Antenatal clinic HIV data found to underestimate actual prevalence declines: evidence from Zambia

Non-participation of female sex workers in HIV sentinel surveillance 2017 in the central zone, and its effect on observed HIV prevalence rate

Background

During HIV sentinel surveillance (HSS) 2017 round, the sampling strategy to recruit female sex workers (FSWs) was changed from consecutive to random sampling. This may affect the participation and HIV positivity rates among FSWs.

Objective

The objective of this study is to estimate the nonparticipation rates among FSWs and its effect on the observed HIV prevalence rate during HSS-2017.

Methods

The data were collected from FSW sentinel sites located in the states of Delhi, Jharkhand, Uttar Pradesh, and Uttarakhand (Central Zone). The HIV positivity rate among FSWs who participated in HSS-2017 was compared with the HIV positivity rate of those who did not participate. HIV status of the participants was obtained from HSS-2017 data. The master list of participating targeted intervention sites was accessed to obtain the last known HIV status of the eligible nonparticipants.

Results

Nonparticipation rate of FSWs from the central zone during HSS2017 was 10.8%. The HIV positivity rate among nonparticipant FSW was four times and six times higher in Delhi and UP, respectively.

Conclusion

Selective nonparticipation of eligible FSWs might have led to the underestimation of the HIV positivity rate in the central zone during the HSS-2017 round.

Contrasting HIV prevalence trends among young women and men in Zambia in the past 12 years: data from demographic and health surveys 2002-2014

BACKGROUND

The HIV epidemic remains a concern on the global health agenda, despite progress made in reducing incidence. Investigation of trends among young people is important for monitoring HIV incidence and informing programming. The study examined geographical and sub-population differences in HIV prevalence trends among young people aged 15-24 years in Zambia.

METHODS

This study analysed data from Zambia Demographic and Health Surveys (ZDHSs) that were conducted in 2001-2, 2007, and 2013-14. A two-stage cluster stratified sampling procedure was used to select samples of 8050, 7969, and 18,052 for the three surveys, respectively. Young people (15-24 years) with known HIV status were selected for analysis. The outcome variable was HIV status. Log binomial regression analysis of generalised linear models was used to test for trends.

RESULTS

Overall HIV prevalence declined over the period 2001-2 to 2013-14 among women and men aged 15-49 years (17.8 and 12.9% to 15.1 and 11.3%, respectively). There was, however, an increase in HIV prevalence among urban young men over this period, from 3.7% in 2001-2 to 7.3% in 2013-14 (aRR 2.17, 95% CI 0.99-4.75), and, in rural areas, from 2.6 to 3.6% (aRR 1.46, 95% CI 0.78-2.75). In contrast, HIV prevalence among women declined over the same period of time. In urban areas, HIV prevalence among women declined from 15.2 to 10.7% (aRR 0.66, 95% CI 0.53-0.93), while in rural areas it declined from 8.2 to 4.8% (aRR 0.41, 95% CI 0.59-0.85). In addition, there was a narrowing gender gap in terms of HIV infection, as the prevalence ratio of females to males declined from 4.2 and 3.1 to 1.5 and 1.3, in urban and rural areas, respectively.

CONCLUSIONS

The increase in HIV prevalence among urban young men over the past 12 years, contrasting declining trends among young women in both urban and rural populations, suggests differential effects of prevention efforts. Furthermore, findings that Zambia's overall national HIV prevalence decline masks some striking sex and rural/urban differentials, indicate the need for reconsidering the prevention efforts for young urban men.

Monitoring HIV Epidemic in Pregnant Women: Are the Current Measures Enough?

Introduction. Burden of HIV in pregnant women follows overall epidemic in India. Hence, it is imperative that prevalence calculations in this group be accurate. The present study was carried out to determine prevalence of HIV in pregnant women attending our hospital, to determine trend of HIV infection and to compare our results with reported prevalence. Methods. All pregnant women are routinely counselled for HIV testing using opt-out strategy. Year-wise positivity and trend were determined in these patients over a period of five years. The positivity in different age groups was determined. Results. 31,609 women were tested of which 279 (0.88%) were positive. Positivity showed a declining trend over study period and significant quadratic trend (biphasic, P < 0.05) was observed. The positivity in older age group ≥35 years (1.64%) was significantly more than younger age groups (0.76% in 15–24-year and 0.94% in 25–34-year age group) (P = 0.0052). Conclusion. A significant decline in HIV positivity was seen over the study period. Taking into account heterogeneous nature of HIV epidemic even within the same district, analysis at local levels especially using the prevention of parent to child transmission of HIV program data is critical for HIV programming and resource allocation.

