HIV prevalence and lifetime risk of dying of AIDS

The paper examines the relationship between the lifetime risk of dying from AIDS and HIV prevalence, using a female stable population model in which the epidemic has stabilized. In addition to prevalence, lifetime risk is determined by various other factors, notably the level of mortality from causes other than AIDS, age at infection, and survival time between infection and death. Typically, the lifetime risk of dying from AIDS is between three and five times the HIV prevalence. Regression equations are developed for estimating lifetime risk from the prevalence and other parameters. The methods are applied to data for Kenya, and it is shown that the 1995 prevalence estimate of 7.5 per cent for the population aged 15 and over would be equivalent to a lifetime risk of about 30 per cent

Animal Conservation and Human Survival: A Case Study of The Tembomvura People of Chapato Ward In The Zambezi Valley, Zimbabwe

This paper describes the predicament of the Tembomvura, a clan of hunter-gatherers dwelling in the Northern Zambezi valley in Zimbabwe, who find their traditional activities strongly circumscribed by the CAMPFIRE programme which regulates the use of wildlife resources in the area. Their expectations and their evaluation of the programme are presented and contrasted with the functioning of the programme as described by information gathered from other interested parties in the area and some of the CAMPFIRE officials. An attempt is made to formulate a critical evaluation of the programme in this area based on its theory and assumptions. The implications of the negative perceptions of the Tembomvura for the future success of the programme are also considered.The Population Counci

Postpartum uptake of contraception in rural northern Malawi: A prospective study.

OBJECTIVES: Cross-sectional estimates of contraceptive use do not provide understanding of time to postpartum uptake. This paper uses a range of Malawian data sources: a prospective study to explore time to uptake of contraception and a cross-sectional survey to assess whether sexually active postpartum women whose fecundity has returned use contraception, and whether abstaining/amenorrheic women report using contraception. STUDY DESIGN: A demographic surveillance site (DSS) in Malawi was used to identify 7393 women aged 15-49 years eligible for a 1-year prospective study of contraception using provider-recorded data on patient-held records (2012-2013). This provided a reliable record of time to uptake of postpartum contraception. The average timing of resumption of sexual activities after postpartum abstinence and return of menses was estimated from a population-based sexual behaviour survey in the DSS (2010-2011). RESULTS: Of 4678 women recruited to the prospective contraception study, 442 delivered an infant during the observation period. Of these, 28.4% used modern contraception within 6 months of delivery. However, at 6-9 months after delivery, only 28.0% women had started menstruation and resumed sexual activities; of these, 77.6% used contraception. Amongst abstaining/amenorrheic women, a quarter reported contraceptive use. CONCLUSIONS: The low uptake of postpartum contraception is likely due to many women abstaining and/or experiencing amenorrhea. Self-reports of contraceptive use amongst abstaining/amenorrheic women bring into question the quality of cross-sectional surveys and demonstrate that contraceptive use by women at low risk of pregnancy could contribute to the Malawi paradox of high contraceptive use and high fertility. Given relatively low risk of pregnancy in the postpartum period in this context, a focus on long-acting/permanent methods may be more effective to avert unintended pregnancies. IMPLICATIONS: There has been increasing interest in the utility of postpartum contraceptive programmes to assist women to space births. Our findings suggest that, although uptake of contraception is low, this is partly due to postpartum abstinence and amenorrhea. Provision of long-acting/permanent methods will be more effective for women after delivery

Adjusting the HIV prevalence for non-respondents using mortality rates in an open cohort in northwest Tanzania.

OBJECTIVE: To estimate HIV prevalence in adults who have not tested for HIV using age-specific mortality rates and to adjust the overall population HIV prevalence to include both tested and untested adults. METHODS: An open cohort study was established since 1994 with demographic surveillance system (DSS) and five serological surveys conducted. Deaths from Kisesa DSS were used to estimate mortality rates and 95% confidence intervals by HIV status for 3- 5-year periods (1995-1999, 2000-2004, and 2005-2009). Assuming that mortality rates in individuals who did not test for HIV are similar to those in tested individuals, and dependent on age, sex and HIV status and HIV, prevalence was estimated. RESULTS: In 1995-1999, mortality rates (per 1000 person years) were 43.7 (95% CI 35.7-53.4) for HIV positive, 2.6 (95% CI 2.1-3.2) in HIV negative and 16.4 (95% CI 14.4-18.7) in untested. In 2000-2004, mortality rates were 43.3 (95% CI 36.2-51.9) in HIV positive, 3.3 (95% CI 2.8-4.0) in HIV negative and 11.9 (95% CI 10.5-13.6) in untested. In 2005-2009, mortality rates were 30.7 (95% CI 24.8-38.0) in HIV positive, 4.1 (95% CI 3.5-4.9) in HIV negative and 5.7 (95% CI 5.0-6.6) in untested residents. In the three survey periods (1995-1999, 2000-2004, 2005-2009), the adjusted period prevalences of HIV, including the untested, were 13.5%, 11.6% and 7.1%, compared with the observed prevalence in the tested of 6.0%, 6.8 and 8.0%. The estimated prevalence in the untested was 33.4%, 21.6% and 6.1% in the three survey periods. CONCLUSION: The simple model was able to estimate HIV prevalence where a DSS provided mortality data for untested residents

Impact of ART on the fertility of HIV-positive women in sub-Saharan Africa.

