THE REPUBLIC OF MALAWI
MINISTRY OF HEALTH
HIV AND SYPHILIS SERO-SURVEY AND NATIONAL HIV PREVALENCE ESTIMATES REPORT 2005
December 2005
Foreword
HIV and Syphilis surveillance is a systematic and routine collection of information on the occurrence and distribution of HIV and syphilis infection as well as the factors associated with their transmission. It monitors the risk of infection among specific populations and this is done on an ongoing basis. Malawi has consistently been monitoring HIV prevalence through antenatal clinic (ANC) attendees in 19 sites since 1994.
The primary objective of the sentinel surveillance survey is to provide data on the occurrence and distribution of HIV infection among women attending antenatal clinics. HIV sentinel surveillance data are not representative of the general population and prevalence in ANC sentinel sites only presents prevalence in the respective sites. In this report, sentinel surveillance data have been used to estimate national HIV prevalence in the general population.
Overall HIV prevalence in Malawi appears to have stabilized and there has been a general decline in HIV prevalence in ANC attendees aged 15 to 24 years since 1999. However, this is not a reason to relax. There is need to scale up our intervention programs to control the HIV and AIDS epidemic in the country.
Syphilis prevalence in pregnant women attending antenatal care continues to decline in Malawi and is much lower than HIV prevalence. The decline in the syphilis prevalence may be due to effective treatment for syphilis. There is, therefore, need to continue with the programmes in the coming year that will help to sustain the low syphilis prevalence.
The HIV and Syphilis Sero-Surveys and National HIV Prevalence Estimates are done to provide data to assist with public health programme decision-making, educate the public on HIV, and guide scientific research.
I am pleased to disseminate the results of the 2005 HIV and Syphilis Sero-Survey and National HIV Prevalence Estimates as a guiding tool for decision making and programme design in the coming year.
Dr W.O.O. Sangala
SECRETARY FOR HEALTH
Acknowledgements
The Ministry of Health extends its appreciation to all members of staff in the sentinel sites for their dedication and support for the actual specimen collection, the Community Health Sciences Unit (CHSU) Mr J. Kandulu, Mr M. Yassin, Mr W. Nanthambwe, Mr A. Phiri and Mr M. Chiwaula for assisting in specimen analysis and supervision during specimen collection; Lilongwe Central Hospital (LCH) Mr H. Feluzi; Malawi College of Health Sciences (Lilongwe Campus) Mr. M. Kazipe, Mzuzu Central Hospital Mr A. F. Kashoti, Mr Pharaoh Mwale, Blantyre DHO Mr L. Chisuwo, Mr J. Bitilinyu Bango for assisting with specimen collection and supervision. The Unit is also greatly indebted to all women sampled, too numerous for individual mention, for providing the data with which to compile this report. Gratitude is extended to the National AIDS Commission (NAC) for financial and technical support, Central Medical Stores (MOH) for providing vironostika ELISA kits and other supplies, the World Health Organisation and Centres for Diseases Control and Prevention Global AIDS Program (CDC-GAP) for technical support in developing the estimates and projection report, and the Epidemiology Unit of the Community Health Sciences Unit for successfully managing the National HIV Sentinel Survey.
Special thanks go to Mr George A. F. Bello (Epidemiology – CHSU), Mr James Kandulu (CHSU-Lab), Mr Blackson Matatiyo (NAC), Mr John B. Chipeta (NAC), Mr Melachias Mwale and Dr. Ben Chilima (CHSU-Lab), for taking the lead in conducting the survey and compiling this report, Dr O’Carlo for editing the document. Thanks also go to Dr. Habib Somanje (Director of Preventive Health Services-MOH) for overall direction in the implementation of the survey and Mr John Aberle-Grasse (CDC-GAP) and Ms Erica Kufa (WHO-AFRO) for providing technical support for production of this report.
The following are acknowledged for their invaluable contributions towards this report; Dr Biziwick Mwale, Dr. Erasmus Morah, Mrs Neema J. Kandoole, Mr Roy Hauya, Mr Cosby Nkwazi, Dr Dorothy Namate, Prof. Anthony Harries, Dr Edwin Libamba, Dr Erik Schouten, Dr Edwin Limbambala, Mrs Nellie Kabwazi. The MOH further wishes to acknowledge Mr H. Mtengo, Mr S. Nazombe and Mrs G. Mwale from the Epidemiology Unit for entering the HIV sentinel surveillance data.
