Background. A genetic bottleneck is known to exist for human immunodeficiency virus (HIV) at the point of sexual transmission. However, the nature of this bottleneck and its effect on viral diversity over time is unclear.
Methods. Interhost and intrahost HIV diversity was analyzed in a stable population in Rakai, Uganda, from 1994 to 2002. HIV-1 envelope sequences from both individuals in initially HIV-discordant relationships in which transmission occurred later were examined using Sanger sequencing of bulk polymerase chain reaction (PCR) products (for 22 couples), clonal analysis (for 3), and next-generation deep sequencing (for 9).
Results. Intrahost viral diversity was significantly higher than changes in interhost diversity (P < .01). The majority of HIV-1–discordant couples examined via bulk PCR (16 of 22 couples), clonal analysis (3 of 3), and next-generation deep sequencing (6 of 9) demonstrated that the viral populations present in the newly infected recipient were more closely related to the donor partner's HIV-1 variants found earlier during infection as compared to those circulating near the estimated time of transmission (P = .03).
Conclusions. These findings suggest that sexual transmission constrains viral diversity at the population level, partially because of the preferential transmission of ancestral as opposed to contemporary strains circulating in the transmitting partner. Future successful vaccine strategies may need to target these transmitted ancestral strains.
Thousands of former child soldiers who were abducted during the prolonged conflict in northern Uganda have returned to their home communities. Programmes that facilitate their successful reintegration continue to face a number of challenges. Although there is increasing knowledge of the dynamics of HIV infection during conflict, far less is known about its prevalence and implications for population health in the post-conflict period. This study investigated the effects of abduction on the prevalence of HIV and HIV-risk behaviours among young people in Gulu District, northern Uganda. An understanding of abduction experiences and HIV-risk behaviours is vital to both the development of effective reintegration programming for former child soldiers and the design of appropriate HIV prevention interventions for all young people.
In 2010, we conducted a cross-sectional study of 2 sub-counties in Gulu District. A demographic and behavioural survey was interview-administered to a purposively selected sample of 384 transit camp residents aged 15–29. Biological specimens were collected for HIV rapid testing in the field and confirmatory laboratory testing. Descriptive statistics were used to describe characteristics of abduction. Additionally, a gender-stratified bivariate analysis compared abductees’ and non-abductees’ HIV risk profiles.
Of the 384 participants, 107 (28%) were former child soldiers (61% were young men and 39% were young women). The median age of participants was 20 and median age at abduction was 13. HIV prevalence was similar among former abductees and non-abductees (12% vs. 13%; p = 0.824), with no differences observed by gender. With respect to differences in HIV vulnerability, our bivariate analysis identified greater risky sexual behaviours in the past year for former abductees than non-abductees, but there were no differences between the two groups’ survival/livelihood activities and food insufficiency experiences, both overall and by gender. The analysis further revealed that young northern Ugandans in general are in desperate need of education, skills development, and support for victims of sexual violence.
This study persuasively demonstrates that all young people in northern Ugandan have been similarly affected by HIV infection during war and displacement. Post-conflict programme planners must therefore abandon rudimentary targeting practices based on abductees as a high-profile category. Instead, they must develop evidence-based HIV interventions that are commensurate with young people’s specific needs. As such programmes will be less stigmatizing, more oriented to self-selection, and more inclusive, they will effectively reach the most vulnerable young people in northern Uganda.
Child soldiers; HIV/AIDS; Post-conflict programming; Young people; Northern Uganda
HIV 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.
Between 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.
Overall 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).
The 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.
HIV-1; willingness to participate in HIV vaccine trials; fishing communities; Uganda
Asymptomatic parasitemia is common among schoolchildren living in areas of high malaria transmission, yet little is known about its effect on cognitive function in these settings. To investigate associations between asymptomatic parasitemia, anemia, and cognition among primary schoolchildren living in a high malaria transmission setting, we studied 740 children enrolled in a clinical trial in Tororo, Uganda. Parasitemia, measured by thick blood smears, was present in 30% of the children. Infected children had lower test scores for abstract reasoning (adjusted mean difference [AMD] −0.6, 95% confidence interval [CI] −1.01 to −0.21) and sustained attention (AMD −1.6 95% CI −2.40 to −0.81) compared with uninfected children. There was also evidence for a dose–response relationship between parasite density and scores for sustained attention. No associations were observed between anemia and either test of cognition. Schoolchildren in high transmission settings may experience cognitive benefits, from interventions aimed at reducing the prevalence of asymptomatic parasitemia.
