Effect of HIV-1 subtypes on disease progression in rural Uganda: a prospective clinical cohort study.

OBJECTIVE: We examined the association of HIV-1 subtypes with disease progression based on three viral gene regions. DESIGN: A prospective HIV-1 clinical cohort study in rural Uganda. METHODS: Partial gag, env and pol genes were sequenced. Cox proportional hazard regression modelling was used to estimate adjusted hazard ratios (aHRs) of progression to: CD4≤250, AIDS onset and death, adjusted for sex, age and CD4 count at enrolment. RESULTS: Between 1990 and 2010, 292 incident cases were subtyped: 25% had subtype A, 45% had D, 26% had A/D recombinants, 1% had C and 4% were other recombinant forms. Of the 278 incident cases included in the disease progression analysis, 62% progressed to CD4≤250, 32% to AIDS, and 34% died with a higher proportion being among subtype D cases. The proportions of individuals progressing to the three endpoints were significantly higher among individuals infected with subtype D. Throughout the study period, individuals infected with subtype D progressed faster to CD4≤250, adjusted HR (aHR), (95% CI) = 1.72 (1.16-2.54), but this was mainly due to events in the period before antiretroviral therapy (ART) introduction, when individuals infected with subtype D significantly progressed faster to CD4≤250 than subtype A cases; aHR (95% CI) = 1.78 (1.01-3.14). CONCLUSIONS: In this population, HIV-1 subtype D was the most prevalent and was associated with faster HIV-1 disease progression than subtype A. Further studies are needed to examine the effect of HIV-1 subtypes on disease progression in the ART period and their effect on the virological and immunological ART outcomes.

Effect of pregnancy on immunological and virological outcomes of women on ART: a prospective cohort study in rural Uganda, 2004-2009.

OBJECTIVES: Before antiretroviral therapy (ART) introduction, pregnancy was associated with a sustained drop in CD4 cell count in HIV-infected women. We examined the effects of pregnancy on immunological and virological ART outcomes. METHODS: Between January 2004 and March 2009, we studied HIV-infected women receiving ART in a prospective open cohort study in rural Uganda. We used random effects regression models to compare the CD4 counts of women who became pregnant and those who did not, and among the pregnant women before and after pregnancy. CD4 count and proportions with detectable viral load (≥400 copies/ml) were compared between the two groups using the Mann-Whitney rank sum test and logistic regression respectively. RESULTS: Of 88 women aged 20-40 years receiving ART, 23 became pregnant. At ART initiation, there were no significant differences between those who became pregnant and those who did not in clinical, immunological and virological parameters. Among women who became pregnant, CD4 cell count increased before pregnancy (average 75.9 cells/mm(3) per year), declined during pregnancy (average 106.0) but rose again in the first year after delivery (average 88.6). Among women who did not become pregnant, the average CD4 cell count rise per year for the first 3 years was 88.5. There was no significant difference in the proportions of women with detectable viral load at last clinic visit among those who became pregnant (8.7%) and those who did not (16.1%), P = 0.499. CONCLUSION: Pregnancy had no lasting effect on the immunological and virological outcomes of HIV-infected women on ART.

Using verbal autopsy to assess the prevalence of HIV infection among deaths in the ART period in rural Uganda: a prospective cohort study, 2006-2008.

BACKGROUND: Verbal autopsy is important for detecting causes of death including HIV in areas with inadequate vital registration systems. Before antiretroviral therapy (ART) introduction, a verbal autopsy study in rural Uganda found that half of adult deaths assessed were in HIV-positive individuals. We used verbal autopsy to compare the proportion of HIV-positive adult deaths in the periods before and after ART introduction. METHODS: Between 2006 and 2008, all adult (≥ 13 years) deaths in a prospective population-based cohort study were identified by monthly death registration, and HIV serostatus was determined through annual serosurveys. A clinical officer interviewed a relative of the deceased using a verbal autopsy questionnaire. Two clinicians independently reviewed the questionnaires and classified the deaths as HIV-positive or not. A third clinician was the tie-breaker in case of nonagreement. The performance of the verbal autopsy tool was assessed using HIV serostatus as the gold standard of comparison. We compared the proportions of HIV-positive deaths as assessed by verbal autopsy in the early 1990s and the 2006-2008 periods. RESULTS: Of 333 deaths among 12,641 adults of known HIV serostatus, 264 (79.3%) were assessed by verbal autopsy, of whom 59 (22.3%) were HIV-seropositive and 68 (25.8%) were classified as HIV-positive by verbal autopsy. Verbal autopsy had a specificity of 90.2% and positive predictive value of 70.6% for identifying deaths among HIV-infected individuals, with substantial interobserver agreement (80.3%; kappa statistic = 0.69). The HIV-attributable mortality fraction estimated by verbal autopsy decreased from 47.0% (pre-ART period) to 25.8% (ART period), p < 0.001. CONCLUSIONS: In resource-limited settings, verbal autopsy can provide a good estimate of the prevalence of HIV infection among adult deaths. In this rural population, the proportion of deaths identified by verbal autopsy as HIV-positive declined between the early 1990s and the 2006-2008 period. Verbal autopsy findings can inform policy on HIV health care needs.

