Prevalence and determinants of being out-of-care among HIV-positive young people aged 15–24 years in Mozambique: findings from the 2021 population-based HIV impact assessment survey

Abstract

Background

Globally, young people are falling behind in the push to end the HIV epidemic. Understanding the characteristics of HIV-positive young people who are out-of-care (not on antiretroviral treatment) in Mozambique is important to effectively reach and ensure access to services for this priority population.

Methods

Using data from the 2021 Mozambique Population-based HIV Impact Assessment, we conducted a sub-analysis of HIV-positive young people aged 15–24 years whose blood specimens were tested for the presence of antiretrovirals. Participants testing negative for the presence of antiretrovirals were classified as out-of-care. Weighted prevalence estimates of HIV-care status and select covariates are reported. We used multivariable logistic regression to assess factors associated with out-of-care status. Analyses were weighted and adjusted for the complex survey design.

Results

Among the 245 HIV-positive young people included, 58.0% (n = 141, 95% Confidence Interval [CI] 49.9–65.7%) were out-of-care. Out-of-care young people were mostly female (75.0%) and living in a rural area (68.3%). In the multivariate model, young people who discussed HIV with a parent or guardian (20.0% of participants) (adjusted Odds Ratio [aOR]: 0.33, 95% CI: 0.17–0.66) or previously heard of pre-exposure prophylaxis (PrEP) (6.1% of participants) (aOR: 0.25, 95% CI: 0.09–0.65) were less likely to be out-of-care than those who had not. Odds of being out-of-care were greater for those from the northern compared to the central provinces (aOR: 2.37, 95% CI: 1.09–5.15) and those who had participated in prevention programs (aOR: 3.19, 95% CI: 1.37–7.41).

Conclusions

Over half of young people with HIV in Mozambique met our definition for out-of-care in 2021. Our results reveal important geographic and sex gaps in HIV care. Strengthening existing programs to include components centered on creating a lasting link to health services could improve the identification of new HIV-positive young people. The important role of parents and guardians in young people’s health behaviors and decision-making presents an opportunity to engage families with interventions to strengthen needed services to this priority population in Mozambique.

Clinical trial number

Not applicable.

Background

Knowledge of human immunodeficiency virus (HIV) status is the first step in preventing HIV transmission and is crucial to ending HIV/AIDS as a global health threat [1]. The Joint United Nations Programme on HIV/AIDS (UNAIDS) 95-95-95 cascade targets envision 95% of people living with HIV (PLHIV) knowing their status, of those, 95% on antiretroviral treatment (ART), and 95% of PLHIV on treatment achieving viral load suppression by 2025. The targets are essential to reaching the United Nation’s Sustainable Development Goal 3.3, which aims to reduce the number of people newly infected with HIV per 1,000 population to 0.05 by 2025 and to 0.025 by 2030 [2].

Increasing the proportion of PLHIV who have viral load suppression is a key strategy for ending the HIV epidemic. PLHIV with an undetectable viral load from daily ART use have essentially no risk of transmitting HIV to their sexual partners [2–6]. A prospective study following 1,166 sero-discordant couples found no transmission between couples with HIV viral suppression (< 200 copies/ml) [5]. The priority for the next phase of HIV epidemic control is to ensure all people living with HIV have access to ART, especially priority populations such as young people aged 15–24 years [7]. Increasing HIV treatment coverage can be achieved through targeted testing and treatment interventions that are based on current epidemiological and demographic profiles.

Over the last five years there have been major advances in prevention and treatment of HIV in Mozambique, including the introduction of HIV self-testing, pre-exposure prophylaxis (PrEP), peer ART adherence counselors, and a large scale expansion of differentiated service delivery models, resulting in a rapid scale up of ART coverage [8, 9]. Despite these advances, many challenges remain, including the testing and inclusion of young people in HIV treatment and care services. In 2021, Mozambique conducted the Mozambican Population-based HIV Impact Assessment (INSIDA) survey, which interviewed participants aged 15 years and older about socio-demographic factors, HIV-related behaviors, and performed a rapid HIV test. Survey results found that 71.6% of PLHIV knew their HIV status and 69.0% of all PLHIV were on ART, still distant from the UNAIDS goals for 2025 [10]. Young PLHIV, aged 15–24 years, had lower levels of knowledge of their HIV serostatus (53.8%) and treatment coverage (42.0%) compared to the general population [10]. The preceding population-based survey in 2015 found that only 38% of young people aged 15–24 years had knowledge of their HIV serostatus and 13.3% were on ART, showcasing both the large gains made in Mozambique between 2015 and 2021 and also the large gaps to achieve HIV epidemic control in this age group [11].