Daily suppression of herpes simplex virus type 2 (HSV-2) reduces plasma HIV-1 concentrations and has been shown to delay HIV-1 disease progression modestly in one clinical trial. We investigated the impact of daily suppressive acyclovir on HIV-1 disease progression in Rakai, Uganda
In a single site trial, 440 HIV-1, HSV-2 dually infected consenting adults with CD4+ T-cell counts 300-400 cells/μL and not on antiretroviral therapy were randomized 1:1 to receive either acyclovir 400 mg orally twice daily or placebo; participants were followed for 24 months. The primary outcome was CD4 <250 or ART initiation for WHO stage IV disease. Intent-to-treat analysis used Cox proportional hazards (CPH) models, adjusting for baseline log10 viral load (VL), CD4 cell count, gender and age to assess the risk of disease progression. The impact of suppressive HSV-2 treatment by baseline VL was also investigated in a CPH model. This trial is registered with clinicaltrials.gov, number NCT00405821.
Overall, 110 participants in the placebo arm and 95 participants in the treatment arm reached the primary endpoint (Adj HR 0.75, 95% CI 0.58-0.99; p=0.040). In a sub-analysis stratified by baseline VL quintile, participants with a baseline VL >= 50,000 copies/ml experienced a 38% reduction in HIV disease progression in the treatment compared to placebo arm (Adj HR 0.62, 95% CI 0.43-0.96;p=0.03).
Acyclovir reduced the rate of disease progression by 25%, with the greatest impact occurring among individuals with high baseline VL. Suppressive acyclovir may be warranted among HSV-2/HIV-1 dually infected individuals with viral loads >= 50,000 copies/ml prior to antiretroviral treatment.
HIV-1; herpes simplex virus; acyclovir; disease progression
CCR5 is the primary coreceptor for HIV entry. Early after infection, the HIV viral population diversifies rapidly into a quasispecies. It is not known whether the initial efficiency of the viral quasispecies to utilize CCR5 is associated with HIV disease progression or if it changes in an infected individual over time. The CCR5 and CXCR4 utilization efficiencies (R5-UE and X4-UE) of the HIV quasispecies were examined using a pseudovirus, single-round infection assay for samples obtained from known seroconverters from Rakai district, Uganda (n=88). Initial and longitudinal R5-UE values were examined to assess the association of R5-UE with HIV disease progression using multivariate Cox proportional hazard models. Longitudinal samples were analyzed for 35 seroconverters who had samples available from multiple time points. There was no association between initial or longitudinal changes in R5-UE and the hazard of HIV disease progression (p=0.225 and p=0.942, respectively). In addition, R5-UE increased significantly over time after HIV seroconversion (p<0.001), regardless of HIV subtype or the emergence of CXCR4-tropic virus. These data demonstrate that the R5-UE of the viral quasispecies early in HIV infection is not associated with disease progression, and that R5-UE levels increase in HIV-infected individuals over time.
Large datasets for investigating vaginal flora change at frequent, repeated intervals are limited and graphical methods for exploring such data are inadequate. We report 2-year weekly vaginal flora changes based on Gram stain using lasagna plots.
Weekly vaginal flora patterns were evaluated among 211 sexually experienced women with 18 months or more of follow-up in Rakai, Uganda. Vaginal flora swabs were self-collected weekly and categorized by Nugent Gram stain criteria (0–3, normal; 4–6, intermediate; 7–10, BV). Vaginal flora patterns were analyzed as the percentage of weekly observations with BV (longitudinal prevalence) and illustrated by lasagna plots. Characteristics of women were compared across tertiles of longitudinal prevalence of BV.
Ninety-five percent of women had at least 1 episode of BV over 2 years with one-third of women spending over half (52–100%) of their time with BV. Vaginal pH > 4.5 increased with increasing tertiles of longitudinal prevalence of BV (p < 0.001). Weekly fluctuation in vaginal flora states, as measured by a change in flora states from the prior to current visit, was highest in the middle (41.9%) compared to the lower (30.1%) and upper tertiles (27.8%, p < 0.001). HIV status and reported vaginal symptoms did not differ significantly across BV tertiles.
Women exhibited different patterns of vaginal flora changes over time, which could not be described by baseline behaviors. Lasagna plots aided in describing the natural history of BV within and across women and may be applied to future BV natural history studies.
Sputum culture is the gold standard for diagnosis of pulmonary tuberculosis (PTB). Although mostly used for research, culture is recommended by the World Health Organization for TB diagnosis among HIV infected smear negative PTB suspects. Even then, the number of sputum samples required remains unspecified. Here, we determined the Incremental Yield (IY) and number of samples required to diagnose an additional PTB case upon second and third serial sputum culture.
