263 (45) 144 (42) 124 (42) 874 (45)
 Female 112 (47) 251 (54) 328 (55) 200 (58) 170 (58) 1,061 (55)
Age group
 <15 years 33 (14) 55 (12) 73 (12) 56 (16) 48 (16) 265 (14)
 ≥15 years 205 (86) 413 (88) 518 (88) 288 (84) 246 (84) 1,670 (86)
Type of leprosy
 Multibacillary 211 (89) 357 (76) 539 (91) 300 (87) 256 (87) 1,663 (86)
 Paucibacillary 27 (11) 111 (24) 52 (9) 44 (13) 38 (13) 272 (14)
Disability grade
 G2D 92 (39) 86 (18) 101 (17) 83 (24) 52 (18) 414 (21)
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Values are n (%); G2D: Grade 2 Disability.

Progress against selected national leprosy programme targets

The annual new-case detection rate increased from 5.5 per 1,000,000 population in 2020 to a peak of 13.1 per 1,000,000 in 2022, before declining to 6.4 per 1,000,000 in 2024. The proportion of child cases remained above the national target of <3% throughout the study period, ranging from 12% to 16%. The child-case detection rate similarly peaked in 2022 at 3.5 per 1,000,000 children and declined to 2.3 per 1,000,000 in 2024. The proportion of newly diagnosed cases presenting with Grade 2 Disability (G2D) also remained above the national target of <5%, ranging from 17% to 39%. Although the G2D detection rate fluctuated, it declined overall from 2.1 per 1,000,000 population in 2020 to 1.1 per 1,000,000 in 2024. Multibacillary disease accounted for more than three-quarters of cases in every year, with no consistent temporal pattern (Table 2).

Table 2. Annual national leprosy programme indicators and progress against selected national targets, Uganda, 2020-2024.

Indicator 2020 2021 2022 2023 2024 National target

by 2024/25
Newly diagnosed cases, n 238 468 591 344 294 –
New-case detection rate per 1,000,000 population 5.5 10.6 13.1 7.4 6.4 –
Child cases aged <15 years, n 33 55 73 56 48 –
Child-case proportion, % 14 12 12 16 16 <3
Child-case detection rate per 1,000,000 children 1.7 2.7 3.5 2.6 2.3 –
Cases presenting with G2D, n 92 86 101 83 52 –
Proportion presenting with G2D, % 39 18 17 24 18 <5
G2D detection rate per 1,000,000 population 2.1 2.0 2.2 1.8 1.1 –
Multibacillary cases, n 211 357 539 300 256 –
Multibacillary proportion, % 89 76 91 87 87 –
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G2D: Grade 2 Disability. Rates were calculated using annual mid-year population estimates from the Uganda Bureau of Statistics. National programme targets are < 3% for child cases and <5% for newly diagnosed cases presenting with G2D by 2024/25.

Regional variation in child-case and Grade 2 Disability proportions

The five-year average proportion of child cases exceeded the national target of <3% in several regions, particularly West Nile (18%), Karamoja (10%), Bukedi (8%), Busoga (7%), and Acholi (6%). The average proportion of newly diagnosed cases presenting with Grade 2 Disability (G2D) also exceeded the national target of <5% in most regions. The highest average G2D proportions were observed in Ankole (54%), Teso (41%), West Nile (26%), and Karamoja (20%) (S1 Fig).

Quarterly trends in national new-case detection rates and Grade 2 Disability proportions

Quarterly leprosy incidence fluctuated between approximately 1.0 and 4.0 cases per 1,000,000 population during the study period (Fig 1a). Incidence increased through 2021 and peaked again in mid-2022 before declining in 2023–2024. However, no significant monotonic trend was detected (Mann–Kendall p = 0.89), indicating overall temporal stability in national incidence (S1 Fig). Similarly, the proportion of Grade 2 Disability (G2D) cases varied substantially across quarters, ranging from approximately 2% to 24% (S1 Fig). Although a weak downward tendency was observed (p = 0.14), the trend was not statistically significant. G2D proportions frequently exceeded the 5% programmatic target, with marked short-term variability rather than a sustained decline (S1 Fig).

Fig 1. Temporal trends in the incidence of leprosy and proportion of G2D, Uganda, 2020–2024.

Fig 1

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Quarterly leprosy incidence fluctuated between approximately 1.0 and 4.0 cases per 1,000,000 population during the study period (Fig 1a). Incidence increased through 2021 and peaked again in mid-2022 before declining in 2023–2024. However, no significant monotonic trend was detected (Mann–Kendall p = 0.89), indicating overall temporal stability in national incidence (Fig 1a).

Similarly, the proportion of Grade 2 Disability (G2D) cases varied substantially across quarters, ranging from approximately 2% to 24% (Fig 1b). Although a weak downward tendency was observed (p = 0.14), the trend was not statistically significant. G2D proportions frequently exceeded the 5% programmatic target, with marked short-term variability rather than a sustained decline (Fig 1b).

Overall incidence among children aged <15 years was 0.7 per 1,000,000 population, compared with 3.7 per 1,000,000 among individuals aged ≥15 years (Fig 2). Incidence among those aged ≥15 years peaked in 2021–2022 at approximately 6–6.5 per 1,000,000, then declined in 2023–2024. In contrast, incidence among children remained substantially lower, fluctuating below 1.6 per 1,000,000 (Fig 2). Despite these fluctuations, no statistically significant monotonic trend was observed for either age group (Mann–Kendall p = 0.72 for ≥15 years; p = 0.33 for <15 years), indicating overall temporal stability in age-specific incidence patterns (Fig 2).

