Rising HIV Prevalence Research Articles

Rising HIV Prevalence Among Married and Unmarried Among Men Who Have Sex with Men: Jinan, China

We report on two waves of bio-behavioral surveillance of MSM in Jinan, Shandong Province, China. HIV prevalence rose from 0.05% in 2007 to 3.1% in 2008. Differences in the two waves of surveys were noted, particularly with respect to marital status, requiring stratified analysis. In multivariable analysis, unmarried, homosexually identified MSM who do not have female sex partners have a greater than sixfold greater chance of being infected with HIV compared to married, non-homosexually identified MSM who do have female partners. Carefully targeted and population-specific messages will be needed for homosexually identified and non-identified MSM in China.

The Evolution of Tuberculosis Virulence

The evolution of Mycobacterium tuberculosis presents several challenges for public health. HIV and resistance to antimycobacterial medications have evolutionary implications for how Mycobacterium tuberculosis will evolve, as these factors influence the host environment and transmission dynamics of tuberculosis strains. We present an evolutionary invasion analysis of tuberculosis that characterizes the direction of tuberculosis evolution in the context of different natural and human-driven selective pressures, including changes in tuberculosis treatment and HIV prevalence. We find that the evolution of tuberculosis virulence can be affected by treatment success rates, the relative transmissibility of emerging strains, the rate of reactivation from latency among hosts, and the life expectancy of hosts. We find that the virulence of tuberculosis strains may also increase as a consequence of rising HIV prevalence, requiring faster case detection strategies in areas where the epidemics of HIV and tuberculosis collide.

Large sharing networks and unusual injection practices explain the rapid rise in HIV among IDUs in Sargodha, Pakistan

BackgroundOf the nearly 100,000 street-based IDUs in Pakistan, 20% have HIV. We investigated the recent rise in HIV prevalence from 12 to 52% among IDUs in Sargodha despite > 70% coverage with syringe exchanges.MethodsWe interviewed approximately 150 IDUs and 30 outreach workers in focus group discussions.ResultsWe found six rural and 28 urban injecting locations. Urban locations have about 20–30 people at any time and about 100 daily; rural locations have twice as many (national average: 4–15). About half of the IDUs started injecting within the past 2 years and are not proficient at injecting themselves. They use street injectors, who have 15–16 clients daily. Heroin is almost exclusively the drug used. Most inject 5–7 times daily.Nearly all injectors claim to use fresh syringes. However, they load, inject and share using a locally developed method called scale. Most Pakistani IDUs prefer to double pump drug the syringe, which allows mixing of blood with drug in the syringe. The injector injects 3 ml and keeps 2 ml (the scale) as injection fee. The injector usually pools all the leftover scale (now with some blood mixed with drug) either for his own use or to sell it. Most IDUs backload the scale they buy into their own fresh syringes.DiscussionUse of an unprecedented method of injecting drugs that largely bypasses fresh syringes, larger size of sharing networks, higher injection frequency and near universal use of street injectors likely explain for the rapid rise in HIV prevalence among IDUs in Sargodha despite high level provision of fresh syringes. This had been missed by us and the national surveillance, which is quantitative. We have addressed this by hiring injectors as peer outreach workers and increasing syringe supply. Our findings highlight both the importance of qualitative research and operations research to enrich the quality of HIV prevention programs.

Uptake of voluntary counselling and testing for HIV by pregnant women in a prevention-of-mother-to-child-transmission programme at Aminu Kano Teaching Hospital, Nigeria

