Abstract
Background
Transfusion transmissible infections (TTIs) such as Human Immunodeficiency Virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis, remain a major public health concern in low-income countries due to inadequate blood donation systems. This highlights the urgent need for continuous surveillance and a deeper understanding of the factors associated with TTIs in Rwanda.
Methods
A retrospective cross-sectional study analyzed voluntary blood donor records from the National Center for Blood Transfusion (NCBT) in Kigali, Rwanda, spanning January 2019 to December 2023. A census of all available records was used to select 38,345 eligible donors aged 18–60 years. Data were extracted from electronic databases and analyzed using SPSS version 25, with chi-square tests and multivariate logistic regression to identify predictors of transfusion-transmissible infections.
Results
The overall prevalence of transfusion-transmissible infections declined from 2019 to 2023, with HBV decreasing from 0.76% to 0.41%, HCV from 0.30% to 0.18%, HIV remaining stable at 0.04%-0.08%, and syphilis slightly increasing to 0.26%. Multivariate analysis showed that male gender was independently associated with HBV (aOR = 2.60, 95% CI: 1.54–4.38, p < 0.001) and HIV (aOR = 3.84, 95% CI: 1.63–9.05, p = 0.002). First-time donor status was independently associated with higher odds of HBV (aOR = 4.09, 95% CI: 2.26–7.39, p < 0.001) and HIV (aOR = 2.95, 95% CI: 0.77–11.34, p < 0.001). Gasabo district was independently associated with lower odds of HBV (aOR = 0.56, 95% CI: 0.34–0.90, p = 0.017) and higher odds of HCV (aOR = 2.34, 95% CI: 1.25–4.40, p = 0.008), relative to Nyarugenge.
Conclusion
TTI prevalence among Kigali blood donors remained low with declining HBV and HCV trends from 2019 to 2023, while HIV rates stayed consistently low. Male gender, older age, first-time donor status, and specific occupations were independently associated with TTI positivity. Rwanda’s blood screening protocols appear effective, though targeted interventions for high-risk groups and continued surveillance are recommended.
Clinical trial number
Not applicable.
Keywords: Transfusion-transmissible infections, Voluntary blood donors, Kigali, Rwanda
Background
Every year, timely blood transfusions save countless number of lives worldwide [1]. However, unsafe transfusion practices can also expose millions of individuals to transfusion transmissible infections (TTIs) [2], including syphilis, hepatitis B, hepatitis C, and Human Immunodeficiency Virus ( HIV), thereby threatening patients’ well-being [3]. Additionally, the risk of TTIs is disproportionately higher in developing nations compared to high-income countries [4]. According to the WHO global database on blood safety (2025), while high-income countries report 99.9% successful screening of donated blood, low-income countries achieve only 76.2%. Consequently, the prevalence of TTIs is highest in resource-limited settings [5].
Studies across the east African region have reported varying rates of TTIs among blood donors. In neighboring countries, prevalence rates ranged from 1.04% to 10.1%, with Tanzania reporting 10.1% in its northern region and 8.4% in Dar es Salaam [6]. In Uganda, the frequency of HCV among blood donors was 7.8% [7], while in Burundi, HBV and HCV were found in 1.04% and 1.12% of blood donors, respectively [8].
In Rwanda, studies have reported varying prevalence rates of TTIs among blood donors. For instance, a study in the western province found a TTI prevalence rate of 2.1% in 2016 [9]. Furthermore, in Rwanda a study conducted on the general population revealed that 4.1% of the first-time donors were infected with Hepatitis B (HBV Ag) [10], highlighting a significant concern for blood safety, especially in regions with high-risk populations.
In Rwanda the National Center for Blood Transfusion (NCBT) oversees, blood donation and transfusion services and significant efforts have been made to reduce the risk of TTIs through improved detection methods and enhanced blood safety measures [9]. Despite these efforts, TTIs continue to pose a public health challenge in Rwanda [11]. NCBT has five regional/provincial NCBTs and we are interested in one of them (NCBT Kigali). Studies conducted in various regions of Rwanda have highlighted the prevalence of TTIs, with Hepatitis B being the most common [8–10]. While previous Rwandan studies reported TTI prevalence in provincial areas, limited data exist on socio-demographic correlates among voluntary donors in Kigali, which serves as the main transfusion hub. This study aims to address this gap by investigating the prevalence and factors associated with TTIs among blood donors in Kigali.
Methods
Study design
The study used a retrospective cross-sectional design with quantitative approach, analyzing records of voluntary Blood donor and TTIs at the NCBT in Kigali, Rwanda from January 2019 to December 2023.
Study setting
The study was conducted in City of Kigali. Rwanda’s capital, which spans 730km2 and includes three Districts: Gasabo, Kicukiro and Nyarugenge. With a population of 1,745,555. Kigali has three major tertiary hospitals and a higher HIV prevalence (3.7%) compared to rural areas (2.5%). In Rwanda, in City of Kigali, a main NCBT oversee, blood donation and transfusion services.
Study population
The study population comprised all voluntary blood donors in Kigali City, both males and females, aged between 18 and 60 years, who donated blood during the five-year period from January 2019 to December 2023.
Inclusion and exclusion criteria
Donors were included if they were within the acceptable age range, weighed 50 kg or more, had no deferral for blood donation, and had provided informed consent prior to donation. This study excluded anyone who had a deferral for blood donation.
Sampling technique
A census of all available records was employed to retrospectively (from 2019 to 2023) select 38,345 donor records that met the study’s eligibility criteria.
Data collection and measurement
This study utilized existing data from the NCBT in Kigali, systematically retrieving information from donor records and laboratory screening reports spanning January 2019 to December 2023. The questionnaire was tested prior to data collection. Data were sourced from records of voluntary blood donors who donated through regional transfusion centers under the Rwanda Biomedical Center (RBC). All collected blood samples were screened for TTIs, specifically HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis, using standardized serological methods performed on both serum and plasma samples. Donor profiles, including key demographic characteristics such as age, gender, occupation, blood group, and place of residence, were extracted and systematically recorded on pre-prepared data collection forms. The dependent variable in this study was the presence of any one of the screened TTIs. A donor was classified as having a TTI if they tested positive for at least one of the infections during the screening process.
