Epidemiology of alcohol use and alcohol use disorder among female sex workers in Mbeya City, Tanzania

Alcohol misuse is a global concern, contributing to 5.3% of total deaths and 132.6 million disability-adjusted life years worldwide. In Sub-Saharan African countries, the prevalence of Alcohol Use Disorder (AUD) has risen, especially among female sex workers, due to increased availability and advertising. However, there are limited studies on alcohol use and AUD among female sex workers in Tanzania. This study aimed to determine the prevalence, patterns, and factors associated with alcohol use and AUD among sex workers in Mbeya city, Tanzania. In this cross-sectional study, 212 female sex workers in Mbeya city, Tanzania, seeking enrolment in the National Institute for Medical Research Mbeya Medical Research Centre's registration cohort from July to November 2022. Structured interviews covered socio-demographics, alcohol screening (AUDIT-C and Timeline Follow Back Calendar), and sexual behaviours data. Data were analysed using Stata version 17. Descriptive analysis assessed alcohol consumption and AUD prevalence. Factors associated with alcohol use and AUD at bivariate analysis were identified using Chi-square/Fisher's exact tests. All variables with p-value ≤ 0.20 were entered into a multivariable logistic regression model to identify factors associated with alcohol use and AUD. Among 212 participants, 86.6% reported alcohol use in the past 12 months, 85% in the past 30 days, and 98.5% met AUD criteria. Factors linked to recent alcohol consumption included primary education or higher, income above the median, and more than 10 sexual partners. Education level, marital status, income, and having dependents were significantly associated with heavy drinking episodes. The prevalence of AUD, alcohol use, and heavy episodic drinking were high among female sex workers in Mbeya city. Socio-demographic factors and risky sexual behaviours were associated with alcohol use and heavy episodic drinking highlighting the need for targeted interventions to combat alcohol abuse among female sex workers within the HIV program.

Dynamics and durability of HIV-1 neutralization are determined by viral replication

Human immunodeficiency virus type 1 (HIV-1)-neutralizing antibodies (nAbs) that prevent infection are the main goal of HIV vaccine discovery. But as no nAb-eliciting vaccines are yet available, only data from HIV-1 neutralizers-persons with HIV-1 who naturally develop broad and potent nAbs-can inform about the dynamics and durability of nAb responses in humans, knowledge which is crucial for the design of future HIV-1 vaccine regimens. To address this, we assessed HIV-1-neutralizing immunoglobulin G (IgG) from 2,354 persons with HIV-1 on or off antiretroviral therapy (ART). Infection with non-clade B viruses, CD4+ T cell counts <200 µl-1, being off ART and a longer time off ART were independent predictors of a more potent and broad neutralization. In longitudinal analyses, we found nAb half-lives of 9.3 and 16.9 years in individuals with no- or low-level viremia, respectively, and 4.0 years in persons who newly initiated ART. Finally, in a potent HIV-1 neutralizer, we identified lower fractions of serum nAbs and of nAb-encoding memory B cells after ART initiation, suggesting that a decreasing neutralizing serum activity after antigen withdrawal is due to lower levels of nAbs. These results collectively show that HIV-1-neutralizing responses can persist for several years, even at low antigen levels, suggesting that an HIV-1 vaccine may elicit a durable nAb response.

Protein dose-sparing effect of AS01B adjuvant in a randomized preventive HIV vaccine trial of ALVAC-HIV (vCP2438) and adjuvanted bivalent subtype C gp120

BACKGROUND

HVTN 120 is a phase 1/2a randomized double-blind placebo-controlled HIV vaccine trial that evaluated the safety and immunogenicity of ALVAC-HIV (vCP2438) and MF59- or AS01B-adjuvanted bivalent subtype C gp120 Env protein at two dose levels in healthy HIV-uninfected adults. Trial registration URL https://clinicaltrials.gov/ct2/show/NCT03122223 and registration number NCT03122223.

METHODS

Participants received ALVAC-HIV (vCP2438) alone or placebo at months 0 and 1. At months 3 and 6, participants received either placebo, ALVAC-HIV (vCP2438) with 200μg of bivalent subtype C gp120 adjuvanted with MF59 or AS01B, or ALVAC-HIV (vCP2438) with 40μg of bivalent subtype C gp120 adjuvanted with AS01B. Primary outcomes were safety and immune responses.

RESULTS

We enrolled 160 participants, 55% females, 18-40 years old (median age 24 years) of whom 150 received vaccine and 10 placebo. Vaccines were generally safe and well tolerated. At months 6.5 and 12, CD4+ T-cell response rates and magnitudes were higher in the AS01B-adjuvanted groups than in the MF59-adjuvanted group. At month 12, HIV-specific Env-gp120 binding antibody response magnitudes in the 40μg gp120/AS01B group were higher than in either of the 200μg gp120 groups.

CONCLUSIONS

The 40μg dose gp120/AS01B regimen elicited the highest CD4+ T-cell and binding antibody responses.

High-risk human papillomavirus genotype distribution among women living with and at risk for HIV in Africa

OBJECTIVE

Cervical cancer is a common preventable cancer among African women living with HIV (WLWH). Molecular diagnostics for high-risk human papillomavirus (HR-HPV) genotypes are standard components of cervical cancer screening in resource-rich countries but not in resource-limited settings. We evaluated HR-HPV genotypes among women with and without HIV in four African countries to inform cervical cancer preventive strategies.

METHODS

The African Cohort Study (AFRICOS) enrolled participants with and without HIV at 12 clinics in Tanzania, Kenya, Uganda, and Nigeria. Cervical cytobrush specimens from women were genotyped for 14 HR-HPV types using the multiplex Seegene Anyplex real-time PCR assay. Robust Poisson regression was used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for factors associated with HR-HPV in WLWH.

RESULTS

From January 2015 to March 2020, 868 WLWH and 134 women living without HIV (WLWoH) were tested for HR-HPV with prevalence of 50.9 and 38.1%, respectively ( P  = 0.007). Among WLWH, 844 (97.4%) were antiretroviral therapy (ART)-experienced and 772 (89.7%) virally suppressed 1000 copies/ml or less. The most frequent HR-HPV types among WLWH were HPV-16 (13.5%), HPV-52 (9.5%), and HPV-35 (9.3%). HR-HPV infection was more common among Tanzanian WLWH (adjusted RR: 1.23, 95% CI 1.05-1.44, P  = 0.012). Also, WLWH with CD4 + T cells of less than 200 cell/μl had 1.51-fold increased risk of having HR-HPV (95% CI 1.23-1.86, P  < 0.001).

CONCLUSION

HR-HPV was common in WLWH in four African countries, particularly among women with low CD4 + cell count. Scale up of HPV vaccines and development of vaccines with broader activity against less common HR-HPV types may improve cervical cancer prevention in Africa.

Increased HIV Incidence in Wuchereria bancrofti Microfilaria Positive Individuals in Tanzania

Background: Infections with Wuchereria bancrofti are associated with reduced immunity against concomitant infections. Indeed, our previous study described a 2.3-fold increased HIV incidence among individuals with W. bancrofti infection, as measured by the circulating filarial antigen of the adult worm. This new study aimed to retrospectively determine microfilariae status of the participants to assess if the previously described increased HIV susceptibility was associated with the presence of MF in the same cohort. Methods: CFA positive but HIV negative biobanked human blood samples (n = 350) were analyzed for W. bancrofti MF chitinase using real time PCR. Results: The PCR provided a positive signal in 12/350 (3.4%) samples. During four years of follow-up (1109 person years (PY)), 22 study participants acquired an HIV infection. In 39 PY of W. bancrofti MF chitinase positive individuals, three new HIV infections occurred (7.8 cases per 100 PY), in contrast to 19 seroconversions in 1070 PY of W. bancrofti MF chitinase negative individuals (1.8 cases per 100 PY, p = 0.014). Conclusions: In the subgroup of MF-producing Wb-infected individuals, the HIV incidence exceeded the previously described moderate increased risk for HIV seen in all Wb-infected individuals (regardless of MF status) compared with uninfected persons from the same area.