Negotiation for safer sex among married women in Cambodia: the role of women's autonomy

Negotiating safer sex among married women has been identified as an important determinant of vulnerability or resilience to new HIV infections. Using the Cambodia Demographic and Health Survey data of 2010, this paper examined negotiation for safer sex among 11,218 married women in the context of Cambodia's highly touted reduction in HIV/AIDS prevalence. The results from a complementary log-log regression model indicate that wealthier and highly educated married women were more likely to report that they can refuse sexual intercourse and ask their husbands to use a condom. Interestingly, while women who were fully involved in decision-making on their own health care were 19% more likely to refuse sex, they were 14% less likely to be able to ask their husbands to use a condom, compared with their counterparts who were not involved in this decision-making. Women who were partially involved in decision-making on family visits were 17% less likely to be able to ask their husbands to use a condom compared with those who were not involved. In this context, involvement in decision-making may have translated into trust and risk compensation. Those who believed in HIV transmission myths were less likely to negotiate safer sex relative to their counterparts who did not hold such myths to be true. Women's ability to negotiate for safer sex is, therefore, a function of their autonomy in terms of their full participation in decision-making in health care, household expenditure and mobility. Policy implications of the capacity of women to negotiate for safer sex are delineated.

Trends in HIV prevalence among young people in generalised epidemics: implications for monitoring the HIV epidemic

Background

Countries measure trends in HIV incidence to assess the impact of HIV prevention and treatment programmes. Most countries have approximated trends in HIV incidence through modelled estimates or through trends in HIV prevalence among young people (aged 15–24 years) assuming they have recently become sexually active and have thus only been recently exposed to HIV.

Methods

Trends in HIV incidence are described and results are compared using three proxy measures of incidence: HIV prevalence among young women attending antenatal clinics (ANCs) in 22 countries; HIV prevalence among young male and female nationally representative household survey respondents in 14 countries; and modelled estimates of adult (ages 15–49 years) HIV incidence in 26 countries. The significance of changes in prevalence among ANC attendees and young survey respondents is tested.

Results

Among 26 countries, 25 had evidence of some decline in HIV incidence and 15 showed statistically significant declines in either ANC data or survey data. Only in Mozambique did the direction of the trend in young ANC attendees differ from modelled adult incidence, and in Mali and Zambia trends among young men differed from trends in adult incidence. The magnitude of change differed by method.

Conclusions

Trends in HIV prevalence among young people show encouraging declines. Changes in fertility patterns, HIV-infected children surviving to adulthood, and participation bias could affect future proxy measures of incidence trends.

Decline in HIV prevalence among young women in Zambia: national-level estimates of trends mask geographical and socio-demographic differences

BACKGROUND

A decline in HIV incidence has been reported in Zambia and a number of other sub-Saharan countries. The trend of HIV prevalence among young people is a good marker of HIV incidence. In this study, different data sources are used to examine geographical and sub-population group differentials in HIV prevalence trends among men and women aged 15-24 years in Zambia.

DESIGN AND METHODS

We analysed ANC data for women aged 15-24 years from 22 sentinel sites consistently covered in the period 1994-2008, and HIV data for young men and women aged 15-24 years from the ZDHS 2001/2 and 2007. In addition, we systematically reviewed peer-reviewed articles that have reported findings on HIV prevalence and incidence among young people.

FINDINGS

Overall trends of the ANC surveillance data indicated a substantial HIV prevalence decline among young women in both urban and rural areas. However, provincial declines differed substantially, i.e. between 10% and 68% among urban women, and from stability to 86% among rural women. Prevalence declines were steeper among those with the highest educational attainments than among the least educated. The ZDHS data indicated a significant reduction in prevalence between the two survey rounds among young women only. Provincial-level ZDHS changes were difficult to assess because the sample sizes were small. ANC-based trend patterns were consistent with those observed in PMTCT-based data (2002-2006), whereas population-based surveys in a selected urban community (1995-2003) suggested that the ANC-based data underestimated the prevalence declines in the general populations of both young both men and women.

CONCLUSION

The overall HIV prevalence declined substantially among young women in Zambia and this is interpreted as indicating a decline in HIV incidence. It is noteworthy that overall national trends masked substantial differences by place and by educational attainment, demonstrating critical limitations in the current focus on overall country-level trends in epidemiological reports.

