Prevalence of HIV antibody in high and low risk groups in England. Public Health Laboratory Service Working Group.

Most studies of the spread of HIV infection have centred on homosexuals and intravenous drug users. To estimate the extent of infection in different groups, including heterosexuals, the prevalence of HIV antibody was studied in 34,222 subjects tested with consent between October 1986 and December 1987 in England. These included subjects in high risk groups for HIV infection, heterosexuals with partners in the high risk groups and heterosexuals with multiple partners or with no identifiable risk factors. The prevalence was highest in homosexual or bisexual men in London (15.1%; 213/1412), being 4.0% (146/3607) outside London. The yearly incidence of infection in 632 homosexual or bisexual men without HIV antibody when retested during the study period was 3%. Among intravenous drug users the prevalence of HIV antibody was 5.7% (36/633) in London and 1.5% (39/2562) outside. Of 3272 heterosexual subjects tested, whose partner was in a risk group, eight of 515 (1.6%) in London and six of 2757 (0.2%) outside were positive for the antibody. Among 20,455 heterosexuals with a history of multiple partners or with no declared risk, only six subjects with HIV antibody were identified, two of whom had been infected abroad. Heterosexual spread of infection in England is evidently still largely confined to subjects whose partner has an identifiable risk.     

Epidemiology of HIV infection and AIDS in Croatia--an overview

This article presents an overview of HIV/AIDS epidemiology and surveillance in Croatia 20 years after the first documented case of AIDS in the country. Here we describe strategies employed for HIV/AIDS surveillance in Croatia as well as preliminary results of HIV seroprevalence among most-at-risk populations (MARPs) research conducted by the Infectious Diseases Epidemiology Service at the Croatian National Institute of Public Health (CNIPH). Croatia has a low incidence and prevalence of HIV and AIDS. At the end of 2005, there were 553 documented cases of HIV infection, 239 of which progressed to AIDS. In Croatia, AIDS is being registered within MARPs only and dominantly among men who have sex with men (MSM). AIDS patients and HIV infected persons are found in all parts of the country. Crude prevalence of HIV among MARPs was found to be 0.9%. It is necessary to continue with current prevention and control measures in the country, and to create a culture of awareness and precaution, a strategy that has proven effective in reducing risk of HIV infection.     

HIV Risk-Reduction Counseling and Testing on Behavior Change of MSM

HIV and AIDS incidence in China is high among men who have sex with men (MSM) and ours was one of few studies in China to evaluate the role of HIV risk reduction counseling and testing. Respondent-driven sampling (RDS) was used to recruit 430 MSM. Participants were followed up at 6, 12 and 18 months to evaluate behavioral changes after counseling to reduce risk behaviors. At baseline, HIV prevalence was 4.7%, whereas HIV incidence was 5.2 per 100 person-years. The incidence was 3.8 during six to 12 months, and 1.1 during 12 to 18 months. During the study period, the reported unprotected anal intercourse (UAI) significantly decreased from 60.9% to 42.9%. The proportion of participants who had one or no partner significantly increased from 40.9% to 48.0%. The study also found that some risk behaviors decreased between baseline and 12 months, followed by a slight increase between 12 and 18 months. Reductions in UAI can be achieved through counseling and testing, but may wane over time. Future programs should consider HIV risk-reduction counseling and testing for interventions in MSM in China.     

Risky behaviour and HIV prevalence among Zambian men

The objective of this paper is to identify demographic, social and behavioural risk factors for HIV infection among men in Zambia. In particular, the role of alcohol, condom use and number of sex partners is highlighted as being significant in the prevalence of HIV. Multivariate logistic regressions were used to analyse the latest cross-sectional population-based demographic health survey for Zambia (2007). The survey included socioeconomic variables and HIV serostatus for consenting men (N = 4434). Risk for HIV was positively related to wealth status. Men who considered themselves to be at high risk of being HIV positive were most likely to be HIV positive. Respondents who, along with their sexual partner, were drunk during the last three times they had sexual intercourse were more likely to be HIV positive (adjusted odds ratio (AOR) 1.60; 95% confidence interval (CI) 1.00-2.56). Men with more than two sexual life partners and inconsistent condom use had a higher risk for being HIV positive (OR 1.89, 95% CI 1.45-2.46; and OR 1.49, 95% CI 1.10-2.02, respectively). HIV prevention programmes in Zambia should focus even more on these behavioural risk factors.     

