Alcohol Consumption Modifies Susceptibility to HIV-1 Entry in Cervical Mucosa-Derived CD4+ T cells of Women Resident in a Fishing Community of Lake Victoria, Uganda.

Background: A significant overlap exists in the burden of Alcohol Use Disorders (AUDs) and the HIV epidemic in Sub-Saharan Africa. Over 60% of HIV infections occur in women, mostly through the cervical mucosa. Absorption and systemic circulation of alcohol induces global physiological and immune effects, including at the genital mucosa. Alcohol alters expression of cell surface receptors, mucosal barrier permeability, inflammatory responses, and lymphocyte trafficking and homing. However, a substantial knowledge gap exists on whether these cellular and or immunological effects of alcohol modify the consumers' CD4+ T cell susceptibility to HIV-1 entry at the cervical mucosa. HIV seronegative women, aged 18-49 years were recruited from Kasenyi and Kigungu fish landing sites of Lake Victoria. They were categorized as Alcohol Consumers (n=27) or non-Alcohol Consumers (n=26) based on the World Health Organization Alcohol-Use-Disorder-Test (WHO-AUDIT) at a cut-off score of >=8/40 and <8/40, respectively. Cytobrush-collected Cervical Mononuclear Cells [CMCs] and Peripheral Blood Mononuclear Cells [PBMCs] from heparinized whole-blood were surface stained for CD4+ T cell immunophenotyping. To measure susceptibility to HIV entry, CMCs and PBMCs were co-cultured overnight with equal amount of GFP-tagged HIV-1 pseudo-virus particles. Both immunophenotyping and HIV entry were measured on a BD LSR II flow cytometer. Results: There was no significant difference in the frequency of CD4+ T cells in blood (p=0.451) or mucosa (p=0.838) compartments across study groups. However, we observed a combined four-fold higher HIV entry (p=0.0001) into cervical versus blood-derived CD4+ T cells regardless of alcohol consumption status. More so, cervical-derived CD4+ T cells of alcohol-consumers showed a two-fold increase in susceptibility to HIV entry (P=0.0185) compared to the non-alcohol consumer group. Double positive α4ß7+CD4+T cells of alcohol consumers exhibited a higher HIV entry compared to those from alcohol non-consumers(p=0.0069). Conclusion: This study demonstrates that cervical CD4+ T cells are more susceptible to HIV entry than those from blood. Also, cervical CD4+ T cells of alcohol consumers are more susceptible than those of non-consumers. Differences in frequencies of α4ß7+ CD4+ T between alcohol consumers and non-consumers' cells may account for the increased susceptibility to HIV entry.

Schistosoma mansoni infection alters the host pre-vaccination environment resulting in blunted Hepatitis B vaccination immune responses.

Schistosomiasis is a disease caused by parasitic flatworms of the Schistosoma spp., and is increasingly recognized to alter the immune system, and the potential to respond to vaccines. The impact of endemic infections on protective immunity is critical to inform vaccination strategies globally. We assessed the influence of Schistosoma mansoni worm burden on multiple host vaccine-related immune parameters in a Ugandan fishing cohort (n = 75) given three doses of a Hepatitis B (HepB) vaccine at baseline and multiple timepoints post-vaccination. We observed distinct differences in immune responses in instances of higher worm burden, compared to low worm burden or non-infected. Concentrations of pre-vaccination serum schistosome-specific circulating anodic antigen (CAA), linked to worm burden, showed a significant bimodal distribution associated with HepB titers, which was lower in individuals with higher CAA values at month 7 post-vaccination (M7). Comparative chemokine/cytokine responses revealed significant upregulation of CCL19, CXCL9 and CCL17 known to be involved in T cell activation and recruitment, in higher CAA individuals, and CCL17 correlated negatively with HepB titers at month 12 post-vaccination. We show that HepB-specific CD4+ T cell memory responses correlated positively with HepB titers at M7. We further established that those participants with high CAA had significantly lower frequencies of circulating T follicular helper (cTfh) subpopulations pre- and post-vaccination, but higher regulatory T cells (Tregs) post-vaccination, suggesting changes in the immune microenvironment in high CAA could favor Treg recruitment and activation. Additionally, we found that changes in the levels of innate-related cytokines/chemokines CXCL10, IL-1ß, and CCL26, involved in driving T helper responses, were associated with increasing CAA concentration. This study provides further insight on pre-vaccination host responses to Schistosoma worm burden which will support our understanding of vaccine responses altered by pathogenic host immune mechanisms and memory function and explain abrogated vaccine responses in communities with endemic infections.

Schistosoma mansoni infection alters the host pre-vaccination environment resulting in blunted Hepatitis B vaccination immune responses.