This was a cross sectional study done between January and March 2011. Serial sputum samples were provided by participants within two days and cultured using Lowenstein Jensen (LJ) and Mycobacteria Growth Indicator Tube (MGIT) methods. A PTB case was defined as a positive culture on either one or both methods. The IY from the second and third serial cultures was determined and the reciprocal of the product of the fractions of IY provided the number of samples required for an additional PTB case. Of the 170 smear negative PTB suspects, 62 (36.5%) met the case definition. The IY of the second sample culture was 12.7%, 23.6% and 12.6% and for the third sample culture was 6.8%, 7.5% and 7.3% with LJ, MGIT and LJ or MGIT, respectively. The number of samples required for an additional PTB case and 95% CI upon the second sample culture were 29.9 (16.6, 156.5), 11.3 (7.6, 21.9) and 20.8 (12.5, 62.7); while for the third sample culture were 55.6 (26.4, 500.4), 35.7 (19.0, 313.8) and 36.1 (19.1, 330.9) by LJ, MGIT and LJ or MGIT respectively.
Among HIV infected smear negative PTB suspects in Kampala, 93% of PTB cases are diagnosed upon the second serial sputum culture. The number of cultures needed to diagnose an additional PTB case, ranges from 11–30 and 35–56 by the second and third sputum samples, respectively.
To describe changes in vaginal microbiota and pH over time among never sexually active adolescents at different menarcheal stages.
A cohort of 49 sexually inexperienced Ugandan adolescents provided weekly self-collected vaginal swabs and behavioral/health information for up to two years. Menarcheal stage was classified as: not experiencing menarche during follow-up (premenarcheal, n=9), achieving menarche during follow-up (perimenarcheal, n=20), and being postmenarcheal (n=20) at enrollment. Vaginal microbiota were characterized as morphotypes of large Gram-positive rods, small Gram-negative or variable rods, and curved Gram-negative rods based on Nugent Gram-stain criteria. Baseline measures were compared using nonparametric tests. Mean changes (β) in morphotypes and pH over time were estimated using longitudinal mixed-effects models.
The baseline median (IQR: interquartile range) Nugent score was 8 (7-8) in premenarcheal, 4.5 (1-8) in perimenarcheal, and 1 (0-3) in postmenarcheal girls (p=0.001). For each respective menarcheal stage, the median counts of (IQR) Gram-positive rods were 0 (0-0), 10 (0-30), and 30 (18-30) (p=0.002) and Gram-negative or variable rods were 30 (30-30), 16 (0.5-30), and 0.5 (0-2.5) (p=0.002) at enrollment. Counts of Gram-positive rods increased (β = 0.259, 95% CI: 0.156, 0.362) and Gram-negative or variable rods decreased (β = -0.201, 95% CI:-0.298,-0.103) significantly over time in premenarcheal girls, but not in other groups. Vaginal pH declined significantly in peri- and postmenarcheal girls only.
Vaginal microbiota composition varied by menarcheal stage at enrollment. Over time, significant changes in vaginal morphotypes occurred in premenarcheal girls, suggesting this may be an important period of transition.
vaginal microbiota; pH; menarche; lactobacilli; bacterial vaginosis; Gram-stain; Nugent score
High viral load (VL) setpoint is a marker for rapid HIV progression, but few studies have examined whether use of hormonal contraception (HC) prior to HIV seroconversion affects VL setpoint.
We determined VL setpoints in 285 HIV seroconverters using blood samples collected six months or more after estimated HIV seroconversion but before disease progression to CD4≤250 or WHO Stage 3 or 4. We used multivariate linear regression to estimate the effect of HC use prior to HIV seroconversion on VL setpoint, and multivariate Cox regression to estimate the hazards ratio of death associated with VL setpoint.
Of 285 women, 42 (15%) reported using HC prior to HIV seroconversion. Mean VL setpoint was 4.49 (SD 0.79) log10 copies/mL among women who used HC prior to HIV seroconversion and 4.47 (SD 0.86) among non-HC users (p=0.88). In multivariate analysis, HC prior to HIV seroconversion was not associated with VL setpoint (+0.11 log10 copies /mL; p=0.47). Higher socioeconomic status was associated with lower VL setpoint (-0.43 log10 copies/mL; p=0.04). VL setpoints above the median were associated with faster time to death (adjHR: 2.54, 95% CI: 1.30-4.98, p-value <0.01).