Fig 2. Temporal trends of leprosy incidence by age and sex, Uganda, 2020–2024.

Fig 2

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Overall, the incidence of leprosy was higher among females (2.4 per 1,000,000) compared to males (2.0 per 1,000,000) (Fig 2). Incidence in both sexes increased during 2021–2022, peaking at approximately 3.5–4.0 per 1,000,000, before declining in 2023–2024. Although females recorded slightly higher incidence than males in several quarters, the differences were small and inconsistent over time. Mann–Kendall analysis demonstrated no statistically significant monotonic trend for females (τ = 0.08, p = 0.65) or males (τ = −0.11, p = 0.54). Theil–Sen estimates further indicated minimal annual change, confirming overall temporal stability in sex-disaggregated incidence (Fig 2).

The quarterly proportion of child leprosy cases fluctuated between 9% and 22% over the study period and remained consistently above the national target of 3% at all time points (Fig 3). Peaks were observed in mid-2020 (~19%), late-2022 (~18%), late-2023 (~20%), and mid-2024 (~22%), while the lowest values occurred in early-2022 (~10%). Despite short-term variability, the overall pattern showed a weak upward tendency, although the Mann–Kendall test indicated no statistically significant monotonic trend (τ = 0.30, p = 0.069) (Fig 3).

Fig 3. Temporal trend in the proportion of child leprosy cases (<15 years), Uganda, 2020–2024.

Fig 3

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Regions exceeding the national child leprosy target of 3% were geographically clustered in Northern and Eastern Uganda throughout the study period (Fig 4) West Nile exceeded 3% in all five years, indicating persistent clustering. Busoga, Bukedi, and parts of Northern Uganda exceeded 3% in at least three consecutive years, while most Central and Southwestern regions remained ≤3% or reported no child cases. Overall, the number of regions above the 3% threshold ranged from 4 to 7 regions annually, demonstrating sustained spatial concentration of child cases in specific geographic areas (Fig 4).

Fig 4. Spatial distribution of the proportion of child leprosy cases (<15 years), Uganda, 2020–2024.

Fig 4

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Choropleth maps show the proportion of child cases among newly diagnosed leprosy cases by region. Regions are categorized according to the national elimination target (≤3%) and above-target (>3%). Persistent exceedance of the threshold suggests ongoing transmission.

Incidence was concentrated in Northern Uganda throughout the study period. West Nile remained in the highest incidence category (>62 cases per 1,000,000) over the five years (Fig 5). Karamoja and Busoga recorded elevated incidence (≥42 per 1,000,000) for ≥3 years, whereas Central and Southwestern regions consistently reported low incidence (≤20 per 1,000,000). Each year, 1–3 regions fell within the highest incidence category, demonstrating sustained geographic clustering (Fig 5).

Fig 5. Spatial distribution of newly diagnosed leprosy cases, Uganda, 2020–2024.

Fig 5

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Source: https://www.naturalearthdata.com.

Across the study period, G2D proportions demonstrated marked geographic concentration in specific regions rather than uniform distribution nationwide. High G2D proportions (>62%) occurred intermittently and were largely confined to Teso and Ankole, with only one region occupying the highest category (>92%) in any given year. Most regions consistently remained within the lower categories (≤61%), and no sustained nationwide decline in G2D distribution was observed (Fig 6).

Fig 6. Proportion of leprosy cases diagnosed with Grade 2 Disability, Uganda, 2020–2024.

Fig 6

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Source: https://www.naturalearthdata.com.

Discussion

From 2020 to 2024, Uganda reported nearly 2,000 leprosy cases, with an overall incidence of 9 per 1,000,000 population. Most cases were multibacillary, female, and occurred among individuals aged 15 years and above. Notably, 14% of cases were in children under 15 years, consistently exceeding the national elimination target of less than 3%. G2D remained high, averaging 21%, suggesting delays in diagnosis and treatment. The spatial analysis showed persistently high incidence in the West Nile region, with emerging hotspots in the Southwestern and Northeastern regions. Several districts, particularly in central, northeastern, and southwestern Uganda, reported very high G2D rates, further underscoring gaps in early case detection and access to care.

Progress toward Uganda’s national leprosy programme targets remained limited. Child cases accounted for 12%–16% of annual notifications, exceeding the national target of <3%, while 17%–39% of newly diagnosed cases presented with G2D, above the < 5% target. Although the G2D detection rate declined from 2.1 to 1.1 per 1,000,000 population between 2020 and 2024, these persistent gaps suggest ongoing transmission and delayed case detection. These findings underscore the need to strengthen active case detection, contact screening, and timely management, particularly in regions with persistently elevated indicators.

The overall incidence of leprosy in Uganda over the five years was relatively low, with an approximately 9 cases per 1,000,000 population reported. The observed decline in incidence after 2022, while encouraging, was not statistically significant and could reflect underreporting or temporary gains. Continued surveillance, combined with community-based interventions like the CAST campaign [16] and the implementation of the Zero Leprosy Roadmap ([17]), are critical to reversing these trends. The CAST campaign was aimed at identifying undiagnosed cases, including those missed during the COVID-19 pandemic [16], which could explain the rise in reported cases during this period. Despite the heightened case detection efforts, the incidence of leprosy remained way below the threshold for public health elimination, defined as a prevalence of <1 per 10,000 population by the World Health Organization [18].

