Risk Factors for Recent HIV Infections among Adults in 14 Countries in Africa Identified by Population-Based HIV Impact Assessment Surveys, 2015-2019.

Identifying persons who have newly acquired HIV infections is critical for characterizing the HIV epidemic direction. We analyzed pooled data from nationally representative Population-Based HIV Impact Assessment surveys conducted across 14 countries in Africa for recent infection risk factors. We included adults 15-49 years of age who had sex during the previous year and used a recent infection testing algorithm to distinguish recent from long-term infections. We collected risk factor information via participant interviews and assessed correlates of recent infection using multinomial logistic regression, incorporating each survey's complex sampling design. Compared with HIV-negative persons, persons with higher odds of recent HIV infection were women, were divorced/separated/widowed, had multiple recent sex partners, had a recent HIV-positive sex partner or one with unknown status, and lived in communities with higher HIV viremia prevalence. Prevention programs focusing on persons at higher risk for HIV and their sexual partners will contribute to reducing HIV incidence.

Improving Biomarker-based HIV Incidence Estimation in the Treatment Era.

BACKGROUND: Estimating HIV-1 incidence using biomarker assays in cross-sectional surveys is important for understanding the HIV pandemic. However, the utility of these estimates has been limited by uncertainty about what input parameters to use for false recency rate (FRR) and mean duration of recent infection (MDRI) after applying a recent infection testing algorithm (RITA). METHODS: This article shows how testing and diagnosis reduce both FRR and mean duration of recent infection compared to a treatment-naive population. A new method is proposed for calculating appropriate context-specific estimates of FRR and mean duration of recent infection. The result of this is a new formula for incidence that depends only on reference FRR and mean duration of recent infection parameters derived in an undiagnosed, treatment-naive, nonelite controller, non-AIDS-progressed population. RESULTS: Applying the methodology to eleven cross-sectional surveys in Africa results in good agreement with previous incidence estimates, except in 2 countries with very high reported testing rates. CONCLUSIONS: Incidence estimation equations can be adapted to account for the dynamics of treatment and recent infection testing algorithms. This provides a rigorous mathematical foundation for the application of HIV recency assays in cross-sectional surveys.

Vital Signs: Progress Toward Eliminating HIV as a Global Public Health Threat Through Scale-Up of Antiretroviral Therapy and Health System Strengthening Supported by the U.S. President's Emergency Plan for AIDS Relief - Worldwide, 2004-2022.

Introduction: In 2004, the U.S. President's Emergency Plan for AIDS Relief (PEPFAR), with CDC as a major U.S. government implementing agency, began providing HIV antiretroviral therapy (ART) worldwide. Through suppression of HIV viral load, effective ART reduces morbidity and mortality among persons with HIV infection and prevents vertical and sexual transmission. Methods: To describe program impact, data were analyzed from all PEPFAR programs and from six countries that have conducted nationally representative Population-based HIV Impact Assessment (PHIA) surveys, including PEPFAR programmatic data on the number of persons with HIV infection receiving PEPFAR-supported ART (2004-2022), rates of viral load coverage (the proportion of eligible persons with HIV infection who received a viral load test) and viral load suppression (proportion of persons who received a viral load test with <1,000 HIV copies per mL of blood) (2015-2022), and population viral load suppression rates in six countries that had two PHIA surveys conducted during 2015-2021. To assess health system strengthening, data on workforce and laboratory systems were analyzed. Results: By September 2022, approximately 20 million persons with HIV infection in 54 countries were receiving PEPFAR-supported ART (62% CDC-supported); this number increased 300-fold from the 66,550 reported in September 2004. During 2015-2022, viral load coverage more than tripled, from 24% to 80%, and viral load suppression increased from 80% to 95%. Despite increases in viral load suppression rates and health system strengthening investments, variability exists in viral load coverage among some subpopulations (children aged <10 years, males, pregnant women, men who have sex with men [MSM], persons in prisons and other closed settings [persons in prisons], and transgender persons) and in viral load suppression among other subpopulations (pregnant and breastfeeding women, persons in prisons, and persons aged <20 years). Conclusions and implications for public health practice: Since 2004, PEPFAR has scaled up effective ART to approximately 20 million persons with HIV infection in 54 countries. To eliminate HIV as a global public health threat, achievements must be sustained and expanded to reach all subpopulations. CDC and PEPFAR remain committed to tackling HIV while strengthening public health systems and global health security.