Use of HC prior to HIV seroconversion was not associated with elevated VL setpoint.
hormonal contraception; viral load setpoint; HIV progression; Uganda
HIV-1 subtype D (HIV-1D) progresses to disease faster and has lower transmissibility than subtype A (HIV-1A). We examined whether these differences could lead to a population level change in the distribution of these subtypes over time. HIV-1 viral RNA was extracted from stored serum samples from HIV-positive subjects participating in a population-based cohort study in Rakai, Uganda in 1994 and 2002. Portions of the viral proteins gag and gp41 were sequenced and subtyped. HIV-1 subtype assignments were generated for 773 subjects in 1994 and 812 subjects in 2002. The change in subtype distribution of the population as a whole as well as quartile age groups were examined for significant changes using a linear model. There was a significant decrease in the proportion of subjects infected with HIV-1D from 70.2% to 62.4% and a significant increase in subjects infected with HIV-1A from 16.7% to 23.3% over the 8-year period (p = 0.005). The most marked changes in proportion of HIV-1D and A were seen in the younger individuals (<25 and 25–30 years; p < 0.05). The percentages of subjects infected with HIV-1C and recombinant subtypes did not change significantly. Over this 8-year period, the overall viral population in this region evolved toward the less virulent HIV-1A strain, most likely as a consequence of the faster disease progression and lower transmissibility of HIV-1D.
Disclosure of HIV seropositive results among HIV-discordant couples in sub-Saharan Africa is generally low. We describe a facilitated couple counselling approach to enhance disclosure among HIV-discordant couples.
Using unique identifiers, 293 HIV-discordant couples were identified through retrospective linkage of married or cohabiting consenting adults individually enrolled into a cohort study and into two randomized trials of male circumcision in Rakai, Uganda. HIV discordant couples and a random sample of HIV-infected concordant and HIV-negative concordant couples (to mask HIV status) were invited to sensitization meetings to discuss the benefits of disclosure and couple counselling. HIV-infected partners were subsequently contacted to encourage HIV disclosure to their HIV uninfected partners. If the index positive partner agreed, the counsellor facilitated the disclosure of HIV results, and provided ongoing support. The proportion of disclosure was determined.
81% of HIV-positive partners in discordant relationships disclosed their status to their HIV-uninfected partners in the presence of the counsellor. The rates of disclosure were 81.3% in male HIV-positive and 80.2% in female HIV-positive discordant couples. Disclosure did not vary by age, education or occupation.
In summary, disclosure of HIV-positive results in discordant couples using facilitated couple counselling approach is high, but requires a stepwise process of sensitization and agreement by the infected partner.
HIV disclosure; Facilitated couple counselling; Discordant couples
Male circumcision reduces HIV acquisition in men. We assessed whether foreskin surface area was associated with HIV acquisition prior to circumcision.
In two randomized trials of male circumcision, the surface area of the foreskin was measured after surgery using standardized procedures. Nine hundred and sixty-five initially HIV-negative men were enrolled in a community cohort who subsequently enrolled in the male circumcision trials, provided 3920.8 person-years of observation prior to circumcision. We estimated HIV incidence per 100 person-years prior to circumcision, associated with foreskin surface area categorized into quartiles.
Mean foreskin surface area was significantly higher among men who acquired HIV (43.3 cm2, standard error 2.1) compared with men who remained uninfected (36.8 cm2, standard error 0.5, P = 0.01). HIV incidence was 0.80/100 person-years (8/994.9 person-years) for men with foreskin surface areas in the lowest quartile ( ≤26.3 cm2), 0.92/100 person-years (9/975.3 person-years) with foreskin areas in the second quartile (26.4–35.0 cm2), 0.90/100 person-years (8/888.5 person-years) with foreskin area in the third quartile (35.2–45.5 cm2) and 2.48/100 person-years (23/926.8 person-years) in men with foreskin surfaces areas in the highest quartile (>45.6 cm2). Compared with men with foreskin surface areas in the lowest quartile, the adjusted incidence rate ratio of HIV acquisition was 2.37 (95% confidence interval 1.05–5.31) in men with the largest quartile of foreskin surface area.