Dissecting drivers of immune activation in chronic HIV-1 infection

Background

Immune activation is a significant contributor to HIV pathogenesis and disease progression. In virally-suppressed individuals on ART, low-level immune activation has been linked to several non-infectious comorbid diseases. However, studies have not been systematically performed in sub-Saharan Africa and thus the impact of demographics, ART and regional endemic co-infections on immune activation is not known. We therefore comprehensively evaluated in a large multinational African cohort markers for immune activation and its distribution in various settings.

Methods

2747 specimens from 2240 people living with HIV (PLWH) and 477 without HIV from the observational African Cohort Study (AFRICOS) were analyzed for 13 immune parameters. Samples were collected along with medical history, sociodemographic and comorbidity data at 12 HIV clinics across 5 programs in Uganda, Kenya, Tanzania and Nigeria. Data were analyzed with univariate and multivariate methods such as random forests and principal component analysis.

Findings

Immune activation was markedly different between PLWH with detectable viral loads, and individuals without HIV across sites. Among viremic PLWH, we found that all immune parameters were significantly correlated with viral load except for IFN-α. The overall inflammatory profile was distinct between men and women living with HIV, in individuals off ART and with HIV viremia. We observed stronger differences in the immune activation profile with increasing viremia. Using machine learning methods, we found that geographic differences contributed to unique inflammatory profiles. We also found that among PLWH, age and the presence of infectious and/or noninfectious comorbidities showed distinct inflammatory patterns, and biomarkers may be used to predict the presence of some comorbidities.

Interpretation

Our findings show that chronic immune activation in HIV-1 infection is influenced by HIV viral load, sex, age, region and ART use. These predictors, as well as associations among some biomarkers and coinfections, influence biomarkers associated with noncommunicable diseases.

Funding

This work was supported by the President's Emergency Plan for AIDS Relief via a cooperative agreement between the Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., and the U.S. Department of Defense [W81XWH-11-2-0174, W81XWH-18-2-0040]. The investigators have adhered to the policies for protection of human subjects as prescribed in AR 70–25. This article was prepared while Michael A. Eller was employed at Henry M. Jackson Foundation for the Advancement of Military Medicine for the U.S. Military HIV Research Program. The views expressed are those of the authors and should not be construed to represent the positions of the US Army or the Department of Defense. The opinions expressed in this article are the author's own, and do not reflect the view of the National Institutes of Health, the U.S. Department of Health and Human Services, or the U.S. government.

Clinical similarities and differences between two large HIV cohorts in the United States and Africa

Background

Washington, DC, and sub-Saharan Africa are both affected by generalized HIV epidemics. However, care for persons living with HIV (PLWH) and clinical outcomes may differ in these geographically and culturally diverse areas. We compared patient and clinical site characteristics among adult persons living with HIV (PLWH) enrolled in two longitudinal HIV cohort studies—the African Cohort Study (AFRICOS) and the DC Cohort.

Methods

The DC Cohort is a clinic-based city-wide longitudinal cohort comprised of PLWH attending 15 HIV clinics in Washington, DC. Patients’ socio-demographic characteristics, clinical evaluations, and laboratory data are retrospectively collected from electronic medical records and limited manual chart abstraction. AFRICOS is a prospective observational cohort of PLWH and uninfected volunteers attending 12 select HIV care and treatment facilities in Nigeria, Kenya, Uganda and Tanzania. AFRICOS study participants are a subset of clinic patients who complete protocol-specific visits every 6 months with history and physical examination, questionnaire administration, and blood/sputum collection for ascertainment of HIV outcomes and comorbidities, and neurocognitive and functional assessments. Among participants aged ≥ 18 years, we generated descriptive statistics for demographic and clinical characteristics at enrollment and follow up and compared them using bivariable analyses.

Results

The study sample included 2,774 AFRICOS and 8,420 DC Cohort participants who enrolled from January 2013 (AFRICOS)/January 2011 (DC Cohort) through March 2018. AFRICOS participants were significantly more likely to be women (58.8% vs 27.1%) and younger (83.3% vs 61.1% aged < 50 years old) and significantly less likely to be MSM (only 0.1% of AFRICOS population reported MSM risk factor) than DC Cohort. Similar rates of current viral suppression (about 75% of both samples), hypertension, hepatitis B coinfection and alcohol use were observed. However, AFRICOS participants had significantly higher rates of CD4<200 and tuberculosis and significantly lower rates of obesity, DM, hepatitis C coinfection and syphilis.

Conclusions

With similar viral suppression outcomes, but many differences between our cohorts noted, the combined sample provides unique opportunities to assess and compare HIV care and treatment outcomes in the U.S. and sub-Saharan Africa. Comparing these two cohorts may inform care and treatment practices and may pave the way for future pathophysiologic analyses.

HIV-1 infections with multiple founders associate with the development of neutralization breadth

Eliciting broadly neutralizing antibodies (bnAbs) is a cornerstone of HIV-1 vaccine strategies. Comparing HIV-1 envelope (env) sequences from the first weeks of infection to the breadth of antibody responses observed several years after infection can help define viral features critical to vaccine design. We investigated the relationship between HIV-1 env genetics and the development of neutralization breadth in 70 individuals enrolled in a prospective acute HIV-1 cohort. Half of the individuals who developed bnAbs were infected with multiple HIV-1 founder variants, whereas all individuals with limited neutralization breadth had been infected with single HIV-1 founders. Accordingly, at HIV-1 diagnosis, env diversity was significantly higher in participants who later developed bnAbs compared to those with limited breadth (p = 0.012). This association between founder multiplicity and the subsequent development of neutralization breadth was also observed in 56 placebo recipients in the RV144 vaccine efficacy trial. In addition, we found no evidence that neutralization breath was heritable when analyzing env sequences from the 126 participants. These results demonstrate that the presence of slightly different HIV-1 variants in acute infection could promote the induction of bnAbs, suggesting a novel vaccine strategy, whereby an initial immunization with a cocktail of minimally distant antigens would be able to initiate bnAb development towards breadth.

Vaccines against viral pathogens protect through the induction of broadly neutralizing antibodies (bnAbs). No HIV-1 vaccine has successfully elicited bnAbs, and a successful HIV-1 vaccine will need to accelerate the process of development of a broadly neutralizing response that typically takes a couple of years to develop in natural infection. We studied diversity in the HIV-1 envelope gene from initial infection to several years out in 126 individuals from two cohorts. We showed that the development of bnAbs at 2–3 years was not due to transmissible viral genetics, but rather associated with diversity during the first month of infection. We propose that designing a vaccine that mimics an infection with multiple, minimally distant founder variants may successfully elicit the development of bnAbs and provide effective prophylaxis against HIV-1.

Clinical signs and symptoms associated with acute HIV infection from an intensely monitored cohort on 2 continents

Define the clinical presentation of acute human immunodeficiency virus infection (AHI) among men and women from 2 continents to create a clinical scoring algorithm.Comparison of incident sign and symptom between those with and without AHI.At-risk human immunodeficiency virus (HIV) negative men and women in Thailand, Kenya, Tanzania, and Uganda underwent twice-weekly testing for HIV. Newly diagnosed participants were evaluated twice weekly for 21 days after infection.Of the 3345 participants enrolled, 56 African females and 36 biological males from Thailand were diagnosed with AHI. Four hundred fifty-two of their encounters were compared to 18,281 HIV negative encounters. Due to a high degree of heterogeneity among incident symptoms, 2 unique subgroups based upon geography and sex were created. Among Thai males, the signs and symptoms with the greatest odds ratio (OR) between AHI and uninfected participants were nausea (OR 16.0, 95% confidence interval [CI] 3.9-60.2, P < .001) and lymphatic abnormalities (OR 11.8, 95% CI 4.2-49.0, P < .001); and among African females were pain behind the eyes (OR 44.4, 95% CI 12.0-158.0, P < .0001) and fatigue (OR 22.7, 95% CI 11.3-44.3, P < .001). The Thai male scoring algorithm had a 66% sensitivity and 84% specificity while the African female algorithm had a sensitivity of 27% and specificity of 98%.The different incident symptoms during AHI necessitated creating 2 different scoring algorithms that can guide diagnostic testing among a particular sex in the appropriate geographic setting. Further research on risk exposure, sex, and demographic specific models is warranted.