OBJECTIVE: Understanding the fertility of HIV-positive women is critical to estimating HIV epidemic trends from surveillance data and to planning resource needs and coverage of prevention of mother-to-child transmission services in sub-Saharan Africa. In the light of the considerable scale-up in antiretroviral therapy (ART) coverage over the last decade, we conducted a systematic review of the impact of ART on the fertility outcomes of HIV-positive women. METHODS: We searched Medline, Embase, Popline, PubMed and African Index Medicus. Studies were included if they were conducted in sub-Saharan Africa and provided estimates of fertility outcomes (live births or pregnancies) among women on ART relative to a comparison group. RESULTS: Of 2070 unique references, 18 published papers met all eligibility criteria. Comparisons fell into four categories: fertility of HIV-positive women relative to HIV-negative women; fertility of HIV-positive women on ART compared to those not yet on ART; fertility differences by duration on ART; and temporal trends in fertility among HIV-positive women. Evidence indicates that fertility increases after approximately the first year on ART and that while the fertility deficit of HIV-positive women is shrinking, their fertility remains below that of HIV-negative women. These findings, however, were based on limited data mostly during the period 2005-2010 when ART scaled up. CONCLUSIONS: Existing data are insufficient to characterise how ART has affected the fertility of HIV-positive women in sub-Saharan Africa. Improving evidence about fertility among women on ART is an urgent priority for planning HIV resource needs and understanding HIV epidemic trends. Alternative data sources such as antenatal clinic data, general population cohorts and population-based surveys can be harnessed to understand the issue

The trade-off between accuracy and accessibility of syphilis screening assays.

The availability of rapid and sensitive methods to diagnose syphilis facilitates screening of pregnant women, which is one of the most cost-effective health interventions available. We have evaluated two screening methods in Tanzania: an enzyme immunoassay (EIA), and a point-of-care test (POCT). We evaluated the performance of each test against the Treponema pallidum particle agglutination assay (TPPA) as the reference method, and the accessibility of testing in a rural district of Tanzania. The POCT was performed in the clinic on whole blood, while the other assays were performed on plasma in the laboratory. Samples were also tested by the rapid plasma Reagin (RPR) test. With TPPA as reference assay, the sensitivity and specificity of EIA were 95.3% and 97.8%, and of the POCT were 59.6% and 99.4% respectively. The sensitivity of the POCT and EIA for active syphilis cases (TPPA positive and RPR titer ≥ 1/8) were 82% and 100% respectively. Only 15% of antenatal clinic attenders in this district visited a health facility with a laboratory capable of performing the EIA. Although it is less sensitive than EIA, its greater accessibility, and the fact that treatment can be given on the same day, means that the use of POCT would result in a higher proportion of women with syphilis receiving treatment than with the EIA in this district of Tanzania

Use of antenatal clinic surveillance to assess the effect of sexual behavior on HIV prevalence in young women in Karonga district, Malawi.

BACKGROUND: Antenatal clinic (ANC) surveillance is the primary source of HIV prevalence estimates in low-resource settings. In younger women, prevalence approximates incidence. Sexual behavior monitoring to explain HIV distribution and trends is seldom attempted in ANC surveys. We explore the use of marital history in ANC surveillance as a proxy for sexual behavior. METHODS: Five ANC clinics in a rural African district participated in surveillance from 1999 to 2004. Unlinked anonymous HIV testing and marital history interviews (including age at first sex and socioeconomic variables) were conducted. Data on women aged <25 years were analyzed. RESULTS: Inferred sexual exposure before marriage and after first marriage increased the adjusted odds of infection with HIV by more than 0.1 for each year of exposure. Increasing years within a first marriage did not increase HIV risk. After adjusting for age, women in more recent birth cohorts were less likely to be infected. CONCLUSIONS: Marital status is useful behavioral information and can be collected in ANC surveys. Exposure in an ongoing first marriage did not increase the odds of infection with HIV in this age group. HIV prevalence decreased over time in young women. ANC surveillance programs should develop proxy sexual behavior questions, particularly in younger women

From HIV diagnosis to treatment: evaluation of a referral system to promote and monitor access to antiretroviral therapy in rural Tanzania