The risk of male HIV acquisition is increased among men with larger foreskin surface areas.
foreskin surface area; HIV acquisition; HIV target cells; male circumcision
In Rakai, Uganda, HIV+ men were randomized to immediate (intervention) or delayed circumcision (controls). Penile swabs were assayed for high risk human papillomavirus (HR-HPV) by Roche HPV Linear Array at enrollment and 24 months (intervention n=103, control n=107). Rate ratios (RR) of HR-HPV were estimated by Poisson regression. At 24 months, HR-HPV prevalence was intervention 55.3% and control 71.7% (RR=0.77, 95%CI 0.62–0.97). Multiple HR-HPV infections were intervention 22.4% and controls 42.5% (RR=0.53, 95%CI 0.33–0.83). New HR-HPV genotypes were acquired by 42.0% of intervention and 57.0% of control arm men (RR=0.74, 95%CI 0.54–1.01, p=0.06). Multiple new HR-HPV genotypes were acquired by 9.9% intervention and 24.7% control arm men (RR = 0.40, 95%CI 0.19–0.84, p = 0.01). Circumcision did not affect the acquisition of single HR-HPV infections (RR=1.00, 95%CI 0.65–1.53) or clearance of HR-HPV (RR=1.09, 95%CI 0.94–1.27). Circumcision of HIV+ men reduced the prevalence and incidence of multiple HR-HPV infections.
Uncircumcised HIV-negative men aged 15-49 years were randomized to immediate circumcision (n=441) or delayed circumcision (n=399). HPV was detected by Roche HPV Linear Array at enrollment, 6, 12 and 24 months. Incident HR-HPV was estimated in men who acquired a new HR-HPV genotype. HR-HPV clearance was determined in men with prior genotype-specific HR-HPV infections. Rate ratios (RR) and 95% confidence intervals (95%CI) of HR-HPV acquisition were estimated by Poisson multiple regression
Enrollment characteristics were comparable between groups. HR-HPV incidence was 19.7/100 py in the intervention (70/355.8 py) and 29.4/100 py (125/424.8 py) in the control arm (RR=0.67, 95%CI 0.51-0.89, p = 0.006.) The incidence of multiple HR-HPV infections was 6.7/100 py in the intervention and 14.8/100 py in control arm (RR = 0.45, 95%CI 0.28-0.73), but there was no significant effect on single infections (RR=0.89, 95%CI 0.60-1.30). HR-HPV incidence was lower in the intervention arm for all genotypes and demographic/behavioral subgroups. The clearance of pre-existing HR-HPV infections was 215.8/100py (205/95 py) in intervention and 159.1/100py (255/160.25 py) in control arm men (adjRR=1.39, 95%CI 1.17-1.64).
Male circumcision reduces the incidence of multiple HR-HPV infections and increases clearance of HR-HPV infections in HIV-uninfected men.
The trial was registered with ClinicalTrials.gov numbers NCT00425984
HIV-1 disease progression is associated with persistent immune activation. However, the nature of this association is incompletely understood. Here, we investigated immune activation in the CD4 T cell compartment of chronically HIV-1 infected individuals from Rakai, Uganda. Levels of CD4 T cell activation, assessed as co-expression of PD-1, CD38 and HLA-DR, correlated directly to viral load and inversely to CD4 count. Deeper characterization of these cells indicated an effector memory phenotype with relatively frequent expression of Ki67 despite their PD-1 expression, and levels of these cells were inversely associated with FoxP3+ regulatory T cells. We therefore use the term deregulated effector memory (DEM) cells to describe them. CD4 T cells with a DEM phenotype could be generated by antigen stimulation of recall responses in vitro. Responses against HIV-1 and CMV antigens were enriched among the DEM CD4 T cells in patients, and the diverse Vβ repertoire of DEM CD4 T cells suggested they include diverse antigen-specificities. Furthermore, the levels of DEM CD4 T cells correlated directly to soluble CD14 (sCD14) and IL-6, markers of innate immune activation, in plasma. The size of the activated DEM CD4 T cell subset was predictive of the rate of disease progression, whereas IL-6 was only weakly predictive and sCD14 was not predictive. Taken together, these results are consistent with a model where systemic innate immune activation and chronic antigen stimulation of adaptive T cell responses both play important roles in driving pathological CD4 T cell immune activation in HIV-1 disease.
Geographical inaccessibility, lack of transport, and financial burdens are some of the demand side constraints to maternal health services in Uganda, while supply side problems include poor quality services related to unmotivated health workers and inadequate supplies. Most public health interventions in Uganda have addressed only selected supply side issues, and universities have focused their efforts on providing maternal services at tertiary hospitals. To demonstrate how reforms at Makerere University College of Health Sciences (MakCHS) can lead to making systemic changes that can improve maternal health services, a demand and supply side strategy was developed by working with local communities and national stakeholders.
This quasi-experimental trial is conducted in two districts in Eastern Uganda. The supply side component includes health worker refresher training and additions of minimal drugs and supplies, whereas the demand side component involves vouchers given to pregnant women for motorcycle transport and the payment to service providers for antenatal, delivery, and postnatal care. The trial is ongoing, but early analysis from routine health information systems on the number of services used is presented.