Trends in sexual behaviour and risk factors for HIV infection among homosexual men, 1984-7.

To assess whether the spread of infection with HIV can be reduced by changes in behaviour among groups most at risk because of their sexual practices sexual behaviour was monitored among 1050 homosexual men tested for HIV infection at a genitourinary medicine clinic in west London from November 1984 to September 1987. Four cohorts, defined by date of presentation, were studied by questionnaire at their presentation, and blood samples were analysed. Between the first and last cohorts there was a considerable fall in the proportion reporting casual relationships (291/329 (88%) v 107/213 (50%] and high risk activities, such as anoreceptive intercourse with casual partners (262/291 (90%) v 74/106 (70%], with the greatest changes occurring before the government information campaign began in 1986. Nevertheless, half of the men in the last cohort studied reported having casual partners. Multiple logistic regression showed that behavioural risk factors for HIV infection most closely resembled those for hepatitis B and that previous sexually transmitted diseases (syphilis, hepatitis B, and anogenital herpes) were themselves independent risk factors. A history of syphilis ranked above anoreceptive intercourse as the strongest predictor of HIV infection. Actively bisexual men showed a much lower prevalence of HIV infection (3/57, 5%) than exclusively homosexual men (113/375, 30%). Sexual behaviour among homosexual men changed during the period studied, and the incidence of HIV infection fell, although more education programmes directed at homosexual men are needed to re-emphasise the dangers of infection.     

Changes in sexual behaviour and the fall in incidence of HIV infection among homosexual men.

To investigate the epidemiology and normal course of infection with HIV the prevalence and incidence of the infection were studied among two cohorts of homosexual men in Amsterdam in 1980-7. The cumulative incidence of infection increased from a weighted 2.2% in 1980 to 39.0% in 1987. The estimated yearly incidence of HIV was 3.0% in 1981, rose to 8.8% in 1984, and fell gradually to 0% in 1987. During the study the sexual behaviour of the cohorts was examined. The number of men with whom anopenetrative intercourse was practised fell from a mean of 10.6 to 1.4 for those positive for HIV antibody, whereas the number with whom anoreceptive intercourse was practised fell from a mean of 3.7 to 0.5 for those negative for the antibody. In addition, there was a reduction in the number of cases of hepatitis B and syphilis among men in general. The decline in infection with HIV was assumed to be linked to changes in sexual behaviour. Such changes practised early in the course of the epidemic probably had a strong effect on the number of cases of AIDS among homosexual men in Amsterdam.     

Household-Based HIV Counseling and Testing as a Platform for Referral to HIV Care and Medical Male Circumcision in Uganda: A Pilot Evaluation

Background

Combination HIV prevention initiatives incorporate evidence-based, biomedical and behavioral interventions appropriate and acceptable to specific populations, aiming to significantly reduce population-level HIV incidence. Knowledge of HIV serostatus is key to linkages to HIV care and prevention. Household-based HIV counseling and testing (HBCT) can achieve high HIV testing rates. We evaluated HBCT as a platform for delivery of combination HIV prevention services in sub-Saharan Africa.

Methods

We conducted HBCT in a semi-urban area in southwestern Uganda. All adults received standard HIV prevention messaging. Real-time electronic data collection included a brief risk assessment and prevention triage algorithm for referrals of HIV seropositive persons to HIV care and uncircumcised HIV seronegative men with multiple sex partners to male circumcision. Monthly follow-up visits for 3 months were conducted to promote uptake of HIV care and male circumcision.

Results

855 households received HBCT; 1587 of 1941 (81.8%) adults were present at the HBCT visit, 1557 (98.1% of those present) were tested and received HIV results, of whom, 46.5% were men. A total of 152 (9.8%) were HIV seropositive, for whom the median CD4 count was 456 cells/µL, and 50.7% were newly-identified as HIV seropositive. Three months after HBCT, 88.5% of HIV seropositive persons had attended an HIV care clinic; among those with CD4 counts <250 cells/µL, 71.4% initiated antiretroviral therapy. Among 123 HIV seronegative men with an HIV+ partner or multiple partners, 62.0% were circumcised by month 3.

Conclusions

HBCT achieves high levels of knowledge of HIV serostatus and is an effective platform for identifying at-risk persons and achieving higher uptake of HIV prevention and care services through referrals and targeted follow-up than has been accomplished through other single focus strategies.     

