BackgroundHigh 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.MethodsA 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.ResultsOverall 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 7.67/100pyar (95% CI;4.62–12.7) while it was 5.67/100pyar (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).ConclusionHIV-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.

IntroductionHIV epidemics in sub-Saharan Africa are generalized, but high-risk subgroups exist within these epidemics. A recent study among fisher-folk communities (FFC) in Uganda showed high HIV prevalence (28.8%) and incidence (4.9/100 person-years). However, those findings may not reflect population-wide HIV rates in FFC since the study population was selected for high-risk behaviour.MethodsBetween September 2011 and March 2013, we conducted a community-based cohort study to determine the population representative HIV rates and willingness to participate (WTP) in hypothetical vaccine trials among FFC, Uganda. At baseline (September 2011–January 2012), a household enumeration census was done in eight fishing communities (one lakeshore and seven islands), after which a random sample of 2200 participants aged 18–49 years was selected from 5360 individuals. Interviewer-administered questionnaire data were collected on HIV risk behaviours and WTP, and venous blood was collected for HIV testing using rapid HIV tests with enzyme-linked immunosorbent assay (EIA) confirmation. Adjusted prevalence proportion ratios (adj.PPRs) of HIV prevalence were determined using log-binomial regression models.ResultsOverall baseline HIV prevalence was 26.7% and was higher in women than men (32.6% vs. 20.8%, p<0.0001). Prevalence was lower among fishermen (22.4%) than housewives (32.1%), farmers (33.1%) and bar/lodge/restaurant workers (37%). The adj.PPR of HIV was higher among women than men (adj.PPR =1.50, 95%; 1.20, 1.87) and participants aged 30–39 years (adj.PPR=1.40, 95%; 1.10, 1.79) and 40–49 years (adj.PPR=1.41, 95%; 1.04, 1.92) compared to those aged 18–24 years. Other factors associated with HIV prevalence included low education, previous marriage, polygamous marriage, alcohol and marijuana use before sex. WTP in hypothetical vaccine trials was 89.3% and was higher in men than women (91.2% vs. 87.3%, p=0.004) and among island communities compared to lakeshore ones (90.4% vs. 85.8%, p=0.004).ConclusionsThe HIV prevalence in the general fisher-folk population in Uganda is similar to that observed in the “high-risk” fisher folk. FFC have very high levels of willingness to participate in future HIV vaccine trials.

We have previously shown that in successful pregnancies increased arginase activity is a mechanism that contributes to the suppression of the maternal immune system. We identified the main type of arginase-expressing cells as a population of activated low-density granulocytes (LDGs) in peripheral blood mononuclear cells and in term placentae. In the present study, we analyzed the phenotype of LDGs and compared it to the phenotype of normal density granulocytes (NDGs) in maternal peripheral blood, placental biopsies and cord blood. Our data reveal that only LDGs but no NDGs could be detected in placental biopsies. Phenotypically, NDGs and LDGs from both maternal and cord blood expressed different levels of maturation, activation and degranulation markers. NDGs from the maternal and cord blood were phenotypically similar, while maternal, cord and placental LDGs showed different expression levels of CD66b. LDGs present in cord blood expressed higher levels of arginase compared to maternal and placental LDGs. In summary, our results show that in maternal and cord blood, two phenotypically different populations of neutrophils can be identified, whereas in term placentae, only activated neutrophils are present.

BackgroundAn effective HIV vaccine is still elusive. Of the 9 HIV preventive vaccine efficacy trials conducted to-date, only one reported positive results of modest efficacy. More efficacy trials need to be conducted before one or more vaccines are eventually licensed. We assessed the suitability of fishing communities in Uganda for future HIV vaccine efficacy trials.MethodsA community-based cohort study was conducted among a random sample of 2191 participants aged 18–49 years. Data were collected on socio-demographic characteristics, HIV risky behaviors, and willingness to participate in future HIV vaccine trials (WTP). Venous blood was collected for HIV serological testing. Retention/follow rates and HIV incidence rates per 100 person years at-risk (pyar) were estimated. Adjusted prevalence proportion ratios (PPRs) of retention and odds ratios (ORs) of lack of WTP were estimated using log-binomial and logistic regression models respectively.ResultsOverall retention rate was 76.9% (1685/2191), highest (89%) among participants who had spent 5+ years in the community and lowest (54.1%) among those with <1 year stay. Significant predictors of retention included tribe/ethnicity, baseline HIV negative status, and longer than 1 year stay in the community. Overall WTP was 89.1% (1953/2191). Lack of WTP was significantly higher among women than men [adj.OR = 1.51 (95% CI, 1.14- 2.00)] and among participants who had stayed in fishing communities for 10 or more years relative to those with less than one year [adj.OR = 1.78 (95% CI, 1.11 - 2.88)]. Overall HIV incidence rate per 100 pyar was 3.39 (95% CI; 2.55 - 4.49). Participants aged 25–29 years had highest incidence rates (4.61 - 7.67/100 pyar) and high retention rates between 78.5 and 83.1%. In a combined analysis of retention and incidence rates participants aged 30+ years had retention rates ~80% but low incidence rates (2.45 - 3.57 per 100 pyar) while those aged 25–29 years had the highest incidence rates (4.61 - 7.67/100 pyar) and retention rates 78.5 - 83.1%.ConclusionsThere is high HIV incidence, retention and WTP among fishing communities around L. Victoria, Uganda which make these communities appropriate for future HIV prevention efficacy studies including vaccine trials.

HIV epidemiology informs prevention trial design and program planning. Nine clinical research centers (CRC) in sub-Saharan Africa conducted HIV observational epidemiology studies in populations at risk for HIV infection as part of an HIV prevention and vaccine trial network. Annual HIV incidence ranged from below 2% to above 10% and varied by CRC and risk group, with rates above 5% observed in Zambian men in an HIV-discordant relationship, Ugandan men from Lake Victoria fishing communities, men who have sex with men, and several cohorts of women. HIV incidence tended to fall after the first three months in the study and over calendar time. Among suspected transmission pairs, 28% of HIV infections were not from the reported partner. Volunteers with high incidence were successfully identified and enrolled into large scale cohort studies. Over a quarter of new cases in couples acquired infection from persons other than the suspected transmitting partner.