Motorcyclists in the community organized themselves to accept vouchers in exchange for transport for antenatal care, deliveries and postnatal care, and have become actively involved in ensuring that women obtain care. Increases in antenatal, delivery, and postnatal care were demonstrated, with the number of safe deliveries in the intervention area immediately jumping from <200 deliveries/month to over 500 deliveries/month in the intervention arm. Voucher revenues have been used to obtain needed supplies to improve quality and to pay health workers, ensuring their availability at a time when workloads are increasing.
Transport and service vouchers appear to be a viable strategy for rapidly increasing maternal care. MakCHS can design strategies together with stakeholders using a learning-by-doing approach to take advantage of community resources.
To determine whether heterosexual transmission of HIV differs according to HIV-1 subtype
Retrospective observational cohort
HIV-1 subtype effects on heterosexual HIV-1 transmission were determined among 268 HIV-discordant couples retrospectively identified from a population cohort in Rakai, Uganda. HIV-1 subtype (gag & gp41 sequencing and MHA) and viral loads (RT-PCR) were determined. Adjusted incidence rate ratios (Adj.IRR) of HIV transmission by subtype were estimated by multivariable Poisson regression adjusting for characteristics of index HIV positive and negative partners.
Adjusting for index HIV positive partners age, viral load (VL), stage of disease, genital ulcer (GUD), and HIV negative partners GUD and non use of condoms, subtype A viruses were associated with a higher rate of transmission than subtype D (Adj.IRR, 1.98; 95% CI, 1.17-3.34), but no differences in transmission were observed between recombinant viruses and subtype D (adj. RR, 1.53, p=0.25). Index positive partners' age <30 years (Adj.IRR, 3.44; 95% CI, 1.75 - 6.78) and VL (Adj.IRR, 2.37; 95% CI, 1.75-3.21), and index negative partners GUD (Adj.IRR, 1.71; 95% CI, 1.08 - 2.70) and non
-use of condoms (Adj.IRR, 1.94, 95% CI, 1.15 - 3.28) were significant determinants of HIV transmission.
In Rakai, Uganda, subtype A viruses have a significantly higher rate of heterosexual transmission than subtype D viruses. Differential subtype transmission efficiency may be important for HIV vaccine evaluation and could contribute to subtype-specific HIV epidemics in sub-Saharan Africa.
HIV-1 subtype; discordant couples; HIV transmission; Uganda
To assess the association between hormonal contraceptive use and HIV progression.
A retrospective analysis of 625 female HIV seroconverters from a Ugandan cohort study.
Multivariate Cox regression analyses incorporating time-varying hormonal contraceptive exposure were used to estimate the adjusted hazard ratios of death, and a composite outcome of AIDS or death, associated with hormonal contraceptive use. Sensitivity analyses included lagging hormonal contraceptive exposure, varying comparison groups, and separately assessing effects of oral and injectable contraceptives.
A total of 27.5% of women reported ever using hormonal contraception. Of 625 women, 104 (16.6%) died and 291 (46.6%) progressed to AIDS or death during observation. Time-varying hormonal contraceptive use was not associated with an increased hazard of death as compared with nonuse of hormonal contraception (adjusted hazard ratio 0.76, 95% confidence interval 0.41–1.39, P = 0.37), and was associated with a significantly reduced hazard of progression to AIDS or death (adjusted hazard ratio 0.70, 95% confidence interval 0.50–0.97, P = 0.03). None of the sensitivity analyses suggested an adverse effect of hormonal contraception on HIV progression.
Hormonal contraceptive use was not associated with faster progression to death, and was associated with a reduced hazard of progression to the composite outcome of AIDS or death.
family planning; HIV progression; hormonal contraception; survival analysis; Uganda
A randomized trial of male circumcision (MC) was conducted among HIV-infected males to test the hypothesis that MC would reduce HIV transmission to female sexual partners.
This randomized, unblinded trial, conducted in Rakai District, Uganda, enrolled 922 uncircumcised, HIV-infected asymptomatic men aged 15–49 with CD4 counts ≥350. Men were randomly assigned to immediate circumcision (intervention) or circumcision delayed for 24 months (control). Concurrently enrolled HIV-negative female partners were followed up at 6, 12 and 24 months, to assess HIV acquisition by male MC assignment (primary outcome). An intention-to-treat analysis assessed women’s HIV acquisition using survival analysis and Cox proportional hazards modeling. The trial was registered in the Clinical Trials.gov Protocol Registration System (NCT00124878).