Clinical factors and outcomes associated with immune non-response among virally suppressed adults with HIV from Africa and the United States

A significant minority of people living with HIV (PLWH) achieve viral suppression (VS) on antiretroviral therapy (ART) but do not regain healthy CD4 counts. Clinical factors affecting this immune non-response (INR) and its effect on incident serious non-AIDS events (SNAEs) have been challenging to understand due to confounders that are difficult to control in many study settings. The U.S. Military HIV Natural History Study (NHS) and African Cohort Study (AFRICOS). PLWH with sustained VS (< 400 copies/ml for at least two years) were evaluated for INR (CD4 < 350 cells/µl at the time of sustained VS). Logistic regression estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for factors associated with INR. Cox proportional hazards regression produced adjusted hazard ratios (aHRs) for factors associated with incident SNAE after sustained VS. INR prevalence was 10.8% and 25.8% in NHS and AFRICOS, respectively. Higher CD4 nadir was associated with decreased odds of INR (aOR = 0.34 [95% CI 0.29, 0.40] and aOR = 0.48 [95% CI 0.40, 0.57] per 100 cells/µl in NHS and AFRICOS, respectively). After adjustment, INR was associated with a 61% increase in relative risk of SNAE [95% CI 1.12, 2.33]. Probability of "SNAE-free" survival at 15 years since sustained VS was approximately 20% lower comparing those with and without INR; nearly equal to the differences observed by 15-year age groups. CD4 monitoring before and after VS is achieved can help identify PLWH at risk for INR. INR may be a useful clinical indicator of future risk for SNAEs.

Routine HIV clinic visit adherence in the African Cohort Study

Background

Retention in clinical care is important for people living with HIV (PLWH). Evidence suggests that missed clinic visits are associated with interruptions in antiretroviral therapy (ART), lower CD4 counts, virologic failure, and overlooked coinfections. We identified factors associated with missed routine clinic visits in the African Cohort Study (AFRICOS).

Methods

In 2013, AFRICOS began enrolling people with and without HIV in Uganda, Kenya, Tanzania, and Nigeria. At enrollment and every 6 months thereafter, sociodemographic questionnaires are administered and clinical outcomes assessed. Missed clinic visits were measured as the self-reported number of clinic visits missed in the past 6 months and dichotomized into none or one or more visits missed. Logistic regression with generalized estimating equations was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between risk factors and missed visits.

Results

Between January 2013 and March 2020, 2937 PLWH were enrolled, of whom 2807 (95.6%) had initiated ART and 2771 had complete data available for analyses. Compared to PLWH 50+, missed clinic visits were more common among those 18–29 years (aOR 2.33, 95% CI 1.65–3.29), 30–39 years (aOR 1.59, 95% CI 1.19–2.13), and 40–49 years (aOR 1.42, 95% CI 1.07–1.89). As compared to PLWH on ART for < 2 years, those on ART for 4+ years were less likely to have missed clinic visits (aOR 0.72, 95% CI 0.55–0.95). Missed clinic visits were associated with alcohol use (aOR 1.34, 95% CI 1.05–1.70), a history of incarceration (aOR 1.42, 95% CI 1.07–1.88), depression (aOR 1.47, 95% CI 1.13–1.91), and viral non-suppression (aOR 2.50, 95% CI 2.00–3.12). As compared to PLWH who did not miss any ART in the past month, missed clinic visits were more common among those who missed 1–2 days (aOR 2.09, 95% CI 1.65–2.64) and 3+ days of ART (aOR 7.06, 95% CI 5.43–9.19).

Conclusions

Inconsistent clinic attendance is associated with worsened HIV-related outcomes. Strategies to improve visit adherence are especially needed for young PLWH and those with depression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-021-00425-0.

Systematic comparison of HIV-1 Envelope-specific IgG responses induced by different vaccination regimens: Can we steer IgG recognition towards regions of viral vulnerability?

Immunogens and vaccination regimens can influence patterns of immune-epitope recognition, steering them towards or away from epitopes of potential viral vulnerability. HIV-1 envelope (Env)-specific antibodies targeting variable region 2 (V2) or 3 (V3) correlated with protection during the RV144 trial, however, it was suggested that the immunodominant V3 region might divert antibody responses away from other relevant sites. We mapped IgG responses against linear Env epitopes in five clinical HIV vaccine trials, revealing a specific pattern of Env targeting for each regimen. Notable V2 responses were only induced in trials administering CRF01_AE based immunogens, but targeting of V3 was seen in all trials, with the soluble, trimeric CN54gp140 protein eliciting robust V3 recognition. Strong V3 targeting was linked to greater overall response, increased number of total recognised antigenic regions, and where present, stronger V2 recognition. Hence, strong induction of V3-specific antibodies did not negatively impact the targeting of other linear epitopes in this study, suggesting that the induction of antibodies against V3 and other regions of potential viral vulnerability need not be necessarily mutually exclusive.

HIV testing and linkage to care-A case of a mobile diagnostic and counseling service in Mbeya, Tanzania; A quantitative study

HIV-care programmes are faced with significant challenges in getting newly diagnosed People Living with Human Immunodeficiency Virus (PLHIV) linked to care despite massive investment in HIV prevention, treatment and care. This study assessed the performance of mobile HIV Testing and Counseling service (mHTC) in provision of HIV-testing and linkage to care of newly diagnosed PLHIV from Key and Vulnerable Populations (KVPs). A retrospective review of the records of 25,248 clients was extracted from the mHTC database from October-2016 to September-2018. Of 25,248 clients, 51.71% were in 25-45 years age group, 55.4% were males, 60.5% were married and 62.1% had primary level of education. The median age of clients was 31 (IQR: 23-42) years. Out of the clients tested, 800 (3.17%) were diagnosed HIV-positive. Positivity was high among females 450 (4%), age group 25-45 years 538 (4.12%), divorced 202 (7.41%) and clients with primary level of education 504 (3.21%). An association between HIV status and sex, age group, relationship status and level of education was observed (P<0001). Out of the 800 HIV-positive clients, 418 (52.30%) were successfully linked to care. Among the positive clients, 5/6 (83.33%) children below 15 years old, 238/450 (52.89%) females and 39/64 (60.94%) widows were successfully linked to care. In the multivariable log binomial regression model age of the clients was associated with successful linkage to care. The mHTC was able to reach KVP clients; overall linkage for both sexes was 52.30% below the recommended UNAIDS 90-90-90 target. Raising the need to address the challenges associated with linkage and specific care for KVPs as a subset of the general population. The mHTC has shown that it is feasible to improve the reach of KVP clients; however, further research is required to examine the quality of this service at the community level.

Perceived satisfaction with HIV care and its association with adherence to antiretroviral therapy and viral suppression in the African Cohort Study

Background

Increased availability of HIV care over the past decade has dramatically reduced morbidity and mortality among people living with HIV (PLWH) in sub-Saharan Africa. However, perceived and experienced barriers to care, including dissatisfaction with services, may impact adherence and viral suppression. We examined the associations between satisfaction with HIV care and antiretroviral therapy (ART) adherence and viral load suppression.