Variable definition
Outcome variable
The primary outcome was defined as testing positive for at least one transfusion-transmissible infection (TTI) among the four pathogens screened: syphilis, HBV, HCV, or HIV. All blood donations underwent mandatory screening using enzyme-linked immunosorbent assay (ELISA) for HIV (anti-HIV-1/2 antibodies), HBsAg for hepatitis B, anti-HCV antibodies for hepatitis C, and anti-Treponema pallidum antibodies for syphilis, following national blood safety protocols. Donors were classified as positive for a specific infection if their screening test was reactive; repeatedly reactive samples were considered positive as per national transfusion service guidelines, and any indeterminate results were excluded from the analysis. The outcome variable was operationalized as a binary measure (positive vs. negative), where donors testing positive for any one or more of these four infections were categorized as TTI-positive, while those testing negative for all four pathogens were classified as TTI-negative.
Independent variables
Independent variables included gender (male/female), age group (18–25, 26–35, 36–45, 46–55, 56–65 years), marital status (married/single), occupation (military, private employed, public servant, security, self-employed, student, unemployed), blood group (A, AB, B, O types), donation frequency (new donor/regular donor), and geographical location (Gasabo, Kicukiro, Nyarugenge districts). These variables were chosen based on the available records, informed by prior research or a literature review.
Data analysis
The test results for syphilis, HBV, HCV and HIV for all donors were extracted from the eProgesa electronic database maintained by the main NCBT. These data were first organized in Microsoft Excel and subsequently imported into Statistical Package for the Social Sciences (SPSS) version 25 for analysis. The analysis was stratified by the three districts of Kigali City: Gasabo, Kicukiro, and Nyarugenge. Donor characteristics, including age, gender, blood group, and occupation, donation frequency, and geographical location were used to explore the epidemiological distribution of TTIs. And also, we stratified the analysis by type of infection (HBV, HCV, syphilis, and HIV). Prevalence of TTIs was calculated as the proportion of infected donations divided by the total number of donations (not unique donors, as repeat donations were included). The Pearson Chi-square test was applied to assess the association between the presence of TTIs (syphilis, HBV, HCV, and HIV) and the independent variables. Missing data were assessed for all variables, with less than 2% missingness observed for socio-demographic variables and complete case analysis was employed whereby records with any missing values for the variables of interest were excluded from the respective analyses. Variables with a p-value < 0.05 in the bivariate analysis were retained for multivariate logistic regression, to allow for the inclusion of potentially relevant factors. Logistic regression analysis was then conducted to identify potential risk factors of TTIs, with odds ratios (aORs) and 95% confidence intervals (CIs) reported for each significant variable. A p-value of less than 0.05 was considered statistically significant for all analyses.
Ethical considerations
This study received ethical approval from the institutional review board of Rwanda Biomedical Center (Ref: No. 4092/RBC/2024), and Mount Kenya University (Ref: MKU/ETHICS/23/01/2024). Secondary data were obtained from the NCBT donor database and were handled with strict confidentiality. All personal identifiers were removed, and data were anonymized using unique codes. Access was restricted to authorized personnel, and data were stored securely on password-protected devices. Informed consent was not applicable in the study as it employed secondary data This study was conducted in accordance with the ethical standards of our institutional review board and with the 1964 Helsinki Declaration and its later amendments.
Results
Socio-demographic characteristics of participants
Table 1, shows the socio-demographic characteristics of voluntary blood donors in Kigali from 2019 − 2013. Among 38,345 voluntary blood donors in Kigali from 2019 to 2023 representing 100% with men age of 33 ± 27, the overall transfusion-transmissible infection (TTI) prevalence was 1.05% (402 cases). New donors had a substantially higher TTI positivity rate (81.1% of positive cases versus 37.6% of total donors), while the demographic distribution of TTI-positive donors largely mirrored the overall donor population across gender (79.1% male), age groups (predominantly 36–45 years), marital status, occupation, blood type (60% Type O), and district location.
Table 1.
Socio-demographic characteristics of voluntary blood donors in Kigali from 2019 to 2023, stratified by TTI status
| Variables | Overall (N = 38,345) | TTI Negative (n = 37,943) | TTI Positive (n = 402) | |||
|---|---|---|---|---|---|---|
| n | % | n | % | n | % | |