Coronavirus Disease 2019 (COVID-19) Mitigation Efforts and Testing During an In-Person Training Event-Uganda, 12-29 October 2020.

Large public-health training events may result in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. Universal SARS-CoV-2 testing during trainings for the Uganda Population-based HIV Impact Assessment identified 28 of 475 (5.9%) individuals with coronavirus disease 2019 (COVID-19) among attendees; most (89.3%) were asymptomatic. Until COVID-19 vaccine is readily available for staff and participants, effective COVID-19 mitigation measures, along with SARS-CoV-2 testing, are recommended for in-person trainings, particularly when trainees will have subsequent contact with survey participants.

Screening for HIV Among Patients at Tuberculosis Clinics - Results from Population-Based HIV Impact Assessment Surveys, Malawi, Zambia, and Zimbabwe, 2015-2016.

The World Health Organization and national guidelines recommend HIV testing and counseling at tuberculosis (TB) clinics for all patients, regardless of TB diagnosis (1). Population-based HIV Impact Assessment (PHIA) survey data for 2015-2016 in Malawi, Zambia, and Zimbabwe were analyzed to assess HIV screening at TB clinics among persons who had positive HIV test results in the survey. The analysis was stratified by history of TB diagnosis* (presumptive versus confirmed†), awareness§ of HIV-positive status, antiretroviral therapy (ART)¶ status, and viral load suppression among HIV-positive adults, by history of TB clinic visit. The percentage of adults who reported having ever visited a TB clinic ranged from 4.7% to 9.7%. Among all TB clinic attendees, the percentage who reported that they had received HIV testing during a TB clinic visit ranged from 48.0% to 62.1% across the three countries. Among adults who received a positive HIV test result during PHIA and who did not receive a test for HIV at a previous TB clinic visit, 29.4% (Malawi), 21.9% (Zambia), and 16.2% (Zimbabwe) reported that they did not know their HIV status at the time of the TB clinic visit. These findings represent missed opportunities for HIV screening and linkage to HIV care. In all three countries, viral load suppression rates were significantly higher among those who reported ever visiting a TB clinic than among those who had not (p<0.001). National programs could strengthen HIV screening at TB clinics and leverage them as entry points into the HIV diagnosis and treatment cascade (i.e., testing, initiation of treatment, and viral load suppression).

Survival and HIV-Free Survival Among Children Aged ≤3 Years - Eight Sub-Saharan African Countries, 2015-2017.

Although mother-to-child transmission (MTCT) of human immunodeficiency virus (HIV) is preventable through antiretroviral treatment (ART) during pregnancy and postpartum, the Joint United Nations Programme on HIV/AIDS (UNAIDS) estimates that 160,000 new HIV infections occurred among children in 2018 (1). Child survival and HIV-free survival rates* are standard measures of progress toward eliminating MTCT† (2). Nationally representative Population-based HIV Impact Assessment (PHIA)§ survey data, pooled from eight sub-Saharan African countries¶ were used to calculate survival probability among children aged ≤3 years by maternal HIV status during pregnancy and HIV-free survival probability among children aged ≤3 years born to women with HIV infection, stratified by maternal ART** status during pregnancy. Survival probability was significantly lower among children born to women with HIV infection (94.7%) than among those born to women without HIV infection (97.6%). HIV-free survival probability of children born to women with HIV infection differed significantly by the timing of initiation of maternal ART: 93.0% among children whose mothers received ART before pregnancy, 87.8% among those whose mothers initiated ART during pregnancy, and 53.4% among children whose mothers did not receive ART during pregnancy. Focusing on prevention of HIV acquisition and, among women of reproductive age with HIV infection, on early diagnosis of HIV infection and ART initiation when applicable, especially before pregnancy, can improve child survival and HIV-free survival.

Human Papillomavirus Vaccination Coverage Among School Girls in a Demonstration Project - Botswana, 2013.