Methods

The African Cohort Study (AFRICOS) is a prospective observational study conducted at PEPFAR-supported clinics in four African countries. At enrollment and twice-yearly study visits, participants received a clinical assessment and a socio-behavioral questionnaire was administered. Participants were classified as dissatisfied with care if they reported dissatisfaction with any of the following: waiting time, health care worker skills, health care worker attitudes, quality of clinic building, or overall quality of care received. Robust Poisson regression was used to estimate prevalence ratios and 95% confidence intervals (CIs) for associations between satisfaction with care and ART adherence and between satisfaction with care and viral suppression (viral load < 1000 copies/mL).

Results

As of 1 March 2020, 2928 PLWH were enrolled and 2311 had a year of follow-up visits. At the first annual follow-up visit, 2309 participants responded to questions regarding satisfaction with quality of care, and 2069 (89.6%) reported satisfaction with care. Dissatisfaction with waiting time was reported by 177 (7.6%), building quality by 59 (2.6%), overall quality of care by 18 (0.8%), health care worker attitudes by 16 (0.7%), and health care worker skills by 15 (0.7%). After adjusting for age and site, there was no significant difference in viral suppression between those who were satisfied with care and those who were dissatisfied (aPR: 1.03, 95% CI 0.97–1.09). Satisfaction with HIV care was moderately associated with ART adherence among AFRICOS participants (aPR: 1.09; 95% CI 1.00–1.16).

Conclusions

While patient satisfaction in AFRICOS was high and the association between perceived quality of care and adherence to ART was marginal, we did identify potential target areas for HIV care improvement, including reducing clinic waiting times.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-021-00414-3.

Phase 1 Human Immunodeficiency Virus (HIV) Vaccine Trial to Evaluate the Safety and Immunogenicity of HIV Subtype C DNA and MF59-Adjuvanted Subtype C Envelope Protein

BACKGROUND

The Pox-Protein Public-Private Partnership is performing a suite of trials to evaluate the bivalent subtype C envelope protein (TV1.C and 1086.C glycoprotein 120) vaccine in the context of different adjuvants and priming agents for human immunodeficiency virus (HIV) type 1 (HIV-1) prevention.

METHODS

In the HIV Vaccine Trials Network 111 trial, we compared the safety and immunogenicity of DNA prime followed by DNA/protein boost with DNA/protein coadministration injected intramuscularly via either needle/syringe or a needle-free injection device (Biojector). One hundred thirty-two healthy, HIV-1-uninfected adults were enrolled from Zambia, South Africa, and Tanzania and were randomized to 1 of 6 arms: DNA prime, protein boost by needle/syringe; DNA and protein coadministration by needle/syringe; placebo by needle/syringe; DNA prime, protein boost with DNA given by Biojector; DNA and protein coadministration with DNA given by Biojector; and placebo by Biojector.

RESULTS

All vaccinations were safe and well tolerated. DNA and protein coadministration was associated with increased HIV-1 V1/V2 antibody response rate, a known correlate of decreased HIV-1 infection risk. DNA administration by Biojector elicited significantly higher CD4+ T-cell response rates to HIV envelope protein than administration by needle/syringe in the prime/boost regimen (85.7% vs 55.6%; P = .02), but not in the coadministration regimen (43.3% vs 48.3%; P = .61).

CONCLUSIONS

Both the prime/boost and coadministration regimens are safe and may be promising for advancement into efficacy trials depending on whether cellular or humoral responses are desired.

CLINICAL TRIALS REGISTRATION

South African National Clinical Trials Registry (application 3947; Department of Health [DoH] no. DOH-27-0715-4917) and ClinicalTrials.gov (NCT02997969).

Factors influencing estimates of HIV-1 infection timing using BEAST

While large datasets of HIV-1 sequences are increasingly being generated, many studies rely on a single gene or fragment of the genome and few comparative studies across genes have been done. We performed genome-based and gene-specific Bayesian phylogenetic analyses to investigate how certain factors impact estimates of the infection dates in an acute HIV-1 infection cohort, RV217. In this cohort, HIV-1 diagnosis corresponded to the first RNA positive test and occurred a median of four days after the last negative test, allowing us to compare timing estimates using BEAST to a narrow window of infection. We analyzed HIV-1 sequences sampled one week, one month and six months after HIV-1 diagnosis in 39 individuals. We found that shared diversity and temporal signal was limited in acute infection, and insufficient to allow timing inferences in the shortest HIV-1 genes, thus dated phylogenies were primarily analyzed for env, gag, pol and near full-length genomes. There was no one best-fitting model across participants and genes, though relaxed molecular clocks (73% of best-fitting models) and the Bayesian skyline (49%) tended to be favored. For infections with single founders, the infection date was estimated to be around one week pre-diagnosis for env (IQR: 3–9 days) and gag (IQR: 5–9 days), whilst the genome placed it at a median of 10 days (IQR: 4–19). Multiply-founded infections proved problematic to date. Our ability to compare timing inferences to precise estimates of HIV-1 infection (within a week) highlights that molecular dating methods can be applied to within-host datasets from early infection. Nonetheless, our results also suggest caution when using uniform clock and population models or short genes with limited information content.

Molecular dating using phylogenetics allows us to estimate the date of an infection from time-stamped within-host sequences alone. There are large datasets of HIV-1 sequences, but genome and gene analyses are not often performed in parallel and rarely with the possibility to compare results against a known narrow window of infection. We showed that all but the longest genes are near-clonal in acute infection, with little information for dating purposes. For infections with single founders, we estimated the eclipse phase—the time between HIV-1 exposure and the first positive diagnostic test—to last between one and two weeks using env, gag, pol and near full-length genomes. This approach could be used to narrow the date of suspected infection in ongoing clinical trials for the prevention of HIV-1 infection.

Impact of age on CD4 recovery and viral suppression over time among adults living with HIV who initiated antiretroviral therapy in the African Cohort Study

INTRODUCTION

With increased use of antiretroviral therapy (ART), HIV mortality rates are declining and people living with HIV (PLWH) are surviving longer. We characterized CD4 recovery and viral suppression among adults aged < 50 and ≥ 50 years living with HIV who initiated ART in the African Cohort Study (AFRICOS).

METHODS

Beginning in January 2013, PLWH at twelve clinics in Kenya, Uganda, Tanzania and Nigeria underwent medical history review, CD4 and viral load testing as part of the ongoing African Cohort Study (AFRICOS). ART-naïve PLWH who initiated ART within 30 days of enrollment and had at least one year of follow-up were included in these analyses. To compare ART response in participants < 50 years and ≥ 50 years old, changes in CD4 count and viral load suppression after ART initiation were examined at different time points using linear and binomial regression with generalized estimating equations. Variables for time since ART initiation and the interaction between age group and time on ART were included in the model to evaluate longitudinal changes in CD4 recovery and viral suppression by age.

RESULTS

Between January 2013 and September 2019, 2918 PLHV were enrolled in the cohort. Of these, 443 were ART naïve and initiated on ART within 30 days of enrollment, with 90% (n = 399) aged < 50 years old at ART initiation. At ART initiation, participants aged 50 and older had a higher median CD4 count compared to participants younger than 50 years of age although it did not reach statistical significance (306 cells/mm3, IQR:130-547 vs. 277cells/mm3, IQR: 132-437). In adjusted models examining CD4 recovery and viral suppression there were no significant differences by age group over time. By the end of follow-up viral suppression was high among both groups of adults (96% of adults ≥ 50 years old and 92% of adults < 50 years old).

CONCLUSION

This study found no difference in long-term CD4 recovery or viral suppression by age at ART initiation. We found that particularly among younger adults participants had lower median CD4 counts at ART initiation, suggesting the importance of identifying and putting this population on treatment earlier in the disease course.

Persistent Low-level Viremia Predicts Subsequent Virologic Failure: Is It Time to Change the Third 90?