| Year | ||||||
| 2019 | 6084 | 15.9 | 5997 | 15.8 | 87 | 21.6 |
| 2020 | 4925 | 12.8 | 4871 | 12.8 | 54 | 13.4 |
| 2021 | 7817 | 20.4 | 7734 | 20.4 | 83 | 20.7 |
| 2022 | 8927 | 23.3 | 8845 | 23.3 | 82 | 20.4 |
| 2023 | 10,592 | 27.6 | 10,496 | 27.7 | 96 | 23.9 |
| Gender | ||||||
| Female | 8473 | 22.1 | 8389 | 22.1 | 84 | 20.9 |
| Male | 29,872 | 77.9 | 29,554 | 77.9 | 318 | 79.1 |
| Age group (year) | ||||||
| 18–25 | 4536 | 11.8 | 4488 | 11.8 | 48 | 11.9 |
| 26–35 | 13,031 | 34 | 12,893 | 34 | 138 | 34.3 |
| 36–45 | 15,127 | 39.5 | 14,967 | 39.4 | 160 | 39.8 |
| 46–55 | 4727 | 12.3 | 4677 | 12.3 | 50 | 12.4 |
| 56–65 | 924 | 2.4 | 918 | 2.4 | 6 | 1.5 |
| Marital status | ||||||
| Married | 23,365 | 60.9 | 23,118 | 60.9 | 247 | 61.4 |
| Single | 14,980 | 39.1 | 14,825 | 39.1 | 155 | 38.6 |
| Occupation | ||||||
| Military | 12,387 | 32.3 | 12,256 | 32.3 | 131 | 32.6 |
| Private employed | 5768 | 15 | 5707 | 15 | 61 | 15.2 |
| Public servant | 1607 | 4.2 | 1590 | 4.2 | 17 | 4.2 |
| Security | 1229 | 3.2 | 1216 | 3.2 | 13 | 3.2 |
| Self employed | 10,784 | 28.1 | 10,670 | 28.1 | 114 | 28.4 |
| Student | 3499 | 9.1 | 3462 | 9.1 | 37 | 9.2 |
| Unemployed | 3071 | 8 | 3042 | 8 | 29 | 7.2 |
| Blood group | ||||||
| A Type | 6715 | 17.5 | 6644 | 17.5 | 71 | 17.7 |
| AB Type | 1797 | 4.7 | 1778 | 4.7 | 19 | 4.7 |
| B Type | 6715 | 17.5 | 6644 | 17.5 | 71 | 17.7 |
| O Type | 23,118 | 60.3 | 22,877 | 60.3 | 241 | 60 |
| Frequency of donation | ||||||
| New donor | 14,406 | 37.6 | 14,080 | 37.1 | 326 | 81.1 |
| Regular | 23,939 | 62.4 | 23,863 | 62.9 | 76 | 18.9 |
| Location/District | ||||||
| Gasabo | 15,614 | 40.7 | 15,449 | 40.7 | 165 | 41 |
| Kicukiro | 11,732 | 30.6 | 11,608 | 30.6 | 124 | 30.9 |
| Nyarugenge | 10,999 | 28.7 | 10,886 | 28.7 | 113 | 28.1 |
TTI: Transfusion transmissible infection, HBV: Hepatitis B virus, HCV: Hepatitis C virus, HIV: Human Immunodeficiency virus
Prevalence of HIV, HBV, HCV, and syphilis among the blood donors in 2019–2023
The Table 2, The overall TTI prevalence among voluntary blood donors in Kigali from 2019 to 2023 was 1.05%, with HBV being the most common infection (0.49%), followed by HCV (0.26%), syphilis (0.24%), and HIV (0.06%). A notable declining trend was observed in overall TTI prevalence, decreasing from 1.43% in 2019 to 0.91% in 2023, primarily driven by reductions in HBV (0.76% to 0.41%) and HCV (0.30% to 0.18%), while HIV prevalence remained consistently low throughout the study period at approximately 0.06%, and syphilis showed fluctuation with a slight increase in 2023 (0.26%) compared to previous years.
Table 2.
Prevalence of HIV, HBV, HCV, and syphilis among voluntary blood donors in Kigali, NCBT 2019 to 2023
| Variables | HBV | HCV | HIV | Syphilis | Any TTI | No TTI | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | % | n | % | n | % | n | % | n | % | n | % | |
| Overall (2019–2023) | 186 | 0.49 | 99 | 0.3 | 23 | 0.06 | 93 | 0.24 | 402 | 1.05 | 37,943 | 98.95 |
| Year | ||||||||||||
| 2019 | 46 | 0.76 | 18 | 0.3 | 4 | 0.07 | 19 | 0.31 | 87 | 1.43 | 5,997 | 98.57 |
| 2020 | 22 | 0.45 | 15 | 0.3 | 2 | 0.04 | 14 | 0.28 | 54 | 1.1 | 4,871 | 98.9 |
| 2021 | 35 | 0.45 | 28 | 0.4 | 6 | 0.08 | 14 | 0.18 | 83 | 1.06 | 7,734 | 98.94 |
| 2022 | 40 | 0.45 | 19 | 0.2 | 5 | 0.06 | 18 | 0.2 | 82 | 0.92 | 8,845 | 99.08 |
| 2023 | 43 | 0.41 | 19 | 0.2 | 6 | 0.06 | 28 | 0.26 | 96 | 0.91 | 10,496 | 99.09 |
Note: Denominators for prevalence calculations: 2019 (N = 6,084), 2020 (N = 4,925), 2021 (N = 7,817), 2022 (N = 8,927), 2023 (N = 10,592); Overall (N = 38,345). Percentages represent the proportion of donors testing positive or negative for TTIs. HBV=Hepatitis B Virus; HCV=Hepatitis C Virus; HIV=Human Immunodeficiency Virus; TTI=Transfusion-Transmissible Infection
Factors associated with TTIs among voluntary blood donors in Kigali city
The bivariate analysis reveals several significant factors associated with transfusion-transmissible infections among blood donors (Table 3). HBV positivity was significantly more common among males (87.1%, p < 0.001), and HIV positivity was more common among males (52.2%, p = 0.001). Age was significantly associated with HCV positivity, with higher rates observed in the 26–45 age groups (p = 0.043). Occupational status was significantly associated with both HBV and syphilis positivity, with HBV and syphilis both more common among military personnel (23.66% for HBV, p = 0.003; 40.86% for syphilis, p = 0.023). Blood group A was associated with significantly higher HBV positivity (17.74%, p = 0.018), and donation frequency was significantly associated with positivity, with new donors showing significantly higher rates of both HBV (91.40%, p < 0.001) and syphilis (67.74%, p < 0.001) compared to regular donors. Geographic location was also associated with infection patterns, with significantly higher syphilis positivity observed in Gasabo district (49.46%, p = 0.024), and marital status was significantly associated with syphilis positivity among married individuals (70.97%, p = 0.031).
Table 3.