Of particular concern is the increasing proportion of child leprosy cases, which averaged 13% over the study period and rose to 17% by 2024, substantially exceeding the WHO 2030 target of a 90% reduction in child case rates per million population [18]. Notably, this upward trend in child cases does not necessarily mirror the overall trend in leprosy incidence. The observed increase may partly reflect misdiagnosis or delayed recognition by health workers [19]. Nevertheless, rising child leprosy cases strongly suggest ongoing and recent transmission of Mycobacterium leprae within communities, particularly among vulnerable pediatric populations [20] The occurrence of leprosy in children is a recognized marker of recent transmission and highlights gaps in health system capacity to interrupt exposure pathways [21]. These findings underscore the need to strengthen contact screening, community health education, and the delivery of post-exposure prophylaxis to household and school contacts in high-burden settings, as well as routine health worker orientation on the signs and symptoms of leprosy, to reduce the risk of misdiagnosis and delayed detection.

The observed upward trend in G2D prevalence in Uganda from 2020 to 2024, with a notable surge in 2022, reflects ongoing challenges in early leprosy detection and timely treatment. The increase in districts reporting G2D prevalence >90%, particularly in the Eastern and Central regions, suggests delays in diagnosis and continued community transmission. Similar trends have been documented in other endemic countries. In India, a significant proportion of new leprosy cases presented with G2D, indicating missed opportunities for early detection and intervention [22]. The sharp rise in G2D prevalence in 2022 may also be partially explained by the indirect effects of the COVID-19 pandemic, which disrupted routine health services and reduced case detection globally [23]. Additionally, a multi-country review found a decline in new leprosy case notifications during the pandemic, followed by a rebound that included an increase in the proportion of G2D cases, likely due to delayed diagnosis [24].

The proportion of MB leprosy cases, which are more likely to transmit the disease increased during the study period. The increasing proportion of MB cases may reflect a higher level of active transmission in certain regions, further emphasizing the need for intensified case detection and treatment efforts [25]. These findings align with previous reports indicating that the majority of leprosy cases in Uganda are MB, which is more infectious and poses a greater challenge to control efforts [26].

Spatially, leprosy incidence and G2D clustering in Central, Eastern, and Northeastern Uganda over the years may reflect regional disparities in health system performance, access to leprosy services, or social determinants of health [27]. These findings reinforce the need for regionally tailored responses, including active case-finding, contact tracing, and decentralized rehabilitation services [28].

Our findings reveal critical public health and policy gaps in leprosy control in Uganda, particularly the persistently high burden of multibacillary cases, child leprosy, and G2D, all of which point to delayed diagnosis and ongoing community transmission. The consistent occurrence of new leprosy cases, child cases, and G2D above national targets, highlights an urgent need to strengthen active case finding, contact tracing, and early detection strategies, especially in high-burden regions like West Nile, Busoga, Bukedi, and Karamoja. National policies should prioritize decentralizing leprosy services, integrating leprosy surveillance into routine health systems, and enhancing community awareness and health worker training to improve timely diagnosis, and interrupt transmission.

Study limitations

While our study provides valuable insights into the trends and distribution of leprosy in Uganda, there are some limitations to consider such as the use of surveillance data which may have been incomplete or inconsistently reported across districts, particularly in remote or underserved areas with limited diagnostic capacity. This could have led to an underestimation of the true leprosy burden. To mitigate this, we analyzed multi-year national data from 2020 to 2024 to capture broader trends and applied spatial analysis to identify consistent hotspots and emerging regions of concern. Secondly, reliance on aggregated routine surveillance data limited the ability to assess individual-level risk factors or explore social determinants of delayed diagnosis. To address this, we focused on internationally recognized indicators such as the proportion of child cases, multibacillary forms, and G2D as proxies for transmission intensity and program performance. Additionally, because incidence estimates were based on routinely notified newly diagnosed cases, incomplete case detection or reporting may have resulted in underestimation of the true incidence, particularly in remote or underserved areas with limited diagnostic capacity. Finally, the five-year surveillance period was insufficient for formal application of the WHO Leprosy Elimination Monitoring Tool and classification of regions across elimination phases. Longer-term analyses using the WHO LEMT framework and more detailed regional data are needed to assess progress towards interruption of transmission and elimination of disease.

Conclusion

Uganda continued to report new leprosy cases from 2020 to 2024. The West Nile region consistently recorded the highest new-case detection rates, while elevated G2D proportions occurred intermittently in selected regions, particularly Ankole and Teso. The proportions of child cases and newly diagnosed cases presenting with G2D remained above the national programme targets, indicating continued transmission and delays in diagnosis. Strengthening active case detection, contact screening, timely referral, and post-exposure prophylaxis in high-burden areas will be important for accelerating progress towards national elimination goals. Moreover, further research is critical to identify the factors contributing to persistent incidence, particularly in high-burden regions, to inform more effective and locally tailored strategies.

Supporting information

S1 Table. Annual denominator populations used for incidence calculations, Uganda, 2020–2024.

(PDF)

pntd.0014450.s001.pdf (135.4KB, pdf)
S1 Fig. Regional leprosy incidence and key elimination indicators by region, Uganda, 2020–2024.

(TIFF)

pntd.0014450.s002.tiff (3.1MB, tiff)
S1 Data. Dataset used for the analysis of temporal and spatial patterns of leprosy in Uganda, 2020–2024.

(RAR)

pntd.0014450.s003.rar (5.4KB, rar)

Acknowledgments

The authors thank the staff of the Public Health Fellowship Program for the technical support and guidance offered during this study. The authors also extend their appreciation to the National TB and leprosy program under the Ministry of Health for giving access to data that was used for our analysis.