High and persistent HIV seroincidence in men who have sex with men across 47 U.S. cities

Objective

To provide HIV seroincidence data among men who have sex with men (MSM) in the United States and to identify predictive factors for seroconversion.

Methods

From 1998–2002, 4684 high-risk MSM, age 18–60 years, participated in a randomized, placebo-controlled HIV vaccine efficacy trial at 56 U.S. clinical trial sites. Demographics, behavioral data, and HIV status were assessed at baseline and 6 month intervals. Since no overall vaccine efficacy was detected, data were combined from both trial arms to calculate HIV incidence based on person-years (py) of follow-up. Predictors of seroconversion, adjusted hazards ratio (aHR), were evaluated using a Cox proportional hazard model with time-varying covariates.

Results

Overall, HIV incidence was 2.7/100 py and was relatively uniform across study sites and study years. HIV incidence was highest among young men and men reporting unprotected sex, recreational drug use, and a history of a sexually transmitted infection. Independent predictors of HIV seroconversion included: age 18–30 years (aHR = 2.4; 95% CI 1.4,4.0), having >10 partners (aHR = 2.4; 95% CI 1.7,3.3), having a known HIV-positive male sex partner (aHR = 1.6; 95% CI 1.2, 2.0), unprotected anal intercourse with HIV positive/unknown male partners (aHR = 1.7; 95% CI 1.3, 2.3), and amphetamine (aHR = 1.6; 95% CI 1.1, 2.1) and popper (aHR = 1.7; 95% CI 1.3, 2.2) use.

Conclusions

HIV seroincidence was high among MSM despite repeated HIV counseling and reported declines in sexual risk behaviors. Continuing development of new HIV prevention strategies and intensification of existing efforts will be necessary to reduce the rate of new HIV infections, especially among young men.     

High Rates of HIV Seroconversion in Pregnant Women and Low Reported Levels of HIV Testing among Male Partners in Southern Mozambique: Results from a Mixed Methods Study

Introduction

Prevention of acute HIV infections in pregnancy is required to achieve elimination of pediatric HIV. Identification and support for HIV negative pregnant women and their partners, particularly serodiscordant couples, are critical. A mixed method study done in Southern Mozambique estimated HIV incidence during pregnancy, associated risk factors and factors influencing partner''s HIV testing.

Methods

Between April 2008 and November 2011, a prospective cohort of 1230 HIV negative pregnant women was followed during pregnancy. A structured questionnaire, HIV testing, and collection of dried blood spots were done at 2–3 scheduled visits. HIV incidence rates were calculated by repeat HIV testing and risk factors assessed by Poisson regression. A qualitative study including 37 individual interviews with men, women, and nurses and 11 focus group discussions (n = 94) with men, women and grandmothers explored motivators and barriers to uptake of male HIV testing.

Results

HIV incidence rate was estimated at 4.28/100 women-years (95%CI: 2.33–7.16). Significant risk factors for HIV acquisition were early sexual debut (RR 3.79, 95%CI: 1.04–13.78, p = 0.04) and living in Maputo Province (RR 4.35, 95%CI: 0.97–19.45, p = 0.05). Nineteen percent of women reported that their partner had tested for HIV (93% knew the result with 8/213 indicating an HIV positive partner), 56% said their partner had not tested and 19% did not know their partner test status. Of the 14 seroconversions, only one reported being in a serodiscordant relationship. Fear of discrimination or stigma was reported as a key barrier to male HIV testing, while knowing the importance of getting tested and receiving care was the main motivator.

Conclusions

HIV incidence during pregnancy is high in Southern Mozambique, but knowledge of partners'' HIV status remains low. Knowledge of both partners'' HIV status is critical for maximal effectiveness of prevention and treatment services to reach elimination of pediatric HIV/AIDS.     