Bivariate analysis for factors associated with TTIs among the voluntary blood donors
| Study characteristics | HBV | HCV | HIV | Syphilis | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Positive N (%) | Negative N (%) | p-value | Positive N (%) | Negative N (%) | p-value | Positive N (%) | Negative N (%) | p-value | Positive N (%) | Negative N (%) | p-value | |
| Gender | ||||||||||||
| Female | 24 (12.9%) | 4924 (12.9%) | <0.001 | 23 (23.0%) | 8796 (23.0%) | 0.550 | 11 (47.8%) | 18328 (47.8%) | 0.001 | 26 (28.0%) | 10694 (28.0%) | 0.056 |
| Male | 162 (87.1%) | 33235 (87.1%) | 77 (77.0%) | 29449 (77.0%) | 12 (52.2%) | 19994 (52.2%) | 67 (72.0%) | 27558 (72.0%) | ||||
| Age group (year) | ||||||||||||
| 18–25 | 23 (12.4%) | 4719 (12.4%) | 0.579 | 17 (17.0%) | 6502 (17.0%) | 0.043 | 4 (17.4%) | 6665 (17.4%) | 0.507 | 4 (4.3%) | 1645 (4.3%) | 0.125 |
| 26–35 | 68 (36.6%) | 13951 (36.6%) | 32 (32.0%) | 12238 (32.0%) | 5 (21.7%) | 8331 (21.7%) | 33 (35.5%) | 13573 (35.5%) | ||||
| 36–45 | 72 (38.7%) | 14771 (38.7%) | 34 (34.0%) | 13003 (34.0%) | 12 (52.2%) | 19994 (52.2%) | 42 (45.2%) | 17275 (45.2%) | ||||
| 46–55 | 22 (11.8%) | 4513 (11.8%) | 13 (13.0%) | 4972 (13.0%) | 2 (8.7%) | 3332 (8.7%) | 13 (14.0%) | 5347 (14.0%) | ||||
| 56–65 | 1 (0.5%) | 205 (0.5%) | 4 (4.0%) | 1530 (4.0%) | 0 (0.0%) | 0 (0.0%) | 1 (1.1%) | 411 (1.1%) | ||||
| Marital status | ||||||||||||
| Married | 107 (57.5%) | 21952 (57.5%) | 0.134 | 58 (58.0%) | 22182 (58.0%) | 0.414 | 16 (69.6%) | 26659 (69.6%) | 0.410 | 66 (71.0%) | 27147 (71.0%) | 0.031 |
| Single | 79 (42.5%) | 16207 (42.5%) | 42 (42.0%) | 16063 (42.0%) | 7 (30.4%) | 11663 (30.4%) | 27 (29.0%) | 11105 (29.0%) | ||||
| Occupation | ||||||||||||
| Military | 44 (23.7%) | 9027 (23.7%) | 0.003 | 44 (44.0%) | 16828 (44.0%) | 0.091 | 5 (21.7%) | 8331 (21.7%) | 0.652 | 38 (40.9%) | 15630 (40.9%) | 0.023 |
| Private employed | 33 (17.7%) | 6770 (17.7%) | 13 (13.0%) | 4972 (13.0%) | 4 (17.4%) | 6665 (17.4%) | 11 (11.8%) | 4524 (11.8%) | ||||
| Public servant | 13 (7.0%) | 2667 (7.0%) | 2 (2.0%) | 765 (2.0%) | 2 (8.7%) | 3332 (8.7%) | 0 (0.0%) | 0 (0.0%) | ||||
| Security | 4 (2.2%) | 821 (2.2%) | 4 (4.0%) | 1530 (4.0%) | 0 (0.0%) | 0 (0.0%) | 5 (5.4%) | 2057 (5.4%) | ||||
| Self employed | 55 (29.6%) | 11284 (29.6%) | 20 (20.0%) | 7649 (20.0%) | 9 (39.1%) | 14996 (39.1%) | 30 (32.3%) | 12339 (32.3%) | ||||
| Student | 21 (11.3%) | 4308 (11.3%) | 10 (10.0%) | 3824 (10.0%) | 2 (8.7%) | 3332 (8.7%) | 4 (4.3%) | 1645 (4.3%) | ||||
| Unemployed | 16 (8.6%) | 3282 (8.6%) | 7 (7.0%) | 2677 (7.0%) | 1 (4.3%) | 1666 (4.3%) | 5 (5.4%) | 2057 (5.4%) | ||||
| Blood group | ||||||||||||
| A Type | 33 (17.7%) | 6770 (17.7%) | 0.018 | 22 (22.0%) | 8414 (22.0%) | 0.121 | 4 (17.4%) | 6665 (17.4%) | 0.963 | 12 (12.9%) | 4936 (12.9%) | 0.241 |
| AB Type | 10 (5.4%) | 2052 (5.4%) | 3 (3.0%) | 1147 (3.0%) | 1 (4.3%) | 1666 (4.3%) | 5 (5.4%) | 2057 (5.4%) | ||||
| B Type | 21 (11.3%) | 4308 (11.3%) | 23 (23.0%) | 8796 (23.0%) | 5 (21.7%) | 8331 (21.7%) | 22 (23.7%) | 9049 (23.7%) | ||||
| O Type | 122 (65.6%) | 25029 (65.6%) | 52 (52.0%) | 19887 (52.0%) | 13 (56.5%) | 21660 (56.5%) | 54 (58.1%) | 22211 (58.1%) | ||||
| Frequency of donation | ||||||||||||
| New donor | 170 (91.4%) | 34877 (91.4%) | < 0.001 | 76 (76.0%) | 29066 (76.0%) | 0.133 | 17 (73.9%) | 28325 (73.9%) | 0.365 | 63 (67.7%) | 25913 (67.7%) | < 0.001 |
| Regular | 16 (8.6%) | 3282 (8.6%) | 24 (24.0%) | 9179 (24.0%) | 6 (26.1%) | 9997 (26.1%) | 30 (32.3%) | 12339 (32.3%) | ||||
| Location (District) | ||||||||||||
| Gasabo | 68 (36.6%) | 13951 (36.6%) | 0.051 | 41 (41.0%) | 15680 (41.0%) | 0.999 | 10 (43.5%) | 16662 (43.5%) | 0.965 | 46 (49.5%) | 18920 (49.5%) | 0.024 |
| Kicukiro | 55 (29.6%) | 11284 (29.6%) | 31 (31.0%) | 11856 (31.0%) | 7 (30.4%) | 11663 (30.4%) | 31 (33.3%) | 12751 (33.3%) | ||||
| Nyarugenge | 63 (33.9%) | 12925 (33.9%) | 28 (28.0%) | 10709 (28.0%) | 6 (26.1%) | 9997 (26.1%) | 16 (17.2%) | 6581 (17.2%) | ||||
HBV: Hepatitis B virus, HCV: Hepatitis C virus, HIV: Human Immunodeficiency virus HBV: Hepatitis B virus, HCV: Hepatitis C virus, HIV: Human Immunodeficiency virus
Multivariate logistic analysis for factors associated with TTIs among the voluntary blood donors
The multivariate logistic regression analysis of TTIs among voluntary blood donors, several factors were independently associated with TTI positivity across different infection types (Table 4). For HBV, males had 2.6 times higher odds of HBV positivity compared to females (aOR = 2.60, 95% CI: 1.54–4.38, p < 0.001), while donors aged 26–35 and 36–45 years had 85% and 86% lower odds of HBV positivity, respectively (aOR = 0.15, 95% CI: 0.03–0.86, p = 0.033; aOR = 0.14, 95% CI: 0.02–0.77, p = 0.024). Public servant occupation was independently associated with higher odds of HBV positivity (aOR = 7.31, 95% CI: 1.44–37.16, p = 0.016), and new donor status was independently associated with over 4 times higher odds of HBV positivity than regular donors (aOR = 4.09, 95% CI: 2.26–7.39, p < 0.001). For Hepatitis C virus (HCV), married status was independently associated with higher odds of HCV positivity (aOR = 1.73, 95% CI: 1.05–2.86, p = 0.032), while student occupation was independently associated with 81% lower odds of HCV positivity (aOR = 0.19, 95% CI: 0.04–0.89, p = 0.035). HIV positivity was significantly associated with male gender (aOR = 3.84, 95% CI: 1.63–9.05, p = 0.002) and new donor status (aOR = 2.95, 95% CI: 0.77–11.34, p < 0.001). Geographic location showed contrasting patterns of association, with Gasabo district showing 44% lower odds of HBV positivity (aOR = 0.56, 95% CI: 0.34–0.90, p = 0.017) but 2.3 times higher odds of HCV positivity (aOR = 2.34, 95% CI: 1.25–4.40, p = 0.008) compared to Nyarugenge district, while Kicukiro district showed double the odds of HCV positivity (aOR = 2.02, 95% CI: 1.04–3.94, p = 0.039) with no significant HBV association.