Young people also have a disproportional impact on Mozambique’s HIV incidence. The UNAIDS Spectrum model estimates that there were 4.7 new infections per 1,000 persons among young people compared to 2.6 new infections per 1,000 persons in the general population in 2023 [12, 13]. With 20% of the national population between the ages of 15 to 24, higher incidence directly impacts new infections in the country [14]. In the same model approximately 38%, or 31,000, of the national new infections were in this age group [12]. The considerable contribution of young people to national incidence is common to countries in the region; in Botswana, 15–24-year-olds make up 35% of the new infections, in Eswatini 34%, in Malawi 27%, and in South Africa 40% [15]. In the Mozambican National Strategic Plan for the HIV/AIDS Response 2021–2025, the first of the nine strategic objectives is to reduce overall new infections by 50% to 65,000 by 2025, prioritizing the identification and treatment of PLHIV, particularly among young people [16]. Multiple factors contribute to the high burden among young people, and without national HIV response programs targeted towards young people, progress toward national and global targets is unlikely to be achieved.

Evidence from Mozambique indicates that stigma plays a significant role in influencing the HIV care continuum. In northern Mozambique, 48% of young people felt like they had no one to talk to about HIV-specific issues, and in the capital, Maputo, 43% of adults on ART had a fear of HIV-related stigma [17, 18]. In the same study, HIV-positive individuals who feared stigma were nearly three times as likely to have advanced HIV disease at the time of diagnosis than those who did not fear stigma [18]. In Sofala province, located in the center of Mozambique, HIV-positive men who anticipated stigma were 35% less likely to have recently tested for HIV than those who did not anticipate stigma [19]. The presence of education programs and family-based social support helps reduce stigma and promote access to care for young PLHIV in Mozambique [20, 21].

Using nationally representative data, this study aims to estimate the proportion of HIV-positive young people in Mozambique who are out-of-care, to describe the out-of-care population, and to describe factors associated with being out-of-care. Findings may inform targeted strategies to identify, test, and link youth to care critical steps towards both national HIV goals and the UNAIDS 95-95-95 targets.

Methods

Study design and procedures

We conducted a sub-analysis using data from the 2021 Mozambique Population-based HIV Impact Assessment (INSIDA) study, a nationally representative, cross-sectional household-based survey conducted between April 2021 and February 2022. INSIDA aimed to measure the progress of the country’s HIV response. The survey used a four-stage probability sample design that randomly selected 11,375 households from 311 enumeration areas throughout Mozambique’s 11 provinces. Eligibility criteria for the interview were age 15 years or older and residency, requiring that respondents (usual household members or visitors) had slept in the sampled household the night before the interview. Interviewers conducted face-to-face interviews with consenting individuals using a standard questionnaire, which included household composition, socio-economic questions, and questions on the HIV testing and care continuum.

Trained phlebotomists collected venous blood draws from all consenting participants through household-based HIV testing and counseling following the two-test national guideline: Determine™ HIV-1/2 rapid diagnostic test followed by the Uni-Gold™ HIV confirmatory test. If the first test returned nonreactive, the sample was classified as HIV-negative. If both tests were reactive, the blood specimen was classified as HIV-positive, however if the confirmatory test was non-reactive the algorithm was repeated. Participants who repeated the algorithm and continued to receive disparate results were considered to have an indeterminate test outcome and were referred to a health facility for repeat testing after four weeks. Household-based HIV test results were returned to the participants the same day, with counseling and HIV services referral.

Participants consented separately to a blood draw, and all blood specimens with a positive or indeterminate result during the household testing were retested in a laboratory with Geenius HIV 1/2 Supplemental Assay (Bio-Rad, Hercules, California, United States). A reactive laboratory result from the assay confirmed HIV-positive status, and these samples were subsequently measured for CD4-T cell count, viral load, and detectable concentrations of the antiretrovirals atazanavir, lopinavir, efavirenz, and dolutegravir. A combination of these medications totaled 99.9% of all antiretrovirals distributed in health facilities with electronic medical records in 2021 [22]. Of the 5,283 participants aged 15–24 years who were interviewed, 4,479 (85.2% weighted response rate) consented to the additional blood draw and received a confirmed laboratory diagnosis, and of those, 245 (5.4% weighted) tested HIV-positive. (Fig. 1).