What is already known on this topic? Human papillomavirus (HPV) infection is common and aggressive in persons infected with human immunodeficiency virus (HIV). With an HIV prevalence of 28% among females aged 15­49, cervical cancer is the leading cause of cancer death among women in Botswana. Before 2013, HPV vaccine had not been used in the public sector in Botswana.What is added by this report? Efforts to expand services for cervical cancer through the Pink Ribbon Red Ribbon initiative focused on HPV-related disease in Botswana. A demonstration project for HPV vaccination was developed by the Ministry of Health for school girls aged ≥9 years in primary schools in one community. A total of 1,967 (79%) of 2,488 eligible girls received 3 doses of vaccine in the immunization effort that was centered in schools.What are the implications for public health practice? Preventing HPV infection in girls is an important component of a national comprehensive cervical cancer control program. HPV vaccination programming is challenging, and demonstration projects can prepare countries for national introduction. The success of the initial HPV vaccination effort in Botswana led to an expanded project in 2014, with implementation of nationwide rollout of the HPV vaccine in 2015. It might be beneficial for future HPV vaccination campaigns to include strategies to reach out-of-school girls.

Follow-up of infants diagnosed with HIV - Early Infant Diagnosis Program, Francistown, Botswana, 2005-2012.

The 2011 prevalence of human immunodeficiency virus (HIV) among pregnant women in Botswana was 30.4%. High coverage rates of HIV testing and antiretroviral prophylaxis have reduced the rate of mother-to-child transmission of HIV in Botswana from as high as 40% with no prophylaxis to <4% in 2011. In June 2005, the national Early Infant Diagnosis (EID) Program began testing HIV-exposed infants (i.e., those born to HIV-infected mothers) for HIV using polymerase chain reaction (PCR) at 6 weeks postpartum. During 2005-2012, follow-up of all HIV-infected infants diagnosed in all 13 postnatal care facilities in Francistown, Botswana, was conducted to ascertain patient outcomes. A total of 202 infants were diagnosed with HIV. As of September 2013, 82 (41%) children were alive and on antiretroviral therapy (ART), 79 (39%) had died, and 41 (20%) were either lost to follow-up, had transferred, or their mothers declined ART. Despite success in preventing mother-to-child transmission in Botswana, results of the EID program highlight the need for early diagnosis of HIV-infected infants, prompt initiation of ART, and retention in care.

People Who Self-Reported Testing HIV-Positive but Tested HIV-Negative: A Multi-Country Puzzle of Data, Serology, and Ethics, 2015-2021.

During population-based HIV impact assessments (PHIAs), some participants who self-reported testing HIV-positive (PSRP) tested negative in one or more subsequent survey HIV tests. These unexpected discrepancies between their self-reported results and the survey results draw into question the validity of either the self-reported status or the test results. We analyzed PSRP with negative test results aged 15-59 years old using data collected from 2015 to 2021 in 13 countries, assessing prevalence, self-report status, survey HIV status, viral load, rapid tests and confirmatory tests, and answers to follow-up questions (such as years on treatment). Across these surveys, 19,026 participants were PSRP, and 256 (1.3%) of these were concluded to be HIV-negative after additional survey-based testing and review. PSRP determined to be HIV-negative trended higher in countries with a higher HIV prevalence, but their number was small enough that accepting self-reported HIV-positive status without testing would not have significantly affected the prevalence estimates for HIV or viral load suppression. Additionally, using more detailed information for Uganda, we examined 107 PSRP with any negative test results and found no significant correlation with years on treatment or age. Using these details, we examined support for the possible reasons for these discrepancies beyond misdiagnosis and false reporting. These findings suggest that those conducting surveys would benefit from a nuanced understanding of HIV testing among PSRP to conduct surveys ethically and produce high-quality results.

Progress towards the UNAIDS 95-95-95 targets in the Fifth Botswana AIDS Impact Survey (BAIS V 2021): a nationally representative survey.