Disclosure: The funders had no role in the study design, data collection, data analysis, and decision to publish or preparation of the manuscript

Abbreviations

CDC

Centers for Disease Control and Prevention

MOH

Ministry of Health

RRH

Regional Referral Hospital

NTLP

National Tuberculosis and Leprosy Program

PB

Paucibacillary

MB

Multibacillary

G2D

Grade 2 Disability

DHIS2

District Health Information System version 2

NSP

National Strategic Plan

CAST

Community Awareness, Screening, Testing, and Treatment to end TB and Leprosy

Data Availability

The data used in this study are routinely collected surveillance data owned by the Uganda Ministry of Health and accessed through the District Health Information System 2 (DHIS2). The authors do not have authority to publicly release Ministry of Health surveillance data, and access is governed by Ministry of Health data-sharing policies. Researchers who meet the criteria for access to confidential health data may request access through the Uganda National Institute of Public Health (UNIPH), Ministry of Health, Uganda (uniph@health.go.ug). The study also utilized publicly available Uganda Bureau of Statistics population projections, available from: https://www.ubos.org.

Funding Statement

The study was supported by the President’s Emergency Plan for AIDS Relief (PEPFAR) through the United States Centers for Disease Control and Prevention (CDC) Cooperative Agreement Number GH001353-01 awarded through Makerere University School of Public Health to the Uganda Public Health Fellowship Program, Ministry of Health, Uganda. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Consent to participate declaration

This was a descriptive analysis study based on aggregated data obtained from the District Health Information Software 2 (DHIS2), an electronic platform used for routine health data reporting in Uganda. As the analysis was conducted on anonymized, non-individual-level data, no human subjects were directly involved, and ethical approval was not required.

References

PLoS Negl Trop Dis. doi: 10.1371/journal.pntd.0014450.r001

Decision Letter 0

Stuart Blacksell, Anil Fastenau

1 Feb 2026

-->PNTD-D-26-00058

Temporal  and spatial patterns of Leprosy in Uganda, 2020–2024: A nationwide surveillance analysis

PLOS Neglected Tropical Diseases

Dear Dr. Abbo,

Thank you for submitting your manuscript to PLOS Neglected Tropical Diseases. After careful consideration, we feel that it has merit but does not fully meet PLOS Neglected Tropical Diseases's publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Please submit your revised manuscript within by Apr 02 2026 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosntds@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pntd/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

* A letter that responds to each point raised by the editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. This file does not need to include responses to any formatting updates and technical items listed in the 'Journal Requirements' section below.

* A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.

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If you would like to make changes to your financial disclosure, competing interests statement, or data availability statement, please make these updates within the submission form at the time of resubmission. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

We look forward to receiving your revised manuscript.

Kind regards,

Anil Fastenau, M.D., M.Sc.

Guest Editor

PLOS Neglected Tropical Diseases

Stuart Blacksell

Section Editor

PLOS Neglected Tropical Diseases

Shaden Kamhawi

co-Editor-in-Chief

PLOS Neglected Tropical Diseases

orcid.org/0000-0003-4304-636XX

Paul Brindley

co-Editor-in-Chief

PLOS Neglected Tropical Diseases

orcid.org/0000-0003-1765-0002

Journal Requirements:

If the reviewer comments include a recommendation to cite specific previously published works, please review and evaluate these publications to determine whether they are relevant and should be cited. There is no requirement to cite these works unless the editor has indicated otherwise.

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4) In the online submission form, you indicated that The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request and with permission from the Uganda Public Health Fellowship Program (UPHFP). . All PLOS journals now require all data underlying the findings described in their manuscript to be freely available to other researchers, either

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Reviewers' Comments:

Reviewer's Responses to Questions

Key Review Criteria Required for Acceptance?

As you describe the new analyses required for acceptance, please consider the following:

Methods

-Are the objectives of the study clearly articulated with a clear testable hypothesis stated?

-Is the study design appropriate to address the stated objectives?

-Is the population clearly described and appropriate for the hypothesis being tested?

-Is the sample size sufficient to ensure adequate power to address the hypothesis being tested?

-Were correct statistical analysis used to support conclusions?

-Are there concerns about ethical or regulatory requirements being met?

Reviewer #1: The authors used DHIS2 for their analysis but there is no discussion on data quality, reporting biases that are critical for interpreting the observed trends.

Statistical analysis: The Mann-Kendall test is appropriately chosen for trend analysis, but the results are presented without confidence intervals or measures of variability. Although the authors have reported p-values from their analysis, complementary analysis like Theil-Sen Estimator (Sen's Slope) would be handy in illustrating the trend magnitude (effect size).

Incidence calculation: The use of 2024 population estimates as denominators for all years may introduce inaccuracies. The incidence should be calculated using the estimated mid-year population for each year.

Spatial analysis: The description of GIS methods is minimal. Clustering methods (e.g., Moran’s I) should be applied to statistically identify hotspots rather than relying solely on visual inspection.

A sub-analysis for the West Nile region would be helpful. It would answer the question: Is the incidence leprosy uniformly distributed in the West Nile region? This would enable targeted interventions within the region.

Spatial analysis of the child leprosy cases would add a lot value to this paper, since it would point to where leprosy transmission is on-going.

Reviewer #2: This is a well written section overall with a clear objective. The objective does not conclude a hypothesis and its assessment. Consider explicitly stating a priori expectations or clearly position this as hypothesis-generating.

Could you elaborate on the underlying definitions for "new leprosy cases", describing how PB/MB and disability grading were typically measured and classified, and whether this was assigned at diagnosis.

Although this is a descriptive assessment, could you provide some justifications for the trend-testing approach ou used. It is not clear everywhere that the quarterly data was used since there is mentioning of annual reporting. Correct this, otherwise the trend tests with 5 annual points may be underpowered if no quarterly data was used.