Coreceptor and cytokine concentrations may not explain differences in disease progression observed in HIV-1 clade A and D infected Ugandans.

BACKGROUND: The use of cellular coreceptors and modulation of cytokine concentrations by HIV to establish a productive infection is well documented. However, it is unknown whether the expression of these proteins affects the course of HIV clade A and D disease, reported to have different progression rates. METHODOLOGY/PRINCIPAL FINDINGS: We investigated whether the number of CD4(+) T-cells expressing CCR5 or CXCR4, the density of these coreceptors and concentrations of specific immune proteins linked to HIV pathogenesis vary between individuals infected with HIV clade A or D. We undertook additional analyses stratifying participants by early (CD4>500 cells/µl) or late (CD4<200 cells/µl) disease stage. Whole blood samples were taken from 50 HIV-1 infected individuals drawn from cohorts in rural south-west Uganda. Late stage participants had less than half the number of CD4(+)/CCR5(+) T-cells (p = 0.0113) and 5.6 times fewer CD4(+)/CXCR4(+) cells (p<0.0001) than early stage participants. There was also a statistically significant difference in the density of CXCR4 on CD4(+) cells between clade A and D infected early stage participants (142 [A] vs 84 [D]; p = 0.0146). Across all participants we observed significantly higher concentration of Th(1) cytokines compared to Th(2) (66.4 vs 23.8 pg/ml; p<0.0001). Plasma concentrations of IFNγ and IL-2 were 1.8 and 2.4 fold lower respectively in Late-D infected participants compared to Late-A participants. MIP-1ß levels also decreased from 118.0 pg/ml to 47.1 pg/ml (p = 0.0396) as HIV disease progressed. CONCLUSIONS/SIGNIFICANCE: We observed specific alterations in the abundance of CD4(+)/CCR5(+) and CD4(+)/CXCR4(+) T-cells, and concentrations of immune proteins across different HIV clades and as infection progresses. Our results suggest that these changes are unlikely to explain the observed differences in disease progression between subtype A and D infections. However, our observations further the understanding of the natural progression of non-clade B HIV infection and how the virus adapts to exploit the host environment.

HIV-1 seroprevalence and risk factors for HIV infection among first-time psychiatric admissions in Uganda.

This study investigated HIV seroprevalence and it's correlates among patients with first-time psychiatric admissions to two national referral hospitals in urban Kampala, Uganda. A structured standardised evaluation was used to assess patients for: Diagnostic and Statistical Manual IV psychiatric diagnosis, socio-demographics, sexual behaviour and HIV status (for those HIV-positive, CDC classification and CD4 cell counts). The HIV-1 seroprevalence was 18.4% (95% CI, 13.8-23.0%). Factors that were independently associated with HIV-1 seropositivity were female gender and older age (41+years) and after adjusting for sex and age group, the nature of the current episode (highest among those with first episode of mental illness) and psychiatric diagnoses (highest in the organic affective disorders and delirium, lowest in those with bipolar affective disorder and psychotic syndromes). These results demonstrate that the prevalence of HIV is high among patients with severe mental illness in Africa and that HIV/AIDS adds to the burden of mental illness in high HIV prevalence countries in sub-Saharan Africa. Both HIV care programmes and psychiatric care clinics should be made aware of the frequent association of HIV infection and mental illness, and adopt important diagnostic and care elements of these complementary disciplines in the training and the day-to-day work of clinicians, nurses and counsellors.

Antiretroviral therapy and sexual behavior in Uganda: a cohort study.

