Longitudinal patterns in indeterminate HIV rapid antibody test results: a population-based, prospective cohort study

Rapid HIV tests are critical to HIV surveillance and universal testing and treatment programs. We assessed longitudinal patterns in indeterminate HIV rapid test results in an African population-based cohort. Prospective HIV rapid antibody test results, defined by two parallel rapid tests, among participants aged 15-49 years from three survey rounds of the Rakai Community Cohort Study, Uganda, from 2013 to 2018, were assessed. An indeterminate result was defined as any weak positive result or when one test was negative and the other was positive. A total of 31,405 participants contributed 54,459 person-visits, with 15,713 participants contributing multiple visits and 7,351 participants contributing 3 visits. The prevalence of indeterminate results was 2.7% (1,490/54,469). Of the participants with multiple visits who initially tested indeterminate (n = 591), 40.4% were negative, 18.6% were positive, and 41.0% were indeterminate at the subsequent visit. Of the participants with two consecutive indeterminate results who had a third visit (n = 67), 20.9% were negative, 9.0% were positive, and 70.2% remained indeterminate. Compared to a prior negative result, a prior indeterminate result was strongly associated with a subsequent indeterminate result [adjusted prevalence ratio, 23.0 (95% CI = 20.0-26.5)]. Compared to men, women were more likely to test indeterminate than negative [adjusted odds ratio, 2.3 (95% CI = 2.0-2.6)]. Indeterminate rapid HIV test results are highly correlated within an individual and 0.6% of the population persistently tested indeterminate over the study period. A substantial fraction of people with an indeterminate result subsequently tested HIV positive at the next visit, underscoring the importance of follow-up HIV testing protocols.IMPORTANCERapid HIV tests are a critical tool for expanding HIV testing and treatment to end the HIV epidemic. The interpretation and management of indeterminate rapid HIV test results pose a unique challenge for connecting all people living with HIV to the necessary care and treatment. Indeterminate rapid HIV test results are characterized by any weak positive result or discordant results (when one test is negative and the other is positive). We systematically tested all participants of a Ugandan population-based, longitudinal cohort study regardless of prior test results or HIV status to quantify longitudinal patterns in rapid HIV test results. We found that a substantial fraction (>15%) of participants with indeterminate rapid test results subsequently tested positive upon follow-up testing at the next visit. Our findings demonstrate the importance of follow-up HIV testing protocols for indeterminate rapid HIV test results.

Hepatitis B virus infection and factors associated with its acquisition among adults in a Lake Victoria HIV hyperendemic fishing community in Kyotera district, Uganda: a cross-sectional observation

OBJECTIVE

To investigate hepatitis B virus (HBV) prevalence and factors associated with viral acquisition in a HIV-hyperendemic fishing community, we tested sera for anti-hepatitis B core (HBc) and hepatitis B surface antigen (HBsAg).

DESIGN

Observational cross-sectional study.

SETTING

Large fishing village on Lake Victoria, one of the HIV-hyperendemic Rakai Community Cohort Study (RCCS) sites (HIV prevalence ~40%).

PARTICIPANTS

Sample of 460 RCCS participants aged 15-49 years from survey conducted from 5 December 2016 to 13 February 2017. These proportionately included HIV-negative, HIV-positive antiretroviral therapy (ART)-naïve and HIV positive on ART participants.

RESULTS

Of the 460 participants, 49.6% (95% CI 45.0% to 54.1%) had evidence of prior HBV infection and 3.7% (95% CI 2.3% to 5.9%) were either acutely or chronically infected. HBV risk increased with age, number of lifetime sex partners and HIV seropositivity. HBV risk decreased with HIV ART use among HIV-positive participants. Prevalence of prior HBV infection was 17.1% in participants aged 15-19 years, 43.2%, 55.3% and 70.1% in participants aged 20-39, 30-39 and 40-49 years, respectively (p<0.001). Additionally, the prevalence of prior HBV infection was 23.8% in participants with 0-1 lifetime sex partners, 43.2% and 54.8% in participants with 2-3 lifetime sex partners and 4+ lifetime sex partners, respectively (p<0.001).