Table 4.
Multivariate logistic analysis for factors associated with TTIs type among the voluntary blood donor
| Characteristics | HBV | HCV | HIV | Syphilis | ||||
|---|---|---|---|---|---|---|---|---|
| aOR (95% CI) | P-value | aOR (95% CI) | P-value | aOR (95% CI) | P-value | aOR (95% CI) | P-value | |
| Gender | ||||||||
| Female | Ref | Ref | ||||||
| Male | 2.60(1.54–4.38) | < 0.001 | 3.84(1.63–9.05) | 0.002 | 0.60(0.35–1.02) | 0.058 | ||
| Age group (year) | ||||||||
| 18–25 | 0.27(0.05–1.66) | 0.158 | 0.46(0.04–4.90) | 0.516 | ||||
| 26–35 | 0.15(0.03–0.86) | 0.033 | 1.57(0.18–13.93) | 0.685 | ||||
| 36–45 | 0.14(0.02–0.77) | 0.024 | 1.78(0.20-15.68) | 0.604 | ||||
| 46–55 | 0.18(0.03–1.08) | 0.06 | 1.76(0.19–16.47) | 0.622 | ||||
| 56–65 | Ref | Ref | ||||||
| Marital status | ||||||||
| Married | 0.74(0.49–1.10) | 0.135 | 1.73(1.05–2.86) | 0.032 | ||||
| Single | Ref | Ref | ||||||
| Occupation | ||||||||
| Military | 1.14(0.33–3.90) | 0.840 | 0.65(0.20–2.13) | 0.480 | ||||
| Private employed | 2.65(0.74–9.55) | 0.136 | 0.35(0.10–1.28) | 0.114 | ||||
| Public servant | 7.31(1.44–37.16) | 0.016 | ||||||
| Security | Ref | Ref | ||||||
| Self employed | 2.09(0.61–7.20) | 0.239 | 0.57(0.17–1.88) | 0.358 | ||||
| Student | 2.95(0.77–11.34) | 0.115 | 0.19(0.04–0.89) | 0.035 | ||||
| Unemployed | 2.77(0.69–11.08) | 0.150 | 0.33(0.08(1.46) | 0.144 | ||||
| Blood group | ||||||||
| A Type | 0.78(0.28–2.16) | 0.63 | 2.40(0.63–9.07) | 0.2 | 0.57(0.17–1.88) | 0.360 | ||
| AB Type | Ref | Ref | Ref | |||||
| B Type | 0.38(0.28–2.16) | 0.065 | 2.56(0.68–9.66) | 0.167 | 1.26(0.40–3.92) | 0.694 | ||
| O Type | 0.92(0.13–2.35) | 0.87 | 1.47(0.41–5.23) | 0.55 | 0.81(0.28–2.35) | 0.696 | ||
| Frequency of donation | ||||||||
| New donor | 4.09(2.26–7.39) | < 0.001 | 0.66(0.38–1.14) | 0.135 | 2.95(0.77–11.34) | < 0.001 | ||
| Regular | Ref | Ref | Ref | |||||
| Location / District | ||||||||
| Gasabo | 0.56(0.34–0.90) | 0.017 | 2.34(1.25–4.40) | 0.008 | ||||
| Kicukiro | 0.63(0.38–1.06) | 0.08 | 2.02(1.04–3.94) | 0.039 | ||||
| Nyarugenge | Ref | Ref | ||||||
HBV: Hepatitis B virus, HCV: Hepatitis C virus, aOR: Adjusted Odd Ratio, CI: Confidence Interval, HIV: Human Immunodeficiency virus
Discussion
This study assessed the prevalence and associated factors of TTIs among voluntary blood donors in Kigali from 2019 to 2023. The prevalence data from this study reveals encouraging trends in TTIs among blood donors from 2019 to 2023, particularly when compared to other sub-Saharan African countries. Our observed TTI prevalence rates (HBV 0.49%, HCV 0.26%, HIV 0.06%, Syphilis 0.24%) are substantially lower than both regional studies and Rwanda’s general population prevalence estimates for HBV (approximately 2.5-4%), HCV (1–2%), HIV (approximately 3% in adults), and syphilis (1–2%) [12], and lower to a study conducted in Ethiopia [13]. These differences likely reflect the “healthy donor effect,” whereby voluntary blood donors represent a self-selected, relatively healthy subset of the population who are screened through pre-donation questionnaires and tend to have lower risk behaviors compared to the general population. Additionally, our declining trend from 2019 (1.43%) to 2023 (0.91%) may be attributed to Rwanda’s strengthened blood safety measures including enhanced donor education programs, improved screening protocols, and increased repeat donor retention (62.4% regular donors), as regular donors consistently demonstrate lower TTI rates than first-time donors. The particularly low HIV prevalence (0.06%) compared to the national adult prevalence likely reflects both effective pre-donation counseling that defers high-risk individuals and the success of Rwanda’s national HIV prevention and treatment programs, which have significantly reduced community viral loads and transmission rates over the study period. In our study, 2020 dip and post-2021 rise in donations, likely COVID-19 disruptions to donor recruitment and how changing denominators can influence observed prevalence.
