Know Your Epidemic, Strengthen Your Response: Developing a New HIV Surveillance Architecture to Guide HIV Resource Allocation and Target Decisions.

To guide HIV prevention and treatment activities up to 2020, we need to generate and make better use of high quality HIV surveillance data. To highlight our surveillance needs, a special collection of papers in JMIR Public Health and Surveillance has been released under the title "Improving Global and National Responses to the HIV Epidemic Through High Quality HIV Surveillance Data." We provide a summary of these papers and highlight methods for developing a new HIV surveillance architecture.

HIV Surveillance Among Pregnant Women Attending Antenatal Clinics: Evolution and Current Direction.

Since the late 1980s, human immunodeficiency virus (HIV) sentinel serosurveillance among pregnant women attending select antenatal clinics (ANCs) based on unlinked anonymous testing (UAT) has provided invaluable information for tracking HIV prevalence and trends and informing global and national HIV models in most countries with generalized HIV epidemics. However, increased coverage of HIV testing, prevention of mother-to-child transmission (PMTCT), and antiretroviral therapy has heightened ethical concerns about UAT. PMTCT programs now routinely collect demographic and HIV testing information from the same pregnant women as serosurveillance and therefore present an alternative to UAT-based ANC serosurveillance. This paper reports on the evolution and current direction of the global approach to HIV surveillance among pregnant women attending ANCs, including the transition away from traditional UAT-based serosurveillance and toward new guidance from the World Health Organization and the Joint United Nations Programme on HIV/AIDS on the implementation of surveillance among pregnant women attending ANCs based on routine PMTCT program data.

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.

Has the quality of serosurveillance in low- and middle-income countries improved since the last HIV estimates round in 2007? Status and trends through 2009.

BACKGROUND: HIV surveillance systems aim to monitor trends of HIV infection, the geographical distribution and its magnitude, and the impact of HIV. The quality of HIV surveillance is a key element in determining the uncertainty ranges around HIV estimates. This paper aims to assess the quality of HIV surveillance systems in low- and middle-income countries in 2009 compared with 2007. METHODS: Four dimensions related to the quality of surveillance systems are assessed: frequency and timeliness of data; appropriateness of populations; consistency of locations and groups; and representativeness of the groups. An algorithm for scoring the quality of surveillance systems was used separately for low and concentrated epidemics and for generalised epidemics. RESULTS: The number of countries categorised as fully functioning in 2009 was 35, down from 40 in 2007. 47 countries were identified as partially functioning, while 56 were categorised as poorly functioning. When compared with 2007, the quality of HIV surveillance remains similar. The number of ANC sites in sub-Saharan Africa has increased over time. The number of countries with low and concentrated epidemics that do not have functioning HIV surveillance systems has increased from 53 to 56 between 2007 and 2009. CONCLUSION: Overall, the quality of surveillance in low- and middle-income countries has remained stable. Still too many countries have poorly functioning surveillance systems. Several countries with generalised epidemics have conducted more than one population-based survey which can be used to confirm trends. In countries with concentrated or low-level epidemics, the lack of data on high-risk populations remains a challenge.

Antiretroviral therapy needs: the effect of changing global guidelines.

BACKGROUND: In 2010 the WHO issued a revision of the guidelines on antiretroviral therapy (ART) for HIV infection in adults and adolescents. The recommendations included earlier diagnosis and treatment of HIV in the interest of a longer and healthier life. The current analysis explores the impact on the estimates of treatment needs of the new criteria for initiating ART compared with the previous guidelines. METHODS: The analyses are based on the national models of HIV estimates for the years 1990-2009. These models produce time series estimates of ART treatment need and HIV-related mortality. The ART need estimates based on ART eligibility criteria promoted by the 2010 WHO guidelines were compared with the need estimates based on the 2006 WHO guidelines. RESULTS: With the 2010 eligibility criteria, the proportion of people living with HIV currently in need of ART is estimated to increase from 34% to 49%. Globally, the need increases from 11.4 million (10.2-12.5 million) to 16.2 million (14.8-17.1 million). Regional differences include 7.4 million (6.4-8.4 million) to 10.6 million (9.7-11.5 million) in sub-Saharan Africa, 1.6 million (1.3-1.7 million) to 2.4 million (2.1-2.5 million) in Asia and 710 000 (610 000-780 000) to 950 000 (810 000-1.0 million) in Latin America and the Caribbean. CONCLUSIONS: When adopting the new recommendations, countries have to adapt their planning process in order to accelerate access to life saving drugs to those in need. These recommendations have a significant impact on resource needs. In addition to improving and prolonging the lives of the infected individuals, it will have the expected benefit of reducing HIV transmission and the future HIV/AIDS burden.