BACKGROUND

World Health Organization (WHO) guidelines identify human immunodeficiency virus (HIV) viral load <1000 copies/mL as the goal of antiretroviral therapy (ART). However, the clinical implications of viremia below this threshold are unclear in the African context. We examined factors associated with persistent low-level viremia (pLLV) and quantified the risk of subsequent virologic.

METHODS

The African Cohort Study enrolled HIV-infected adults at clinics in Uganda, Kenya, Tanzania, and Nigeria, with assessments every 6 months. We evaluated participants prescribed ART for at least 6 months without virologic failure for pLLV. We used multinomial logistic regression to evaluate associations between prespecified factors of interest and 3 levels of pLLV (<200, 200-499, and 500-999 copies/mL). We used Anderson-Gill extended Cox proportional hazards to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for viremia category associations with time to failure.

RESULTS

We included 1511 participants with 4382 person-years of follow-up. PLLV <200 copies/mL was observed at 20% of visits while 2% of visits had pLLV 200-499 and 500-999 copies/mL each, with substantial variation by site. Protease inhibitor-containing ART was associated with increased risk of pLLV. Compared to undetectable viral load, pLLV ≥200 copies/mL doubled the risk of developing virologic failure (pLLV 200-499: HR, 1.81 [95% CI, 1.08-3.02]); pLLV 500-999: HR, 2.36 [95% CI, 1.52-3.67]).

CONCLUSIONS

Participants with pLLV ≥200 copies/mL were at increased risk of subsequent virologic failure. Optimized HIV care in this setting should target viral suppression <200 copies/mL.

Noninfectious Comorbidity in the African Cohort Study

BACKGROUND

Noninfectious comorbid diseases (NCDs) contribute to morbidity and mortality in human immunodeficiency virus (HIV)-infected populations in resource-rich countries. With antiretroviral therapy (ART) scale-up in Africa, understanding burden NCD informs public health strategy.

METHODS

At enrollment, participants at 11 HIV clinics in Kenya, Uganda, Tanzania, and Nigeria underwent medical history, physical, laboratory, and neuropsychological assessments to identify elevated blood pressure, hypercholesterolemia, dysglycemia, renal insufficiency, and cognitive impairment. Poisson regression models estimated adjusted relative risks (ARRs) and 95% confidence intervals (CIs) for the number of NCDs associated with factors of interest. Logistic regression was used to evaluate each NCD separately among HIV-infected participants.

RESULTS

Among 2720 participants with complete NCD data, 2159 (79.4%) were HIV-infected. Of those, 1426 (66.0%) were taking ART and 813 (37.7%) had at least 1 NCD. HIV infection was associated with more NCDs, especially with ART (ARR, 1.42; 95% CI, 1.22-1.66). In addition to age, body mass index, and program site, ART usage was associated with more NCDs (ARR, 1.50; 95% CI, 1.27-1.78 for virologically suppressed and ARR, 1.38; 95% CI, 1.13-1.68 for viremic) among HIV-infected participants. In participants taking ART, CD4 nadir below 200 cells/mm3 was associated with more NCDs (ARR, 1.43; 95% CI, 1.06-1.93). ART use was independently associated with hypercholesterolemia and dysglycemia. Program site was significantly associated with all comorbidities except renal insufficiency.

CONCLUSIONS

HIV infection was a risk for NCDs, which were common in HIV-infected participants, geographically variable, and largely consistent with metabolic complications of first-line ART.

Predictors and Barriers to Condom Use in the African Cohort Study

Consistent condom use is an inexpensive and efficacious HIV prevention strategy. Understanding factors associated with condom use and barriers to use can inform strategies to increase condom uptake. The ongoing African Cohort Study prospectively enrolls adults at 12 clinical sites in Uganda, Kenya, Tanzania, and Nigeria. At enrollment, participants are asked about condom use at last sex with a regular partner. Robust Poisson regression models were used to evaluate predictors of self-reported condom use. Participants who reported not using condoms were asked to provide reasons. From January 2013 to September 2019, 2482 participants reported having at least one regular sexual partner in the preceding 6 months. Of those, 1577 (63.5%) reported using a condom at last sex. Condom use was more common among older participants, males, HIV-infected participants, and those with an HIV-infected partner. Married participants, those with a partner of unknown HIV status, and those reporting alcohol use were less likely to report condom use at last sex. Condom use at last sex also varied significantly by clinical site. Partner disapproval or refusal to use a condom was a consistent driver of disparities in condom use among participants who were HIV infected, female, and aged 18-24 years. Effective HIV prevention programs should integrate condom education with the tools necessary to negotiate condom use with regular partners.

High turnaround times and low viral resuppression rates after reinforced adherence counselling following a confirmed virological failure diagnostic algorithm in HIV-infected patients on first-line antiretroviral therapy from Tanzania

OBJECTIVE

Early identification of confirmed virological failure is paramount to avoid accumulation of drug resistance in patients on antiretroviral therapy (ART). Scale-up of HIV-RNA monitoring in Africa and timely switch to second-line regimens are challenged.

METHODS

A WHO adapted confirmed virological treatment screening algorithm (HIV-RNA screening, enhanced adherence counselling, confirmatory HIV-RNA testing) was evaluated in HIV-infected patients on first-line ART from Tanzania. The main endpoints included viral resuppression and virological failure rates, retention and turnaround time of the screening algorithm until second-line ART initiation. Secondary endpoints included risk factors for virological treatment failure and patterns of genotypic drug resistance.

RESULTS

HIV-RNA >1000 copies/ml at first screening was detected in 58/356 (16.3%) patients (median time-on-treatment 6.3 years, 25% immunological treatment failure). Adjusted risk factors for virological failure were age <30 years (RR 5.2 [95% CI: 2.5-10.8]), years on ART ≥3 years (RR 3.0 [1.0-8.9]), CD4-counts <200 cells/µl (RR 9.3 [4.0-21.8]) and poor self-reported treatment adherence (RR 2.0 [1.2-3.4]). Resuppression of HIV-RNA <1000 copies/ml was observed in 5/50 (10%) cases after enhanced adherence counselling. Confirmatory testing within 3 months was performed in only 46.6% and switch to second-line ART within 6 months in 60.4% of patients. Major NNRTI-mutation were detected in all of 30 patients, NRTI mutations in 96.7% and ≥3 thymidine-analogue mutations in 40%. No remaining NRTI options were predicted in 57% and limited susceptibility in 23% of patients.

CONCLUSION

We observed low levels of viral resuppression following adherence counselling, associated with high levels of accumulated drug resistance. High visit burden and turnaround times for confirmed virological failure diagnosis further delayed switching to second-line treatment which could be improved using novel point-of-care viral load monitoring systems.

Molecular dating and viral load growth rates suggested that the eclipse phase lasted about a week in HIV-1 infected adults in East Africa and Thailand

Most HIV-1 infected individuals do not know their infection dates. Precise infection timing is crucial information for studies that document transmission networks or drug levels at infection. To improve infection timing, we used the prospective RV217 cohort where the window when plasma viremia becomes detectable is narrow: the last negative visit occurred a median of four days before the first detectable HIV-1 viremia with an RNA test, referred below as diagnosis. We sequenced 1,280 HIV-1 genomes from 39 participants at a median of 4, 32 and 170 days post-diagnosis. HIV-1 infections were dated by using sequence-based methods and a viral load regression method. Bayesian coalescent and viral load regression estimated that infections occurred a median of 6 days prior to diagnosis (IQR: 9–3 and 11–4 days prior, respectively). Poisson-Fitter, which analyzes the distribution of hamming distances among sequences, estimated a median of 7 days prior to diagnosis (IQR: 15–4 days) based on sequences sampled 4 days post-diagnosis, but it did not yield plausible results using sequences sampled at 32 days. Fourteen participants reported a high-risk exposure event at a median of 8 days prior to diagnosis (IQR: 12 to 6 days prior). These different methods concurred that HIV-1 infection occurred about a week before detectable viremia, corresponding to 20 days (IQR: 34–15 days) before peak viral load. Together, our methods comparison helps define a framework for future dating studies in early HIV-1 infection.