Monitoring trends in HIV prevalence among young people, aged 15 to 24 years, in Manicaland, Zimbabwe

Background

In June 2001, the United Nations General Assembly Special Session (UNGASS) set a target of reducing HIV prevalence among young women and men, aged 15 to 24 years, by 25% in the worst-affected countries by 2005, and by 25% globally by 2010. We assessed progress toward this target in Manicaland, Zimbabwe, using repeated household-based population serosurvey data. We also validated the representativeness of surveillance data from young pregnant women, aged 15 to 24 years, attending antenatal care (ANC) clinics, which UNAIDS recommends for monitoring population HIV prevalence trends in this age group. Changes in socio-demographic characteristics and reported sexual behaviour are investigated.

Methods

Progress towards the UNGASS target was measured by calculating the proportional change in HIV prevalence among youth and young ANC attendees over three survey periods (round 1: 1998-2000; round 2: 2001-2003; and round 3: 2003-2005). The Z-score test was used to compare differences in trends between the two data sources. Characteristics of participants and trends in sexual risk behaviour were analyzed using Student's and two-tailed Z-score tests.

Results

HIV prevalence among youth in the general population declined by 50.7% (from 12.2% to 6.0%) from round 1 to 3. Intermediary trends showed a large decline from round 1 to 2 of 60.9% (from 12.2% to 4.8%), offset by an increase from round 2 to 3 of 26.0% (from 4.8% to 6.0%). Among young ANC attendees, the proportional decline in prevalence of 43.5% (from 17.9% to 10.1%) was similar to that in the population (test for differences in trend: p value = 0.488) although ANC data significantly underestimated the population prevalence decline from round 1 to 2 (test for difference in trend: p value = 0.003) and underestimated the increase from round 2 to 3 (test for difference in trend: p value = 0.012). Reductions in risk behaviour between rounds 1 and 2 may have been responsible for general population prevalence declines.

Conclusions

In Manicaland, Zimbabwe, the 2005 UNGASS target to reduce HIV prevalence by 25% was achieved. However, most prevention gains occurred before 2003. ANC surveillance trends overall were an adequate indicator of trends in the population, although lags were observed. Behaviour data and socio-demographic characteristics of participants are needed to interpret ANC trends.

Estimating the HIV incidence rate: recent and future developments

PURPOSE OF REVIEW

To describe the needs for information on the rate of new HIV infections (incidence) in epidemics and review developments in various methods for its estimation.

RECENT FINDINGS

Epidemiological methods for estimating incidence with models using prevalence data have been useful, but the expansion of antiretroviral treatment programmes could now challenge their reliability. Laboratory-based HIV incidence assays that can be used to measure HIV incidence using a cross-sectional survey, provide a promising concept, but current technologies have not been sufficiently accurate. New statistical methods have been developed that show that if the properties of the assay are properly measured then unbiased estimates of incidence can be derived, and that assays meeting certain criteria can produce estimates of acceptable accuracy and precision. Encouragingly, some new assays and algorithms show signs of potentially meeting those criteria. Among the next challenges will be the systematic evaluation of assay performance in many different types of specimen and the validation of those methods through comparison with other measurements of incidence.

SUMMARY

Recent developments in epidemiological and incidence assay-based methods of measuring incidence have been substantial and are likely to eventually lead to a revolution in the way that worldwide HIV epidemics are routinely tracked.

A decline in new HIV infections in South Africa: estimating HIV incidence from three national HIV surveys in 2002, 2005 and 2008

BACKGROUND

Three national HIV household surveys were conducted in South Africa, in 2002, 2005 and 2008. A novelty of the 2008 survey was the addition of serological testing to ascertain antiretroviral treatment (ART) use.

METHODS AND PRINCIPAL FINDINGS

We used a validated mathematical method to estimate the rate of new HIV infections (HIV incidence) in South Africa using nationally representative HIV prevalence data collected in 2002, 2005 and 2008. The observed HIV prevalence levels in 2008 were adjusted for the effect of antiretroviral treatment on survival. The estimated "excess" HIV prevalence due to ART in 2008 was highest among women 25 years and older and among men 30 years and older. In the period 2002-2005, the HIV incidence rate among men and women aged 15-49 years was estimated to be 2.0 new infections each year per 100 susceptible individuals (/100pyar) (uncertainty range: 1.2-3.0/100pyar). The highest incidence rate was among 15-24 year-old women, at 5.5/100pyar (4.5-6.5). In the period 2005-2008, incidence among men and women aged 15-49 was estimated to be 1.3/100 (0.6-2.5/100pyar), although the change from 2002-2005 was not statistically significant. However, the incidence rate among young women aged 15-24 declined by 60% in the same period, to 2.2/100pyar, and this change was statistically significant. There is evidence from the surveys of significant increases in condom use and awareness of HIV status, especially among youth.