Changes in antiretroviral therapy guidelines: implications for public health policy and public purses.

INTRODUCTION: The World Health Organization (WHO) published a revision of the antiretroviral therapy (ART) guidelines and now recommends ART for all those with a CD4 cell count ≤350/mm(3), for people with HIV and active tuberculosis (TB) or chronic active hepatitis B irrespective of CD4 cell count and all HIV-positive pregnant women. A study was undertaken to estimate the impact of the new guidelines using four countries as examples. METHODS: The current WHO/UNAIDS country projections were accessed based on the 2007 estimates for Zambia, Kenya, Cameroon and Vietnam. New projections were created using Spectrum. CD4 progression rates to need for ART were modified and compared with the baseline projections. RESULTS: The pattern of increased need for treatment is similar across the four projections. Initiating treatment at a CD4 count <250/mm(3) will increase the need for treatment by a median of 22% immediately, initiating ART at a CD4 count <350/mm(3) increases the need for treatment by a median of 60%, and the need for treatment doubles if ART is commenced at a CD4 count <500/mm(3). Initiating ART at a CD4 cell count <250/mm(3) would increase the need for treatment by a median of around 15% in 2012; initiating treatment at a CD4 count <350/mm(3) increases the need for treatment by a median of 42% across the same projections and about 84% if CD4 <500/mm(3) was used. CONCLUSIONS: The projections indicate that initiating ART earlier in the course of the disease by increasing the threshold for the initiation of ART would increase the numbers of adults in need of treatment immediately and in the future.

Lives saved by Global Fund-supported HIV/AIDS, tuberculosis and malaria programs: estimation approach and results between 2003 and end-2007.

BACKGROUND: Since 2003, the Global Fund has supported the scale-up of HIV/AIDS, tuberculosis and malaria control in low- and middle-income countries. This paper presents and discusses a methodology for estimating the lives saved through selected service deliveries reported to the Global Fund. METHODS: Global Fund-supported programs reported, by end-2007, 1.4 million HIV-infected persons on antiretroviral treatment (ARV), 3.3 million new smear-positive tuberculosis cases detected in DOTS (directly observed TB treatment, short course) programs, and 46 million insecticide-treated mosquito nets (ITNs) delivered. We estimated the corresponding lives saved using adaptations of existing epidemiological estimation models. RESULTS: By end-2007, an estimated 681,000 lives (95% uncertainty range 619,000-774,000) were saved and 1,097,000 (993,000-1,249,000) life-years gained by ARV. DOTS treatment would have saved 1.63 million lives (1.09-2.17 million) when compared against no treatment, or 408,000 lives (265,000-551,000) when compared against non-DOTS treatment. ITN distributions in countries with stable endemic falciparum malaria were estimated to have achieved protection from malaria for 26 million of child-years at risk cumulatively, resulting in 130,000 (27,000-232,000) under-5 deaths prevented. CONCLUSIONS: These results illustrate the scale of mortality effects that supported programs may have achieved in recent years, despite margins of uncertainty and covering only selected intervention components. Evidence-based evaluation of disease impact of the programs supported by the Global Fund with international and in-country partners must be strengthened using population-level data on intervention coverage and demographic outcomes, information on quality of services, and trends in disease burdens recorded in national health information systems.

Estimating HIV Incidence in Populations Using Tests for Recent Infection: Issues, Challenges and the Way Forward.