Mother-to-child transmission is the main mode of HIV infection among children in developing countries. In 2003, as a result of government policy, a prevention-of-mother-to-child-transmission (PMTCT) programme was introduced at Aminu Kano Teaching Hospital in Nigeria. The aim of this study was to determine the pattern of voluntary counselling and testing (VCT) uptake and HIV seroprevalence among pregnant women using the service. VCT has become part of routine antenatal care at the hospital; in addition, antiretroviral prophylaxis/treatment, modification of obstetric practices, and counselling on infant feeding options are provided for HIV-positive pregnant women. Data on clients' socio-demographic characteristics, VCT uptake, and HIV seropositivity for a three-year period (from January 2004 to December 2006) were taken from nationally prepared PMTCT registers kept at the hospital, and prospectively entered into a database. During the period, 6 887 women newly accessed antenatal care (i.e. repeat pregnancies were excluded). All the women were group counselled, and 6 702 (97.3%) agreed to undergo HIV testing. Overall HIV prevalence among these pregnant women for the study period was 5.9% (95% CI 5.2–6.3%). The data have shown a statistically significant trend of rising HIV prevalence in this group: at 4.5%, prevalence was lowest in 2004; rose to 4.9% in 2005; and peaked at 7.6% in 2006 (χ2 trend = 21.9; p < 0.001). Overall HIV seroprevalence was 3.5% among 15- to 19-year-old women, 7% among 25- to 29-year-old women, and 4.5% among women over age 40. There was an inverse relationship between parity (number of children borne) and HIV seroprevalence such that women of low parity had high HIV prevalence, and vice versa (χ2 trend = 13.1; p < 0.01). Respectively, 11.4%, 5.7%, and 5.5% of the pregnant women first using VCT in the first, second, and third trimesters of their pregnancy were found to be HIV-positive. All women testing HIV-positive were informed of their serostatus and the modes of preventing mother-to-child transmission of HIV. There is a relatively high uptake of VCT for PMTCT at this tertiary hospital, while an increasingly higher proportion of HIV-positive pregnant women are being identified and provided with opportunities to prevent HIV transmission to their babies. PMTCT should be universally accessible to women in developing countries.

Shift of preference of location for sexual partnership in men having sex with men in an Asian population

In Hong Kong, heterosexual transmission has long been the major mode of HIV spread. Reported HIV infection has, however, gradually risen in men who have sex with men (MSM), overtaking heterosexual contacts in men as the main route of HIV transmission after the year 2004. A survey in 2006/ 2007 confirmed that 4% of tested MSM were positive for HIV antibody. Engaging in unsafe sex is often considered the reason behind the rising HIV prevalence in MSM. To understand the dynamics of HIV transmission in Hong Kong, we conducted a study to explore the partnership pattern of MSM before their HIV diagnosis. In the 8-week period between November 2006 and January 2007, 121 HIV-positive Chinese MSM attending a specialist clinic were successfully interviewed. Overall, 53 (46.1%) were infected during or before 2000, whereas 62 (53.9%) were infected afterwards. Using the same cut-off year, the age of infection was higher (33.7 v. 30.1, t= –2.02, P< 0.05) in those infected after v. during or before 2000. There was in general a 1–2 year lag period between infection and diagnosis, a phenomenon that has not changed over years. A Likert scale was used to assess mixing pattern and sexual activities. A majority indicated that their sex partners were people of similar age (72%) or not more than 10 years older or younger. A higher proportion of older individuals above the age of 38 had sex partners more than 10 years younger (27.9% v. 10.3% odds ratio [OR] 3.35; 95% confidence interval [CI] 1.22–9.23), but there has been no change after 2000. Over 90% expressed that they largely (Likert scale 4–6) had sex with local Chinese. There was no demonstrable difference in the pattern of mixing in terms of age and ethnicity, between those infected during or before and after 2000. The type of sexual activities was assessed. There was no statistically significant difference during or before and after 2000 in the proportion of respondents who practised anal sex (54.7% v. 62.9%), oral sex (79.2% v. 83.9%) and/or masturbation (84.9% v. 85.5%) predominantly (Likert scale 4–6). The use of a condom for anal sex has remained the same (64.2% v. 68.3%), whereas that for oral sex has, however, declined (21.2% v. 9.8%, OR= 2.2, P < 0.05). Similarly, the proportion of those admitting the use of soft drugs has increased (39.6% v. 53.2%, OR= 1.73, P < 0.05) after 2000. Table 1 shows the distribution of locations that MSM in our study population used for sourcing partners and for sex. The internet has become one of the most important modes of becoming acquainted with sex partners after 2000 (45.2% v. 7.5% OR= 10.09, P< 0.05). The frequency of anal sex was higher in internet users (71.4% v. 50.8%, OR= 2.41, P < 0.05), but there was no difference in the use of condom for both anal and oral sex. Interestingly, the respondents’ home has now stood as one of the most popular locations for sex for those infected after 2000 (26.4% v. 45.2%, OR= 2.29, P < 0.05). In this study we observed major changes in the networking pattern of Chinese MSM in Hong Kong, a phenomenon that might have predated the rising HIV prevalence. Apparently, the Table 1. Comparison of locations for sexual partnership in men who have sex with men between two time periods – those infected with HIV in 2000 or before and others in 2001 or after *P < 0.05