Determinants of human immunodeficiency virus (HIV) prevalence in homosexual and bisexual men screened for admission to a cohort study of HIV negatives in Belo Horizonte,Brazil: Project Horizonte

Project Horizonte, an open cohort of homosexual and bisexual human immunodeficiency virus (HIV-1) negative men, is a component of the AIDS Vaccine Program, in Belo Horizonte, Minas Gerais, Brazil. The objective of this study was to compare volunteers testing HIV positive at cohort entry with a sample of those who tested HIV negative in order to identify risk factors for prevalent HIV infection, in a population being screened for enrollment at Project Horizonte. A nested case-control study was conducted. HIV positive volunteers at entry (cases) were matched by age and admission date to three HIV negative controls each. Selected variables used for the current analysis included demographic factors, sexual behavior and other risk factors for HIV infection. During the study period (1994-2001), among the 621 volunteers screened, 61 tested positive for HIV. Cases were matched to 183 HIV negative control subjects. After adjustments, the main risk factors associated with HIV infection were unprotected sex with an occasional partners, OR = 3.7 (CI 95% 1.3-10.6), receptive anal intercourse with an occasional partner, OR = 2.8 (95% CI 0.9-8.9) and belonging to the negro racial group, OR = 3.4 (CI 95% 1.1-11.9). These variables were associated with an increase in the risk of HIV infection among men who have sex with men at the screening for admission to an open HIV negative cohort.     

Circumcision of male children for reduction of future risk for HIV: acceptability among HIV serodiscordant couples in Kampala, Uganda

Introduction

The ultimate success of medical male circumcision for HIV prevention may depend on targeting male infants and children as well as adults, in order to maximally reduce new HIV infections into the future.

Methods

We conducted a cross-sectional study among heterosexual HIV serodiscordant couples (a population at high risk for HIV transmission) attending a research clinic in Kampala, Uganda on perceptions and attitudes about medical circumcision for male children for HIV prevention. Correlates of willingness to circumcise male children were assessed using generalized estimating equations methods.

Results

318 HIV serodiscordant couples were interviewed, 51.3% in which the female partner was HIV uninfected. Most couples were married and cohabiting, and almost 50% had at least one uncircumcised male child of ≤18 years of age. Overall, 90.2% of male partners and 94.6% of female partners expressed interest in medical circumcision for their male children for reduction of future risk for HIV infection, including 79.9% of men and 87.6% of women who had an uncircumcised male child. Among both men and women, those who were knowledgeable that circumcision reduces men''s risk for HIV (adjusted prevalence ratio [APR] 1.34 and 1.14) and those who had discussed the HIV prevention effects of medical circumcision with their partner (APR 1.08 and 1.07) were significantly (p≤0.05) more likely to be interested in male child circumcision for HIV prevention. Among men, those who were circumcised (APR 1.09, p = 0.004) and those who were HIV seropositive (APR 1.09, p = 0.03) were also more likely to be interested in child circumcision for HIV prevention.

Conclusions

A high proportion of men and women in Ugandan heterosexual HIV serodiscordant partnerships were willing to have their male children circumcised for eventual HIV prevention benefits. Engaging both parents may increase interest in medical male circumcision for HIV prevention.     

A Qualitative Exploration of Sexual Risk and HIV Testing Behaviors among Men Who Have Sex with Men in Beirut,Lebanon

Men who have sex with men (MSM) may account for most new HIV infections in Lebanon, yet little is known about the factors that influence sexual risk behavior and HIV testing in this population. Qualitative interviews were conducted with 31 MSM living in Beirut, and content analysis was used to identify emergent themes. Mean age of the participants was 28.4 years, and all identified as either gay (77%) or bisexual (23%). Half reported not using condoms consistently and one quarter had not been HIV-tested. Many described not using condoms with a regular partner in the context of a meaningful relationship, mutual HIV testing, and a desire to not use condoms, suggesting that trust, commitment and intimacy play a role in condom use decisions. Condoms were more likely to be used with casual partners, partners believed to be HIV-positive, and with partners met online where men found it easier to candidly discuss HIV risk. Fear of infection motivated many to get HIV tested and use condoms, but such affect also led some to avoid HIV testing in fear of disease and social stigma if found to be infected. Respondents who were very comfortable with their sexual orientation and who had disclosed their sexuality to family and parents tended to be more likely to use condoms consistently and be tested for HIV. These findings indicate that similar factors influence the condom use and HIV testing of MSM in Beirut as those observed in studies elsewhere of MSM; hence, prevention efforts in Lebanon can likely benefit from lessons learned and interventions developed in other regions, particularly for younger, gay-identified men. Further research is needed to determine how prevention efforts may need to be tailored to address the needs of men who are less integrated into or do not identify with the gay community.     

Controlling HIV Epidemics among Injection Drug Users: Eight Years of Cross-Border HIV Prevention Interventions in Vietnam and China

Introduction

HIV in Vietnam and Southern China is driven by injection drug use. We have implemented HIV prevention interventions for IDUs since 2002–2003 in Lang Son and Ha Giang Provinces, Vietnam and Ning Ming County (Guangxi), China.