CONCLUSIONS

Findings from this fishing community suggest the need to provide HBV vaccination to adults at risk of sexual transmission who have not been previously immunised.

Prevalence and Predictors of Persistent Human Immunodeficiency Virus Viremia and Viral Rebound After Universal Test and Treat: A Population-Based Study

BACKGROUND

There are limited data on individual human immunodeficiency virus (HIV) viral load (VL) trajectories at the population-level after the introduction of universal test and treat (UTT) in sub-Saharan Africa.

METHODS

Human immunodeficiency virus VLs were assessed among HIV-positive participants through 3 population-based surveys in 4 Ugandan fishing communities surveyed between November 2011 and August 2017. The unit of analysis was a visit-pair (2 consecutive person-visits), which were categorized as exhibiting durable VL suppression, new/renewed VL suppression, viral rebound, or persistent viremia. Adjusted relative risks (adjRRs) and 95% confidence intervals (CIs) of persistent viremia were estimated using multivariate Poisson regression.

RESULTS

There were 1346 HIV-positive participants (n = 1883 visit-pairs). The population-level prevalence of durable VL suppression increased from 29.7% to 67.9% during UTT rollout, viral rebound declined from 4.4% to 2.7%, and persistent viremia declined from 20.8% to 13.3%. Younger age (15-29 vs 40-49 years; adjRR = 1.80; 95% CI = 1.19-2.71), male sex (adjRR = 2.09, 95% CI = 1.47-2.95), never being married (vs currently married; adjRR = 1.88, 95% CI = 1.34-2.62), and recent migration to the community (vs long-term resident; adjRR = 1.91, 95% CI = 1.34-2.73) were factors associated with persistent viremia.

CONCLUSIONS

Despite increases in durable VL suppression during roll out of UTT in hyperendemic communities, a substantial fraction of the population, whose risk profile tended to be younger, male, and mobile, remained persistently viremic.

HIV serologically indeterminate individuals: Future HIV status and risk factors

BACKGROUND

Indeterminate HIV test results are common, but little is known about the evolution of indeterminate serology and its sociodemographic and behavioral correlates. We assessed future HIV serological outcomes for individuals with indeterminate results and associated factors in Rakai, Uganda.

METHODS

115,944 serological results, defined by two enzyme immunoassay (EIAs), among 39,440 individuals aged 15-49 years in the Rakai Community Cohort Study were assessed. Indeterminate results were defined as contradictory EIAs. Modified Poisson regression models with generalized estimating equations were used to assess prevalence ratios (PRs) of subsequent HIV serological outcomes and factors associated with HIV indeterminate results.

RESULTS

The prevalence of HIV serologically indeterminate results was 4.9%. Indeterminate results were less likely among women than men (adjPR 0.76, 95% CI 0.71,0.81), in unmarried participants than married participants (adjPR 0.92, 95% CI 0.85,99), and in individuals with primary (adjPR 0.90, 95% CI 0.80,1.02), secondary (adjPR 0.83, 95% CI 0.73,0.96) and post-secondary (adjPR 0.75, 95% CI 0.60,0.94) education, relative to no education. The proportions of persons with indeterminate results progressing to HIV positive, negative or indeterminate results in subsequent visits was 5%, 71% and 24%, respectively.

CONCLUSION

HIV serologically indeterminate results were associated with gender and marital status. HIV surveillance programs should develop a protocol for reporting individuals with mixed or persistently indeterminate HIV results on multiple follow-up visits. Most indeterminate results became HIV-negative over time, but follow-up is still needed to detect positive serologies.