Fig. 1.

Unweighted number and weighted proportion of young people, 15–24 years old, with survey interview, blood draw and antiretroviral detection, INSIDA 2021

Data analysis

Among HIV-positive young people aged 15–24 years with a valid HIV-positive test result, antiretroviral screening results were used to define the HIV care status outcome. In this study, participants with detectable antiretroviral concentrations in their blood sample were classified as “in care” and those without antiretrovirals detected as “out-of-care”. This method of biomarkers confirmation for care status has been used in analysis of other population-based HIV surveys, including in Nigeria, where findings supported the use of laboratory testing to determine accurate clinical status in HIV research [23]. Participants missing antiretroviral testing results were excluded from analysis. Descriptive analyses were conducted among young people in and out of care, and weighted proportions with corresponding 95% confidence intervals (CI) are reported. Weighted chi-square tests were used for descriptive comparisons and to identify variables potentially associated with being out-of-care. We then used bivariate logistic regression to identify demographic and behavioral factors associated with out-of-care status. Variables associated with out-of-care status (chi-square p-value < 0.15) were considered for inclusion in the multivariate model. Variables were removed in a stepwise fashion, comparing Akaike information criterion (AIC) scores, until the “best” model was found. Variables removed during stepwise selection were individually added back and retained if their inclusion changed the adjusted odds ratio (aOR) of any remaining covariate by ≥ 10%. Odds ratios (OR) associated 95% confidence intervals, and p-values are reported. All analyses were performed using R version 4.1.3, and were weighted and adjusted using the jackknife replication method to account for complex sampling [24].

To assess the relationship between participation in an HIV prevention program and being in/out-of-care, a “prevention program participation” variable was created during the analysis. The prevention programs are youth-focused initiatives which include DREAMS (Determined, Resilient, Empowered, AIDS-free, Mentored and Safe) and SAAJ (Serviços Amigos dos Adolescentes e Jovens) programs. Both focus on reducing HIV incidence through health education and HIV prevention methods [25, 26]. To assess the relationship between social/familiar support and care status, the variable “Additional HIV+ person in the household” was created from household HIV testing results. These two variables were retained in the final model as exposures of programmatic interest.

Results

Of the 245 HIV-positive young people included in our analysis, 58.0% (n = 141) were out-of-care, of whom 31.7% were aged 15–19 years (Table 1). Most out-of-care participants were female (75.0%), lived in a rural area (68.3%) in the northern provinces of Cabo Delgado, Nampula and Niassa (43.9%), had primary education (56.2%), were either married or living together (46.6%), and had not worked in the past 12 months (73.6%). Among out-of-care young people with HIV, most believed it would be easy to obtain a condom (53.8%), had never discussed sex (87.5%) or HIV (80.0%) with their parents or guardians, had never heard of PrEP (93.9%), and had not participated in an HIV-prevention program (81.2%). Finally, 33.2% of HIV-positive out-of-care young people lived in a household with another HIV-positive individual. More in-care young people resided in the central provinces of Zambézia, Tete, Manica, and Sofala (51.1%), were never married (40.4%), and achieved a secondary education or higher education level (48.3%).

Table 1.

Demographic and social characteristics among HIV-positive young people (15–24 years old) by HIV care status, Mozambique, 2021 (n = 245)