The observed uptick in syphilis prevalence in 2023 may reflect either genuine increase in sexually transmitted infection transmission due to post-COVID-19 pandemic changes in sexual health-seeking behaviors and reduced access to STI screening services during lockdowns. Increased test sensitivity from potential changes in screening algorithms or reagent batches, or enhanced case-finding through improved pre-donation counseling practices. To address this trend, we recommend implementing enhanced risk-based sexual health counseling for all donors with structured behavioral questionnaires, establishing a confirmatory testing workflow using treponemal-specific assays (TPPA or FTA-ABS) to reduce false positives [14]. And strengthening linkage to care protocols that include partner services notification and treatment, and conducting periodic surveillance of syphilis trends in the general population to contextualize donor findings within broader epidemiological patterns in Rwanda.
The findings show notably lower prevalence rates than those reported in comparable regional studies, where HBV, HCV, syphilis and HIV prevalence were 4.1, 3.6, 3.1 and 4.2%, respectively, in Nigeria [15], and HBsAg positivity was found in 0.6% of donors, anti-HCV positivity in 0.01%, anti-HIV positivity in 0.03% and syphilis positivity in 0.3% in Somalia [16]. The declining trends in HBV (from 0.76% to 0.41%) and HCV (from 0.30% to 0.18%) likely reflect successful implementation of national prevention strategies, including expanded vaccination programs for hepatitis B and improved blood donor screening protocols. Similar declining trends have been observed in other Rwandan studies, attributed to vaccination campaigns among people at risk for HBV [9]. The consistently low HIV prevalence (0.04%-0.08%) demonstrates the effectiveness of Rwanda’s comprehensive HIV prevention programs and rigorous donor selection criteria, while the slight increase in syphilis prevalence in 2023 (0.26%) may indicate emerging challenges requiring enhanced screening and public health interventions. This pattern of decreasing TTI trends has been observed across East Africa, although prevalence of certain infections like HBV and syphilis remains elevated in some regions [17], suggesting that Rwanda’s blood safety measures have been particularly effective compared to regional standards.
The substantially higher TTI prevalence among new donors (81.1% of positive cases) necessitates enhanced pre-donation education programs with structured risk assessment tools and behavioral counseling to improve self-deferral among high-risk individuals. The elevated HBV prevalence (0.49%), particularly among older age groups, supports implementing catch-up hepatitis B vaccination campaigns targeting adults over 35 years who missed childhood immunization programs introduced in Rwanda in 2002. The observed district-level variations in syphilis prevalence (Gasabo 49.5%, Kicukiro 33.3%, Nyarugenge 17.2%) warrant district-specific outreach strategies with tailored community mobilization in lower-prevalence areas. The identification of district-level variations in infection patterns highlights the importance of geographic considerations in blood safety strategies. These results suggest that Rwanda’s blood screening and donor selection protocols have been effective in maintaining blood safety, though the slight increase in syphilis prevalence and the higher risk profile of first-time donors indicate areas requiring continued vigilance and targeted interventions. The declining overall TTI trend associated with increased repeat donor retention underscores the need for donor loyalty programs with short message service (SMS) reminders, recognition certificates, and mobile collection drives to convert first-time donors into regular donors, complemented by quarterly refresher training for blood bank staff on donor screening protocols and counseling techniques to maintain high standards of donor selection and blood safety.
Our findings reveal potential gaps in current donor recruitment and deferral strategies, particularly evidenced by the substantially higher TTI prevalence among new donors (81.1% of positive cases) compared to regular donors (18.9%), suggesting that initial screening and risk assessment protocols may not adequately identify high-risk individuals. The persistent male predominance in TTI-positive cases (79.1%) and variations across districts (Gasabo 41%, Kicukiro 30.9%, Nyarugenge 28.1%) indicate opportunities for targeted interventions including enhanced pre-donation risk-based counseling focused on male donors, strengthened donor education programs emphasizing repeat donation among low-risk individuals, and district-specific outreach strategies that prioritize recruitment from communities with historically lower TTI prevalence.
The findings from this multivariate analysis are consistent with several established patterns in transfusion-transmissible infection epidemiology across sub-Saharan Africa, while revealing some unique characteristics specific to the Rwandan context. The higher adjusted odds of HBV (aOR 2.60, 95% CI 1.54–4.38) and HIV infections (aOR 3.84, 95% CI 1.63–9.05) among male donors is consistent with studies conducted in Mali and South Africa, where male gender was associated with higher HBV prevalence [18]. This gender disparity may reflect differences in health-seeking behaviour, occupational exposure patterns, or other unmeasured factors that differ by gender and were not captured in this dataset.
The lower adjusted odds of HBV positivity observed among younger age groups (26–45 years) contrasts with some studies from Kenya, where age above 30 years was associated with higher HBV prevalence [1]. This inverse relationship in Rwanda may be attributed to improved vaccination coverage among younger cohorts, as Rwanda implemented universal hepatitis B vaccination in 2002, providing protection for individuals now in their 20s and 30s. The higher HBV positivity observed among older donors (56–65 years) may reflect their exposure during an era of limited vaccination coverage and potentially less stringent blood safety measures in healthcare settings.
The striking occupational disparity, particularly the 7-fold higher adjusted odds of HCV positivity among public servants, warrants further investigation. This pattern differs from studies in Kerala, India, where drivers, businessmen, and men in uniform showed higher TTI prevalence [19], suggesting context-specific occupational associations. The higher HCV positivity observed among public servants in Rwanda may reflect historical occupational exposures in healthcare or administrative settings with inadequate infection control measures, or it could indicate socioeconomic factors that influence healthcare access and health-seeking behaviour. Future studies should conduct systematic audits to verify occupational coding accuracy, investigate workplace-specific screening and health promotion practices, and explore whether occupational findings reflect true biological risk differences or artifacts of classification and referral patterns within Rwanda’s blood donation system.