This also affects proper display of applying the Mann-Kendall.

The manuscript states that 2024 census population estimates were used as denominators for incidence/prevalence calculations. Using a single-year denominator for multiple years can bias rates. Consider using annual population estimates, or interpolated annual denominators)

Please add some specific details on the GIS mapping part: This should include the shapefile source, mapping unit, classification approach. Also avoid language using "hotspot" or "clusters" unless it relates to a precise method where this is commonly measured.

There is an internal inconsistency: one section indicates ethics approval was not required because data were anonymized and aggregated, while another states protocols were approved by US CDC IRB and Uganda MoH.

Reviewer #3: The objective is clearly stated.

The study design is sound, but the presentation of the data and the conclusions use obsolete techniques and indicators.

**********

Results

-Does the analysis presented match the analysis plan?

-Are the results clearly and completely presented?

-Are the figures (Tables, Images) of sufficient quality for clarity?

Reviewer #1: Table 1 is incomplete; it only shows counts and percentages for sex, type, and G2D but lacks annual breakdowns, or regional data. Annual breakdowns are needed for temporal trends while regional data is needed for spatial trends.

Reviewer #2: Overall, results align broadly with the described descriptive, trend, and spatial mapping approach, but there are presentation inconsistencies that require correction or clarification. See the explanations above on annual or quarterly trend testing. Also look at precise and consistent reporting on incidence vs proportion.

The total in table 1 is not equal the n for less than 15 years and 15 and above years. Please correct and ensure that all subtotals sum to the stated total.

In the age-stratified incidence narrative, there is wording that reads as contradictory (higher incidence in ≥15, then statements suggesting the opposite). Please revise for accuracy and consistency with Figure 2.

The manuscript uses G2D prevalence and regional prevalence (~92%) but appears to be mapping the proportion of new cases with G2D, not population prevalence. Please use correct terminology throughout (proportion among new cases vs prevalence in population).

Key findings are clearly stated. However, readers would benefit from uncertainty measures (CIs) for incidence and proportions, especially when comparing against targets.

Reviewer #3: The authors have the data needed for the analysis (in the national DHIS2 system) but do not use it well.

1. Mapping: it would be much better to use the new WHO tool for geographical analysis - the LEMT, which maps child and adult cases separately, as well as going down to district level, which is much more helpful than the regional level used here. See https://www.who.int/publications/i/item/9789290210474 The LEMT does link directly to DHIS2.

2. Child cases are important as they indicate ongoing transmission, but it is obsolete to focus on the child proportion, which fluctuates too much in relation to changes in the denominator (total cases). It is much better to use the actual number of child cases in situations of decreasing endemicity. Using the LEMT will clearly show the districts (probably not that many) where transmission still occurs, and therefore where intensive case-finding and PEP are required.

3. In general, while disability is important, it is not very useful as an epidemiological indicator. In most cases, the disability rate goes up as incidence goes down and diagnosis is less easy. Figure 6 in this paper is very misleading, as it implies that disability is much worse in the southern regions of Uganda, whereas the denominator (new cases) is so low that the proportion of G2D cases is meaningless. I suggest removing the discussion of G2D. Whoever set a target of 3% for G2D obviously doesn't have much experience of leprosy epidemiology.

A good paper to show how this analysis could be presented is "Iqbal, M., Fastenau, A., Salam, A., Sadia, I. I., Fernandes, I., Murtaza, A., ... & Hasker, E. (2025). Pakistan on the Road to Zero Leprosy, an analysis of routine data for the period 1980–2022: a retrospective cohort study. The Lancet Global Health, 13(8), e1458-e1465."

**********

Conclusions

-Are the conclusions supported by the data presented?

-Are the limitations of analysis clearly described?

-Do the authors discuss how these data can be helpful to advance our understanding of the topic under study?

-Is public health relevance addressed?

Reviewer #1: The conclusion is somewhat vague and could be more specific to the study findings.

The limitations of the analysis are not fully described. For instance, there is no discussion/justification for use of 2024 census data to analyze incidence in 2020. Similarly, variations in reporting rates over the years or in different regions that could skew the interpretation of observed trends are not discussed. The spatial analysis assumes homogenous distribution within the region. The limitation of using proportions to analyze trends grade 2 disability especially in regions notifying few cases in not described.

Reviewer #2: The conclusion that leprosy remains endemic and that high child case proportion and G2D burden indicate ongoing transmission and delayed diagnosis is broadly supported by the presented indicators.

Consider adding potential diagnostic misclassification to the limitations, as well as possible reporting changes during or after the CAST.

The paper provides updated national surveillance evidence and highlights geographic heterogeneity and programmatic red flags, such as child cases, G2D. You could strengthen the interpretation by clearly distinguishing true epidemiologic change from surveillance intensity changes.

I want to thank the authors with this highly relevant contribution to public health, which is directly tied to national and WHO targets and program planning. The recommended actions are very relevant.

Reviewer #3: The conclusions are poorly stated, due to the underlying analysis, which is inadequate.

**********

Editorial and Data Presentation Modifications?

Use this section for editorial suggestions as well as relatively minor modifications of existing data that would enhance clarity. If the only modifications needed are minor and/or editorial, you may wish to recommend “Minor Revision” or “Accept”.

Reviewer #1: Writing and formatting:

- Several typographical errors and inconsistent spacing exist (e.g., lines 9–10, 25–26).

- Abbreviations should be defined at first use (e.g., CAST in line 65 is defined later in the abbreviations list).

- The references are incomplete in the submitted PDF (many URLs are truncated or non-functional).