Characteristic		Out-of-Care (n = 141)		In-Care (n = 104)		N	Chi-Sq p-value
		Percent	95% CI	Percent	95% CI
Sex
Male		25.0	18.6–32.4	20.7	12.3–31.6	53	0.472
Female		75.0	67.6–81.4	79.3	68.4–87.7	192
Age Group (Years)
15–19		31.7	23.4–41.1	29.8	20.1–41.1	66	0.762
20–24		68.3	58.9–76.6	70.2	58.9–79.9	179
Residence
Urban		35.4	23.7–48.7	46.0	29.7–63.1	111	0.139
Rural		64.6	51.3–76.3	54.0	36.9–70.3	134
Geographic Area of Residence
North (Cabo Delgado, Nampula, Niassa)		43.9	31.8–56.6	25.5	15.9–37.3	80	0.030
Central (Zambézia, Tete, Manica, Sofala)		37.2	27.7–47.5	51.1	38.3–63.9	92
South (Inhambane, Gaza, Maputo, Maputo Cidade)		18.9	12.0-27.5	23.4	14.9–33.8	73
Education
No education		12.7	6.9–20.9	13.0	7.7–20.1	29	0.023
Primary education		56.2	47.2–64.9	38.7	28.3–49.9	114
Secondary or higher		31.1	23.6–39.3	48.3	36.4–60.4	100
Marital Status
Never married		32.7	24.8–41.5	40.4	29.3–52.1	93	0.501
Married or living together		46.6	37.5–55.9	44.0	31.8–56.7	107
Divorced, separated or widowed		20.7	12.6–31.0	15.7	8.4–25.7	45
Employed in the past 12 months
Yes		26.4	18.5–35.5	18.1	10.2–28.6	64	0.189
No		73.6	64.5–81.5	81.9	71.4–89.8	181
Easy to Access Condoms
Yes		53.8	44.8–62.6	63.0	53.3–71.9	152	0.116
No		25.4	17.5–34.6	26.8	17.4–38.1	59
Missing (3)		20.8	13.8–29.4	10.2	4.4–19.5	34
Have you ever talked with a parent or guardian about sex?
Yes		12.5	7.6–19.1	21.0	14.1–29.3	45	0.048
No		87.5	80.9–92.4	79.0	70.7–85.9	198
Have you ever discussed HIV with your parents or guardian?
Yes		20.0	13.6–27.9	40.0	28.0–53.0	71	0.002
No		80.0	72.1–86.4	60.0	47.0–72.0	174
Have you previously heard of PrEP?
Yes		6.1	2.9–10.9	16.8	8.6–28.3	25	0.013
No		93.9	89.1–97.1	83.2	71.7–91.4	216
Participated in a Prevention Program
1 or more		13.8	6.9–23.8	11.4	4.9–21.4	29	0.749
No		81.2	73.1–87.7	84.5	76.8–90.5	205
Missing (2)		5.0	2.0-10.1	4.1	0.9–11.2	11
Additional HIV+ person in the household
1 or more		33.2	26.4–40.5	40.0	30.8–49.9	87	0.234
No		66.8	59.5–73.6	60.0	50.1–69.2	158

CI = Confidence Interval, N = number

Percentages and confidence intervals are weighted and adjusted to account for the survey design. Respondents with missing values were excluded from tabulations (education, 2; ever discussed sex with a parent/guardian, 2; ever heard of PrEP, 4)

In the bivariate regression (Table 2), we did not detect an association between HIV care status and sex, age, residence, and employment status. Young people who were divorced, separated, or widowed (OR: 0.44, 95% CI: 0.24–0.81) had decreased odds of being out-of-care compared to those who were married or living together. Odds of being out of care were decreased among those who had discussed sex (OR: 0.54, 95% CI: 0.29-1.00) or HIV (OR: 0.38, 95% CI: 0.20–0.71) with their parents or guardians compared to those who had not.

Table 2.

Unadjusted and adjusted logistic regression models of association with being out-of-care among HIV-positive young people 15–24 years old by select demographic and social factors, Mozambique, 2021

Characteristic		OR (out of care)	95% CI	p-value	aOR (out of care)	95% CI	p-value
Sex
Male		1.28	0.65–2.49	0.473
Female		(ref)
Age Group (Years)
15–19 (4)		1.10	0.60-2.00	0.763
20–24 (5)		(ref)
Residence
Urban		0.64	0.36–1.16	0.142
Rural		(ref)
Geographic Area of Residence
North (Cabo Delgado, Nampula, Niassa)		2.36	1.14–4.87	0.020	2.37	1.09–5.15	0.030
Central (Zambézia, Tete, Manica, Sofala)		(ref)			(ref)
South (Inhambane, Gaza, Maputo, Maputo Cidade)		1.11	0.57–2.16	0.757	1.29	0.59–2.82	0.520
Education
No education		0.77	0.39–1.50	0.436	0.82	0.30–2.21	0.692
Primary education		(ref)			(ref)
Secondary or higher		1.25	0.53–2.95	0.613	0.53	0.24–1.18	0.119
Marital Status
Never married		0.67	0.29–1.58	0.361
Married or living together		(ref)
Divorced, separated or widowed		0.44	0.24–0.81	0.009
Employed in the past 12 months
Yes		1.62	0.79–3.32	0.185
No		(ref)
Easy to Access Condoms
Yes		(ref)			(ref)
No		1.11	0.58–2.11	0.757	0.81	0.40–1.64	0.554
Missing		2.38	1.02–5.56	0.045	1.32	0.52–3.31	0.557
Have you ever talked with a parent or guardian about sex?
Yes		0.54	0.29-1.00	0.049
No		(ref)
Have you ever discussed HIV with your parents or guardians?
Yes		0.38	0.20–0.71	0.003	0.33	0.17–0.66	0.002
No		(ref)			(ref)
Have you previously heard of PrEP?
Yes		0.32	0.13–0.79	0.013	0.25	0.09–0.65	0.005
No		(ref)			(ref)
Participated in a Prevention Program
1 or more		1.27	0.66–2.42	0.470	3.19	1.37–7.41	0.007
No		(ref)			(ref)
Missing		1.27	0.41–3.96	0.680	1.33	0.41–4.26	0.631
Additional HIV+ person in the household
1 or more		0.74	0.46–1.21	0.235	0.70	0.39–1.26	0.230
No		(ref)			(ref)