Treatment outcome of TB/HIV positive and TB/HIV negative patients on directly observed treatment, short course (DOTS) in Sagamu, Nigeria

The World Health Organisation marked 10 years of implementation of Directly Observed Treatment short course (DOTS). One key factor affecting the success of the DOTS strategy is the rising HIV prevalence among TB patients. The study was embarked upon to compare the treatment outcome of TB/HIV positive and TB/HIV negative patients in Sagamu, Nigeria. A prospective study of 353 smear positive TB patients aged 15 years and above who were registered for 8 months anti-tuberculosis (DOTS) therapy between January 2001 and December 2003 at the Olabisi Onabanjo University Teaching Hospital, Sagamu, Nigeria. Treatment outcome indicators of cure, default, transfer to another district and death were assessed in relation to the HIV status of the patients. There were 353 eligible patients of which 58 (16.4%) were HIV positive. The clinical symptoms and signs of TB were similar in both HIV positive and negative TB patients. The cure rate was 76.8%.patients. The cure rate was significantly lower in HIV infected compared with non-HIV infected TB patients (60.3% v 80.0%;p = 0.0001). However, among survivors it was not significant (71.4% v 82.5%; p = 0.07). Overall mortality was 5.1% which was significantly higher in HIV positive compared to HIV negative TB patients (15.5% v 3.1%; p = 0.00007). On the whole, 17% defaulted treatment and 1.1% failed treatment. These were however not significantly related to HIV status. The cure rate in this study is still lower than the recommended 85% target by the WHO. Mortality rate in TB/HIV positive patients was higher than in HIV negative patients. The option of a community based TB programme using volunteers or family members to supervise administration of anti-TB drugs so as to ensure adherence to TB treatment may be considered.

HIV/AIDS in Ethiopia: where is the epidemic heading?

Objectives: A possible decline in prevalence of HIV in some sub-Saharan African countries has been reported recently. The present study aimed to evaluate the prevalence and incidence of HIV and...

Current trends in Rwanda’s HIV/AIDS epidemic

Objective: To review the trajectory of Rwanda’s HIV epidemic, including long term trends and more recent trends in HIV prevalence, markers of HIV incidence, and behavioural indicators. Methods: This paper...

The changing pattern of bloodstream infections associated with the rise in HIV prevalence in northeastern Thailand

A survey of bloodstream infections was conducted in the large regional hospital in Ubon Ratchatani, northeastern Thailand between 1989 and 1998, during the onset of the HIV epidemic. The incidence of Staphylococcus aureus, Escherichia coli, Klebsiella/Enterobacter and Pseudomonas aeruginosa bacteraemias remained constant whereas infections caused by Burkholderia pseudomallei, non-typhoid Salmonellae, Cryptococcus neoformans, Penicillum marneffei and to a lesser extent Streptococcus pneumoniae all rose. Burkholderia pseudomallei infections were unrelated to HIV, whereas the other infections were associated directly with HIV. Group D non-typhoid Salmonellae bloodstream infections (mainly Salmonella enteritidis) rose coincident with the increase in HIV seroprevalence, and preceded the increase in the other HIV-associated infections. Other non-typhoid Salmonella bacteraemias increased two years after the rise in group D infections, and invasive yeast infections increased four years later, coincident with the increase in AIDS. Increasing Group D non-typhoid Salmonella bloodstream infections are an early warning signal of an impending rise in AIDS.

HIV prevalence in pregnant women in an ethnically diverse population in the UK: 1998-2002.