The impact of endemic infections on protective immunity is critical to inform vaccination strategies. In this study, we assessed the influence of Schistosoma mansoni infection on host responses in a Ugandan fishing cohort given a Hepatitis B (HepB) vaccine. Concentrations of schistosome-specific circulating anodic antigen (CAA) pre-vaccination showed a significant bimodal distribution associated with HepB titers, which were lower in individuals with high CAA. We established that participants with high CAA had significantly lower frequencies of circulating T follicular helper (cTfh) subpopulations pre- and post-vaccination and higher regulatory T cells (Tregs) post-vaccination. Polarization towards higher frequencies of Tregs: cTfh cells can be mediated by changes in the cytokine environment favoring Treg differentiation. In fact, we observed higher levels of CCL17 and soluble IL-2R pre-vaccination (important for Treg recruitment and development), in individuals with high CAA that negatively associated with HepB titers. Additionally, alterations in pre-vaccination monocyte function correlated with HepB titers, and changes in innate-related cytokines/chemokine production were associated with increasing CAA concentration. We report, that by influencing the immune landscape, schistosomiasis has the potential to modulate immune responses to HepB vaccination. These findings highlight multiple Schistosoma -related immune associations that could explain abrogated vaccine responses in communities with endemic infections. Author Summary: Schistosomiasis drives host immune responses for optimal pathogen survival, potentially altering host responses to vaccine-related antigen. Chronic schistosomiasis and co-infection with hepatotropic viruses are common in countries where schistosomiasis is endemic. We explored the impact of Schistosoma mansoni ( S. mansoni ) infection on Hepatitis B (HepB) vaccination of individuals from a fishing community in Uganda. We demonstrate that high schistosome-specific antigen (circulating anodic antigen, CAA) concentration pre-vaccination, is associated with lower HepB antibody titers post-vaccination. We show higher pre-vaccination levels of cellular and soluble factors in instances of high CAA that are negatively associated with HepB antibody titers post-vaccination, which coincided with lower frequencies of circulating T follicular helper cell populations (cTfh), proliferating antibody secreting cells (ASCs), and higher frequencies of regulatory T cells (Tregs). We also show that monocyte function is important in HepB vaccine responses, and that high CAA is associated with alterations in the early innate cytokine/chemokine microenvironment. Our findings suggest that in individuals with high CAA and likely high worm burden, schistosomiasis creates and sustains an environment that is polarized against optimal host immune responses to the vaccine, which puts many endemic communities at risk for infection against HepB and other diseases that are preventable by vaccines.

An Overview of Rift Valley Fever Vaccine Development Strategies.

Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that causes high fetal and neonatal mortality in ruminants and a mild to fatal hemorrhagic fever in humans. There are no licensed RVF vaccines for human use while for livestock, commercially available vaccines are all either live attenuated or inactivated and have undesirable characteristics. The live attenuated RVF vaccines are associated with teratogenicity and residual virulence in ruminants while the inactivated ones require multiple immunisations to induce and maintain protective immunity. Additionally, nearly all licensed RVF vaccines lack the differentiating infected from vaccinated animals (DIVA) property making them inappropriate for use in RVF nonendemic countries. To address these limitations, novel DIVA-compatible RVF vaccines with better safety and efficacy than the licensed ones are being developed, aided fundamentally by a better understanding of the molecular biology of the RVF virus and advancements in recombinant DNA technology. For some of these candidate RVF vaccines, sterilizing immunity has been demonstrated in the discovery/feasibility phase with minimal adverse effects. This review highlights the progress made to date in RVF vaccine research and development and discusses the outstanding research gaps.

Hepatitis B prevalence and incidence in the fishing communities of Lake Victoria, Uganda: a retrospective cohort study.