BACKGROUND: Individuals diagnosed with HIV in developing countries are not always successfully linked to onward treatment services, resulting in missed opportunities for timely initiation of antiretroviral therapy, or prophylaxis for opportunistic infections. In collaboration with local stakeholders, we designed and assessed a referral system to link persons diagnosed at a voluntary counselling and testing (VCT) clinic in a rural district in northern Tanzania with a government-run HIV treatment clinic in a nearby city. METHODS: Two-part referral forms, with unique matching numbers on each side were implemented to facilitate access to the HIV clinic, and were subsequently reconciled to monitor the proportion of diagnosed clients who registered for these services, stratified by sex and referral period. Delays between referral and registration at the HIV clinic were calculated, and lists of non-attendees were generated to facilitate tracing among those who had given prior consent for follow up.Transportation allowances and a "community escort" from a local home-based care organization were introduced for patients attending the HIV clinic, with supportive counselling services provided by the VCT counsellors and home-based care volunteers. Focus group discussions and in-depth interviews were conducted with health care workers and patients to assess the acceptability of the referral procedures. RESULTS: Referral uptake at the HIV clinic averaged 72% among men and 66% among women during the first three years of the national antiretroviral therapy (ART) programme, and gradually increased following the introduction of the transportation allowances and community escorts, but declined following a national VCT campaign. Most patients reported that the referral system facilitated their arrival at the HIV clinic, but expressed a desire for HIV treatment services to be in closer proximity to their homes. The referral forms proved to be an efficient and accepted method for assessing the effectiveness of the VCT clinic as an entry point for ART. CONCLUSION: The referral system reduced delays in seeking care, and enabled the monitoring of access to HIV treatment among diagnosed persons. Similar systems to monitor referral uptake and linkages between HIV services could be readily implemented in other settings

Measuring the impact of antiretroviral therapy roll-out on population level fertility in three African countries

BackgroundUNAIDS official estimates of national HIV prevalence are based on trends observed in antenatal clinic surveillance, after adjustment for the reduced fertility of HIV positive women. Uptake of ART may impact on the fertility of HIV positive women, implying a need to re-estimate the adjustment factors used in these calculations. We analyse the effect of antiretroviral therapy (ART) provision on population-level fertility in Southern and East Africa, comparing trends in HIV infected women against the secular trends observed in uninfected women.MethodsWe used fertility data from four community-based demographic and HIV surveillance sites: Kisesa (Tanzania), Masaka and Rakai (Uganda) and uMkhanyakude (South Africa). All births to women aged 15–44 years old were included in the analysis, classified by mother’s age and HIV status at time of birth, and ART availability in the community. Calendar time period of data availability relative to ART Introduction varied across the sites, from 5 years prior to ART roll-out, to 9 years after. Calendar time was classified according to ART availability, grouped into pre ART, ART introduction (available in at least one health facility serving study site) and ART available (available in all designated health facilities serving study site). We used Poisson regression to calculate age adjusted fertility rate ratios over time by HIV status, and investigated the interaction between ART period and HIV status to ascertain whether trends over time were different for HIV positive and negative women.ResultsAge-adjusted fertility rates declined significantly over time for HIV negative women in all four studies. However HIV positives either had no change in fertility (Masaka, Rakai) or experienced a significant increase over the same period (Kisesa, uMkhanyakude). HIV positive fertility was significantly lower than negative in both the pre ART period (age adjusted fertility rate ratio (FRR) range 0.51 95%CI 0.42–0.61 to 0.73 95%CI 0.64–0.83) and when ART was widely available (FRR range 0.57 95%CI 0.52–0.62 to 0.83 95%CI 0.78–0.87), but the difference has narrowed. The interaction terms describing the difference in trends between HIV positives and negatives are generally significant.ConclusionsDifferences in fertility between HIV positive and HIV negative women are narrowing over time as ART becomes more widely available in these communities. Routine adjustment of ANC data for estimating national HIV prevalence will need to allow for the impact of treatment

Evaluation of a village-informant driven demographic surveillance system in Karonga, Northern Malawi

This paper describes and evaluates the first demographic surveillance system (DSS) in Malawi, covering a rural population of 30,000. Unlike others, the Karonga DSS relies on trained village informants using formatted registers for the primary notification of vital events and migrations. Seven project enumerators subsequently collect detailed data on events notified by the village informants, using stringent identification procedures for households and individuals. Internal movements are traced systematically to augment event registration and data quality. Continuous evaluation of data collection is built into the methods. A re-census conducted after 2 years indicated that the routine system had registered 97% of 1,588 births, 99% of 521 deaths and 92% of 13,168 movements.demographic surveillance system, evaluation, INDEPTH network, Karonga, Malawi, methods, migration, village informant, vital registration