The trial was terminated for futility. Ninety three concurrently enrolled female partners of intervention arm men and 70 partners of control arm men provided follow up data. Cumulative probabilities of female HIV infection at 24 months were 21.7% (95% CI 12.7–33.4) in the intervention arm and 13.4% (95% CI 6.7–25.8) in the control arm (adjusted hazard ratio= 1.49, 95% CI 0.62–3.57, p = 0.368). At 6 months, intervention arm male-to-female transmission in couples who resumed intercourse ≥5 days prior to certified surgical wound healing was 27.8% (5/18), compared to 9.5% in couples who abstained longer post-surgically (6/63, p = 0.06) and 7.9% in control arm couples (5/63, p = 0.04)
Circumcision of HIV-infected men did not reduce HIV transmission to female partners over 24 months, and transmission risk may be increased with early post-surgical resumption of intercourse. Longer-term effects could not be assessed. Post surgical sexual abstinence and subsequent consistent condom are essential for HIV prevention.
Male circumcision; randomized trial; HIV-infected men; female HIV acquisition; Uganda
Data on the effect of HIV-1 viral subtype on CD4+ T-cell decline are limited.
We assessed the rate of CD4+ T-cell decline per year among 312 HIV seroincident persons infected with different HIV-1 subtypes. Rates of CD4+ decline by HIV-1 subtype were determined by linear mixed effects models, using an unstructured convariance structure.
A total of 59.6% had D, 15.7% A, 18.9% recombinant viruses (R), and 5.8% multiple subtypes (M). For all subtypes combined, the overall rate of CD4+ T-cell decline was −34.5 [95% confidence interval (CI), −47.1, −22.0] cells/μL per yr, adjusted for age, sex, baseline CD4+ counts, and viral load. Compared with subtype A, the adjusted rate of CD4 cell loss was −73.7/μL/yr (95% CI, −113.5, −33.8, P < 0.001) for subtype D, −43.2/μL/yr (95% CI, −90.2, 3.8, P = 0.072) for recombinants, and −63.9/μL/yr (95% CI, −132.3, 4.4, P = 0.067) for infection with multiple HIV subtypes. Square-root transformation of CD4+ cell counts did not change the results.
Infection with subtype D is associated with significantly faster rates of CD4+ T-cell loss than subtype A. This may explain the more rapid disease progression for subtype D compared with subtype A.
HIV-1 subtypes; rate of CD4+; cell decline; HIV disease progression
It has been hypothesized that HIV-1 viral load set-point is a surrogate measure of HIV-1 viral virulence, and that it may be subject to natural selection in the human host population. A key test of this hypothesis is whether viral load set-points are correlated between transmitting individuals and those acquiring infection. We retrospectively identified 112 heterosexual HIV-discordant couples enrolled in a cohort in Rakai, Uganda, in which HIV transmission was suspected and viral load set-point was established. In addition, sequence data was available to establish transmission by genetic linkage for 57 of these couples. Sex, age, viral subtype, index partner, and self-reported genital ulcer disease status (GUD) were known. Using ANOVA, we estimated the proportion of variance in viral load set-points which was explained by the similarity within couples (the ‘couple effect’). Individuals with suspected intra-couple transmission (97 couples) had similar viral load set-points (p = 0.054 single factor model, p = 0.0057 adjusted) and the couple effect explained 16% of variance in viral loads (23% adjusted). The analysis was repeated for a subset of 29 couples with strong genetic support for transmission. The couple effect was the major determinant of viral load set-point (p = 0.067 single factor, and p = 0.036 adjusted) and the size of the effect was 27% (37% adjusted). Individuals within epidemiologically linked couples with genetic support for transmission had similar viral load set-points. The most parsimonious explanation is that this is due to shared characteristics of the transmitted virus, a finding which sheds light on both the role of viral factors in HIV-1 pathogenesis and on the evolution of the virus.
During the long period of asymptomatic infection with HIV-1 there is considerable variability in viral load set-point between infected individuals. Higher viral load set-points increase infectivity and decrease survival. Previous work has shown that the most commonly observed viral load set-points are those intermediate viral load set-points which lead to the largest number of opportunities to transmit HIV-1 in an infectious person's lifetime, balancing survival and infectiousness. This coincidence between the most common viral load set-points and the optimum for lifetime transmission could be the result of population-level selection acting on HIV-1. However, this could only have happened if viral load set-point is a heritable characteristic of the virus, i.e. if viral load set-points are similar between both partners of transmitting couples. By studying viral load set-points amongst heterosexual couples, we show that viral load set-points are similar in these couples. When we study only those couples with strong genetic support for transmission, their viral loads are even more similar than when we study the whole group. These results suggest that there are viral factors which are passed from one infected individual to the next which play a role in determining viral load set-point and that population-level selection could act upon these viral factors.