INTRODUCTION: Hepatitis B is a serious potentially fatal hepatocellular disease caused by the hepatitis B virus. In the fishing communities of Lake Victoria Uganda, the hepatitis B virus infection burden is largely unknown. This study assessed the prevalence and incidence of hepatitis B in these communities. METHODS: This was a retrospective cohort study that tested serum samples collected from 13 to 49-year-old study participants that were residing in two Ugandan Lake Victoria fishing communities of Kasenyi (a mainland) and Jaana (an island). The samples were collected between 2013 and 2015 during the conduct of an HIV epidemiological cohort study in these communities. A total of 467 twelve-month follow-up and 50 baseline visit samples of participants lost to follow-up were tested for hepatitis B serological markers to determine prevalence. To determine hepatitis B virus incidence, samples that were hepatitis B positive at the follow-up visit had their baseline samples tested to identify hepatitis B negative samples whose corresponding follow-up samples were thus incident cases. RESULTS: The baseline mean age of the 517 study participants was 31.1 (SD ± 8.4) years, 278 (53.8%) of whom were females. A total of 36 (7%) study participants had hepatitis B virus infection, 22 (61.1%) of whom were male. Jaana had a higher hepatitis B virus prevalence compared to Kasenyi (10.2% vs 4.0%). In total, 210 (40.6%) study participants had evidence of prior hepatitis B virus infection while 48.6% had never been infected or vaccinated against this disease. A total of 20 (3.9%) participants had results suggestive of prior hepatitis B vaccination. Hepatitis B incidence was 10.5 cases/100PY (95% CI: 7.09-15.53). Being above 25 years of age and staying in Jaana were significant risk factors for hepatitis B virus acquisition (AOR 1.6, 95% CI: 1.1-2.2; p < 0.01 and 1.4, 95% CI: 1.1-1.8; p < 0.01 respectively). CONCLUSION: Hepatitis B virus incidence in Lake Victoria fishing communities of Uganda is very high, particularly in the islands. Interventions to lower hepatitis B virus transmission in these communities are urgently needed.

Prevalence and correlates of HIV infection among adolescents and young people living in fishing populations along Lake Victoria Fishing Communities in Uganda.

INTRODUCTION: fishing communities in Uganda are key populations for HIV, with persistently higher prevalence and incidence than the general population. METHODS: between March and August 2014, a cross sectional survey was conducted in 10 fishing communities of Lake Victoria in Uganda. Data was collected on socio-behavioural characteristics using interviewer administered questionnaires and venous blood collected for HIV testing. Prevalent HIV infections among adolescents and young people aged 13 to 24 years was estimated and the factors associated with those infections determined using multi variable logistic regression modelling. RESULTS: HIV prevalence was 10.8% among the 630 (96.5%) who provided a blood sample. Females were 3.5 times as likely to have HIV infection as males (aOR=3.52, 95% CI: 1.34-9.22). Young people aged 20-24 years were twice as likely to be HIV infected as those aged 13-19 years (aOR=1.77, 95% CI: 0.05-2.10), participants without formal education or those who had studied up to primary level were more likely to be HIV infected than those who had post primary education ((aOR=2.45, 95% CI: 1.19-5.07) or (5.29 (1.35-20.71) respectively). Reporting more than one sexual partner in the past 6 months was associated with HIV prevalent infection than those reporting no sexual partners (aOR=6.44, 95% CI: 1.27-32.83). CONCLUSION: adolescents and young people aged 13-24 years in fishing communities around Lake Victoria, Uganda, have a high HIV prevalence, with females having a three-fold higher level than males. These findings highlight-the need to improve HIV prevention among young females living in these fishing communities.

Characterization of CD4+ T cell subsets and HIV susceptibility in the inner and outer foreskin of Ugandan men.

PROBLEM: Biological mechanisms of foreskin HIV acquisition are poorly defined. The inner foreskin is preferentially infected in explant models, so we hypothesized that this site would be enriched for HIV-susceptible CD4+ T cells and proinflammatory/chemoattractant cytokines. METHOD OF STUDY: A total of 42 HIV-uninfected Ugandan men without genital symptoms provided foreskin tissues and swabs at the time of elective penile circumcision. The immune phenotype of foreskin-derived CD4+ T cells and entry of a CCR5-tropic HIV pseudovirus was characterized, and specific cytokine levels assayed by multiplexed chemiluminescent ELISA. RESULTS: Unexpectedly, outer foreskin CD4+ T cells more frequently expressed CCR5 (median 29.2% vs 22.9%, P = 0.01) and CD69 (median 36.5% vs 15%, P < 0.01), and on a per-cell basis, HIV entry was higher. However, overall CD4+ T cell density was approximately twofold higher in the inner foreskin, and several highly susceptible T cell subsets were increased at this site, including Th17 cells (20.0% vs 14.1%, P = 0.0021). Specific pro-inflammatory cytokine levels were also higher on the inner foreskin surface (IL-17, IL-8, RANTES and IL-1ß; all P < 0.05). CONCLUSION: There was marked heterogeneity in CD4+ T cell populations and immune milieu between inner and outer foreskin tissues. Despite higher per-cell viral entry into CD4+ T cells from the outer foreskin, the higher target cell density and enriched pro-inflammatory cytokines of the inner foreskin suggest that this may be a preferential site for HIV acquisition.

Field Performance of PIMA Point-of-Care Machine for CD4 Enumeration Under a Mobile HIV Counseling and Testing Program in Remote Fishing Communities of Lake Victoria, Uganda.