For questions or further information contact George Bello, Epidemiology Unit CHSU, MOH, or +265 8 892 212Table of Contents
1.0Executive Summary...... 5
2.0Introduction...... 7
3.0Background...... 7
4.0Objectives...... 8
5.0Methodology...... 9
5.1Sentinel Population...... 9
5.2Sentinel Site Selection...... 9
5.3Sampling...... 9
5.4Specimen Handling and Laboratory Testing...... 9
5.5Quality Control and Assurance...... 10
5.6Syphilis Case Management...... 10
5.7Data Management...... 10
5.8Estimation and Projection...... 11
5.9Limitations...... 13
6.0Results...... 14
6.1Demographic Distribution of the Sample......
6.2HIV Prevalence......
6.3Syphilis Prevalence...... 20
6.4HIV and Syphilis Trends...... 21
6.5Estimates and Projections......
7.0Discussion......
8.0Conclusion and Recommendations...... 26
Glossary......
Annex 1 Second Generation Surveillance...... 29
Annex 2 Antenatal Serosurveillance Survey form...... 30
Annex 3 Curve Fitting...... 32
Annex 4 Spectrum PMTCT and ART targets...... 38
Annex 5 Additional Estimates and Projections from Spectrum...... 38
1.0Executive Summary
This report presents findings from the Malawi 2005 antenatal clinic (ANC) sentinel surveillance and results of the National HIV Prevalence Estimates and Projections workshop.
The primary objective of ANC sentinel surveillance was to provide data on the occurrence and distribution of HIV infection among women attending antenatal clinics. HIV sentinel surveillance data are not representative of the general population. However, sentinel surveillance data have been used as input to develop estimates of HIV prevalence in the general population.
The 2005 ANC sentinel surveillance was carried out in nineteen sites distributed across all three regions of the country, as it has been since 1994. A total of 8,953 pregnant women were captured in the survey from 1st August 2005 through end September 2005. Over 80% of the women sampled were less than 30 years of age and about 60% aged less than 25 years. The age pattern of the women recruited in the survey is very similar to the previous surveys done since 1998.
The overall HIV prevalence for all antenatal attendees in 2005, was 16.9%. The median HIV prevalence in 2005 was 15.0%, and has declined from 2003 (17.0 %), 2001 (16.9%) and in 1999 (22.8%). Median prevalence is a better figure to compare to previous years since it is not affected by changes in site sample size, and is less effected by extreme site results.
Site-specific HIV prevalence ranged from 6.3% at Thonje Health Centre, a rural site in the central region to 27.0% at Limbe Health Centre, an urban site in the southern region of the country. HIV prevalence in the southern region (21.7%) remains higher than in the northern (14.0%) and central (14.3%) regions. Overall HIV prevalence in the urban (20.4%) areas continued to be high and significantly different from semi urban (17.0%) and rural areas (13.0%)
HIV prevalence was significantly higher among women with post secondary school education (33.3%) as compared to women with no education (17.9%) and those reporting to have gone up to std 1-5 (16.1%) and std 6-8 (15.4%).
Overall syphilis prevalence was 1.9%. Prevalence of syphilis ranged from 0% in Gawanani, Kasina Thonje and Mzuzu Health Centres to 10.8% in Nsanje. There was a direct relationship between age and syphilis infection from 15 to 44 years of age. Syphilis prevalence rates among women by age group were as follows; 15-19 (1.1%), 20-24(1.5%) 25-29 (2.3%) 30-34 (2.7%) 35-39 (3.8) and 40-44 (5.1%). The observed syphilis prevalence rates across regions are not statistically different. However, syphilis prevalence in the southern region (2.4%) remains higher than the central (1.8%) and northern (1.6%) regions. Overall, there appears to be a decline in syphilis prevalence over the years.
There was a general association between HIV and syphilis infection in the study sample. This result shows that syphilis and HIV were not occurring independently.
The 2005 sentinel surveillance survey results have been used to estimate national HIV prevalence in Malawi using internationally recommended methods; antenatal clinic data and the modeling computer software Estimation and Projection Package (EPP) and Spectrum.