OBJECTIVE: To assess evidence for sexual behavior change in response to antiretroviral therapy (ART) among members of a Ugandan clinical cohort. Secondarily, to examine factors associated with both sexual behavior and ART independently, that may help to assess the impact that ART is likely to have on the HIV epidemic. DESIGN: Retrospective analysis of data from an open cohort. METHODS: ART roll-out began in the cohort in 2004. Using 3-monthly data from 2002 to 2009, we conducted regression and descriptive analyses to examine associations between timing of ART initiation and sexual behavior among HIV-infected, and timing of ART availability and sexual behavior among HIV-uninfected. We also examined partner turnover rates, and the proportion of HIV-infected on ART - two important factors for modeling the potential impact of ART on the HIV epidemic. RESULTS: Risky sexual behavior among HIV-infected people rose on several indicators after ART initiation, but not to levels higher than two or more years before initiation. Some evidence suggests that the availability of ART may impact risky behavior among HIV-uninfected people, although this was inconsistent across different reported behavior variables. CONCLUSION: The HIV-uninfected is larger than the HIV-infected population. If risky behavior among this population increases due to the feeling of safety that ART provides, this will affect the impact of ART on the HIV epidemic. Policy makers are urged to intensify messages associating sexual behavior and HIV and to target both HIV-infected and uninfected people.

HIV prevalence and incidence are no longer falling in southwest Uganda: evidence from a rural population cohort 1989-2005.

BACKGROUND: Throughout the 1990s, HIV-1 prevalence and incidence were falling in Uganda. Recently, some researchers have noticed that HIV-1 prevalence is levelling off. We examine prevalence, incidence, and sexual behaviour trends in a rural population cohort in Uganda over 16 years. METHODS: We report prevalence by survey round and incidence by calendar year from a prospective general population cohort study. Using logistic regression Wald tests, we examined casual partners, condom use, and pregnancies. We examined age at sexual debut by means of life tables. RESULTS: HIV-1 prevalence declined from 8.5% in 1990/1991 to 6.2% in 1999/2000, and thereafter rose to 7.7% in 2004/2005. Incidence (per 1000 person-years at risk) fell from 7.5 in 1990 to 4.1 in 1998, and thereafter increased to 5.0 by 2004. The 2005 incidence estimate reached an all-time low of 2.5, but the preliminary 2006 estimate shows a rise again. Incidence trends varied by age and sex. Some sexual behaviour indicators showed more risky behaviour in recent years compared with the 1990s, whereas others indicated that the reduction in risky behaviour that began in the 1990s continues. CONCLUSION: HIV-1 prevalence is rising in this cohort. Incidence is stabilizing, and shows signs of increasing among some subgroups. The extent to which changing sexual behaviour has played a role in these epidemiological trends is unclear, but it is likely to have contributed. To solidify the success that Uganda had throughout the 1990s in controlling the HIV epidemic, the efforts in HIV prevention need to be re-strengthened, using all strategies known.

Duration from seroconversion to eligibility for antiretroviral therapy and from ART eligibility to death in adult HIV-infected patients from low and middle-income countries: collaborative analysis of prospective studies.

BACKGROUND: Estimation of the number of people in need of antiretroviral therapy (ART) in resource-limited settings requires information on the time from seroconversion to ART eligibility and from ART eligibility to death. OBJECTIVES: To estimate duration from seroconversion to different ART eligibility criteria and from ART eligibility to death in HIV-infected adults in low-income and middle-income countries. METHODS: Participants with documented seroconversion from five cohorts (two cohorts from Uganda, two from Thailand and one from Côte d'Ivoire) were analysed. We used Weibull survival models and Bayesian simulation methods to model true (unobserved) first time of treatment eligibility. We set a consistency constraint so that the mean duration from seroconversion to death was equal to the mean from seroconversion to ART eligibility plus the mean from eligibility to death. RESULTS: We analysed data from 2072 participants, 16 157 person-years of follow-up and 794 deaths. For the criterion CD4 T-lymphocyte count <200 cells x10(6)/l, the median duration from seroconversion to ART eligibility was 6.1 years (95% credibility interval 3.3-10.4) for all studies and 7.6 years (95% credibility interval 3.4-15.2) for all but the Thai cohorts. Corresponding estimates for the time from CD4 T-lymphocyte count <200 cells x10(6)/l to death were 2.1 years (0.7-4.8) and 2.7 years (0.8-8.4). When including all cohorts, the mean time from serconversion to CD4 T-lymphocyte count <200 cells x10(6)/l and from CD4 T-lymphocyte count <200 cells x10(6)/l to death represented 66% (38-87%) and 34% (13-62%), respectively of the total survival time. CONCLUSIONS: The duration of different ART eligibility criteria to death was longer than the estimates used in previous calculations of the number of people needing ART. However, uncertainty in estimates was considerable and heterogeneity across cohorts important.

Anaemia in a rural Ugandan HIV cohort: prevalence at enrolment, incidence, diagnosis and associated factors.