CONCLUSIONS

Our analysis demonstrates how serial measures of HIV prevalence obtained in population-based surveys can be used to estimate national HIV incidence rates. We also show the need to determine the impact of ART on observed HIV prevalence levels. The estimation of HIV incidence and ART exposure is crucial to disentangle the concurrent impact of prevention and treatment programs on HIV prevalence.

Heterogeneous and decreasing HIV prevalence among women seeking antenatal care in Kinshasa, Democratic Republic of Congo

BACKGROUND

We examined HIV prevalence trends over 4.5 years among women receiving antenatal care in Kinshasa, Democratic Republic of Congo, by geographic location, clinic management and urbanicity.

METHODS

Quarterly proportions and 95% confidence intervals (CIs) of pregnant women with HIV positive results were determined using aggregate service provision and uptake data from 22 maternity units that provided vertical HIV prevention services from October 2004 to March 2009. Assuming linearity, proportions were assessed for trend via the Cochran-Armitage test. Multivariable binomial regression was used to describe detailed prevalence trends.

RESULTS

HIV testing was offered to 220,006 pregnant women; 210,348 (95.6%) agreed to be tested and 191,216 (90.9%) received their results. A total of 3999 women were found to be HIV positive, a prevalence of 1.90% (95% CI: 1.84-1.96%). The median quarterly proportion of women testing positive for HIV was 1.94% (range: 1.44-2.44%). Prevalence was heterogeneous in terms of maternity management, urbanicity and geographic location. Modeling suggested that the overall prevalence dropped from 2.04% (95% CI: 1.92-2.16%) to 1.77% (95% CI: 1.66-1.88%) over 4.5 years, a relative decrease of 13.2% (95% CI: 3.53-22.9%). Trend testing corroborated this decline (P < 0.01).

CONCLUSIONS

The decreasing HIV prevalence among Kinshasa antenatal care seekers is robust and encouraging. The relatively low prevalence and the weak existing healthcare system require prevention of mother-to-child transmission interventions that strengthen maternal and child healthcare service delivery. Complacency would be unwarranted: assuming a uniform national crude birth rate of 50/1000 and 1.8% antenatal HIV prevalence, approximately 7000 pregnant HIV infected women in Kinshasa, and 60,000 nationwide, are in need of care and prevention services yearly.

Prevalence and correlates of concurrent sexual partnerships in Zambia

Concurrent partnerships may cause more rapid spread of HIV in a population. We examined how the prevalence of parallel relationships changed among men and women aged 15-49 in Zambia from 1998 to 2003 using data collected during the Sexual Behavior Surveys 1998, 2000, and 2003. Predictors of concurrent partnerships among men were studied by univariate and multivariate regression analyses. Thirteen percent of rural and 8% of urban men reported more than one ongoing relationship in 1998, and these proportions declined to 8% and 6%, respectively in 2003. The proportion of women reporting concurrent relationships was 0-2%. The most important predictors of concurrency were early sexual debut, being married, early marriage and absence from home. The reduction in concurrent sexual partnerships is consistent with reductions in other sexual risk behaviors found in other studies and may have contributed to the recently observed decline in HIV prevalence in Zambia.

Distribution of HIV in Cambodia: findings from the first national population survey

OBJECTIVES

A limited number of studies in Asia have investigated HIV transmission in the general population in order to better guide preventive efforts. We examine HIV prevalence patterns in men and women aged 15-49 years in Cambodia.

METHODS

The first national population-based survey was conducted in 2005, including HIV-related questionnaires and HIV test. Data were analysed separately for men and women. Logistic regression analysis, adjusted by age, was used to determine factors associated with HIV. To estimate the HIV prevalence, it was standardized by age, sex and place of residence.

RESULTS

Among 6514 men and 8188 women, HIV prevalence was 0.61% [95% confidence interval (CI) 0.2-1.8] and 0.62% (95% CI 0.3-2.1), respectively. The prevalence in urban areas was approximately three times higher than in rural settings. The likelihood among women of being HIV positive increased with increasing age differentials between spouses. HIV among men increased with household wealth (odds ratio 5.7; 95% CI 2.0-16.4) and education (odds ratio 3.7; 95% CI 0.8-17.8). About 10% of men reported multiple partners, a behaviour strongly associated with HIV (odds ratio 4.0; 95% CI 1.3-12.5).

CONCLUSION

This study revealed HIV prevalence to be relatively low in the general population and substantially below previous estimates. Multiple observations were consistent with the hypothesis that the bulk of infections among men are related to sex work and most women are infected in marriage. Intervention should be focused on reducing the transmission among spouses and empower women with better access to information, education and care while sustaining preventive efforts related to sex work.