The substantially higher adjusted odds of TTI positivity among first-time donors (4-fold for HBV, 3-fold for HIV) compared to regular donors is a notable finding that aligns with global blood safety literature [20, 21]. This pattern suggests that the donor screening and education processes effectively identify and retain safer repeat donors, while new donors may include individuals with higher risk profiles who have not previously been screened. The geographic variations, with Gasabo showing lower HBV but higher HCV prevalence compared to Nyarugenge, may reflect differences in healthcare infrastructure, socioeconomic status, or historical transmission patterns specific to different districts within Rwanda.
Limitation
This study has several limitations that should be considered when interpreting the findings. The retrospective cross-sectional design limits the ability to establish causal relationships between socio-demographic factors and transfusion-transmissible infections, as temporal sequences cannot be determined from the available data. Reliance on secondary data analysis restricts the study to variables already collected in existing records, potentially missing important confounding factors or detailed behavioral and lifestyle information that could influence infection risk. Additionally, the study is limited to voluntary blood donors in Kigali, which may not represent the broader Rwandan population or other donor populations, potentially limiting the generalizability of findings to different geographic regions or donor recruitment strategies. The cross-sectional nature of the data prevents assessment of temporal trends in infection rates or the long-term effectiveness of screening and prevention interventions, and cannot infer causality. The sexual behavior, prior testing, and vaccination status were not evaluated in this study. While our multivariate models identify important correlates of specific TTIs, we recognize the limitations of interpreting these as causal relationships without formal causal modeling. The different variables retained across TTI-specific models reflect varying strengths of association rather than a single unified causal structure, and future studies employing causal inference frameworks would be valuable to establish true causal pathways. The multiple statistical tests performed increase the likelihood of type I errors, and findings should be interpreted cautiously, particularly for associations with borderline significance (p-values between 0.01 and 0.05). The observed associations between occupation and specific TTI types, particularly the elevated HBV risk among public servants (aOR = 7.31, 95% CI: 1.44–37.16), should be considered hypothesis-generating rather than definitive due to small sample sizes, potential overlap in occupational definitions, and possible coding inconsistencies during donor registration. As our study did not collect GPS coordinates or Geographic Information System (GIS) data at the individual donor level, generating a spatially precise distribution map was not feasible, though we have acknowledged this as a limitation and recommend that future studies incorporate GIS-based data collection to enable such spatial analyses.
Conclusion
This study demonstrates that TTI prevalence among voluntary blood donors in Kigali, Rwanda remains low, with declining trends for HBV and HCV from 2019 to 2023 and consistently stable HIV rates. Socio-demographic factors including male gender, older age, first-time donor status, and occupational category were independently associated with TTI positivity patterns. These findings support risk-based donor counseling, enhanced screening for high-risk groups, and district-specific prevention strategies to further strengthen blood supply safety. Future research should prioritize prospective designs to establish causal relationships, evaluate linkage-to-care outcomes for TTI-positive donors, and conduct spatial analyses to guide targeted interventions.
Acknowledgements
I express my sincere gratitude to Rwanda Biomedical Center and Mount Kenya University for granting ethical approval to conduct this study. I am also deeply thankful to the voluntary blood donors who donated their blood to save peoples’ live.
Abbreviations
- aOR
Adjusted odd ratio
- cOR
Crude odd ratio
- CI
Confidence interval
- HBV
Hepatitis B virus
- HCV
Hepatitis C virus
- HIV
Human immunodeficiency virus
- NCBT
National center for blood transfusion
- RBC
Rwanda biomedical center
- SMS
Short message service
- SPSS
Statistical package for the social sciences
- TTIs
Transfusion transmissible infections
- WHO
World Health Organization
Author contributions
PU conceptualized the study and wrote the initial draft. ES reviewed and participate in writing the final manuscript. CG Reviewed the manuscript, GJ reviewed the manuscript, and AKA supervised study and reviewed the manuscript. All authors critically reviewed the manuscript for important intellectual content. All authors read and approved the final version of the manuscript for publication.
Funding
This study was not funded.
Data availability
The datasets generated and analyzed during this study are available from the corresponding author upon reasonable request. The statistical analysis code used in this study is also available upon request.
Declarations
Human ethic and consent to participate
This study received ethical approval from the institutional review board of Rwanda Biomedical Center (Ref: No. 4092/RBC/2024), and Mount Kenya University (Ref: MKU/ETHICS/23/01/2024). Secondary data were obtained from the NCBT donor database and were handled with strict confidentiality. All personal identifiers were removed, and data were anonymized using unique codes. Access was restricted to authorized personnel, and data were stored securely on password-protected devices. Informed consent was not applicable in the study as it employed secondary data This study was conducted in accordance with the ethical standards of our institutional review board and with the 1964 Helsinki Declaration and its later amendments.
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Bartonjo G, Oundo J, Ng’ang’a Z. Prevalence and associated risk factors of transfusion transmissible infections among blood donors at Regional Blood Transfusion Center Nakuru and Tenwek Mission Hospital, Kenya. Pan Afr Med J. 2019;34:31. 10.11604/pamj.2019.34.31.17885 . PubMed PMID: 31762899; PubMed Central PMCID: PMC6859030. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.E D, S A, A G. Blood safety and prevalence of transfusion-transmissible viral infections among donors at the Red Cross Blood Bank in Gondar University Hospital. Ethiop Med J. 2008;46(1). PubMed PMID: 18711984. [PubMed]
- 3.Mulugeta H, Dessie G, Wagnew F, Jara D, Leshargie CT, Negesse A. Seroprevalence and trend of human immunodeficiency virus among blood donors in Ethiopia: a systematic review and meta-analysis. BMC Infect Dis. 2019;19(1):383. 10.1186/s12879-019-4012-5. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Drew VJ, Barro L, Seghatchian J, Burnouf T. Towards pathogen inactivation of red blood cells and whole blood targeting viral DNA/RNA: design, technologies, and future prospects for developing countries. Blood Transfus Trasfus Sangue. 2017;15(6):512–21. 10.2450/2017.0344-16 . PubMed PMID: 28488960; PubMed Central PMCID: PMC5649960. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.WHO. Blood safety and availability [Internet]. 2025 [cited 2025 Nov 25]. Available from: https://www.who.int/news-room/fact-sheets/detail/blood-safety-and-availability.