To describe trends in the prevalence of HIV in an ethnically diverse population of pregnant women in the United Kingdom. Data on parental country of birth from national birth registration records were linked to neonatal dried blood spot samples routinely collected for neonatal screening in the North Thames region between 1998 and 2002. Identifiers were subsequently irreversibly deleted prior to establishing maternal HIV status by testing the neonatal samples. A total of 491 213 dried blood spot samples were collected, and 490 879 (99.93%) were tested for HIV. Of these, 1029 were seropositive. There was an overall significant increasing trend (P-value = 0.001) between 1998 and 2002. Maternal region of birth was available for 89.8% of HIV-infected samples, and, among these, 80.5% of mothers were born in sub-Saharan Africa and 11.1% in the UK. The highest prevalences of HIV were in women born in sub-Saharan Africa (2.09%). If both parents were born in the UK, overall seroprevalence was 0.016%. HIV infection in pregnant women in the UK continues to occur predominantly in women born in sub-Saharan Africa with prevalence in this group increasing significantly. Although the absolute number of HIV-infected women rose in some other groups, there was no evidence for a statistically significant rise in HIV prevalence in women born outside sub-Saharan Africa. Over 93% of children at risk of vertical transmission of HIV had at least one parent born abroad. This paper underlines the value of data linkage in monitoring HIV prevalence in a diverse population.

Epidemiological and demographic HIV/AIDS projections: South Africa

The Epidemic Projection Package (EPP) recently developed by the UNAIDS Reference Group on Estimates, Models and Projections and the Spectrum model program developed by the Futures Group were used to model the South African HIV epidemic, project future trends in HIV/AIDS and estimate the demographic impact of AIDS. The national HIV prevalence surveys among pregnant women from 1990–2001 and the first national, population-based HIV survey in 2002 served as the data sets used to calibrate the input HIV prevalence values for the model. The scenario created by the model showed that a dramatic rise in HIV prevalence during the 1990s has peaked in 2002 with 4.69 million infected people and it is projected that the epidemic in South Africa has now begun to level off. Adult (15–49 years) incidence rates have decreased substantially in the past five years since 1997 (4.2%) and are expected to reach a level of 1.7% in 2003. The annual number of deaths due to AIDS is projected to peak with 487 320 AIDS deaths in the year 2008. By 2020, the total population of South Africa is expected to be 23% smaller than it would be without AIDS, however, a negative population growth rate is not expected during the projection period. Life expectancy at birth is expected to hit a low of 45.6 years in the time period 2005–2010, which is 22 years less than it would have been in the absence of AIDS. Ten years from now over 2.5 million AIDS orphans are projected for South Africa. Models play an important role in estimating HIV variables that are difficult to measure. Projections of the future HIV/AIDS burden in South Africa underscore the importance of acting now to reduce the number of new infections and plan for medical and social care needs.

Sexual mixing patterns and sex-differentials in teenage exposure to HIV infection in rural Zimbabwe

HIV-1 prevalence typically rises more rapidly at young ages in women than in men in sub-Saharan Africa. Greater susceptibility to infection on exposure in women is believed to be a contributory factor as is greater exposure to previously infected sexual partners of the opposite sex. We investigated the latter hypothesis using data from a field study in rural Manicaland, Zimbabwe. Quantitative data on onset and degree of sexual activity, numbers of partners, concurrent partnerships, condom use, and partner characteristics were used in conjunction with epidemiological data on age and sex specific prevalence of HIV infection to do statistical analyses of association between key variables. Mathematical models and qualitative data were used to aid analysis and interpretation. Older age of sexual partner was associated with increased risk of HIV-1 infection in men (odds ratio 1.13 [95% CI 1.02-1.25]) and women (1.04 [1.01-1.07]). Young women form partnerships with men 5-10 years older than themselves, whereas young men have relationships with women of a similar age or slightly younger. Greater number of lifetime partners is also associated with increased risk of HIV (1.03 [1.00-1.05]). Young men report more partners than do women but infrequent coital acts and greater use of condoms. These behaviour patterns are underpinned by cultural factors including the expectation that women should marry earlier than men. A strong gender effect remains after factors that affect exposure to infected partners are controlled for (6.04 [1.49-24.47]). The substantial age difference between female and male sexual partners in Manicaland is the major behavioural determinant of the more rapid rise in HIV prevalence in young women than in men. Theoretical studies have suggested that this difference is an important determinant of observed epidemiological patterns but the study reported in this paper provides clear empirical evidence of association.

Cost-effectiveness of the Mpowerment Project, a community-level intervention for young gay men.