OR = Odds Ratio, aOR = Adjusted Odds Ratio, CI = Confidence Interval, ref = reference group

Six respondents with missing values for one or more variables excluded from final model

The final multivariable model was adjusted for region, education, access to condoms, having discussed HIV with a parent or guardian, having heard of PrEP, participating in an HIV-prevention program, and having an HIV-positive person in the household (Table 2). Young people with HIV residing in the northern provinces (Cabo Delgado, Nampula, Niassa) (aOR: 2.37, 95% CI: 1.09–5.15) had increased odds to be out-of-care than those in central provinces (Sofala, Manica, Zambézia, Tete). Those who had discussed HIV with their parents or guardians (aOR: 0.33, 95% CI: 0.17–0.66) or who had previously heard of PrEP (aOR: 0.25, 95% CI: 0.09–0.65) had decreased odds to be out-of-care than those who hadn’t. Young people who participated in at least one HIV prevention program had over three times the odds of being out of care (aOR: 3.19, 95% CI: 1.37–7.41) compared to those who had never participated. The crude analysis between prevention program participation and being out-of-care showed no association, but after adjusting for covariates the association strengthened, suggesting variables in the model were suppressing the crude association.

Discussion

Over half (58.0%) of HIV-positive young people aged 15 to 24 years were not on antiretroviral treatment in Mozambique in 2021. This finding presents a major gap for reaching epidemic control in the country and is substantially below the regional coverage of 78.2% found in four neighboring countries for young people aged 15 to 19 years [27]. Although there exists low coverage of ART nationwide in this age group, young people residing in the northern provinces of Cabo Delgado, Niassa, and Nampula had a 2.37 increased odds of being out-of-care [10]. A variety of factors may have influenced these findings, including distance from the economic and political capital of Maputo, on-going insurgent activity centered in the north, quality and availability of healthcare services and providers, and a greater percentage of the population residing in rural areas where health literacy could be lower and health care access may be more difficult [28, 29]. Universal HIV care is emphasized as a priority intervention in the Mozambican National Strategic Plan for the HIV/AIDS Response 2021–2025, and this finding suggests that, though progress has been made since 2015 when only 23.6% of all PLHIV in rural areas were in HIV care, considerable gaps remain, including for young people [11, 16].

Socio-behavioral factors, such as civil status and health knowledge, were associated with care status. Our finding that divorced, separated or widowed individuals were less likely to be out of care compared to those who were married or living together might reflect the complexities of navigating testing and HIV status within a sexual relationship [30]. Consistent with studies elsewhere, we found that young people who were able to talk about HIV with their parents or guardians had increased odds of being on ART. Family support and HIV disclosure were positively associated with ART adherence in a study in Thailand and identified as an important factor in a mixed-method study of treatment adherence in adolescents in Mozambique [17, 31]. Frequent conversations about HIV were found to be positively associated with HIV testing in South Africa and Zambia [32, 33]. These findings are important not just for prevention in their peer group, but also for potentially decreasing intergenerational HIV transmission that is helping drive the epidemic forward [34, 35]. Strengthening existing programs or creating new initiatives focused on guided intra-familial discussions, such as community-based health literacy programs or family-based self-testing, could bring the necessary testing and treatment services to out-of-care young people.