HIV-1 infected individuals rarely know when they became infected but knowing when an infection occurred provides critical information regarding HIV-1 pathogenesis and epidemiology. Using a unique cohort in which infection was known to have occurred in a narrow interval, we investigated methods to estimate the timing of infections. Several methods suggested that HIV-1 infection typically occurs a median of one week before the infection can be detected by HIV-1 RNA testing. Going forward, we provide a strategy that can be used to elucidate the origin of an acute/early infection.

Dynamic MAIT cell response with progressively enhanced innateness during acute HIV-1 infection

Mucosa-associated invariant T (MAIT) cell loss in chronic HIV-1 infection is a significant insult to antimicrobial immune defenses. Here we investigate the response of MAIT cells during acute HIV-1 infection utilizing the RV217 cohort with paired longitudinal pre- and post-infection samples. MAIT cells are activated and expand in blood and mucosa coincident with peak HIV-1 viremia, in a manner associated with emerging microbial translocation. This is followed by a phase with elevated function as viral replication is controlled to a set-point level, and later by their functional decline at the onset of chronic infection. Interestingly, enhanced innate-like pathways and characteristics develop progressively in MAIT cells during infection, in parallel with TCR repertoire alterations. These findings delineate the dynamic MAIT cell response to acute HIV-1 infection, and show how the MAIT compartment initially responds and expands with enhanced function, followed by progressive reprogramming away from TCR-dependent antibacterial responses towards innate-like functionality.

Here, using longitudinal pre- and post-infection samples from the RV217 Early Capture HIV Cohort Study, the authors show that mucosa-associated invariant T (MAIT) cells become activated and expand during the early acute phase of HIV infection, with subsequent reprogramming towards innate-like functionality.

Wuchereria bancrofti infection is linked to systemic activation of CD4 and CD8 T cells

Background

Susceptibility to HIV has been linked to systemic CD4+ T cell activation in cohorts of seronegative individuals with high HIV-exposure risk. We recently described an increased risk of HIV transmission in individuals infected with Wuchereria bancrofti, the causative agent for lymphatic filariasis, in a prospective cohort study. However, the reason for this phenomenon needs further investigation.

Methodology/Principal findings

Two-hundred and thirty-five HIV negative adults were tested using Trop Bio ELISA for detection of W. bancrofti infection and Kato Katz urine filtration and stool based RT-PCR for detection of soil transmitted helminths and schistosomiasis. FACS analysis of the fresh peripheral whole blood was used to measure T cell activation markers (HLA-DR, CD38), differentiation markers (CD45, CD27), markers for regulatory T cells (FoxP3, CD25) and the HIV entry receptor CCR5. Frequencies of activated HLA-DR^pos CD4 T cells were significantly increased in subjects with W. bancrofti infection (n = 33 median: 10.71%) compared to subjects without any helminth infection (n = 42, median 6.97%, p = 0.011) or those with other helminths (Schistosoma haematobium, S. mansoni, Trichuris trichiura, Ascaris lumbricoides, hookworm) (n = 151, median 7.38%, p = 0.009). Similarly, a significant increase in HLA-DR^posCD38^pos CD4 T cells and effector memory cells CD4 T cells (CD45RO^posCD27^neg) was observed in filarial infected participants. Multivariable analyses further confirmed a link between W. bancrofti infection and systemic activation of CD4 T cells independent of age, fever, gender or other helminth infections.

Conclusions/Significance

W. bancrofti infection is linked to systemic CD4 T cell activation, which may contribute to the increased susceptibility of W. bancrofti infected individuals to HIV infection.

The importance of CD4 T cell activation for HIV susceptibility has been emphasized in several studies focusing on HIV transmission and prevention. Particularly, activated HLA-DR+ CD4 T cells may play a major role in HIV susceptibility. In this analysis we describe systemic activation of CD4 T cells in individuals infected with W. bancrofti the causative agent of lymphatic filariasis. This helminth disease leads to debilitating pathology in some of the individuals; however, the majority of infected persons remain asymptomatic. We recently described an increased HIV incidence in subjects infected with W. bancrofti compared to uninfected individuals from the same area. To decipher underlying reasons for this phenomenon, we measured immune activation parameters in CD4 and CD8 T cells. The increased percentage of HLADR positive and HLADR/CD38 positive CD4 T cells and also effector memory CD4 T cells that we describe here could be a possible mechanism to explain our previous findings of increased HIV incidence in individuals infected with this filarial nematode.

OC 8491 PREPVACC: A PHASE III, MAMS ADAPTIVE PROPHYLACTIC HIV VACCINE TRIAL WITH A SECOND RANDOMISATION TO COMPARE F/TAF WITH TDF/FTC PREP

Background

There remains an urgent need for a prophylactic HIV vaccine to control generalised epidemics. PrEP has demonstrated effectiveness of 86% and is recommended by WHO; uptake is generally high, but retention is disappointing in some settings. The EDCTP2 project PrEPVacc will assess the efficacy of two combination prophylactic vaccine regimens (DNA, MVA and Env protein/adjuvant) each compared to placebo and the proportion of infections averted by F/TAF in comparison to TDF/FTC. A Registration Cohort, recruiting HIV negative volunteers at risk of HIV will precede the trial.

Methods

The PrEPVacc partnership agreed that 70% vaccine efficacy had public health relevance. The trial uses nstage software for multi-arm, multi-stage designs (MAMS) and the averted infections ratio (AIR) methodology with participants randomised (i) 1:1:1 to active product or placebo (ii) 1:1 to TDF/FTC : F/TAF until week 26 (presumed peak immunogenicity). Access to PrEP in the Registration Cohort and after week 26 will be standard of care. HIV seroconversions occurring between weeks 0–26 will inform the PrEP analysis, incorporating HIV incidence amongst those who do not take up PrEP locally in the Registration Cohort. Seroconversions after week 26 will inform vaccine analyses.

Results

Up to 556 participants per group affords 92% power to detect vaccine efficacy of 70% at the final analysis, assuming incidence of 4/100-person years and 10% loss with 81% and 97% power to conclude that F/TAF can avert half or more of the infections prevented by TDF/FTC if effectiveness of TDF/FTC is 70% and 80%, respectively.

Conclusion

PrEPVacc adopts a pragmatic approach to uncertainties around HIV incidence in settings where PrEP is increasingly available. This innovative adaptive trial design uses validated software to determine vaccine efficacy and a novel methodology to evaluate a new PrEP agent, overcoming the challenge of demonstrating non-inferiority when adherence to TDF/FTC is high and the number of outcome events very low.

HIV virologic failure and its predictors among HIV-infected adults on antiretroviral therapy in the African Cohort Study

INTRODUCTION

The 2016 WHO consolidated guidelines on the use of antiretroviral drugs defines HIV virologic failure for low and middle income countries (LMIC) as plasma HIV-RNA ≥ 1000 copies/mL. We evaluated virologic failure and predictors in four African countries.

MATERIALS AND METHODS

We included HIV-infected participants on a WHO recommended antiretroviral therapy (ART) regimen and enrolled in the African Cohort Study between January 2013 and October 2017. Studied outcomes were virologic failure (plasma HIV-RNA ≥ 1000 copies/mL at the most recent visit), viraemia (plasma HIV-RNA ≥ 50 copies/mL at the most recent visit); and persistent viraemia (plasma HIV-RNA ≥ 50 copies/mL at two consecutive visits). Generalized linear models were used to estimate relative risks with their 95% confidence intervals.