BACKGROUND: In 2014, UNAIDS set a goal to end the AIDS epidemic by achieving targets for the percentage of people living with HIV who were aware of their status, on antiretroviral therapy (ART), and virally suppressed. In 2020, these targets were revised to 95% for each measure (known as 95-95-95), to be reached among people living with HIV by 2025. We used data from the Fifth Botswana AIDS Impact Survey (BAIS V) to measure progress towards these testing and treatment targets in Botswana. METHODS: BAIS V used a two-stage cluster design to obtain a nationally representative sample of people aged 15-64 years in Botswana. During March-August, 2021, 14 763 consenting participants were interviewed and tested for HIV in their households by survey teams. HIV-positive specimens were tested for viral load, presence of antiretroviral drugs, and recency of infection using the HIV-1 limiting antigen avidity enzyme immunoassay. Estimates of HIV-positive status and use of ART were based on self-report and the analysis of blood specimens for antiretroviral drugs. Viral load suppression was defined as an HIV RNA concentration of less than 1000 copies per mL. HIV incidence was calculated using the recent infection testing algorithm. Data were weighted to account for the complex survey design. FINDINGS: The national HIV prevalence in Botswana among people aged 15-64 years was 20·8% and the annual incidence of HIV infection was 0·2%. 95·1% (men 93·0%, women 96·4%) of people living with HIV aged 15-64 years were aware of their status, 98·0% (men 97·2%, women 98·4%) of those aware were on ART, and 97·9% (men 96·6%, women 98·6%) of those on ART had viral load suppression. Among young people (aged 15-24 years) living with HIV, 84·5% were aware of their status, 98·5% of those aware were on ART, and 91·6% of those on ART had viral load suppression. The prevalance of viral load suppression among all people living with HIV was 91·8%, and varied by district-ranging from 85·3% in Gaborone to 100·0% in Selibe Phikwe. INTERPRETATION: BAIS V is the first population-based survey worldwide to report the achievement of the UNAIDS 95-95-95 goals, both overall and among women. Strategies to reach undiagnosed men and young people, including young women, are needed. FUNDING: US President's Emergency Plan for AIDS Relief.

Brief Report: Self-Reported HIV-Positive Status but Subsequent HIV-Negative Test Results in Population-Based HIV Impact Assessment Survey Participants-11 Sub-Saharan African Countries, 2015-2018.

BACKGROUND: HIV testing is a critical step to accessing antiretroviral therapy (ART) because early diagnosis can facilitate earlier initiation of ART. This study presents aggregated data of individuals who self-reported being HIV-positive but subsequently tested HIV-negative during nationally representative Population-Based HIV Impact Assessment surveys conducted in 11 countries from 2015 to 2018. METHOD: Survey participants aged 15 years or older were interviewed by trained personnel using a standard questionnaire to determine HIV testing history and self-reported HIV status. Home-based HIV testing and counseling using rapid diagnostic tests with return of results were performed by survey staff according to the respective national HIV testing services algorithms on venous blood samples. Laboratory-based confirmatory HIV testing for all participants identified as HIV-positives and self-reported positives, irrespective of HIV testing results, was conducted and included Geenius HIV-1/2 and DNA polymerase chain reaction if Geenius was negative or indeterminate. RESULTS: Of the 16,630 participants who self-reported as HIV-positive, 16,432 (98.6%) were confirmed as HIV-positive and 198 (1.4%) were HIV-negative by subsequent laboratory-based testing. Participants who self-reported as HIV-positive but tested HIV-negative were significantly younger than 30 years, less likely to have received ART, and less likely to have received a CD4 test compared with participants who self-reported as HIV-positive with laboratory-confirmed infection. CONCLUSIONS: A small proportion of self-reported HIV-positive individuals could not be confirmed as positive, which could be due to initial misdiagnosis, deliberate wrong self-report, or misunderstanding of the questionnaire. As universal ART access is expanding, it is increasingly important to ensure quality of HIV testing and confirmation of HIV diagnosis before ART initiation.

Estimation of HIV-1 Incidence Using a Testing History-Based Method; Analysis From the Population-Based HIV Impact Assessment Survey Data in 12 African Countries.

BACKGROUND: Estimating HIV incidence is essential to monitoring progress in sub-Saharan African nations toward global epidemic control. One method for incidence estimation is to test nationally representative samples using laboratory-based incidence assays. An alternative method based on reported HIV testing history and the proportion of undiagnosed infections has recently been described. METHODS: We applied an HIV incidence estimation method which uses history of testing to nationally representative cross-sectional survey data from 12 sub-Saharan African nations with varying country-specific HIV prevalence. We compared these estimates with those derived from laboratory-based incidence assays. Participants were tested for HIV using the national rapid test algorithm and asked about prior HIV testing, date and result of their most recent test, and date of antiretroviral therapy initiation. RESULTS: The testing history-based method consistently produced results that are comparable and strongly correlated with estimates produced using a laboratory-based HIV incidence assay (ρ = 0.85). The testing history-based method produced incidence estimates that were more precise compared with the biomarker-based method. The testing history-based method identified sex-, age-, and geographic location-specific differences in incidence that were not detected using the biomarker-based method. CONCLUSIONS: The testing history-based method estimates are more precise and can produce age-specific and sex-specific incidence estimates that are informative for programmatic decisions. The method also allows for comparisons of the HIV transmission rate and other components of HIV incidence among and within countries. The testing history-based method is a useful tool for estimating and validating HIV incidence from cross-sectional survey data.