OBJECTIVES: To determine the prevalence and incidence of anaemia in HIV-positive and negative individuals; to identify risk factors for anaemia, prior to the introduction of HAART; and to determine the validity of the clinical diagnosis of anaemia. METHODS: Between 1990 and 2003, we followed a rural population based cohort of HIV-infected and uninfected participants. Prevalence and incidence of anaemia were determined clinically and by laboratory measurements. The sensitivity, specificity and predictive values of clinical diagnosis were calculated. RESULTS: The prevalence of anaemia at enrolment was 18.9% among HIV-positive and 12.9% among HIV-negative participants (P = 0.065). Incidence of anaemia increased with HIV disease progression, from 103 per 1000 person-years of observation among those with CD4 counts >500 to 289 per 1000 person-years of observation among those with CD4 counts <200. Compared to laboratory diagnosis, the clinical diagnosis of anaemia had a sensitivity of 17.8%, specificity of 96.8%, a positive predictive value of 50.6% and a negative predictive value of 86.4%. Being female, low CD4 cell counts, HIV-positive, wasting syndrome, WHO stage 3 or 4, malaria, fever, pneumonia and oral candidiasis were associated with prevalent anaemia. CONCLUSIONS: Anaemia prevalence and incidence were higher among HIV-positive than negative participants. Compared to laboratory diagnosis, clinical detection of anaemia had a low sensitivity. Clinicians working in settings with limited laboratory support must be conscious of the risk of anaemia when managing HIV/AIDS patients, particularly when using antiretroviral drugs which by themselves may cause anaemia as a side effect. We recommend that haemoglobin should be measured before starting ART and monthly for the first three months.

HIV-1 disease progression and mortality before the introduction of highly active antiretroviral therapy in rural Uganda.

OBJECTIVE: To provide estimates of survival and progression to different HIV disease endpoints after HIV infection among adults in a rural Ugandan setting. DESIGN: A prospective population-based cohort study. METHODS: Eligible individuals at least 15 years of age with documented HIV seroconversion were recruited from a general population cohort in rural Uganda, along with a randomly selected proportion of HIV-prevalent and HIV-negative individuals. All participants were followed up every 3 months, and CD4 cell counts taken every 6 months in HIV-positive participants. Life tables and Kaplan-Meier functions were used to estimate survival patterns for all endpoints [death, time to World Health Organization (WHO) stage 2, 3, AIDS and CD4 cell count < 200 cells/mul]. Analysis of follow-up time was truncated when antiretroviral therapy (ART) became available in the area in January 2004. RESULTS: We recruited 240 HIV incident cases, 108 prevalent cases and 257 HIV-negative controls. Crude mortality rates were 70.0 per 1000 person-years in HIV-positive, and 12.1 per 1000 person-years in HIV-negative individuals. The median time from seroconversion to death was 9.0 years (N = 240) and 6.2 years to a CD4 cell count less than 200 cells/mul or WHO stage 4 (N = 229). The median time from ART eligibility (CD4 cell count < 200 cells/mul, < 350 cells/mul and WHO stage 3, or WHO stage 4) to death was 34.7 months. Older age at seroconversion was a risk factor for faster progression to death and ART eligibility. CONCLUSION: HIV progression in this African cohort is similar to that reported in industrialized countries before the widespread introduction of ART.

HIV incidence and recent injections among adults in rural southwestern Uganda.

Thirty-six incident HIV cases were matched for age, sex and time period with 36 controls to examine associations with recent injections. A significant association between HIV incidence and a history of injections was detected that was not reduced after adjusting for available sexual behaviour variables. This association could either be the result of injections causing HIV infection or, more likely, injections for seroconversion illnesses or other consequences of unsafe sex.

Estimating 'net' HIV-related mortality and the importance of background mortality rates.

OBJECTIVES: To estimate mortality directly attributable to HIV in HIV-infected adults in low and middle income countries and discuss appropriate methodology. DESIGN: : Illustrative analysis of pooled data from six studies across sub-Saharan Africa and Thailand with data on individuals with known dates of seroconversion to HIV. METHODS: Five of the studies also had data from HIV-negative subjects and one had verbal autopsies. Data for HIV-negative cohorts were weighted by the initial age and sex distribution of the seroconverters. Using the survival of the HIV-negative group to represent the background mortality, net survival from HIV was calculated for the seroconverters using competing risk methods. Mortality from all causes and 'net' mortality were modelled using piecewise exponential regression. Alternative approaches are explored in the dataset without information on mortality of uninfected individuals. RESULTS: The overall effect of the net mortality adjustment was to increase survivorship proportionately by 2 to 5% at 6 years post-infection. The increase ranged from 2% at ages 15-24 to 22% in those 55 and over. Mortality rate ratios between sites were similar to corresponding ratios for all-cause mortality. CONCLUSION: Differences between HIV mortality in different populations and age groups are not explained by differences in background mortality, although this does appear to contribute to the excess at older ages. In the absence of data from uninfected individuals in the same population, model life tables can be used to calculate background rates.