Studies on long-term nonprogressors (LTNP) have been conducted in the USA and Europe. This study examined the frequency of LTNPs and HIV controllers among 637 HIV-1 seroconverters in rural Uganda.
Design and Methods
LTNPs were defined as being infected for more than 7 years with a CD4+ T-cell count above 600 cells per microliter, and HIV controllers as having undetectable viral loads on 3 separate occasions without antiretroviral treatment. HIV-1 viral load and subtype distribution between LTNP and non-LTNP populations were determined.
Of the HIV seroconverters, 9.1% (58/637) were LTNPs and 1.4% (9/637) were HIV controllers. LTNPs had a significantly lower viral load at set point than non-LTNP participants (P < 0.001). The Kaplan–Meier joint probability of surviving to 7 years with a CD4 count >600 was 19.2%. Individuals who survived 7 years had a significantly higher frequency of HIV-1 subtype A (P < 0.05), but seroconverters infected with HIV-1A did not have a significantly higher probability of becoming an LTNP.
The frequency of LTNPs appears to be relatively high in Uganda and it may be important to take this into account when designing studies of viral pathogenesis and performing HIV vaccine trials in sub-Saharan Africa.
Africa; HIV; HIV disease progression; long-term nonprogressors
To assess effects of male circumcision on female genital symptoms, and vaginal infections.
HIV-negative men enrolled in a trial were randomized to immediate or delayed circumcision (control arm). Genital symptoms, BV and trichomonas were assessed in HIV-negative wives of married participants. Adjusted prevalence risk ratios (adjPRR) and 95% confidence intervals (95%CI) were assessed by multivariable log-binomial regression, intent-to-treat analyses.
783 wives of control and 825 wives of intervention arm men were comparable at enrollment. BV at enrollment was higher in control (38.3%) than intervention arm spouses (30.5%, p=0.001). At one year follow up, intervention arm wives reported lower rates of genital ulceration (adjPRR 0.78, 95%CI 0.63–0.97), but there were no differences in vaginal discharge or dysuria. The risk of trichomonas was reduced in intervention arm wives (adjPRR 0.52, 95%CI 0.05–0.98), as were the risks of any BV (adjPRR 0.60, 95%CI 0.38–0.94) and severe BV (PRR = 0.39, 95%CI 0.24–0.64).
Male circumcision reduces the risk of ulceration, trichomonas and BV in female partners.
To analyze antiretroviral drug susceptibility in HIV from recently infected adults in Rakai, Uganda, prior to the availability of antiretroviral drug treatment.
Samples obtained at the time of HIV seroconversion (1998–2003) were analyzed using the GeneSeq HIV and PhenoSense HIV assays (Monogram Biosciences, Inc., South San Francisco, California, USA).
Test results were obtained for 104 samples (subtypes: 26A, 1C, 66D, 9A/D, 1C/D, 1 intersubtype recombinant). Mutations used for genotypic surveillance of transmitted antiretroviral drug resistance were identified in six samples: three had nucleoside reverse transcriptase inhibitor (NRTI) surveillance mutations (two had M41L, one had K219R), and three had protease inhibitor surveillance mutations (I47V, F53L, N88D); none had nonnucleoside reverse transcriptase inhibitor (NNRTI) surveillance mutations. Other resistance-associated mutations were identified in some samples. However, none of the samples had a sufficient number of mutations to predict reduced antiretroviral drug susceptibility. Ten (9.6%) of the samples had reduced phenotypic susceptibility to at least one drug (one had partial susceptibility to didanosine, one had nevirapine resistance, and eight had resistance or partial susceptibility to at least one protease inhibitor). Fifty-three (51%) of the samples had hypersusceptibility to at least one drug (seven had zidovudine hypersusceptibility, 28 had NNRTI hypersusceptibility, 34 had protease inhibitor hypersusceptibility). Delavirdine hyper-susceptibility was more frequent in subtype A than D. In subtype D, efavirenz hypersusceptibility was associated with substitutions at codon 11 in HIV-reverse transcriptase.
Phenotyping detected reduced antiretroviral drug susceptibility and hypersusceptibility in HIV from some antiretroviral-naive Ugandan adults that was not predicted by genotyping. Phenotyping may complement genotyping for analysis of antiretroviral drug susceptibility in populations with nonsubtype B HIV infection.
antiretroviral drug; hypersusceptibility; phenotype; resistance; subtype; Uganda