Uganda is among the most HIV/AIDS-afflicted countries, and many HIV-infected persons live in remote areas with poor access to health care. The success of HIV care programs relies in part on patient monitoring using CD4 T cell counts. We conducted an evaluation of the point-of-care PIMA test using BD FACSCount as a gold standard. One hundred fifty-one participants were enrolled, provided venous blood and samples tested at the point of care with the Alere PIMA™ CD4 Analyzer and the BD FACSCount in the UVRI-IAVI main laboratory. Correlation between the methods was assessed, as was the ability of the Pima Analyzer to predict values <200, <350, and ≥500 CD4 cells/mm3 when compared with BD FACSCount as the gold standard. A near-perfect positive Pearson correlation coefficient (r = 0.948; p < .0001) between the two methods was observed. The Alere PIMA Analyzer had a mean bias of -32.5 cells/mm3. The sensitivity and specificity, for PIMA to predict CD4 lymphocyte count less than 200 cells/mm3, were 71.4% and 100%, respectively; less than 350 cells/mm3 were 84.6% and 94.6%, respectively; and at CD4 count less than 500 cells/mm3 were 94.4% and 100%. The Alere Pima Analyzer provides reliable CD4 cell count measurement and is suitable for monitoring and screening eligible HIV patients in hard-to-reach settings.

Evaluation of HIV-1 rapid tests and identification of alternative testing algorithms for use in Uganda.

INTRODUCTION: The World Health Organization recommends that countries conduct two phase evaluations of HIV rapid tests (RTs) in order to come up with the best algorithms. In this report, we present the first ever such evaluation in Uganda, involving both blood and oral based RTs. The role of weak positive (WP) bands on the accuracy of the individual RT and on the algorithms was also investigated. METHODS: In total 11 blood based and 3 oral transudate kits were evaluated. All together 2746 participants from seven sites, covering the four different regions of Uganda participated. Two enzyme immunoassays (EIAs) run in parallel were used as the gold standard. The performance and cost of the different algorithms was calculated, with a pre-determined price cut-off of either cheaper or within 20% price of the current algorithm of Determine + Statpak + Unigold. In the second phase, the three best algorithms selected in phase I were used at the point of care for purposes of quality control using finger stick whole blood. RESULTS: We identified three algorithms; Determine + SD Bioline + Statpak; Determine + Statpak + SD Bioline, both with the same sensitivity and specificity of 99.2% and 99.1% respectively and Determine + Statpak + Insti, with sensitivity and specificity of 99.1% and 99% respectively as having performed better and met the cost requirements. There were 15 other algorithms that performed better than the current one but rated more than the 20% price. None of the 3 oral mucosal transudate kits were suitable for inclusion in an algorithm because of their low sensitivities. Band intensity affected the performance of individual RTs but not the final algorithms. CONCLUSION: We have come up with three algorithms we recommend for public or Government procurement based on accuracy and cost. In case one algorithm is preferred, we recommend to replace Unigold, the current tie breaker with SD Bioline. We further recommend that all the 18 algorithms that have shown better performance than the current one are made available to the private sector where cost may not be a limiting factor.

HIV-1 transmission networks in high risk fishing communities on the shores of Lake Victoria in Uganda: A phylogenetic and epidemiological approach.

BACKGROUND: Fishing communities around Lake Victoria in sub-Saharan Africa have been characterised as a population at high risk of HIV-infection. METHODS: Using data from a cohort of HIV-positive individuals aged 13-49 years, enrolled from 5 fishing communities on Lake Victoria between 2009-2011, we sought to identify factors contributing to the epidemic and to understand the underlying structure of HIV transmission networks. Clinical and socio-demographic data were combined with HIV-1 phylogenetic analyses. HIV-1 gag-p24 and env-gp-41 sub-genomic fragments were amplified and sequenced from 283 HIV-1-infected participants. Phylogenetic clusters with ≥2 highly related sequences were defined as transmission clusters. Logistic regression models were used to determine factors associated with clustering. RESULTS: Altogether, 24% (n = 67/283) of HIV positive individuals with sequences fell within 34 phylogenetically distinct clusters in at least one gene region (either gag or env). Of these, 83% occurred either within households or within community; 8/34 (24%) occurred within household partnerships, and 20/34 (59%) within community. 7/12 couples (58%) within households clustered together. Individuals in clusters with potential recent transmission (11/34) were more likely to be younger 71% (15/21) versus 46% (21/46) in un-clustered individuals and had recently become resident in the community 67% (14/21) vs 48% (22/46). Four of 11 (36%) potential transmission clusters included incident-incident transmissions. Independently, clustering was less likely in HIV subtype D (adjusted Odds Ratio, aOR = 0.51 [95% CI 0.26-1.00]) than A and more likely in those living with an HIV-infected individual in the household (aOR = 6.30 [95% CI 3.40-11.68]). CONCLUSIONS: A large proportion of HIV sexual transmissions occur within house-holds and within communities even in this key mobile population. The findings suggest localized HIV transmissions and hence a potential benefit for the test and treat approach even at a community level, coupled with intensified HIV counselling to identify early infections.