- Repetitive content: The background and introduction cover similar ground; consider condensing.

- Targets and indicators: The national targets for child cases (<3%) and G2D (<5%) are clearly stated, but their derivation or alignment with WHO thresholds could be briefly explained.

Reviewer #2: Available upon reasonable request with permission may not meet PLOS expectations for unrestricted access to underlying data.

Reviewer #3: The paper has the right approach, but needs to use updated tools and methods.

**********

Summary and General Comments

Use this section to provide overall comments, discuss strengths/weaknesses of the study, novelty, significance, general execution and scholarship. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. If requesting major revision, please articulate the new experiments that are needed.

Reviewer #1: The manuscript addresses an important public health issue with national and global relevance, and the analysis is based on a substantial national dataset. However, the current version has significant methodological gaps, incomplete results presentation and structural issues that hinder its scientific rigor and clarity. With careful revision—particularly in the methods, results presentation, and discussion—the study could make a valuable contribution to the leprosy elimination literature. I recommend major revision with the expectation that the authors will:

1. Clarify and expand the methods section, especially regarding data quality, statistical approaches, and spatial analysis.

2. Provide a complete Table 1 with annual and geographic breakdowns.

3. Strengthen the discussion by better integrating spatial and temporal findings and addressing limitations more explicitly.

4. Ensure consistent and accurate use of epidemiological terms (incidence vs. prevalence).

5. Correct formatting, referencing, and language issues throughout.

Reviewer #2: This is a timely national-level assessment using routine surveillance with policy-relevant indicators aligned with national and WHO targets. The inclusion of spatial distribution adds programmatic value, identifying persistent high-burden regions such as West Nile and shifting high G2D areas.

Reviewer #3: This is a very worthwhile project, but the analysis and presentation of results need to be redone.

**********

PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: Yes: Paul Saunderson

[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

Figure resubmission:

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-->After uploading your figures to PLOS’s NAAS tool - https://ngplosjournals.pagemajik.ai/artanalysis, NAAS will process the files provided and display the results in the "Uploaded Files" section of the page as the processing is complete. If the uploaded figures meet our requirements (or NAAS is able to fix the files to meet our requirements), the figure will be marked as "fixed" above. If NAAS is unable to fix the files, a red "failed" label will appear above. When NAAS has confirmed that the figure files meet our requirements, please download the file via the download option, and include these NAAS processed figure files when submitting your revised manuscript.-->--> -->-->Reproducibility: -->

To enhance the reproducibility of your results, we recommend that authors of applicable studies deposit laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. Additionally, PLOS ONE offers an option to publish peer-reviewed clinical study protocols. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols

-->

Attachment

Submitted filename: Reviewer Report for Manuscript PNTD.docx

pntd.0014450.s004.docx (16.6KB, docx)
PLoS Negl Trop Dis. doi: 10.1371/journal.pntd.0014450.r003

Decision Letter 1

Stuart Blacksell, Anil Fastenau, Stuart Blacksell, Anil Fastenau

14 May 2026

-->PNTD-D-26-00058R1-->-->Temporal  and spatial patterns of Leprosy in Uganda, 2020–2024: A nationwide surveillance analysis-->-->PLOS Neglected Tropical Diseases-->-->Dear Dr. Abbo,-->-->Thank you for submitting your manuscript to PLOS Neglected Tropical Diseases. After careful consideration, we feel that it has merit but does not fully meet PLOS Neglected Tropical Diseases's publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.-->-->Please submit your revised manuscript by Jun 13 2026 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosntds@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pntd/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.-->-->Please include the following items when submitting your revised manuscript:-->-->* A letter that responds to each point raised by the editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. This file does not need to include responses to any formatting updates and technical items listed in the 'Journal Requirements' section below.-->-->* A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.-->-->* An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.-->-->If you would like to make changes to your financial disclosure, competing interests statement, or data availability statement, please make these updates within the submission form at the time of resubmission. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.-->-->As the corresponding author, your ORCID iD is verified in the submission system and will appear in the published article. PLOS supports the use of ORCID, and we encourage all coauthors to register for an ORCID iD and use it as well. Please encourage your coauthors to verify their ORCID iD within the submission system before final acceptance, as unverified ORCID iDs will not appear in the published article. Only the individual author can complete the verification step; PLOS staff cannot verify ORCID iDs on behalf of authors.-->-->We look forward to receiving your revised manuscript.-->-->Kind regards,-->-->Anil Fastenau, M.D., M.Sc.-->-->Guest Editor-->-->PLOS Neglected Tropical Diseases-->-->Stuart Blacksell-->-->Section Editor-->-->PLOS Neglected Tropical Diseases-->-->

Shaden Kamhawi

co-Editor-in-Chief

PLOS Neglected Tropical Diseases

orcid.org/0000-0003-4304-636XX

Paul Brindley

co-Editor-in-Chief

PLOS Neglected Tropical Diseases

orcid.org/0000-0003-1765-0002

-->-->Reviewers' comments: -->-->Reviewer's Responses to Questions

Key Review Criteria Required for Acceptance?

As you describe the new analyses required for acceptance, please consider the following:

Methods

-Are the objectives of the study clearly articulated with a clear testable hypothesis stated?

-Is the study design appropriate to address the stated objectives?

-Is the population clearly described and appropriate for the hypothesis being tested?

-Is the sample size sufficient to ensure adequate power to address the hypothesis being tested?

-Were correct statistical analysis used to support conclusions?

-Are there concerns about ethical or regulatory requirements being met?