INTRODUCTION: HIV incidence is the rate of new infections in a population over time. HIV incidence is a critical indicator needed to assess the status and trends of the HIV epidemic in populations and guide and assess the impact of prevention interventions. METHODS: Several methods exist for estimating population-level HIV incidence: direct observation of HIV incidence through longitudinal follow-up of persons at risk for new HIV infection, indirect measurement of HIV incidence using data on HIV prevalence and mortality in a population, and direct measurement of HIV incidence through use of tests for recent infection (TRIs) that can differentiate "recent" from "non-recent" infections based on biomarkers in cross-sectional specimens. Given the limitations in measuring directly observed incidence and the assumptions needed for indirect measurements of incidence, there is an increasing demand for TRIs for HIV incidence surveillance and program monitoring and evaluation purposes. RESULTS: Over ten years since the introduction of the first TRI, a number of low-, middle-, and high-income countries have integrated this method into their HIV surveillance systems to monitor HIV incidence in the population. However, the accuracy of these assays for measuring HIV incidence has been unsatisfactory to date, mainly due to misclassification of chronic infections as recent infection on the assay. To improve the accuracy of TRIs for measuring incidence, countries are recommended to apply case-based adjustments, formula-based adjustments using local correction factors, or laboratory-based adjustment to minimize error related to assay misclassification. Multiple tests may be used in a recent infection testing algorithm (RITA) to obtain more accurate HIV incidence estimates. CONCLUSION: There continues to be a high demand for improved TRIs and RITAs to monitor HIV incidence, determine prevention priorities, and assess impact of interventions. Current TRIs have noted limitations, but with appropriate adjustments, interpreted in parallel with other epidemiologic data, may still provide useful information on new infections in a population. New TRIs and RITAs with improved accuracy and performance are needed and development of these tools should be supported.

Advances and future directions in HIV surveillance in low- and middle-income countries.

PURPOSE OF REVIEW: To present recent advances in HIV/AIDS surveillance methods in low- and middle-income countries. RECENT FINDINGS: From 2001 to 2008, 30 low- and middle-income countries implemented national population-based surveys with HIV testing. Antenatal clinic HIV sentinel surveillance sites in sub-Saharan Africa increased from just over 1000 in 2003-2004 to almost 2500 in 2005-2006, becoming more representative of rural areas. Between 2003 and 2007, at least 122 behavioral surveys in low- and middle-income countries used respondent-driven sampling for surveillance among high-risk populations, although many countries with concentrated epidemics continue to have major sentinel surveillance gaps. Improvements have been made in modeling estimates of number of persons HIV infected, and systems are now in place to measure HIV drug resistance. However, the reliable monitoring of trends and the measuring of HIV incidence, morbidity, and mortality is still a challenge. SUMMARY: In the past 5 years, there have been substantial improvements in the quantity and quality of HIV surveillance studies, especially in the countries with high prevalence. Further efforts should be made in countries that lack fully implemented surveillance systems to improve HIV incidence, morbidity, and mortality surveillance and to use data more effectively.

Understanding the HIV epidemic in the Dominican Republic: a prevention success story in the Caribbean?

OBJECTIVE: To analyze the general dynamics and trends of the HIV epidemic in the Dominican Republic (DR). METHODS: Thorough review of available HIV seroprevalence and sexual behavioral data from the DR. RESULTS: Multiple sources of data suggest that the DR's HIV epidemic has generally declined. Between the mid-1990s and about 2002, HIV-1 prevalence fell among pregnant women in the capital, Santo Domingo, particularly among young women. Declines in prevalence were also observed over the same period among sexually transmitted infection clinic patients, blood bank donors, US entry visa applicants, and female sex workers. National household surveys found 1.0% (confidence interval: 0.9% to 1.1%) adult prevalence in 2002 and 0.8% (0.6% to 0.9%) in 2007. Among largely Haitian immigrant residents of the impoverished former "sugarcane plantations," prevalence was much higher but declined from 5.0% to 3.2% between 2002 and 2007. The DR's heterogeneous epidemic includes an important men-having-sex-with-men (MSM) and bisexual component. The proportion of reported AIDS cases among men remained constant from 1989 to 2006, accounting for about two thirds of both total cumulative and year 2006 cases. Some survey and qualitative data also suggest a considerable occurrence of MSM-related risk behaviors. HIV prevalence remains relatively high in MSM, with no evidence of significant decrease. CONCLUSIONS: As in several other developing countries that have succeeded in slowing HIV transmission, HIV reductions in the DR seem mainly due to changes in sexual behavior, particularly increased condom use, especially for sex work, and partner reduction in men. Similarly favorable HIV declines and reported behavior change have occurred in some other Caribbean countries, including neighboring Haiti. However, of concern is that anal sex, both male-male and heterosexual, remains a taboo yet apparently common practice largely ignored by existing prevention campaigns. And although the DR epidemic has generally stabilized, there is a danger of complacency, and some recent data suggest that HIV prevalence is no longer declining (and may even be increasing) in some populations.