Trends in HIV prevalence, incidence, and progress towards the UNAIDS 95-95-95 targets in Malawi among individuals aged 15-64 years: population-based HIV impact assessments, 2015-16 and 2020-21.

BACKGROUND: In 2014, UNAIDS set the goal of ending the AIDS epidemic by 2030 through the achievement of testing and treatment cascade targets. To evaluate progress achieved and highlight persisting gaps in HIV epidemic control in Malawi, we aimed to compare key indicators (prevalence, incidence, viral load suppression, and UNAIDS 95-95-95 targets) from the 2015-16 and 2020-21 Malawi Population-based HIV Impact Assessment (PHIA) survey results. METHODS: The Malawi PHIAs were nationally representative, cross-sectional surveys with a two-stage cluster sampling design. The first survey was conducted between Nov 27, 2015, and Aug 26, 2016; the second survey was conducted between Jan 15, 2020, and April 26, 2021. Our analysis included survey participants aged 15-64 years. Participants were interviewed and a 14 mL blood sample was collected and tested for HIV infection using the national rapid testing algorithm. For each survey, we estimated key HIV epidemic indicators and achievement of 95-95-95 targets. The risk ratio (RR) of the indicators between surveys were computed and considered significant at a confidence level of 0·05. All results were weighted, and self-reported awareness and treatment status were adjusted to account for detection of antiretrovirals. FINDINGS: Our analysis included 17 187 participants aged 15-64 years in 2015-16 and 21 208 in 2020-21 who participated in the surveys and blood draw. In the 2020-21 survey, 88·4% (95% CI 86·7-90·0) of people living with HIV were aware of their HIV-positive status; of those aware, 97·8% (97·1-98·5) were on antiretroviral therapy; and of those on treatment, 96·9% (95·9-97·7) were virally suppressed. Between surveys, the national HIV prevalence decreased significantly from 10·6% (10·0-11·2) to 8·9% (8·4-9·5) with RR 0·85 (95% CI 0·78-0·92; p<0·0001). The annual HIV incidence decreased from 0·37% (0·20-0·53) to 0·22% (0·11-0·34) with RR 0·61 (95% CI 0·31-1·20; p=0·15). The population viral load suppression increased from 68·3% (66·0-70·7) in 2015-16 to 87·0% (85·3-88·5) in 2020-21 (RR 1·27 [95% CI 1·22-1·32]; p<0·0001). INTERPRETATION: These results suggest that Malawi had already surpassed the UNAIDS viral load suppression target for 2030 (85·7%) by 2020-21. Through strategies and evidence-informed interventions implemented in the last half decade, especially scale-up of effective HIV treatment, Malawi has made tremendous progress, including decreasing HIV prevalence and incidence and achieving both the second and third 95 targets ahead of 2030. To address the first 95, efforts in HIV diagnosis should focus on males and younger age groups. There is a continued need for effective linkage to care, retention on antiretroviral therapy, and adherence support to maintain and build on progress. FUNDING: US President's Emergency Plan for AIDS Relief through the US Centers for Disease Control and Prevention.

Point of Care CD4 Testing in National Household Surveys - Results and Quality Indicators from Eleven Population-Based HIV Impact Assessment (PHIA) Surveys.