Quantifying HIV transmission flow between high-prevalence hotspots and surrounding communities: a population-based study in Rakai, Uganda

BACKGROUND

International and global organisations advocate targeting interventions to areas of high HIV prevalence (ie, hotspots). To better understand the potential benefits of geo-targeted control, we assessed the extent to which HIV hotspots along Lake Victoria sustain transmission in neighbouring populations in south-central Uganda.

METHODS

We did a population-based survey in Rakai, Uganda, using data from the Rakai Community Cohort Study. The study surveyed all individuals aged 15-49 years in four high-prevalence Lake Victoria fishing communities and 36 neighbouring inland communities. Viral RNA was deep sequenced from participants infected with HIV who were antiretroviral therapy-naive during the observation period. Phylogenetic analysis was used to infer partial HIV transmission networks, including direction of transmission. Reconstructed networks were interpreted through data for current residence and migration history. HIV transmission flows within and between high-prevalence and low-prevalence areas were quantified adjusting for incomplete sampling of the population.

FINDINGS

Between Aug 10, 2011, and Jan 30, 2015, data were collected for the Rakai Community Cohort Study. 25 882 individuals participated, including an estimated 75·7% of the lakeside population and 16·2% of the inland population in the Rakai region of Uganda. 5142 participants were HIV-positive (2703 [13·7%] in inland and 2439 [40·1%] in fishing communities). 3878 (75·4%) people who were HIV-positive did not report antiretroviral therapy use, of whom 2652 (68·4%) had virus deep-sequenced at sufficient quality for phylogenetic analysis. 446 transmission networks were reconstructed, including 293 linked pairs with inferred direction of transmission. Adjusting for incomplete sampling, an estimated 5·7% (95% credibility interval 4·4-7·3) of transmissions occurred within lakeside areas, 89·2% (86·0-91·8) within inland areas, 1·3% (0·6-2·6) from lakeside to inland areas, and 3·7% (2·3-5·8) from inland to lakeside areas.

INTERPRETATION

Cross-community HIV transmissions between Lake Victoria hotspots and surrounding inland populations are infrequent and when they occur, virus more commonly flows into rather than out of hotspots. This result suggests that targeted interventions to these hotspots will not alone control the epidemic in inland populations, where most transmissions occur. Thus, geographical targeting of high prevalence areas might not be effective for broader epidemic control depending on underlying epidemic dynamics.

FUNDING

The Bill & Melinda Gates Foundation, the National Institute of Allergy and Infectious Diseases, the National Institute of Mental Health, the National Institute of Child Health and Development, the Division of Intramural Research of the National Institute for Allergy and Infectious Diseases, the World Bank, the Doris Duke Charitable Foundation, the Johns Hopkins University Center for AIDS Research, and the President's Emergency Plan for AIDS Relief through the Centers for Disease Control and Prevention.

The Effect of Antiretroviral Therapy Initiation on the Vaginal Microbiome in HIV-Infected Women

Background

The impact of antiretroviral therapy (ART) initiation on the vaginal microbiome is unknown. This is of particular importance among women living in sub-Saharan Africa. Understanding this relationship could help elucidate if and how the host immune system interacts with the vaginal microbiome.

Methods

The vaginal microbiome of HIV-1/HSV-2-coinfected women (n = 92) in Uganda was evaluated from self-collected vaginal swabs 1 month pre-ART and at 4 and 6 months post-ART initiation. The vaginal microbiome was characterized by 16S rRNA gene-based sequencing and quantitative polymerase chain reaction. Vaginal community state types (CSTs) were identified using proportional abundance data. Changes in microbiome composition were assessed with permutational analyses of variance (PerMANOVA).

Results

Five vaginal CSTs were identified, which varied significantly by bacterial load (P < .01): CST-1 was characterized by Lactobacillus iners, CST-2 by Gardnerella, CST-3 by Gardnerella and Prevotella, CST-4 by Lactobacillus crispatus, and CST-5 was highly diverse. Vaginal microbiome composition also did not change significantly after ART initiation (P = .985). Immune reconstitution after ART initiation did not affect vaginal microbiome CST assignment (P = .722) or individual-level changes in bacterial load (log response ratio [interquartile range], -0.50 [-2.75 to 0.38] vs -0.29 [-2.03 to 1.42]; P = .40).