Population attributable fraction of incident HIV infections associated with alcohol consumption in fishing communities around Lake Victoria, Uganda.

BACKGROUND: Although the association between alcohol consumption and HIV risk is well documented, few studies have examined the magnitude of new HIV infections that could be prevented by controlling alcohol use. We report the population attributable fraction (PAF) of incident HIV infections due to alcohol consumption among the HIV high-risk population of fishing communities along Lake Victoria, Uganda. METHODS: In a community-based cohort study, 1607 HIV sero-negative participants aged 18-49 years were enrolled from eight fishing communities along Lake Victoria, Uganda. At follow up 12 months later, 1288 (80.1%) were seen and interviewed. At baseline and follow-up visits, participants completed interviewer-administered questionnaires on alcohol consumption, demographics, and sexual risk behavior, and were tested for HIV infection. HIV incidence and adjusted incident rate ratios (adjusted IRRs) were estimated using Poisson regression models; the crude and adjusted PAFs of incident HIV infections associated with alcohol consumption were calculated using the Greenland and Drescher method for cohort studies. RESULTS: Among the 1288 participants seen at follow up, 53.5% reported drinking alcohol of whom 24.4% drank occasionally (2 days a week or less) and 29.1% drank regularly (3-7 days a week). Forty eight incident HIV infections occurred giving an incidence rate of 3.39/100 person years at-risk (pyar) (95% CI, 2.55-4.49). Compared to non-drinkers, the adjusted IRR of HIV was 3.09 (1.13-8.46) among occasional drinkers and 5.34 (2.04-13.97) among regular drinkers. The overall adjusted PAF of incident HIV infections due alcohol was 64.1 (95% CI; 23.5-83.1); ranging from 52.3 (11.9-74.2) among Muslims to 71.2 (32.6-87.7) for participants who reported ≥ 2 sexual partners in the past 12 months. CONCLUSION: In fishing communities along Lake Victoria, Uganda, 64% of new HIV infections can be attributed to drinking alcohol. Interventions to reduce alcohol consumption should be integrated in HIV/AIDS prevention activities for populations in whom both HIV and alcohol consumption are highly prevalent.

High incidence of HIV-1 infection in a general population of fishing communities around Lake Victoria, Uganda.

BACKGROUND: High HIV-1 incidence rates were reported among persons in fisherfolk communities (FFC) in Uganda who were selected for high risk behaviour. We assessed the incidence of HIV-1 and associated risk factors in a general population FFC to determine population-wide HIV rates. METHODS: A community-based cohort study was conducted among a random sample of 2191 participants aged 18-49 years. At baseline and 12 months post-baseline, data were collected on socio-demographic characteristics and risky behaviors (including number of partners, new partners, condom use, use of alcohol and illicit drug use). Venous blood was collected for HIV serological testing. HIV incidence was calculated per 100 person years at-risk (pyar) and adjusted incidence rate ratios (Adj.IRR) were estimated by multivariable Poisson regression. RESULTS: Overall follow up at 12 months was 76.9% (1685/2191) and was significantly higher among HIV uninfected persons and those with at least 1 year duration of stay in community. Overall HIV-1 incidence was 3.39/100 pyar (95% CI: 2.55-4.49). Among the 25-29 years who drank alcohol, HIV incidence was 7.67/100 pyar (95% CI;4.62-12.7) while it was 5.67/100 pyar (95% CI;3.14-10.2) for 18-24 year olds who drank alcohol. The risk of HIV infection was higher among 25-29 years (adj.IRR = 3.36; 95% CI: 1.48-7.65) and 18-24 years (adj.IRR = 2.65; 95% CI: 1.05-6.70) relative to 30+ years. Compared to non-drinkers, HIV incidence increased by frequency of alcohol drinking--occasional drinkers (adj.IRR = 3.18; 95% CI: 1.18-8.57) and regular drinkers (adj.IRR = 4.93; 95% CI: 1.91-12.8). CONCLUSION: HIV-1 incidence in general fisherfolk population along L. Victoria, Uganda, is high and is mainly associated with young age and alcohol drinking. HIV prevention and control strategies are urgently needed in this population.