Previous evaluation demonstrated that the Mpowerment Project community-level intervention for young gay men reduces HIV risk behaviors. The current analysis was undertaken to estimate the intervention's health and economic outcomes. We conducted a retrospective cost-effectiveness analysis. We estimated HIV infections averted, the gain in quality-adjusted life years (QALYs), cost per infection averted, and net cost. Using a population-level model, we portrayed two epidemic scenarios: the first with stable HIV prevalence and the other with rising HIV prevalence. Inputs included behavior change resulting from the intervention and program cost data. Cost was calculated from three perspectives: societal; societal excluding volunteer time; and that of a community-based organization (CBO). Outcomes were calculated for 1, 5 (baseline), and 20 years. The Mpowerment Project averted an estimated 2.0 to 2.3 HIV infections in the first year (according to the epidemic scenario), 5.0 to 6.2 over 5 years, and 9.2 to 13.1 over 20 years. The societal cost per HIV infection averted was estimated at between $14,600 and $18,300 over 5 years. Costs per infection averted were 28% lower when excluding volunteer time and 35% lower from the CBO perspective. Net savings were $700,000 to $900,000 over 5 years from the societal perspective. The Mpowerment Project is cost-effective compared with many other HIV prevention strategies. The cost per HIV infection prevented is far less than the lifetime medical costs of HIV disease.

The Impact and Cost-Effectiveness of HIV Prevention Strategies in Sub-Saharan Africa: Comparative Analysis of Four Intervention Strategies in Three Randomized trials.

Background and Rationale: Resources for HIV prevention are limited, and policy makers urgently need reliable information on the impact and cost-effectiveness of alternative control strategies. Objectives: To provide information on the cost-effectiveness of alternative HIV control strategies in a range of population settings in rural Africa. Methods: Three randomized trials investigating the impact on HIV of four intervention strategies have been published or are in progress in Mwanza (Tanzania), Masaka (Uganda), and Rakai (Uganda). Cost data from the three trials are being standardized, and the cost and impact of the intervention strategies are being compared. Comparisons of impact are complicated by variations in HIV/STD prevalence and other differences between the three study populations. To address this problem, the microsimulation model STDSIM is being fitted to the extensive data from the three trials in order to predict the impact of the different control strategies within each population. Results: Preliminary modeling work investigating the impact of a single round of mass treatment (MT) in a rural African population with a low but rising HIV prevalence (Mwanza, Tanzania) predicts that MT would achieve a steep and significant decline in STD prevalence and HIV incidence. In the first 2 years of the simulated interventions MT reduced HIV incidence by 36% compared to 30% with improved syndromic treatment. Conclusions: STDSIM has been successfully applied to field data from rural Africa and used to predict the effects of intervention strategies. Further development of the model is underway to facilitate the comparative analysis of intervention studies, and work continues on the application of the model to data from the East African trials.

HIV-1 seroprevalence among childbearing women in northern Thailand: monitoring a rapidly evolving epidemic.

To describe trends in prevalence of HIV-1 infection among women giving birth at Chiang Rai Hospital (CRH) and to assess risk factors associated with HIV infection in this population. Analysis of hospital registry data for all deliveries at CRH from 1990 to mid-1997. From 1990 to mid-1997, women giving birth at CRH were tested for HIV-1 infection using enzyme immunoassay (EIA); positive sera were confirmed using a different manufacturer's EIA. Demographic and clinical data were abstracted from delivery-ward log books. Data from 40723 deliveries indicated that overall HIV-1 seroprevalence increased sharply, from 1.3% in 1990 to a peak of 6.4% in 1994, and then declined to 4.6% in the first 6 months of 1997. Prevalence was highest, at 7.0%, among young (age < or = 24 years) primigravidas, compared with 2.4% among older (age > or = 25 years) multigravidas. When we controlled for age, prevalence declined 40% from 1994 to 1997 among young primigravidas (95% confidence interval for percentage reduction, 16-57). Amongst older multigravid women, prevalence was consistently lower but increased steadily from 2.7% in 1994 to 3.4% in 1997. A rapid rise in HIV prevalence in childbearing women was followed by a sharp decline among young primigravidas. In each year, the prevalence was highest among young primigravidas. They may be the best subgroup of pregnant women for monitoring HIV epidemic trends, but they also represent a challenging prevention priority that will require its own targeted interventions.