Adjusting HIV prevalence data from a program for the prevention of mother-to-child transmission for surveillance purposes in Uganda.

OBJECTIVES: To evaluate a method for adjusting estimates of HIV prevalence based on data from a program for the prevention of mother-to-child transmission (PMTCT) of HIV infection for the potential bias attributable to refusal of PMTCT-related testing. METHODS: Age-specific logistic regression models were used to estimate the HIV risk coefficients for 10 predictor variables among women who accepted the PMTCT-related testing (n = 1874) at an antenatal clinic in northern Uganda. These risk coefficients were used to predict the prevalence among women who were not tested (n = 1719) and to adjust the PMTCT-based prevalence for nonparticipation bias. Crude and adjusted PMTCT-based prevalence estimates were compared with the prevalence among women who were anonymously tested as part of routine sentinel surveillance (n = 2225). RESULTS: The PMTCT-based prevalence represented an underestimate compared with that based on anonymous surveillance in 2004 (9.0% vs. 10.5%); in 2005, it constituted an overestimate (11.8% vs. 10.9%). Adjusting the PMTCT-based prevalence reduced the difference attributable to nonparticipation bias by approximately 70% in both years, so that the adjusted prevalence (10.1% in 2004 and 11.2% in 2005) was similar to the surveillance-based prevalence. CONCLUSIONS: The adjustment method was effective in reducing the nonparticipation bias. Further studies are needed to assess the utility of PMTCT program data for HIV surveillance.

Resultados de la encuesta nacional de la infección por el VIH en Guinea Ecuatorial en 2004 / No disponible

Objetivos: Determinar la situación actual de la epidemia de VIH en Guinea Ecuatorial en población adulta de 15 a 49 años y calibrar los resultados con los actuales sistemas de vigilancia de la infección por el VIH en el país. Introducción: Las estimaciones de la carga de VIH en el África subsahariana presentan potenciales sesgos porque están basadas en los sistemas de vigilancia centinela obtenidos de las clínicas prenatales. Las encuestas nacionales de hogares pueden aportar datos para mejorar las estimaciones de la infección por el VIH. Material y Métodos: Se diseñó una encuesta nacional con muestreo polietápico por conglomerados y estratificado entre zonas rurales y urbanas. Se recogió sangre capilar en papel de filtro Whatmann Nº4 y se realizó detección de anticuerpos frente a VIH-1/2 mediante ELISA y posterior confirmación por Inmunoblot. Resultados: De las 1.449 muestras de sangre recogidas un total de 52 muestras resultaron positivas, 51 para VIH-1 y 1 para VIH-2. La prevalencia total de VIH fue del 3,2% IC = [2,0-4,4]. Para las mujeres fue de 3,4% [2,0-4,8] y para los hombres algo inferior, 2,9% [1,1-4,8] aunque sin diferencias estadísticamente significativas. Los resultados por estratos fueron para la población rural de 3,1% [1,4-4,7]) y en la zona urbana 3,3% (..) (AU)

Objective: To establish the reference situation of HIV epidemic in Equatorial Guinea in adult population aged 15-49 years and to calibrate the results with the current sentinel surveillance of the HIV infection in the country. Introduction: The estimates of HIV burden in sub-Saharan Africa are potentially biases because they are based on the sentinel surveillance among pregnant women attending antenatal clinics. National population based surveys can contribute additional information to improve the HIVestimates. Population and methods: A national survey was drawn using stratified (rural and urban settlement) multi-stage cluster sampling. Blood samples were collected on Whatmann Nº4 filter paper and were tested for HIV-1/2 antibodies by ELISA and Inmunoblot was used for confirmation. Results: From 1.449 dried blood spots collected a total of 52 samples were HIV positive, 51 were infected by HIV-1 and 1 by HIV-2. For the whole country HIV prevalence was 3,2% CI = [2,0-4,4]. In females, the prevalence was 3,4% [2,0-4,8] and in males it was slightly low, 2,9% [1,1-4,8]though without statistically significant differences. The results for each strata were 3,1% [1,4-4,7]), for the rural population, and 3,3% [1,5-5,1] in the urban area. A significant association was detected between HIV and; age, had suffered from STIs (OR=2,62; CI 95% = [1,21-5,7]), to manicure(2,53; [1,16-5,55]) and in the use of traditional medicine (8,26; [2,24-30,47]). Also between those who use condom sometimes versus those whonever use it (2,92; [1,24-6,89]).Conclusions: HIV prevalence in Equatorial Guinea is in intermediate levels between central (..) (AU)

HIV prevalence and trends in sub-Saharan Africa: no decline and large subregional differences.