Conclusions

The vaginal microbiome of HIV-infected women was not affected by the initiation of ART or immune reconstitution in this observational study. Further research is needed to explore the long-term effects of ART treatment on the vaginal microbiome.

Antiretroviral Therapy is Highly Effective Against Incident Hepatitis B Disease Acquisition Among HIV-Infected Adults in Rakai, Uganda

Abstract 30

Background and objective:

Co-infection with Hepatitis B (HBV) and HIV is common in sub-Saharan Africa (SSA) and accelerates progression of liver disease to cirrhosis, hepatocellular carcinoma (HCC) and other complications. About 60% of HCC in Africa is attributed to HBV. In Uganda, 80% of HCC patients have HBV and 20% have HIV/HBV coinfection. HCC is the 4th commonest cancer among Ugandan males and the 6th commonest in females. It is almost always a fatal malignancy in SSA. Prevention of HBV is best achieved through vaccination. Vaccination of HIV-infected adults for HBV is standard of care in developed countries but not in SSA where HBV is believed to be acquired in childhood and where there is lack of HBV incidence data. We investigated the incidence and risk factors associated with HBV among HIV-infected adults in Rakai, Uganda.

Methods:

We screened stored sera from 944 HIV infected adults enrolled in the Rakai Community Cohort Study between September 2003 and March 2015 for evidence of HBV exposure using the anti-HBc marker. Serum from participants who tested anti-HBc negative (497) at the baseline round was tested over 3-7 consecutive survey rounds for either anti-HBc or HBsAg sero-conversion. The time of HBV incidence was defined as the median date between the last anti-Hbc or HBsAg negative sample and the first positive anti-HBc or HBsAg serum sample. Almost all ART treatment regimens contained at least one HBV active medication. Exact poisson incidence methods were used to estimate the incidence of HBV with 95% confidence intervals while the Cox proportional regression methods were used to estimate adjusted hazard ratios of ART use and other confounders.

Results:

Thirty nine infections occurred (8 positive for both HBsAg and anti-HBc, 3 for HBsAg only, and 28 for anti-HBc only) over 3,342 person-years (pys), incidence 1.17/100 person-years. HBV incidence was significantly lower with ART use: 0.48 /100 person-years with ART use and 2.34/100 person-years without ART (p<0.001) and with HIVRNA suppression: 0.6/100pys with HIVRNA ≤400 copies/mL 6.0/100pys with >400copies/mL (p<0.001). It also decreased significantly with age: 2.60/100 pys if aged 15-29 years, 1.32/100 pys if aged 30-39 years and 0.48/100 pys if aged 40-50 years (p<0.001). The adjusted hazard ratios of HBV incidence significantly differed by ART use: non ART use versus ART use, aHR=0.24 (95% CI, 0.1-0.5), lamivudine (3TC) use: no ART versus 3TC-based ART, aHR= 0.24(0.1-0.5), p=<0.001), HIVRNA suppression ≤400 versus >400copies/mL, aHR= 6.4(2.2-19.0) and by age: 40-50 years versus 15-29 years, aHR= 3.66 (1.3-10.2); 40-50 years versus 30-39 years, aHR=2.18(0.9-5.4). No new HBV infections occurred among participants on a tenofovir-based regimen and there was no statistical significant differences by gender, occupation, marital status or number of sex partners, duration on ART or baseline CD4 count.

Conclusion:

The protective effects of HBV-active ART medications underscores additional benefits of earlier initiation of ART. Ongoing HBV transmission demonstrated by this study represents an opportunity for vaccine preventive strategies which could ultimately significantly reduce the burden of HCC in SSA.

AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST:

Emmanuel Seremba No relationship to disclose Victor Ssempijja No relationship to disclose Sarah Kalibbala No relationship to disclose Ronald Gray No relationship to disclose Maria Wawer No relationship to disclose Fred Nalugoda No relationship to disclose Corey Casper Consulting or Advisory Role: Temptime Corporation, GlaxoSmithKline Research Funding: Janssen Pharmaceuticals Travel, Accommodations, Expenses: GlaxoSmithKline, TempTime Warren T. Phipps No relationship to disclose Ponsiano Ocama No relationship to disclose David L. Thomas No relationship to disclose Steven J. Reynolds No relationship to disclose

Immunological Signaling During Herpes Simplex Virus-2 and Cytomegalovirus Vaginal Shedding After Initiation of Antiretroviral Treatment

Vaginal proinflammatory cytokine expression during herpes virus reactivation was examined in human immunodeficiency virus-infected women before and after initiation of antiretroviral therapy (ART). Vaginal swabs were screened for levels of cytokines interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, tumor necrosis factor (TNF)-α, and interferon-γ. The relative risk (RR) of herpes simplex virus-2 or cytomegalovirus (CMV) shedding being associated with cytokine levels above the median were estimated. Herpes simplex virus-2 shedding was significantly associated with higher levels of IL-6 (RR = 1.4, P = .003) and TNF-α (RR = 1.3, P = .010), whereas CMV shedding was associated with higher IL-6 (RR = 1.3, P = .006) and IL-2 (RR = 1.4, P = .01). The association of viral shedding with higher IL-6 levels suggests that herpes virus reactivation may be playing a role in immune activation after ART initiation.

Decreased monocyte activation with daily acyclovir use in HIV-1/HSV-2 coinfected women

OBJECTIVES

Several clinical trials have demonstrated that daily treatment of HIV-infected individuals with the antiherpes drug acyclovir slightly decreases HIV-1 viral load and slows disease progression. This study examines if this slowing in clinical progression is a direct cause of the decrease in viral load or an indirect effect of lower immune activation due to lower levels of herpetic reactivation.

METHODS

Women who participated in a randomised clinical trial of daily acyclovir use (n=301) were monitored every 6 months for changes in immune activation. Soluble CD14 (sCD14), a marker for monocyte activation, and C-reactive protein (CRP), a marker for general immune activation, were measured by ELISA.

RESULTS

Initial levels of sCD14 and CRP were not predictive of HIV disease progression when controlling for initial CD4+ cell count and HIV viral load. sCD14 levels, but not CRP, decreased in the acyclovir treatment arm at a significantly faster rate than the placebo group, which was independent of changes in HIV viral load and CD4+ cell count in a multivariant mixed-effects model (p=0.039). However, the magnitude of this decrease was relatively small with a total estimated decrease of sCD14 of 15% of initial levels.

CONCLUSIONS

These data suggest that decreased monocyte activation may play a minor role in the ability of daily acyclovir use to slow HIV disease progression.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00405821.

Vaginal Cytomegalovirus Shedding Before and After Initiation of Antiretroviral Therapy in Rakai, Uganda

Vaginal shedding of cytomegalovirus (CMV) DNA was determined longitudinally among 96 women coinfected with human immunodeficiency virus (HIV), herpes simplex virus 2, and CMV starting antiretroviral therapy (ART) during a placebo-controlled trial of HSV-2 suppression with acyclovir in Rakai, Uganda. Vaginal CMV was detected in 75 of 96 women (78.0%) and 379 of 1080 individual visits (35.1%). ART status, higher HIV RNA viral load before ART initiation, and younger age were significantly associated with increased frequency of CMV shedding (P < .01). Compared to pre-ART, CMV shedding peaked from month 2 to month 4 after ART initiation, suggesting possible immune reconstitution inflammatory syndrome. Further studies need to determine the clinical significance of asymptomatic CMV shedding.

Field evaluation of PIMA point-of-care CD4 testing in Rakai, Uganda

Objective

To assess the accuracy of PIMA Point-of-Care (POC) CD4 testing in rural Rakai, Uganda.