The epidemiology of HIV infection among young people aged 15-24 years in southern Africa

OBJECTIVES

To investigate epidemiological patterns and trends of HIV infection and sexual behaviour among young people aged 15-24 years in the nine countries in southern Africa most affected by the HIV epidemic.

METHODS

Data on HIV prevalence among young people in the general population were obtained from national population-based surveys conducted between 2000 and 2007, whereas data on sexual behaviour were obtained from repeat surveys between 1994 and 2007. Linear or exponential regression was used to analyse HIV prevalence trends among young women attending antenatal clinics in recent years.

RESULTS

Patterns of HIV infection among young people are similar across the countries included in this analysis. The prevalence of HIV increases after the age of 15 years, more rapidly among women than among men, reaching a peak among women in their twenties and men in their thirties. Between 2000 and 2007 the prevalence of HIV among antenatal clinic attendees was constant in Mozambique and South Africa and declining in Lesotho, Namibia, Swaziland, Zambia, Botswana, Malawi and Zimbabwe, but only reached statistical significance (P < 0.05) in the last three. Changes towards safer sexual behaviour were observed over time among young men and women in the general population in this region.

CONCLUSION

Sexual behaviour changes among young people are encouraging and are associated with declines in HIV prevalence among young antenatal clinic attendees over time. More research is needed to understand the recent changes and the very high prevalence among young women in this region. Interventions aimed at reducing risky behaviour need to be supported and expanded while incorporating new approaches to prevention.

Association between fertility and HIV status: what implications for HIV estimates?

BACKGROUND

Most estimates of HIV prevalence have been based on sentinel surveillance of pregnant women which may either under-estimate or over-estimate the actual prevalence in adult female population. One situation which can lead to either an underestimate or an overestimate of the actual HIV prevalence is where there is a significant difference in fertility rates between HIV-positive and HIV-negative women. Our aim was to compare the fertility rates of HIV-infected and HIV-uninfected women in Cameroon in order to make recommendations on the appropriate adjustments when using antenatal sentinel data to estimate HIV prevalence.

METHODS

Cross-sectional, population-based study using data from 4493 sexually active women aged 15 to 49 years who participated in the 2004 Cameroon Demographic and Health Survey.

RESULTS

In the rural area, the age-specific fertility rates in both HIV positive and HIV negative women increased from 15-19 years age bracket to a maximum at 20-24 years and then decreased monotonically till 35-49 years. Similar trends were observed in the urban area. The overall fertility rate for HIV positive women was 118.7 births per 1000 woman-years (95% Confidence Interval [CI] 98.4 to 142.0) compared to 171.3 births per 1000 woman-years (95% CI 164.5 to 178.2) for HIV negative women. The ratio of the fertility rate in HIV positive women to the fertility rate of HIV negative women (called the relative inclusion ratio) was 0.69 (95% CI 0.62 to 0.75).

CONCLUSION

Fertility rates are lower in HIV-positive than HIV-negative women in Cameroon. The findings of this study support the use of summary RIR for the adjustment of HIV prevalence (among adult female population) obtained from sentinel surveillance in antenatal clinics.

Lost opportunities in HIV prevention: programmes miss places where exposures are highest

Background

Efforts at HIV prevention that focus on high risk places might be more effective and less stigmatizing than those targeting high risk groups. The objective of the present study was to assess risk behaviour patterns, signs of current preventive interventions and apparent gaps in places where the risk of HIV transmission is high and in communities with high HIV prevalence.

Methods

The PLACE method was used to collect data. Inhabitants of selected communities in Lusaka and Livingstone were interviewed about where people met new sexual partners. Signs of HIV preventive activities in these places were recorded. At selected venues, people were interviewed about their sexual behaviour. Peer educators and staff of NGOs were also interviewed.

Results

The places identified were mostly bars, restaurants or sherbeens, and fewer than 20% reported any HIV preventive activity such as meetings, pamphlets or posters. In 43% of places in Livingstone and 26% in Lusaka, condoms were never available. There were few active peer educators. Among the 432 persons in Lusaka and 676 in Livingstone who were invited for interview about sexual behaviour, consistent condom use was relatively high in Lusaka (77%) but low in Livingstone (44% of men and 34% of women). Having no condom available was the most common reason for not using one. Condom use in Livingstone was higher among individuals socializing in places where condoms always were available.

Conclusion

In the places studied we found a high prevalence of behaviours with a high potential for HIV transmission but few signs of HIV preventive interventions. Covering the gaps in prevention in these high exposure places should be given the highest priority.