BACKGROUND: Expansion of HIV surveillance systems in sub-Saharan Africa is leading to downward adjustments to the size of the AIDS epidemic. However, only analysis of surveillance data from the same populations over time can provide insight into trends of HIV prevalence. We have used data from the same antenatal clinics to document recent empirical trends. METHODS: We collated data from antenatal clinics on HIV prevalence between 1997 and 2003. Data were obtained from 140?000 pregnant women attending more than 300 antenatal clinics in 22 countries in sub-Saharan Africa. Additionally, long-term trend data are available for 57 urban areas and provinces. FINDINGS: Median HIV prevalence in 148 antenatal clinic sites in southern Africa increased from 21.3% (IQR 11.5-28.2%) in 1997/98 to 23.8% (15.6-29.2%) in 2002. At more than half the sites (58%) an increase of at least one-tenth was noted, but at a fifth of sites, prevalence dropped by at least one-tenth. In eastern Africa, median HIV prevalence decreased from 12.9% (7.0-16.9%) in 1997/98 to 8.5% (5.3-13.0%) in 2002, with prevalence rising in four (7%) sites, but falling at 25 (43%) sites. In west Africa, median HIV prevalence was 3.5% (2.2-5.9%) and 3.2% (2.3-6.1%) for 1997/98 and 2002, respectively, with reductions and increases in prevalence being noted in equal proportions. The long-term trends in urban areas in sub-Saharan Africa show a similar pattern, with increasing evidence of stabilisation during the past 2-3 years compared with the previous decade. INTERPRETATION: Evidence from surveillance of mostly urban antenatal clinic attendees indicates that the growth in the AIDS epidemic in sub-Saharan Africa has levelled off since the late 1990s but only eastern Africa shows a decline in HIV prevalence. Very large differences persist between subregions. Workers planning a response to the AIDS epidemic must take more careful consideration of these variations to allow locally appropriate responses to the epidemic.

Estimating HIV/AIDS prevalence in countries with low-level and concentrated epidemics: the example of Honduras.

Estimates of HIV/AIDS prevalence are important, because they are the primary measure of the current state of the epidemic in a country. How estimates of HIV/AIDS are made depends on the level of the epidemic. For estimates of HIV/AIDS prevalence in low-level and concentrated epidemics it is necessary to disaggregate the total adult population into sub-groups based on the relative risk of infection. For each group, the major issues and questions are: identifying risk groups, estimating the size of the populations, and estimating HIV prevalence in these groups. The greatest difficulty in making estimates of prevalence in low-level and concentrated epidemics is often establishing the size of various populations. Because of the uncertainty inherent in making an estimate of population size for these groups at high risk, low and high estimates are used. In order to demonstrate the method the case of Honduras was used. The most recent HIV prevalence data and the estimates of population sizes were applied. It was estimated that Honduras, which has a total population of 6,575,000 (United Nations Population Division sources), has approximately 55,000 adults living with HIV/AIDS, with a range of uncertainty between 30,000 and 80,000. Estimations of the burden of HIV is a continuous process and should be updated on a regular basis according to the most recent and relevant information available.

Access to antiretroviral treatment in Latin American countries and the Caribbean.

OBJECTIVES: To assess the access to antiretroviral therapy in the Latin America and Caribbean region and the main issues involved. METHODS: A review of National AIDS Programmes reports, published studies on HIV access to antiretroviral drugs, and personal communications from National AIDS Programmes in the region. RESULTS: Most countries have, or are in the process of developing, laws and regulations to ensure better access to antiretroviral drugs for people in need. However, there are still many countries that either have not implemented policies or do not have policies. There has been an important decrease in the cost of drugs, but prices are still too high for all countries to afford them. The benefits in decreased mortality and hospitalizations in the countries with high coverage are significant. The number of people receiving antiretroviral therapy has been estimated to be close to 170,000 individuals; however, this figure only represents a fraction of the people in need in the region. Some different strategies will have to be implemented in order to increase coverage. CONCLUSION: Renewed efforts are needed from both governments and international community organizations to strengthen the health services and increase access to antiretroviral drugs.