Population-based HIV Impact Assessments (PHIAs) are national household (HH) surveys that provide HIV diagnosis and CD4 testing with an immediate return of results. Accurate CD4 results improve HIV-positive participants' clinical care and inform the effectiveness of HIV programs. Here, we present CD4 results from the PHIA surveys that were conducted in 11 countries in sub-Saharan Africa between 2015 and 2018. All of the HIV-positive participants and 2 to 5% of the HIV-negative participants were offered Pima CD4 (Abbott, IL, USA) point-of-care (POC) tests. The quality of the CD4 test was ensured by conducting instrument verification, comprehensive training, quality control, a review of testing errors and an analysis of unweighted CD4 data by HIV status, age, gender, and antiretroviral (ARV) treatment status. Overall, CD4 testing was completed for 23,085 (99.5%) of the 23,209 HIV-positive and 7,329 (2.7%) of the 270,741 negative participants in 11 surveys. The instrument error rate was 11.3% (range, 4.4% to 15.7%). The median CD4 values among HIV-positive and HIV-negative participants (aged 15+) were 468 cells/mm3 (interquartile range [IQR], 307 to 654) and 811 cells/mm3 (IQR, 647 to 1,013), respectively. Among the HIV-positive participants (aged 15+), those with detectable ARVs had higher CD4 values (508 cells/mm3) than those with undetectable ARVs (385.5 cells/mm3). Among the HIV-positive participants (aged 15+), 11.4% (2,528/22,253) had a CD4 value of less than 200 cells/mm3, and approximately half of them (1,225/2,528 = 48.5%) had detectable ARVs, whereas 51.5% (1,303/2,528) had no detectable ARVs (P < 0.0001). We successfully implemented high quality POC CD4 testing using Pima instruments. Our data come from nationally representative surveys in 11 countries and provide unique insights regarding the CD4 distribution among HIV-positive individuals as well as the baseline CD4 values among HIV-negative individuals. IMPORTANCE The manuscript describes CD4 levels among HIV-positive individuals and baseline CD4 levels among HIV-negative individuals from 11 sub-Saharan countries, thereby highlighting the importance of CD4 markers in the context of the HIV epidemic. Despite increased ARV access in each country, advanced HIV disease (CD4 < 200 cells/mm3) persists among approximately 11% of HIV-positive individuals. Therefore, it is important that our findings are shared with the scientific community to assist with similar implementations of point-of-care testing and to conduct a review of HIV programmatic gaps.

HIV Incidence, Recent HIV Infection, and Associated Factors, Kenya, 2007-2018.

Nationally representative surveys provide an opportunity to assess trends in recent human immunodeficiency virus (HIV) infection based on assays for recent HIV infection. We assessed HIV incidence in Kenya in 2018 and trends in recent HIV infection among adolescents and adults in Kenya using nationally representative household surveys conducted in 2007, 2012, and 2018. To assess trends, we defined a recent HIV infection testing algorithm (RITA) that classified as recently infected (<12 months) those HIV-positive participants that were recent on the HIV-1 limiting antigen (LAg)-avidity assay without evidence of antiretroviral use. We assessed factors associated with recent and long-term (≥12 months) HIV infection versus no infection using a multinomial logit model while accounting for complex survey design. Of 1,523 HIV-positive participants in 2018, 11 were classified as recent. Annual HIV incidence was 0.14% in 2018 [95% confidence interval (CI) 0.057-0.23], representing 35,900 (95% CI 16,300-55,600) new infections per year in Kenya among persons aged 15-64 years. The percentage of HIV infections that were determined to be recent was similar in 2007 and 2012 but fell significantly from 2012 to 2018 [adjusted odds ratio (aOR) = 0.31, p < .001]. Compared to no HIV infection, being aged 25-34 versus 35-64 years (aOR = 4.2, 95% CI 1.4-13), having more lifetime sex partners (aOR = 5.2, 95% CI 1.6-17 for 2-3 partners and aOR = 8.6, 95% CI 2.8-26 for ≥4 partners vs. 0-1 partners), and never having tested for HIV (aOR = 4.1, 95% CI 1.5-11) were independently associated with recent HIV infection. Although HIV remains a public health priority in Kenya, HIV incidence estimates and trends in recent HIV infection support a significant decrease in new HIV infections from 2012 to 2018, a period of rapid expansion in HIV diagnosis, prevention, and treatment.

Comparison of demographic and behavioral characteristics of men who have sex with men by enrollment venue type in the National HIV Behavioral Surveillance System.

BACKGROUND: During 2003-2005, the National HIV Behavioral Surveillance System (NHBS) enrolled men who have sex with men (MSM) from 12 different venue types in 15 metropolitan areas in the United States. Our goal was to examine whether limiting NHBS enrollment venues to gay bars and dance clubs could increase efficiency without changing the overall results and conclusions. METHODS: We used logistic regression analysis to compare the demographic characteristics and reported HIV risk behaviors among MSM enrolled in gay bars and dance clubs with those enrolled in sex venues and those enrolled in other venues. RESULTS: Of the 11,471 eligible men included in the analysis, 6419 (56%) were enrolled at bars and clubs, 481 (4%) at sex venues, and 4571 (40%) at other venues. Compared with men enrolled at bars and clubs, men enrolled at sex venues were more likely to be older, of nonwhite race/ethnicity, bisexual, infrequent gay venue attendees, and to have 10 or more male sex partners in the past 12 months. Men enrolled at other venues were more likely to be older and less likely to use noninjecting drugs in the past 12 months. The absolute differences in these characteristics between men enrolled in bars and clubs and those enrolled in comparison venue categories were small in most instances. CONCLUSIONS: Although the differences in characteristics by venue category were not large in magnitude, there was evidence that restricting NHBS enrollment to bars and clubs would affect national estimates of behavioral risk factors among MSM.