Methods

Interventions provide peer education and needle/syringe distribution. Evaluation employed serial cross-sectional surveys of IDUs 26 waves from 2002 to 2011, including interviews and HIV testing. Outcomes were HIV risk behaviors, HIV prevalence and incidence. HIV incidence estimation used two methods: 1) among new injectors from prevalence data; and 2) a capture enzyme immunoassay (BED testing) on all HIV+ samples.

Results

We found significant declines in drug-related risk behaviors and sharp reductions in HIV prevalence among IDUs (Lang Son from 46% to 23% [p<0.001], Ning Ming: from 17% to 11% [p = 0.003], and Ha Giang: from 51% to 18% [p<0.001]), reductions not experienced in other provinces without such interventions. There were significant declines in HIV incidence to low levels among new injectors through 36–48 months, then some rebound, particularly in Ning Ming, but BED-based estimates revealed significant reductions in incidence through 96 months.

Discussion

This is one of the longest studies of HIV prevention among IDUs in Asia. The rebound in incidence among new injectors may reflect sexual transmission. BED-based estimates may overstate incidence (because of false-recent results in patients with long-term infection or on ARV treatment) but adjustment for false-recent results and survey responses on duration of infection generally confirm BED-based incidence trends. Combined trends from the two estimation methods show sharp declines in incidence to low levels. The significant downward trends in all primary outcome measures indicate that the Cross-Border interventions played an important role in bringing HIV epidemics among IDUs under control. The Cross-Border project offers a model of HIV prevention for IDUs that should be considered for large-scale replication.     

Estimating HIV pre-exposure prophylaxis need and impact in Malawi,Mozambique and Zambia: A geospatial and risk-based analysis

BackgroundPre-exposure prophylaxis (PrEP), a WHO-recommended HIV prevention method for people at high risk for acquiring HIV, is being increasingly implemented in many countries. Setting programmatic targets, particularly in generalised epidemics, could incorporate estimates of the size of the population likely to be eligible for PrEP using incidence-based thresholds. We estimated the proportion of men and women who would be eligible for PrEP and the number of HIV infections that could be averted in Malawi, Mozambique, and Zambia using prioritisation based on age, sex, geography, and markers of risk.Methods and findingsWe analysed the latest nationally representative Demographic and Health Surveys (DHS) of Malawi, Mozambique, and Zambia to determine the proportion of adults who report behavioural markers of risk for HIV infection. We used prevalence ratios (PRs) to quantify the association of these factors with HIV status. Using a multiplier method, we combined these proportions with the number of new HIV infections by district, derived from district-level modelled HIV estimates. Based on these numbers, different scenarios were analysed for the minimum number of person-years on PrEP needed to prevent 1 HIV infection (NNP).An estimated total of 38,000, 108,000, and 46,000 new infections occurred in Malawi, Mozambique, and Zambia in 2016, corresponding with incidence rates of 0.43, 0.63, and 0.57 per 100 person-years. In these countries, 9%–20% of new infections occurred among people with a sexually transmitted infection (STI) in the past 12 months and 40%–42% among people with either an STI or a non-regular sexual partner (NP) in the past 12 months (STINP). The models estimate that around 50% of new infections occurred in districts with incidence rates ≥1.0% in Mozambique and Zambia and ≥0.5% in Malawi. In Malawi, Mozambique, and Zambia, 35.1%, 21.9%, and 12.5% of the population live in these high-incidence districts. In the most parsimonious scenario, if women aged 15–34 years and men 20–34 years with an STI in the past 12 months living in high-incidence districts were to take PrEP, it would take a minimum of 65.8 person-years on PrEP to avert 1 HIV infection per year in Malawi, 35.2 in Mozambique, and 16.4 in Zambia. Our findings suggest that 3,300, 5,200, and 1,700 new infections could be averted per year in the 3 countries, respectively. Limitations of our study are that these values are based on modelled estimates of HIV incidence and self-reported behavioural risk factors from national surveys.ConclusionsA large proportion of new HIV infections in these 3 African countries were estimated to occur among people who had either an STI or an NP in the past year, providing a straightforward means to set PrEP targets. Greater prioritisation of PrEP by district, sex, age, and behavioural risk factors resulted in lower NNPs thereby increasing PrEP cost-effectiveness, but also diminished the overall impact on reducing new infections

Dominik Stelzle and co-workers estimate impact of antiretroviral pre-exposure prophylaxis use on HIV infections in 3 African countries.     