Reviewer #1: Study Design

The authors state in line 77-78 the objective of the study as to evaluate Uganda's progress towards leprosy elimination. Use of the WHO Leprosy Elimination Monitoring Tool (LEMT) would be more appropriate if they had data for a longer duration. The LEMT would visualize the temporal & spatial trends and clearly show the progress of the regions towards elimination. For instance, which regions have progressed from phase 1 (until interruption of transmission) to phase 2 (Interruption of transmission until elimination of disease). If the authors opt not to use the LEMT, they should at the minimum compare the rates per million with the elimination targets for 2023 or 2025.

Statistical Analysis

In line 121-125, the authors report using annual mid-year population estimates to calculate the incidence rates. They however do not provide a reference [full citation]or actual denominator values making it hard to reproduce the results. The appropriate reference should include the mid-year population estimates together with the disaggregation by sex (male/female), age (<15 and>/= 15 and the population of the regions.

Reviewer #2: (No Response)

Reviewer #3: The Methods are acceptable.

**********

Results

-Does the analysis presented match the analysis plan?

-Are the results clearly and completely presented?

-Are the figures (Tables, Images) of sufficient quality for clarity?

Reviewer #1: Does the analysis Presented match the analysis plan?

-Table 1 is incomplete [lacks geographical data] making the spatial analysis presented not transparent.

-Temporal trends on the proportion of child leprosy cases have been presented instead of absolute numbers or incidence of child leprosy cases. The proportion of child leprosy cases can increase even if child cases are stable or declining, if adult cases decline faster [ Or decrease even if child cases are rising, if adult cases rise faster].

-Spatial distribution of the proportion of leprosy cases diagnosed with Grade 2 disability has been presented. However, given the variation in the denominator across the regions, the analysis may be misleading. That is; regions with too few notifications may appear to have a disproportionately higher burden of disability due to leprosy.

Are the figures (Tables, Images) of sufficient quality for clarity?

-The authors present number of annual cases in Table 1. However, in figure 1-3, they presented quarterly incidence rates. Figures 1-3 can thus not be reproduced using data in table 1. Unless the authors are interested in seasonal trends, use of annual cases would increase clarity for the readers.

Reviewer #2: Figure cross-reference confusion. Lines 185–190 describe the spatial distribution of child leprosy cases but repeatedly cite "(Figure 5)" when this content corresponds to Figure 4. This appears to be a residual numbering error from the revision and should be corrected before publication.

Mild overclaim in the Conclusion. Line 291–292 states "an increasing rate of child case detection" as a confirmed finding, but the Mann-Kendall result for the child proportion trend was p = 0.069 — not statistically significant. The language should be softened to "a non-significant upward tendency" to stay consistent with the Results section.

Reviewer #3: The analysis is sound.

**********

Conclusions

-Are the conclusions supported by the data presented?

-Are the limitations of analysis clearly described?

-Do the authors discuss how these data can be helpful to advance our understanding of the topic under study?

-Is public health relevance addressed?

Reviewer #1: Discussion:

The authors stated in line 77-78 that the objective of the study is to evaluate the progress towards leprosy elimination. However, the discussion does not clearly show what progress has/has not been made since it is not anchored to elimination targets/ sub-targets. The WHO's "Towards Zero Leprosy" strategy (2021–2030) explicitly targets a 90% reduction in the child case rate per million population by 2030, not a reduction in the proportion of child cases. The authors attempt in lines 241-243 to compare proportions of child leprosy with the 2030 target [in rates per million population, which is confusing. The discussion would be enriched if the authors commented on weather the data [ annual incidence of cases, rate of new cases with G2D per million population and new child cases per million population] compares with the the sub- targets of 2023/ 2025.

Conclusion

In line 291-297, the authors need to clearly indicate if there are any temporal or spatial trends/patterns and what progress has been made towards leprosy elimination (if any).

Reviewer #2: (No Response)

Reviewer #3: The conclusions are reasonable.

**********

Editorial and Data Presentation Modifications?

Use this section for editorial suggestions as well as relatively minor modifications of existing data that would enhance clarity. If the only modifications needed are minor and/or editorial, you may wish to recommend “Minor Revision” or “Accept”.

Reviewer #1: (No Response)

Reviewer #2: Numerical inconsistency in the Discussion. The abstract and Table 1 correctly state that 21% of cases presented with G2D, but line 227 in the Discussion states "G2D remained high, averaging 24%." This discrepancy needs a one-line correction.

Reviewer #3: No comment

**********

Summary and General Comments

Use this section to provide overall comments, discuss strengths/weaknesses of the study, novelty, significance, general execution and scholarship. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. If requesting major revision, please articulate the new experiments that are needed.

Reviewer #1: (No Response)

Reviewer #2: Thank you. The authors handled the major concerns well. Year-specific population denominators are now used correctly. Sen's slope was added alongside Mann-Kendall, which meaningfully improves interpretability. The West Nile sub-analysis (Figure 6) is a genuine addition and not merely cosmetic. The spatial analysis of child cases fills a gap that Reviewer 1 rightly flagged. Case definitions (new case, PB/MB, G2D) are now clearly articulated in the Methods, which was a notable weakness before.

The study addresses a genuine public health need — national leprosy surveillance data from sub-Saharan Africa over a five-year period are rare and valuable. The use of DHIS2 data is appropriate and the limitations are honestly acknowledged. The spatial findings, particularly the persistent West Nile concentration and the child case clustering in Northern and Eastern Uganda, are actionable and well-presented. The journal fit with PLOS NTDs is strong.

After addressing the last minor issues, the manuscript can be accepted for publication.

Reviewer #3: Acceptable.