RESULTS

2054 participants were included in this analysis. Viraemia, persistent viraemia and virologic failure were observed in 396 (19.3%), 160 (7.8%) and 184 (9%) participants respectively. Of the participants with persistent viraemia, only 57.5% (92/160) had confirmed virologic failure. In the multivariate analysis, attending clinical care site other than the Uganda sitebeing on 2nd line ART (aRR 1.8, 95% CI 1·28-2·66); other ART combinations not first line and not second line (aRR 3.8, 95% CI 1.18-11.9), a history of fever in the past week (aRR 3.7, 95% CI 1.69-8.05), low CD4 count (aRR 6.9, 95% CI 4.7-10.2) and missing any day of ART (aRR 1·8, 95% CI 1·27-2.57) increased the risk of virologic failure. Being on 2nd line therapy, the site where one receives care and CD4 count < 500 predicted viraemia, persistent viraemia and virologic failure.

CONCLUSION

In conclusion, these findings demonstrate that HIV-infected patients established on ART for more than six months in the African setting frequently experienced viraemia while continuing to be on ART. The findings also show that being on second line, low CD4 count, missing any day of ART and history of fever in the past week remain important predictors of virologic failure that should trigger intensified adherence counselling especially in the absence of reliable or readily available viral load monitoring. Finally, clinical care sites are different calling for further analyses to elucidate on the unique features of these sites.

Correction: Rare HIV-1 transmitted/founder lineages identified by deep viral sequencing contribute to rapid shifts in dominant quasispecies during acute and early infection

[This corrects the article DOI: 10.1371/journal.ppat.1006510.].

Rare HIV-1 transmitted/founder lineages identified by deep viral sequencing contribute to rapid shifts in dominant quasispecies during acute and early infection

In order to inform the rational design of HIV-1 preventive and cure interventions it is critical to understand the events occurring during acute HIV-1 infection (AHI). Using viral deep sequencing on six participants from the early capture acute infection RV217 cohort, we have studied HIV-1 evolution in plasma collected twice weekly during the first weeks following the advent of viremia. The analysis of infections established by multiple transmitted/founder (T/F) viruses revealed novel viral profiles that included: a) the low-level persistence of minor T/F variants, b) the rapid replacement of the major T/F by a minor T/F, and c) an initial expansion of the minor T/F followed by a quick collapse of the same minor T/F to low frequency. In most participants, cytotoxic T-lymphocyte (CTL) escape was first detected at the end of peak viremia downslope, proceeded at higher rates than previously measured in HIV-1 infection, and usually occurred through the exploration of multiple mutational pathways within an epitope. The rapid emergence of CTL escape variants suggests a strong and early CTL response. Minor T/F viral strains can contribute to rapid and varied profiles of HIV-1 quasispecies evolution during AHI. Overall, our results demonstrate that early, deep, and frequent sampling is needed to investigate viral/host interaction during AHI, which could help identify prerequisites for prevention and cure of HIV-1 infection.

Effect of Wuchereria bancrofti infection on HIV incidence in southwest Tanzania: a prospective cohort study

BACKGROUND

The past decades have seen an ongoing controversial debate about whether the immune activation induced by helminths has an effect on the susceptibility of individuals to HIV. In view of this, we assessed the effect of lymphatic filariasis, a chronic helminth disease elicited by Wuchereria bancrofti, on HIV incidence in southwest Tanzania.

METHODS

In this population-based cohort study, we enrolled a geographically stratified randomly chosen sample of about 10% of the households in nine distinct sites in southwest Tanzania. All household members present were followed up and tested for HIV and circulating filarial antigen, an indicator of W bancrofti adult worm burden. Our main outcome of interest was HIV incidence in participants with or without lymphatic filariasis.

FINDINGS

Between May 29, 2006, and June 16, 2011, we enrolled 4283 households with roughly 18 000 participants. Of these, 2699 individuals from Kyela district participated in at least one round of the EMINI study. In the 1055 initially HIV-negative adolescents and adults with clearly defined lymphatic filariasis status, 32 new HIV infections were observed in 2626 person-years. HIV incidence in lymphatic filariasis-positive participants (1·91 cases per 100 person-years) was significantly higher than the incidence in lymphatic filariasis-negative participants (0·80 cases per 100 person-years). The age-adjusted and sex-adjusted incidence rate ratio was 2·17 (95% CI 1·08-4·37, p=0·0300). Lymphatic filariasis status remained an independent and significantly relevant risk factor for HIV infection when controlled for other known risk factors such as sexual behaviour and socioeconomic factors.

INTERPRETATION

To our knowledge, this is the first prospective study demonstrating a significantly increased risk of acquiring HIV for lymphatic filariasis-infected individuals. Immunological studies and interventional treatment studies that eliminate the adult worms and not only the microfilariae are needed to follow up on the results presented.

FUNDING

European Union as part of EuropAid; German Federal Ministry of Education and Research; German Center for Infection Research.

Temporal Dynamics of CD8+ T Cell Effector Responses during Primary HIV Infection

The loss of HIV-specific CD8⁺ T cell cytolytic function is a primary factor underlying progressive HIV infection, but whether HIV-specific CD8⁺ T cells initially possess cytolytic effector capacity, and when and why this may be lost during infection, is unclear. Here, we assessed CD8⁺ T cell functional evolution from primary to chronic HIV infection. We observed a profound expansion of perforin⁺ CD8⁺ T cells immediately following HIV infection that quickly waned after acute viremia resolution. Selective expression of the effector-associated transcription factors T-bet and eomesodermin in cytokine-producing HIV-specific CD8⁺ T cells differentiated HIV-specific from bulk memory CD8⁺ T cell effector expansion. As infection progressed expression of perforin was maintained in HIV-specific CD8⁺ T cells with high levels of T-bet, but not necessarily in the population of T-bet^Lo HIV-specific CD8⁺ T cells that expand as infection progresses. Together, these data demonstrate that while HIV-specific CD8⁺ T cells in acute HIV infection initially possess cytolytic potential, progressive transcriptional dysregulation leads to the reduced CD8⁺ T cell perforin expression characteristic of chronic HIV infection.

Previous studies have demonstrated that HIV-specific CD8⁺ T cells are critical for the initial control of HIV infection. However, this control is typically incomplete, being able to neither clear infection nor maintain plasma viremia below undetectable levels. Mounting evidence has implicated CD8⁺ T cell cytotoxic capacity as a critical component of the HIV-specific response associated with spontaneous long-term control of HIV replication. CD8⁺ T cell cytotoxic responses are largely absent in the vast majority of HIV chronically infected individuals and it is unclear when or why this functionality is lost. In this study we show that HIV-specific CD8⁺ T cells readily express the cytolytic protein perforin during the acute phase of chronic progressive HIV infection but rapidly lose the ability to upregulate this molecule following resolution of peak viremia. Maintenance of perforin expression by HIV-specific CD8⁺ T cells appears to be associated with the expression level of the transcription factor T-bet, but not with the T-bet paralogue, Eomes. These findings further delineate qualitative attributes of CD8⁺ T cell-mediated immunity that may serve as targets for future HIV vaccine and therapeutic research.

Prospective Study of Acute HIV-1 Infection in Adults in East Africa and Thailand

BACKGROUND

Acute human immunodeficiency virus type 1 (HIV-1) infection is a major contributor to transmission of HIV-1. An understanding of acute HIV-1 infection may be important in the development of treatment strategies to eradicate HIV-1 or achieve a functional cure.

METHODS

We performed twice-weekly qualitative plasma HIV-1 RNA nucleic acid testing in 2276 volunteers who were at high risk for HIV-1 infection. For participants in whom acute HIV-1 infection was detected, clinical observations, quantitative measurements of plasma HIV-1 RNA levels (to assess viremia) and HIV antibodies, and results of immunophenotyping of lymphocytes were obtained twice weekly.