Efficient Identification of HIV Serodiscordant Couples by Existing HIV Testing Programs in South Brazil

Objective

To examine the feasibility of identifying HIV negative at risk individuals in HIV serodiscordant couples, during voluntary HIV testing in South Brazil.

Methods

We surveyed HIV testers at 4 public testing sites in Rio Grande do Sul. We obtained information on risk behaviors and sexual partnerships. HIV testing and testing for recent infection were performed; HIV prevalence and risk behaviors were assessed among subjects who reported having a steady partner who was HIV positive (serodiscordant group) and compared with the general testing population.

Results

Among 3100 patients, 490 (15.8%) reported being in a steady relationship with an HIV positive partner. New HIV infections were diagnosed in 23% of the serodiscordant group (vs. 13% in the general population, p = 0.01); among newly positive subjects, recent HIV infections were more frequent (23/86, 26.7%) among testers with positive partners than among the general testing group (52/334; 15.6%; p = 0.016). Less than half of the serodiscordant testers reported having used a condom during the last sexual intercourse with their HIV-positive partner. Participants with inconsistent condom use with steady partner were four times more likely to test positive for HIV compared to those who reported always using condoms with the steady partner (OR: 4.2; 95% CI: 2.3 to 7.5).

Conclusion

It is highly feasible to identify large numbers of HIV susceptible individuals who are in HIV serodiscordant relationships in South Brazil testing sites. Condom use within HIV serodiscordant couples is low in this setting, suggesting urgent need for biomedical prevention strategies to reduce HIV transmission.     

Risk factors for male to female transmission of HIV. European Study Group.

OBJECTIVE--To identify risk factors for sexual transmission of HIV from infected men to their female sexual partners. DESIGN--Cross sectional analysis as part of a continuing study. Data were obtained by interviewing heterosexual couples in which the man was infected with HIV. Risks were assessed by comparing couples in which transmission had occurred (woman infected with HIV) with those in which it had not (woman not infected) and estimated by independent odds ratios and their 95% confidence intervals. SETTING--Infectious disease and public health departments from nine centres in six European countries. PARTICIPANTS--153 Male index patients (mean age 30.4 years) and their 155 female partners (mean age 27.8 years). INTERVENTIONS--Women were tested to determine their HIV antibody state. Women with a risk of infection with HIV other than sexual contact with their infected partner were excluded. END POINT--Three risk factors for male to female transmission of HIV. MEASUREMENTS AND MAIN RESULTS--Three risk factors were identified: a history of sexually transmitted disease in the previous five years for the female partner (odds ratio 3.1, 95% confidence interval 1.1 to 8.6); index patient with full blown AIDS (5.4, 1.2 to 25.2); and practice of anal intercourse (5.8, 2.3 to 14.8). The proportion of women positive for HIV antibody was 27% (42/155), ranging from 7% (1 to 13%) (4/60) for couples with none of the three risk factors to 67% (45 to 89%) (12/18) for those with two or three of the risk factors. Duration of the relationship (median three years), frequency of sexual contacts, sexual practices other than anal intercourse, and contraceptive behaviour were not associated with infection of the partner. CONCLUSIONS--The risk of sexual transmission of HIV from an infected man to his female partner varies considerably according to the characteristics of the couple. The differences in rates of transmission in high risk groups may be considerably reduced if the risk factors are taken into account during individual and public health counselling.     

Incident HIV during Pregnancy and Postpartum and Risk of Mother-to-Child HIV Transmission: A Systematic Review and Meta-Analysis

Background

Women may have persistent risk of HIV acquisition during pregnancy and postpartum. Estimating risk of HIV during these periods is important to inform optimal prevention approaches. We performed a systematic review and meta-analysis to estimate maternal HIV incidence during pregnancy/postpartum and to compare mother-to-child HIV transmission (MTCT) risk among women with incident versus chronic infection.