- 6.Mohamed Z, Kim JU, Magesa A, Kasubi M, Feldman SF, Chevaliez S, et al. High prevalence and poor linkage to care of transfusion-transmitted infections among blood donors in Dar-es-Salaam, Tanzania. J Viral Hepat. 2019;26(6):750–6. 10.1111/jvh.13073 . PubMed PMID: 30712273; PubMed Central PMCID: PMC6563112. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Nankya-Mutyoba J, Apica BS, Otekat G, Kyeyune DB, Nakyagaba L, Nabunje J, et al. Hepatitis C in Uganda: Identification of infected blood donors for micro-elimination. J Virus Erad. 2021;7(2):100041. 10.1016/j.jve.2021.100041 . PubMed PMID: 34188952; PubMed Central PMCID: PMC8219885. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Kwizera R, Moibéni A, Shenawy F, Youssif M. The prevalence of hepatitis B and C among blood donors at the National Blood Transfusion Center (CNTS) in Burundi. Pan Afr Med J. 2018;31:119. 10.11604/pamj.2018.31.119.14571 . PubMed PMID: 31037179; PubMed Central PMCID: PMC6462377. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Nsekuye O, Omolo J, El-Khatib Z, Matsiko E, Uwayo HD, Ndicunguye F, et al. Risk factors associated with transfusion transmissible infections among blood donors at Karongi Regional Centre for Blood Transfusion-Western Province of Rwanda. J Interv Epidemiol Public Health. 2024;7(2):2. 10.11604/JIEPH.supp.2024.7.3.1361. [DOI] [Google Scholar]
- 10.T T, Td GS, Jb WML. Hepatitis B virus strains from Rwandan blood donors are genetically similar and form one clade within subgenotype A1. BMC Infect Dis. 2017;17(1). 10.1186/s12879-016-2149-z. PubMed PMID: 28056881. [DOI] [PMC free article] [PubMed]
- 11.Makuza JD, Soe P, Jeong D, Nisingizwe MP, Dushimiyimana D, Umutesi J, et al. Epidemiology of sexually transmitted infections: trends among patients screened for sexually transmitted infections in rwandan health facilities 2014–2020. BMC Infect Dis. 2022;22(1):701. 10.1186/s12879-022-07685-9 . PubMed PMID: 35987614; PubMed Central PMCID: PMC9392439. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Umutesi J, Simmons B, Makuza JD, Dushimiyimana D, Mbituyumuremyi A, Uwimana JM, et al. Prevalence of hepatitis B and C infection in persons living with HIV enrolled in care in Rwanda. BMC Infect Dis. 2017;17(1):315. 10.1186/s12879-017-2422-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Gebreyes DS, Kifetew K, Gizaw A, Abebe TA, Shenkutie TT, Genetu D, et al. Prevalence and Risk Factors of Transfusion-Transmissible Infections Among Voluntary Blood Donors in North Shoa, Amhara Region, Ethiopia: A Cross‐Sectional Study. Health Sci Rep. 2025;8(5):e70769. 10.1002/hsr2. 70769 PubMed PMID: 40330765; PubMed Central PMCID: PMC12051436. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Soreng K, Levy R, Fakile Y. Serologic Testing for Syphilis: Benefits and Challenges of a Reverse Algorithm. Clin Microbiol Newsl. 2014;36(24):195–202. 10.1016/j.clinmicnews.2014.12.001 . PubMed PMID: 28845073; PubMed Central PMCID: PMC5568569. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Okoroiwu HU, Okafor IM, Asemota EA, Okpokam DC. Seroprevalence of transfusion-transmissible infections (HBV, HCV, syphilis and HIV) among prospective blood donors in a tertiary health care facility in Calabar, Nigeria; an eleven years evaluation. BMC Public Health. 2018;18(1):645. 10.1186/s12889-018-5555-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Doğan S, Mohamud SM, Ali AM, Orhan Z, Doğan A, Mohamud RYH. Seroprevalence of hepatitis C, hepatitis B, hiv and syphilis among blood donors at a tertiary care hospital in Mogadishu-Somalia in 2020–2022: a retrospective study. BMC Public Health. 2024;24(1):2463. 10.1186/s12889-024-19837-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Kanyike AM, Kakuba F, Mayambala P, Nalunkuma R, Nakandi RM, Mulumba Y, et al. Prevalence trends of transfusion-transmitted infections at a tertiary private hospital blood bank in Uganda: a retrospective 6-year review (2017–2022). BMC Infect Dis. 2025;25(1):672. 10.1186/s12879-025-10882-x . PubMed PMID: 40335905; PubMed Central PMCID: PMC12060397. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Jary A, Dienta S, Leducq V, Le Hingrat Q, Cisse M, Diarra AB, et al. Seroprevalence and risk factors for HIV, HCV, HBV and syphilis among blood donors in Mali. BMC Infect Dis. 2019;19(1):1064. 10.1186/s12879-019-4699-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Pv JM, Pk SSS, N S, S S. Profile of transfusion-transmissible infections and associated risk factors among blood donors of Kerala. Indian J Pathol Microbiol. 2002;45(3). PubMed PMID: 12785175. [PubMed]
- 20.Habibu I, Abubakar BM, Moi IM, Abdulrazaq R. Seroprevalence of HIV, HBV, HCV and Syphilis among blood donors in a Nigerian tertiary medical centre. BMC Infect Dis. 2025;25:638. 10.1186/s12879-025-11024-z . PubMed PMID: 40307693. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Puerto-Meredith S, Singogo E, Chagomerana M, Nthani T, Likaka A, Gondwe A, et al. Systematic review of prevalence and risk factors of transfusion transmissible infections among blood donors, and blood safety improvements in Southern Africa. Transfus Med. 2023;33(5):355–71. 10.1111/tme.12988. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets generated and analyzed during this study are available from the corresponding author upon reasonable request. The statistical analysis code used in this study is also available upon request.