The estimated HIV/AIDS prevalence in adults (15 to 49 years) in Malawi in 2005 is 14.0%, with a range from 12% to 17% giving a total of 790,000 infected adults. The analysis indicates that levels of HIV infection in the adult population of Malawi have remained constant for the last nine years. The prevalence estimate was 21.6% in urban areas and 12.1% in rural areas
The stable prevalence at 12 to 17 percent does not mean the HIV/AIDS problem has gone away. Every year at least 86,592 people are dying from AIDS and as many as 96,552 new infections occur. . The stable high prevalence could be attributed to high incidence in the younger age groups, especially adolescents (15-19 years).
Infection levels are above 10 percent in all sentinel sites except three rural sites in the Central Region. HIV prevalence is very high, 23.1 - 27 percent, in Blantyre, Mulanje and Nsanje.
The total number of people infected with HIV is estimated to be between 780,000 and 1,120,000 people in 2005. This figure includes 69,000 – 100,000 children under the age of 15 who are infected. One-third of those infected live in urban areas and two-thirds in rural areas.
A total of 187,336 people living with HIV and AIDS (PLWHA) were in need of antiretroviral therapy (ART) in 2005 and it was projected that by the end of 2010, a total of 233,675 PLWHA would be in need of ART. The estimates and projections for AIDS cases and deaths, adults and children needing ART are based on the assumptions that ART coverage will increase to 50% and prevention of mother to child transmission (PMTCT) coverage will increase to 433,000 pregnant women by 2010.
2.0Introduction
HIV/AIDS is a major public health problem in Malawi. It is the leading cause of death in young adults, the most economically productive age group. The continuing high rates of infant and child mortality in the country have been attributed to HIV/AIDS.
HIV sentinel surveillance in pregnant women attending ANC is the main source of data for routinely monitoring HIV prevalence trends. In Malawi, this system was established in 1994 in 19 sites and these have been maintained up to now. The 2005 HIV sentinel survey was conducted for a period of up to 8 weeks starting from 1 August 2005.
Results of the HIV sentinel survey were used to estimate and project the national prevalence, incidence and impact. This was done using EPP and Spectrum modeling software developed by UNAIDS and WHO.
This report presents the findings of the 2005 HIV sentinel survey. The trends in HIV and syphilis prevalence are also presented. The report summarizes the methodology for the survey and the process for estimation and projection. National estimates for HIV prevalence and incidence, AIDS incidence and mortality and impact are also presented.
The report is expected to be used by programme managers, policy makers, academics, NGOs, UN Agencies, partners and other stakeholders involved in HIV/AIDS as a resource for monitoring and evaluation as well as advocacy.
3.0Background
Malawi is classified as a least developed country on the UN human development index. Between the 1992 and 1998, the Gross Domestic Product (GDP) per capita decreased from US$ 200 to US$ 165[1]. The Malawi National Human Development Report, 2001[2] estimates the national poverty incidence at 65.3%, of which 66.5% and 54.9% are rural and urban poverty incidences respectively.
The projected population for 2005 according to the last Malawi Population Census is estimated at about 12.5 million, with an annual growth rate of 3.3%[3]. The Census showed that the national sex ratio was 96 males per 100 females. Malawi also has a high fertility rate of 6.2 children per woman due to early child bearing, a low contraceptive prevalence rate, high female illiteracy rates, and desire for large families2,3. This puts a huge stress on the country’s limited land and natural resources, and social services. Most Malawians live in rural areas, though it is expected that by 2015, 44% of Malawians will be living in urban areas, a substantial increase from the 24% as was reported in 19992.
The HIV epidemic in Malawi started in the early 1980s and the first AIDS case was reported and confirmed in 1985, in Blantyre. Several studies were conducted in different sub populations to determine HIV and AIDS prevalence and to identify risk factors. However, the studies focussed on urban sub-populations. By 1990, routine data on pregnant women attending antenatal clinics (ANC) were collected in selected sites across the country.
Sentinel surveillance is the serial collection of HIV prevalence data over time and place in selected sites and groups of population in order to monitor trends in HIV infection and demographic variations in HIV prevalence. According to WHO/UNAIDS, HIV/AIDS epidemics are classified as low level, concentrated or generalised[4]. Malawi is experiencing a generalised epidemic, that is HIV prevalence among pregnant women attending ANC is consistently more than 1%. HIV is mainly transmitted through unprotected intercourse with an infected partner. In a generalised epidemic, HIV sentinel surveillance among pregnant women is the standard method for monitoring trends in HIV infection.