Methods and Findings

We searched PubMed, Embase, and AIDS-related conference abstracts between January 1, 1980, and October 31, 2013, for articles and abstracts describing HIV acquisition during pregnancy/postpartum. The inclusion criterion was studies with data on recent HIV during pregnancy/postpartum. Random effects models were constructed to pool HIV incidence rates, cumulative HIV incidence, hazard ratios (HRs), or odds ratios (ORs) summarizing the association between pregnancy/postpartum status and HIV incidence, and MTCT risk and rates. Overall, 1,176 studies met the search criteria, of which 78 met the inclusion criterion, and 47 contributed data. Using data from 19 cohorts representing 22,803 total person-years, the pooled HIV incidence rate during pregnancy/postpartum was 3.8/100 person-years (95% CI 3.0–4.6): 4.7/100 person-years during pregnancy and 2.9/100 person-years postpartum (p = 0.18). Pooled cumulative HIV incidence was significantly higher in African than non-African countries (3.6% versus 0.3%, respectively; p<0.001). Risk of HIV was not significantly higher among pregnant (HR 1.3, 95% CI 0.5–2.1) or postpartum women (HR 1.1, 95% CI 0.6–1.6) than among non-pregnant/non-postpartum women in five studies with available data. In African cohorts, MTCT risk was significantly higher among women with incident versus chronic HIV infection in the postpartum period (OR 2.9, 95% CI 2.2–3.9) or in pregnancy/postpartum periods combined (OR 2.3, 95% CI 1.2–4.4). However, the small number of studies limited power to detect associations and sources of heterogeneity.

Conclusions

Pregnancy and the postpartum period are times of persistent HIV risk, at rates similar to “high risk” cohorts. MTCT risk was elevated among women with incident infections. Detection and prevention of incident HIV in pregnancy/postpartum should be prioritized, and is critical to decrease MTCT. Please see later in the article for the Editors'' Summary     

Bayesian Spatial Semi-Parametric Modeling of HIV Variation in Kenya

Spatial statistics has seen rapid application in many fields, especially epidemiology and public health. Many studies, nonetheless, make limited use of the geographical location information and also usually assume that the covariates, which are related to the response variable, have linear effects. We develop a Bayesian semi-parametric regression model for HIV prevalence data. Model estimation and inference is based on fully Bayesian approach via Markov Chain Monte Carlo (McMC). The model is applied to HIV prevalence data among men in Kenya, derived from the Kenya AIDS indicator survey, with n = 3,662. Past studies have concluded that HIV infection has a nonlinear association with age. In this study a smooth function based on penalized regression splines is used to estimate this nonlinear effect. Other covariates were assumed to have a linear effect. Spatial references to the counties were modeled as both structured and unstructured spatial effects. We observe that circumcision reduces the risk of HIV infection. The results also indicate that men in the urban areas were more likely to be infected by HIV as compared to their rural counterpart. Men with higher education had the lowest risk of HIV infection. A nonlinear relationship between HIV infection and age was established. Risk of HIV infection increases with age up to the age of 40 then declines with increase in age. Men who had STI in the last 12 months were more likely to be infected with HIV. Also men who had ever used a condom were found to have higher likelihood to be infected by HIV. A significant spatial variation of HIV infection in Kenya was also established. The study shows the practicality and flexibility of Bayesian semi-parametric regression model in analyzing epidemiological data.     

HIV Prevention in Care and Treatment Settings: Baseline Risk Behaviors among HIV Patients in Kenya,Namibia, and Tanzania

HIV care and treatment settings provide an opportunity to reach people living with HIV/AIDS (PLHIV) with prevention messages and services. Population-based surveys in sub-Saharan Africa have identified HIV risk behaviors among PLHIV, yet data are limited regarding HIV risk behaviors of PLHIV in clinical care. This paper describes the baseline sociodemographic, HIV transmission risk behaviors, and clinical data of a study evaluating an HIV prevention intervention package for HIV care and treatment clinics in Africa. The study was a longitudinal group-randomized trial in 9 intervention clinics and 9 comparison clinics in Kenya, Namibia, and Tanzania (N = 3538). Baseline participants were mostly female, married, had less than a primary education, and were relatively recently diagnosed with HIV. Fifty-two percent of participants had a partner of negative or unknown status, 24% were not using condoms consistently, and 11% reported STI symptoms in the last 6 months. There were differences in demographic and HIV transmission risk variables by country, indicating the need to consider local context in designing studies and using caution when generalizing findings across African countries. Baseline data from this study indicate that participants were often engaging in HIV transmission risk behaviors, which supports the need for prevention with PLHIV (PwP).

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01256463","term_id":"NCT01256463"}}NCT01256463