Genotypic variation in the pol gene of HIV type 1 in an antiretroviral treatment-naive population in rural southwestern Uganda.

The majority of studies of HIV-1 drug resistance have involved subtype B viruses. Here we have characterized subtype distribution and determined the levels of polymorphism at protease (PR) and reverse transcriptase (RT) drug resistance positions, in antiretroviral treatment-naive HIV-positive Ugandan patients. We have also investigated codon usage variability at these positions and assessed intersubtype recombination within the pol gene. The study population consisted of 187 patients, from a cohort established by the UK Medical Research Council Programme on AIDS in Uganda in 1990. Results indicate that 28.3% of patients were infected with subtype A (n = 53), 64.2% subtype D (n = 120), 6.4% A/D recombinant (n = 12), and 1.1% subtype C (n = 2). Variation in amino acid usage at drug resistance-associated positions was minimal between the two main subtypes (A and D) in RT, but there was appreciable variation in PR. Codon usage, however, was considerably more variable between subtypes A and D in both PR and RT. Thus, while no natural high-level resistance to antiretroviral therapy was detected in this cohort, subtypes A and D may possess different genetic barriers to be overcome in order to achieve resistance. With the increasing introduction of antiretroviral therapy into Africa, such information will be vital in our understanding and evaluation of the development of drug resistance as it occurs, and how to interpret resistance data the type of which has rarely previously been seen. This analysis also significantly increases the number of Ugandan PR and RT sequences characterized to date.

HIV-1 disease progression and fertility: the incidence of recognized pregnancy and pregnancy outcome in Uganda.

OBJECTIVES: To estimate the association between HIV disease progression and the incidence of recognized pregnancy; to estimate the risk of subsequent fetal loss. METHODS: A total of 191 women (92 HIV seropositive and 99 HIV seronegative at enrolment) aged 15-49 years in an HIV clinical cohort were invited to attend routine clinic visits every 3 months. Information on HIV progression collected at the visit was related to whether there was a pregnancy beginning in the following 3 months. Visits were excluded where the woman was already pregnant, lactating, using modern contraceptives or if there was inadequate follow-up. RESULTS: There were 2524 eligible visits and 216 recognized pregnancies. The reported frequency of sexual intercourse diminished with advancing HIV disease. The adjusted odds ratio (OR) for pregnancy when the woman was in WHO stage 1 compared with HIV seronegatives was 0.58 [95% confidence interval (CI), 0.36-0.93]; stage 2, 0.47 (95% CI, 0.25-0.91); stage 3, 0.43 (95% CI, 0.25-0.74); and stage 4, (AIDS) 0.14 (95% CI, 0.02-1.09). The findings were similar for CD4 cell count, time from seroconversion and time before AIDS. There was an increase in fetal loss from the early stages of HIV infection (adjusted OR for stage 1, 5.38; 95% CI, 1.57-18.44), there were very few recognized pregnancies in the advanced stages. CONCLUSIONS: Fertility is reduced from the earliest asymptomatic stage of HIV infection resulting from both a reduced incidence of recognized pregnancy and increased fetal loss. The greatest reduction in fertility was observed following progression to AIDS when there was a very low incidence of recognized pregnancies.

Failure of targeted urban supplemental measles vaccination campaigns (1997-1999) to prevent measles epidemics in Mozambique (1998-2001).

This study assessed the effect of urban supplemental measles vaccination campaigns (1997-1999) in Mozambique that targeted children aged 9-59 months. Reported measles cases were analyzed to the end of 2001 to determine campaign impact. Hospital inpatient data were collected in the national capital and in three provincial capitals where epidemics occurred the year after the campaigns. Measles epidemics followed campaigns in the capital city, in 4 of 9 provincial capitals, and in 39 of 126 districts. Reasons for limited campaign impact included a low proportion of urban dwellers, the geographic location of some provincial capitals, the limited target age group, and low routine and campaign coverage. Routine immunization and disease surveillance should be strengthened and campaigns must achieve >90% coverage and target wider age groups and geographic areas in order to reach a high proportion of persons susceptible to measles.