**********

PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review?  For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

-->-->[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]-->-->Figure resubmission: -->-->-->While revising your submission, we strongly recommend that you use PLOS’s NAAS tool (https://ngplosjournals.pagemajik.ai/artanalysis) to test your figure files. NAAS can convert your figure files to the TIFF file type and meet basic requirements (such as print size, resolution), or provide you with a report on issues that do not meet our requirements and that NAAS cannot fix.-->-->

After uploading your figures to PLOS’s NAAS tool - https://ngplosjournals.pagemajik.ai/artanalysis, NAAS will process the files provided and display the results in the "Uploaded Files" section of the page as the processing is complete. If the uploaded figures meet our requirements (or NAAS is able to fix the files to meet our requirements), the figure will be marked as "fixed" above. If NAAS is unable to fix the files, a red "failed" label will appear above. When NAAS has confirmed that the figure files meet our requirements, please download the file via the download option, and include these NAAS processed figure files when submitting your revised manuscript.-->-->-->Reproducibility: -->-->To enhance the reproducibility of your results, we recommend that authors of applicable studies deposit laboratory protocols in protocols.io, where a protocol can be assigned its own identifier (DOI) such that it can be cited independently in the future. Additionally, PLOS ONE offers an option to publish peer-reviewed clinical study protocols. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols-->

PLoS Negl Trop Dis. doi: 10.1371/journal.pntd.0014450.r005

Decision Letter 2

Stuart Blacksell, Anil Fastenau, Stuart Blacksell, Anil Fastenau, Stuart Blacksell, Anil Fastenau

8 Jun 2026

Dear Field Epidemiology fellow Abbo,

We are pleased to inform you that your manuscript 'Temporal  and spatial patterns of Leprosy in Uganda, 2020–2024: A nationwide surveillance analysis' has been provisionally accepted for publication in PLOS Neglected Tropical Diseases.

Before your manuscript can be formally accepted you will need to complete some formatting changes, which you will receive in a follow up email. A member of our team will be in touch with a set of requests.

Please note that your manuscript will not be scheduled for publication until you have made the required changes, so a swift response is appreciated.

IMPORTANT: The editorial review process is now complete. PLOS will only permit corrections to spelling, formatting or significant scientific errors from this point onwards. Requests for major changes, or any which affect the scientific understanding of your work, will cause delays to the publication date of your manuscript.

Should you, your institution's press office or the journal office choose to press release your paper, you will automatically be opted out of early publication. We ask that you notify us now if you or your institution is planning to press release the article. All press must be co-ordinated with PLOS.

Thank you again for supporting Open Access publishing; we are looking forward to publishing your work in PLOS Neglected Tropical Diseases.

Best regards,

Anil Fastenau, M.D., M.Sc.

Guest Editor

PLOS Neglected Tropical Diseases

Stuart Blacksell

Section Editor

PLOS Neglected Tropical Diseases

Shaden Kamhawi

co-Editor-in-Chief

PLOS Neglected Tropical Diseases

orcid.org/0000-0003-4304-636XX

Paul Brindley

co-Editor-in-Chief

PLOS Neglected Tropical Diseases

orcid.org/0000-0003-1765-0002

***********************************************************

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PLoS Negl Trop Dis. doi: 10.1371/journal.pntd.0014450.r006

Acceptance letter

Stuart Blacksell, Anil Fastenau, Stuart Blacksell, Anil Fastenau, Stuart Blacksell, Anil Fastenau

Dear Field Epidemiology fellow Abbo,

We are delighted to inform you that your manuscript, "Temporal  and spatial patterns of Leprosy in Uganda, 2020–2024: A nationwide surveillance analysis," has been formally accepted for publication in PLOS Neglected Tropical Diseases.

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Best regards,

Shaden Kamhawi

co-Editor-in-Chief

PLOS Neglected Tropical Diseases

Paul Brindley

co-Editor-in-Chief

PLOS Neglected Tropical Diseases

Associated Data

    This section collects any data citations, data availability statements, or supplementary materials included in this article.

    Supplementary Materials

    S1 Table. Annual denominator populations used for incidence calculations, Uganda, 2020–2024.

    (PDF)

    pntd.0014450.s001.pdf (135.4KB, pdf)
    S1 Fig. Regional leprosy incidence and key elimination indicators by region, Uganda, 2020–2024.

    (TIFF)

    pntd.0014450.s002.tiff (3.1MB, tiff)
    S1 Data. Dataset used for the analysis of temporal and spatial patterns of leprosy in Uganda, 2020–2024.

    (RAR)

    pntd.0014450.s003.rar (5.4KB, rar)
    Attachment

    Submitted filename: Reviewer Report for Manuscript PNTD.docx

    pntd.0014450.s004.docx (16.6KB, docx)
    Attachment

    Submitted filename: Point by Point Response to Reviewers revised 19.3.26.docx

    pntd.0014450.s006.docx (26.6KB, docx)
    Attachment

    Submitted filename: Point by Point Response to Reviewers V4.docx

    pntd.0014450.s007.docx (28.5KB, docx)

    Data Availability Statement

    The data used in this study are routinely collected surveillance data owned by the Uganda Ministry of Health and accessed through the District Health Information System 2 (DHIS2). The authors do not have authority to publicly release Ministry of Health surveillance data, and access is governed by Ministry of Health data-sharing policies. Researchers who meet the criteria for access to confidential health data may request access through the Uganda National Institute of Public Health (UNIPH), Ministry of Health, Uganda (uniph@health.go.ug). The study also utilized publicly available Uganda Bureau of Statistics population projections, available from: https://www.ubos.org.

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