The HIV sentinel surveillance system was established in 1994 with data being collected from 19 sites. The sites were selected to represent the 3 regions of the country and the urban, semi-urban and rural areas. To date, nine sentinel surveys have been conducted from 1994-2000, 2001, 2003 and 2005.
4.0Objectives
The general objective was to provide data for monitoring and evaluating HIV and AIDS programmes in Malawi.
The specific objectives were:
To determine the HIV and syphilis prevalence among pregnant women presenting at antenatal care clinics.
To determine trends in HIV and syphilis prevalence among pregnant women presenting antenatal care clinics.
To estimate the national HIV and AIDS prevalence, incidence, mortality and impact.
To project national HIV and AIDS prevalence, incidence, mortality and impact.
5.0Methodology
5.1 Sentinel Population
All women regardless of age, attending antenatal clinic for the first visit during the current pregnancy were sampled for the study.
5.2 Sentinel Site Selection
The nineteen sites that have been used since 1994 were included in 2005. These sites are classified as urban, semi-urban and rural. Urban sites consisted of Limbe Health Centre in Blantyre, Lilongwe Bottom Hospital and Mzuzu Health Centre. Semi-urban sites comprised district and mission hospitals. Health centres away from urban or semi-urban areas are classified as rural sentinel sites. All the three urban sites were purposefully selected to get a picture of HIV prevalence in the three Malawian cities of Blantyre, Lilongwe and Mzuzu. On the other hand, the semi-urban and rural sites were selected through simple random sampling after stratifying by region and locality (semi-urban and rural).
5.3 Sampling
5.3.1Sample size
The target sample sizes were 300 women in rural sites, 500 women in semi-urban sites and 800 women in urban sites. Previously, 200 women were sampled in rural sites. Routine demographic data including age, gravidity, level of education, marital status, occupation of the mother and her partner were collected before drawing blood specimens.
5.3.2Sampling scheme
Every consecutive woman attending antenatal clinic services for the first time during the current pregnancy was enrolled throughout the survey period in all the 19 sites.
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5.3.3Sampling Period
Sampling was done for a period of up to 8 weeks starting on 1 August 2005.
5.3.4.Inclusion and Exclusion Criteria
All women attending ANC for the first time during the current pregnancy were included in the survey. Women attending ANC for a repeat visit were excluded.
5.4 Specimen Handling and Laboratory Testing
Blood samples were collected using dried blood spots (DBS) on filter paper cards. In rural sites sample collection was conducted by mobile teams of laboratory technicians, whereas in semi-urban and urban sites procedures were carried out by technicians at the respective sentinel sites. All DBS were labelled with unique identification numbers with the corresponding data collection instrument and were transported to the Community Health Sciences Unit (CHSU) Lab for anonymous and unlinked HIV testing.
All women were screened for syphilis on site using Determine syphilis rapid tests. All reactive samples were considered to be infected with syphilis and the women were offered treatment onsite. All DBS cards were tested for HIV using Vironostika ELISA assay reference at the CHSU reference laboratory in accordance with the standard procedures. All samples reactive to this single test were regarded as HIV positive.
5.5 Quality Control and Assurance
Supervisory visits were organized during the survey period to ensure that blood samples and demographic data were collected according to protocols.
Potency of reagents, technical irregularities by different technicians and performance of ELISA reading machines were controlled for by external quality control samples as well as those provided with the test kits to standardize the results. Also, CHSU participates in external quality assurance with the CDC Laboratories in Atlanta and the WHO External Assurance programme.
5.6 Syphilis Case Management
All women reactive to the Determine rapid syphilis test on site were treated with a single 2.4 MU intramuscular injection of Benzathine Penicillin G. Women presenting with vaginal sores in addition to the rapid test result were also prescribed Erythromycin orally for five days. In cases of allergy to Penicillin, Erythromycin to be taken orally six-hourly for fifteen days was provided. Syphilis reactive women were also encouraged to bring their partners and any other contacts for treatment.
5.7 Data Management
All data were entered into an Epi Info computer database at the CHSU. Verification of data entry was done through exploratory analysis to identify inaccuracies in data entry or collection. Discrepant entries especially on HIV and syphilis test results were examined by checking all the entries using the field data collection instrument. Data entry errors were then corrected. Data analysis was also carried out in Epi Info for windows version 3.2.