Our study did not find an association between ART status and living with an additional HIV-positive member in the household [17, 36, 37]. Disclosure of HIV-positive status is difficult in Mozambique due to stigma, and in the INSIDA survey 21.2% of young people with ART biomarkers falsely reported a negative or unknown HIV status [38]. Young people wishing to disclose their HIV status may be confronted with various cultural and societal hurdles including anticipated stigma, gender roles, and a lack of knowledge. As such, the challenges faced with HIV disclosure for young people may feel unsurmountable and result in their non-disclosure, nullifying associated benefits.

Finally, programs such as DREAMS and SAAJ are key initiatives to reduce HIV transmission in Mozambique and provide initial support to link young people to care in the case of seroconversion [25, 26]. Young people who had previously participated in a prevention program were three times more likely to be out-of-care. Despite programmatic focus on HIV-negative populations, these findings may present a missed opportunity for ensuring sustained engagement in health services upon program completion. Reinforcing the inclusion of up-to-date information on prevention and testing in these programs, especially focused on testing continuation post program graduation, may create additional synergies if coupled with the deliberate involvement of parents or other family members in health literacy lessons, encouraging discussions and support around HIV and sex.

Limitations

While these findings provide crucial information regarding young people and their enrollment in care and treatment services, our analysis is subject to some limitations. Estimates of recent infections in INSIDA were not powered below the national level, thus this analysis could not accurately differentiate between new HIV-positive persons and those who may have fallen out of care. Similarly, reliance on ART laboratory testing without triangulation with viral load or CD4 results limited our ability to distinguish between individuals retained in care, those in care but non-adherent, and those out of care. There is the possibility of social desirability bias or self-selection bias during the interview, such that a young person who is out-of-care, but knowledgeable of their status, may be less likely to consent to survey participation due to confidentiality concerns. Temporality was not possible to assess in a cross-sectional survey, and missing values were included as a separate category to maintain sample size in the analysis, which assumes that missingness is itself informative and may have influenced the associations.

Conclusions

Our results revealed that more than half of HIV-positive young people in Mozambique were not in HIV care in 2021, with disparities in coverage by region and sex. The heightened HIV transmission risk from, and among, young people threatens Mozambique’s progress towards meeting the 2025 UNAIDS targets in Mozambique. Future programs focused on social and demographic factors from this analysis, including geographic residence, the influence of parents and guardians in young people’s health knowledge and behaviors, and missed opportunities for reinforcing continual health engagement in existing prevention programs, may help address remaining coverage gaps and improve linkage to care in this priority population.

Abbreviations

ART

Antiretroviral treatment

aOR

Adjusted Odds Ratio

AIC

Akaike information criterion

CNBS

Mozambique National Bioethics Committee

DREAMS

Determined, Resilient, Empowered, AIDS-free, Mentored and Safe

HIV

Human immunodeficiency virus

INSIDA

Mozambican Population-based HIV Impact Assessment

OR

Odds ratios

PLHIV

People living with HIV

PrEP

Pre-exposure prophylaxis

PEPFAR

President’s Emergency Plan for AIDS Relief

SAAJ

Serviços Amigos dos Adolescentes e Jovens

UNAIDS

The Joint United Nations Programme on HIV/AIDS

Author contributions

O.F.T., K.C.M, J.W and C.S.B conceived the study. K.C.M conducted the analyses. O.F.T drafted the manuscript with support from K.C.M in the methods and results sections. All authors contributed to critical review of the manuscript.

Funding

The 2021 Mozambique Population-based HIV Impact Assessment was funded by the President’s Emergency Plan for AIDS Relief through the Centers for Disease Control and Prevention under the terms of cooperative agreement award #U2GGH002173. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the funding agencies.

Data availability

The 2021 INSIDA public release datasets, questionnaire, and related files are available at the ICAP PHIA website ([https://phia-data.icap.columbia.edu/datasets?country_id=15]). Survey data, manuals and documentation are available for download with an account.

Declarations

Human ethics and consent to participate

The study was conducted in accordance with the Declaration of Helsinki and was reviewed and approved by the Mozambique National Bioethics Committee (CNBS), the Columbia University Medical Center, and the U.S. Centers for Disease Control and Prevention (protocol #7258) Institutional Review Boards.1 All participants provided written informed consent prior to the interview and blood draw, and additional parental informed consent was given for all respondents ages 15 to 17 years. A detailed description of the study protocol and procedures to protect confidentiality can be found in the final INSIDA report [10].

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.