Toward elimination of mother-to-child transmission of HIV in Malawi: Findings from the Malawi Population-based HIV Impact Assessment (2015-2016).

BACKGROUND: Malawi spearheaded the development and implementation of Option B+ for prevention of mother-to-child transmission of HIV (PMTCT), providing life-long ART for all HIV-positive pregnant and breastfeeding women. We used data from the 2015-2016 Malawi Population-based HIV Impact Assessment (MPHIA) to estimate progress toward 90-90-90 targets (90% of those with HIV know their HIV-positive status; of these, 90% are receiving ART; and of these, 90% have viral load suppression [VLS]) for HIV-positive women reporting a live birth in the previous 3 years. METHODS: MPHIA was a nationally representative household survey; consenting eligible women aged 15-64 years were interviewed on pregnancies and outcomes, including HIV status during their most recent pregnancy, PMTCT uptake, and early infant diagnosis (EID) testing. Descriptive analyses were weighted to account for the complex survey design. Viral load (VL) results were categorized by VLS (<1,000 copies/mL) and undetectable VL (target not detected/below the limit of detection). RESULTS: Of the 3,153 women included in our analysis, 371 (10.1%, 95% confidence interval [CI]: 8.8%-11.3%) tested HIV positive in the survey. Most HIV-positive women (84.2%, 95% CI: 79.9%-88.6%) reported knowing their HIV-positive status; of these, 94.9% (95% CI: 91.7%-98.2%) were receiving ART; and of these, 91.2% (95% CI: 87.4%-95.0%) had VLS. Among the 371 HIV-positive women, 76.0% (95% CI: 70.4%-81.7%) had VLS and 66.5% (95% CI: 59.8%-73.2%) had undetectable VL. Among 262 HIV-exposed children, 50.8% (95% CI: 42.8%-58.8%) received EID testing within 2 months of birth, whereas 17.9% (95% CI: 11.9%-23.8%) did not receive EID testing. Of 190 HIV-exposed children with a reported HIV test result, 2.1% (95% CI: 0.0%-4.6%) had positive results. CONCLUSIONS: MPHIA data demonstrate high PMTCT uptake at a population level. However, our results identify some gaps in VLS in postpartum women and EID testing.

Correcting for selection bias in HIV prevalence estimates: an application of sample selection models using data from population-based HIV surveys in seven sub-Saharan African countries.

INTRODUCTION: Population-based biomarker surveys are the gold standard for estimating HIV prevalence but are susceptible to substantial non-participation (up to 30%). Analytical missing data methods, including inverse-probability weighting (IPW) and multiple imputation (MI), are biased when data are missing-not-at-random, for example when people living with HIV more frequently decline participation. Heckman-type selection models can, under certain assumptions, recover unbiased prevalence estimates in such scenarios. METHODS: We pooled data from 142,706 participants aged 15-49 years from nationally representative cross-sectional Population-based HIV Impact Assessments in seven countries in sub-Saharan Africa, conducted between 2015 and 2018 in Tanzania, Uganda, Malawi, Zambia, Zimbabwe, Lesotho and Eswatini. We compared sex-stratified HIV prevalence estimates from unadjusted, IPW, MI and selection models, controlling for household and individual-level predictors of non-participation, and assessed the sensitivity of selection models to the copula function specifying the correlation between study participation and HIV status. RESULTS: In total, 84.1% of participants provided a blood sample to determine HIV serostatus (range: 76% in Malawi to 95% in Uganda). HIV prevalence estimates from selection models diverged from IPW and MI models by up to 5% in Lesotho, without substantial precision loss. In Tanzania, the IPW model yielded lower HIV prevalence estimates among males than the best-fitting copula selection model (3.8% vs. 7.9%). CONCLUSIONS: We demonstrate how HIV prevalence estimates from selection models can differ from those obtained under missing-at-random assumptions. Further benefits include exploration of plausible relationships between participation and outcome. While selection models require additional assumptions and careful specification, they are an important tool for triangulating prevalence estimates in surveys with substantial missing data due to non-participation.