RESULTS

Fifty of 112 volunteers with acute HIV-1 infection had two or more blood samples collected before HIV-1 antibodies were detected. The median peak viremia (6.7 log10 copies per milliliter) occurred 13 days after the first sample showed reactivity on nucleic acid testing. Reactivity on an enzyme immunoassay occurred at a median of 14 days. The nadir of viremia (4.3 log10 copies per milliliter) occurred at a median of 31 days and was nearly equivalent to the viral-load set point, the steady-state viremia that persists durably after resolution of acute viremia (median plasma HIV-1 RNA level, 4.4 log10 copies per milliliter). The peak viremia and downslope were correlated with the viral-load set point. Clinical manifestations of acute HIV-1 infection were most common just before and at the time of peak viremia. A median of one symptom of acute HIV-1 infection was recorded at a median of two study visits, and a median of one sign of acute HIV-1 infection was recorded at a median of three visits.

CONCLUSIONS

The viral-load set point occurred at a median of 31 days after the first detection of plasma viremia and correlated with peak viremia. Few symptoms and signs were observed during acute HIV-1 infection, and they were most common before peak viremia. (Funded by the Department of Defense and the National Institute of Allergy and Infectious Diseases.).

Prevalence of Lymphatic Filariasis and Treatment Effectiveness of Albendazole/ Ivermectin in Individuals with HIV Co-infection in Southwest-Tanzania

BACKGROUND

Annual mass treatment with ivermectin and albendazole is used to treat lymphatic filariasis in many African countries, including Tanzania. In areas where both diseases occur, it is unclear whether HIV co-infection reduces treatment success.

METHODOLOGY

In a general population study in Southwest Tanzania, individuals were tested for HIV and circulating filarial antigen, an indicator of Wuchereria bancrofti adult worm burden, before the first and after 2 consecutive rounds of anti-filarial mass drug administration.

PRINCIPLE FINDINGS

Testing of 2104 individuals aged 0-94 years before anti-filarial treatment revealed a prevalence of 24.8% for lymphatic filariasis and an HIV-prevalence of 8.9%. Lymphatic filariasis was rare in children, but prevalence increased in individuals above 10 years, whereas a strong increase in HIV was only seen above 18 years of age. The prevalence of lymphatic filariasis in adults above 18 years was 42.6% and 41.7% (p = 0.834) in HIV-negatives and-positives, respectively. Similarly, the HIV prevalence in the lymphatic filariasis infected (16.6%) and uninfected adult population (17.1%) was nearly the same. Of the above 2104 individuals 798 were re-tested after 2 rounds of antifilarial treatment. A significant reduction in the prevalence of circulating filarial antigen from 21.6% to 19.7% was found after treatment (relative drop of 8.8%, McNemar's exact p = 0.036). Furthermore, the post-treatment reduction of CFA positivity was (non-significantly) larger in HIV-positives than in HIV-negatives (univariable linear regression p = 0.154).

CONCLUSION/SIGNIFICANCE

In an area with a high prevalence for both diseases, no difference was found between HIV-infected and uninfected individuals regarding the initial prevalence of lymphatic filariasis. A moderate but significant reduction in lymphatic filariasis prevalence and worm burden was demonstrated after two rounds of treatment with albendazole and ivermectin. Treatment effects were more pronounced in the HIV co-infected subgroup, indicating that the effectiveness of antifilarial treatment was not reduced by concomitant HIV-infection. Studies with longer follow-up time could validate the observed differences in treatment effectiveness.

Evaluation of health research capacity strengthening trainings on individual level: validation of a questionnaire

RATIONALE, AIMS AND OBJECTIVES

In the field of global health, research capacity strengthening is becoming a common concept for defining and improving research competencies on individual, organizational, national and supranational level. However, HRCS activities often lack evaluation procedures to measure their impact and to ensure their quality. The aim of this study was to develop and validate a short questionnaire to evaluate trainings in the field of health research capacity strengthening (HRCS).

METHOD

The questionnaire was developed by an interdisciplinary research team and tested in four different training settings at the Mbeya Medical Research Center and Mbeya Referral Hospital, Tanzania. Construct validity of the questionnaire was tested based on 97 responses of the participants of four trainings.

RESULTS

Iterative checking of Cronbach's alpha of the subscales and exploratory factor analysis revealed a four-factor solution that differed from the original structure and subscales of the questionnaire. The instrument was adapted accordingly and consists now of four subscales with 19 items, three global impression items, and open questions for participants' comments and recommendations.

CONCLUSIONS

The result of the study is a short, validated questionnaire for the evaluation of HRCS trainings on the individual level. The tool can be applied both to measure the short-term effects of international health research capacity trainings and to ensure their quality. In the future, after collecting larger sample sizes, a confirmatory factor analysis should be done to further support the four factors.

Low specificity of determine HIV1/2 RDT using whole blood in south west Tanzania

Objective

To evaluate the diagnostic performance of two rapid detection tests (RDTs) for HIV 1/2 in plasma and in whole blood samples.

Methods

More than 15,000 study subjects above the age of two years participated in two rounds of a cohort study to determine the prevalence of HIV. HIV testing was performed using the Determine HIV 1/2 test (Abbott) in the first (2006/2007) and the HIV 1/2 STAT-PAK Dipstick Assay (Chembio) in the second round (2007/2008) of the survey. Positive results were classified into faint and strong bands depending on the visual appearance of the test strip and confirmed by ELISA and Western blot.

Results

The sensitivity and specificity of the Determine RDT were 100% (95% confidence interval  = 86.8 to 100%) and 96.8% (95.9 to 97.6%) in whole blood and 100% (99.7 to 100%) and 97.9% (97.6 to 98.1%) in plasma respectively. Specificity was highly dependent on the tested sample type: when using whole blood, 67.1% of positive results were false positive, as opposed to 17.4% in plasma. Test strips with only faint positive bands were more often false positive than strips showing strong bands and were more common in whole blood than in plasma. Evaluation of the STAT-PAK RDT in plasma during the second year resulted in a sensitivity of 99.7% (99.1 to 99.9%) and a specificity of 99.3% (99.1 to 99.4%) with 6.9% of the positive results being false.

Conclusions

Our study shows that the Determine HIV 1/2 strip test with its high sensitivity is an excellent tool to screen for HIV infection, but that – at least in our setting – it can not be recommended as a confirmatory test in VCT campaigns where whole blood is used.

Low sensitivity of a urine LAM-ELISA in the diagnosis of pulmonary tuberculosis

Background

The development and evaluation of rapid and accurate new diagnostic tools is essential to improve tuberculosis (TB) control in developing countries. In a previous study, the first release of a urine LAM-ELISA by Chemogen (Portland, USA) has been evaluated with a promising sensitivity and specificity for the diagnosis of pulmonary TB. In the present study, the now commercially available assay has been clinically assessed regarding its diagnostic value alone and in combination with clinical co-factors.

Methods

The test was applied to two urine samples from 291 consecutively enrolled Tanzanian patients with suspected pulmonary tuberculosis. The participants were subsequently assigned to classification groups according to microbiological, clinical and radiological findings at recruitment and during a maximum follow up period of 56 days.

Results

Only 35 out of 69 pulmonary TB cases -confirmed by smear microscopy and/or solid culture and/or liquid culture- showed at least one positive LAM-ELISA result (sensitivity 50.7%). The sensitivity was noticeably higher in females (66.7%) and in HIV positive participants (62.0%). The specificity amounted to 87.8% and was determined in participants with negative results in all microbiological tests and with sustained recovery under antibiotic treatment at day 56. Correlation with urinalysis revealed that proteinuria was significantly and positively associated with LAM-positivity (P = 0.026).

Conclusion

This commercially available generation of LAM-ELISA does not appear to be useful as an independent diagnostic test for pulmonary tuberculosis. The question whether the assay is suitable as a supplemental device in the diagnosis of HIV-associated TB, requires further investigations.