Methods

903 HIV positive persons attending field clinics provided a venous blood sample assessed on site using PIMA analyzers per manufacturer's specifications. The venous samples were then run on FACSCalibur flow cytometry at a central facility. The Bland–Altman method was used to estimate mean bias and 95% limits of agreement (LOA). Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) were calculated for a CD4 threshold of <350 and <500 cells/uL for antiretroviral eligibility.

Results

There was a high correlation between PIMA and FACSCalibur CD4 counts (r = 0.943, p<0.001). Relative to FACSCalibur, the PIMA POC CD4 had negative mean bias of −34.6 cells/uL (95% LOA: −219.8 to 150.6) overall. The dispersion at CD4<350 cells/uL was 5.1 cells/uL (95% LOA: −126.6 to 136.8). For a threshold of CD4<350 cells/uL, PIMA venous blood had a sensitivity of 88.6% (95%CI 84.8–92.4%), specificity of 87.5% (95%CI 84.9–90.1%), NPV of 94.9% (95%CI 93.1–96.7%), and PPV of 74.4% (95%CI 69.6–79.2%). PIMA sensitivity and PPV significantly increased to 96.1% and 88.3% respectively with increased threshold of 500 cells/uL.

Conclusions

Overall, PIMA POC CD4 counts demonstrated negative bias compared to FACSCalibur. PIMA POC sensitivity improved significantly at a higher CD4 threshold of 500 than a 350 cells/uL threshold.

Evaluation of current rapid HIV test algorithms in Rakai, Uganda

Rapid HIV tests are a crucial component of HIV diagnosis in resource limited settings. In Uganda, the Ministry of Health allows both serial and parallel HIV rapid testing using Determine, Stat-Pak and Uni-Gold. In serial testing, a non-reactive result on Determine ends testing. The performance of serial and parallel algorithms with Determine and Stat-Pak test kits was assessed. A cross-sectional diagnostic test accuracy evaluation using three rapid HIV test kits as per the recommended parallel test algorithm was followed by EIA-WB testing with estimates of the performance of serial testing algorithm. In 2520 participants tested by parallel rapid algorithms, 0.6% had weakly reactive result. Parallel testing had 99.7% sensitivity and 99.8% specificity. If Stat-Pak was used as the first screening test for a serial algorithm, the sensitivity was 99.6% and specificity was 99.7%. However, if Determine was used as the screening test, sensitivity was 97.3% and specificity was 99.9%. Serial testing with Stat-Pak as the initial screening test performed as well as parallel testing, but Determine was a less sensitive screen. Serial testing could be cost saving.

Sensitivity and specificity of HIV-1 testing of urine compared with serum specimens: Rakai, Uganda. The Rakai Project Team

BACKGROUND AND OBJECTIVES

To evaluate a urine HIV-1 test.

STUDY DESIGN

Paired urine and blood samples from a sample of 222 subjects were assayed for HIV-1 using Calypte HIV-1 Urine enzyme immunoassay (EIA) with Western blot (WB) confirmation, and sera were tested by EIA and WB. Masked assays were done on stored, refrigerated urine at Johns Hopkins University (JH), and on fresh specimens at the Rakai Project, Entebbe (RP). We assessed the sensitivity and specificity of the urine relative to serum assays.

RESULTS

Compliance with provision of urine samples (95.0%) was higher than provision of serum (90.5%). Ninety-six sera were HIV-positive; 92 were HIV-positive on stored urine at JH (sensitivity 95.8%, CI 91.8-99.8%); and 94 (100%) were positive on fresh samples at the RP laboratory (sensitivity = 100.0%). Among serum HIV-negative subjects, all frozen urine were negative at JH and 97.7% of fresh samples were negative at RP.

CONCLUSIONS

The Calypte urine HIV-1 EIA with WB is sensitive and specific. In this population, provision of urine was more acceptable than provision of blood samples.