Prevalence of and factors associated with late diagnosis of HIV in Malawi, Zambia, and Zimbabwe: Results from population-based nationally representative surveys.

INTRODUCTION: Late diagnosis of HIV (LD) increases the risk of morbidity, mortality, and HIV transmission. We used nationally representative data from population-based HIV impact assessment (PHIA) surveys in Malawi, Zambia, and Zimbabwe (2015-2016) to characterize adults at risk of LD and to examine associations between LD and presumed HIV transmission to cohabiting sexual partners. METHODS: We estimated the prevalence of LD, defined as CD4 count <350 cells/µL, among adults newly diagnosed with HIV during the surveys and odds ratios for associated factors. We linked newly diagnosed adults (index cases) to their household sexual partners and calculated adjusted odds ratios for associations between LD of the index case, viral load of the index case, and duration of HIV exposure in the relationship, and the HIV status of the household sexual partner. RESULTS: Of 1,804 adults who were newly diagnosed with HIV in the surveys, 49% (882) were diagnosed late. LD was associated with male sex, older age, and almost five times the odds of having an HIV-positive household sexual partner (adjusted odds ratio [aOR], 4.65 [95% confidence interval: 2.56-8.45]). Longer duration of HIV exposure in a relationship and higher viral load of the index case were both independently associated with higher odds of having HIV-positive household sexual partners. Individuals with HIV exposure of more than 5 years had more than three times (aOR 3.42 [95% CI: 1.63-7.18]) higher odds of being HIV positive than those with less than 2 years HIV exposure. The odds of being HIV positive were increased in individuals who were in a relationship with an index case with a viral load of 400-3499 copies/mL (aOR 4.06 [95% CI 0.45-36.46]), 3,500-9,999 copies/mL (aOR 11.32 [95% CI: 4.08-31.39]), 10,000-49,999 copies/mL (aOR 17.07 [95% CI: 9.18-31.72]), and ≥50,000 copies/mL (aOR 28.41 [95% CI: 12.18-66.28]) compared to individuals who were in a relationship with an index case with a viral load of <400 copies/mL. CONCLUSIONS: LD remains a challenge in Southern Africa and is strongly associated with presumed HIV transmission to household sexual partners. Our study underscores the need for earlier HIV diagnosis, particularly among men and older adults, and the importance of index testing.

Performance of HIV rapid testing algorithm in Nigeria: Findings from a household-based Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS).

BACKGROUND: The Nigeria AIDS Indicator and Impact Survey (NAIIS), a cross-sectional household survey, was conducted in 2018 with primary objectives to estimate HIV prevalence, HIV-1 incidence, and status of UNAIDS 90-90-90 cascade. We conducted retrospective analysis of the performance of HIV rapid tests and the national HIV testing algorithm used in Nigeria. METHODS: The national algorithm included Determine HIV-1/2 as test 1 (T1), Unigold HIV-1/2 as test 2 (T2), and StatPak HIV-1/2 as the tie-breaker test (T3). Individuals reactive with T1 and either T2 or T3 were considered HIV-positive. HIV-positive specimens from the algorithm were further confirmed for the survey using supplemental test Geenius HIV-1/2. If Geenius did not confirm HIV-positive status, HIV-1 Western blot was performed. We calculated the concordance between tests and positive predictive value (PPV) of the algorithm on unweighted data. RESULTS: Of 204,930 participants (ages ≥18 months) 5,103 (2.5%) were reactive on T1. Serial testing of T1 reactive specimens with T2 or if needed by tiebreaker T3 identified 2958 (1.44%) persons as HIV-positive. Supplemental testing confirmed 2,800 (95%) as HIV-positive (HIV-1 = 2,767 [98.8%]; HIV-2 = 5 [0.2%]; dual infections = 22 [0.8%]). Concordance between T1 and T2 was 56.6% while PPV of the national algorithm was 94.5%. CONCLUSIONS: Our results show high discordant rates and poor PPV of the national algorithm with a false-positive rate of about 5.5% in the NAIIS survey. Considering our findings have major implications for HIV diagnosis in routine HIV testing services, additional evaluation of testing algorithm is warranted in Nigeria.