Performance of commercially available enzyme immunoassays for detection of antibodies against herpes simplex virus type 2 in African populations.

Data are accumulating on the performance of enzyme immunoassays (EIAs) for the detection of herpes simplex virus type 2 (HSV-2) infection in North America and Europe, but little is known about their performance in other populations. Nine test kits were evaluated with 330 serum samples from sub-Saharan Africa. The tests were first compared to the monoclonal antibody (MAb) EIA (Central Public Health Laboratory, London, United Kingdom).

Trends in tuberculosis and the influence of HIV infection in northern Malawi, 1988-2001.

Objective: To document the changing incidence and patterns of tuberculosis (TB) in rural Africa and the extent to which they are influenced by HIV.

Methods: As part of longstanding epidemiological studies in Karonga District, Malawi, a series of case control studies of TB and HIV were conducted from 1988 onwards. Data from these studies, from a total population survey, and from the Malawi national census have been used to reconstruct the changes in the TB epidemic in the area from 1988 to 2001, examining the role of HIV.

Tuberculosis and gender: exploring the patterns in a case control study in Malawi.

Background: In many populations there is an excess of tuberculosis in young women and older men. We explored possible explanations for these patterns, concentrating on human immunodeficiency virus (HIV) status, pregnancy, smoking, cooking smoke exposure, contact with tuberculosis cases within the household or outside, and gender differences in health service usage and diagnostic delay.

Design: Case control study in Karonga District, Malawi.

Induced abortion among women attending antenatal clinics in Yaounde, Cameroon.

Objectives: Unsafe abortion is a public health concern because of its impact on maternal morbidity and mortality. The objective of this study was to document on induced abortion in Yaounde, Cameroon.

Design: Cross-sectional study.

HIV and pulmonary tuberculosis: the impact goes beyond those infected with HIV.

Background: HIV infection increases the risk of tuberculosis. The HIV epidemic is also likely to have an indirect effect on the incidence of tuberculosis because of the increased number of infectious individuals in the population. This should be apparent as an increase in tuberculosis among HIV-negative individuals, but this has not previously been demonstrated directly.

Does increased general schooling protect against HIV infection? A study in four African cities.

Background: The association between educational attainment and risk of HIV infection varies between populations and over time. Earlier studies in sub-Saharan Africa have found that those with more education are at increased risk of HIV infection.

Methods: We investigated the associations between general schooling and both HIV and herpes simplex-2 (HSV-2) infection using data from the multicentre study on factors determining the differential spread of HIV in four African cities.

Mycobacterium tuberculosis Beijing genotype.

Molecular epidemiologic studies of strains of Mycobacterium tuberculosis are currently conducted worldwide. The genetically distinct Beijing family of strains has been associated with large outbreaks of tuberculosis, increased virulence, and multidrug resistance. However, in this first population-based search for Beijing strains in the Danish DNA fingerprint database, analysis of 97% of all culture-positive tuberculosis patients in 1992 to 2001 showed that 2.

Trends and measurement of HIV prevalence in northern Malawi.

Background: Most data on HIV prevalence in Malawi come from antenatal clinic (ANC) surveillance and are, therefore, subject to bias.

Objectives: HIV prevalence and risk factors were measured using population-based data to assess the accuracy of ANC surveillance and changes in prevalence and risk factors for HIV over time.

Methods: HIV prevalence was measured in 1988-1993 and 1998-2001 in community controls from case-control studies of mycobacterial disease in Karonga District, Malawi.

HIV risk in relation to marriage in areas with high prevalence of HIV infection.

In sub-Saharan Africa, the prevalence of HIV infection among young women is much higher than that among young men. Many women enter marriage HIV-infected, suggesting that men may be predominantly infected by their wives. Using data from cross-sectional surveys in Kisumu, Kenya, and Ndola, Zambia, in 1997, the prevalence of HIV infection at marriage was estimated from age at marriage and age- and sex-specific prevalence of HIV infection among unmarried individuals.

Highly divergent HIV type 1 group M sequences evident in Karonga District, Malawi in early 1980s.

Six divergent HIV-1 partial env and gag genome sequences have been characterized in five subjects in Malawi, from whom blood spot samples were collected between 1982 and 1989, at the time that the AIDS epidemic there was starting. These sequences could not be classified with any of the recognized subtypes or circulating recombinant forms of HIV-1. They showed no consistent and/or supported associations with other subtypes by either env or gag gene phylogenetic analysis.

Age-related changes in mature CD4+ T cells: cell cycle analysis.

T cell proliferative responses decrease with age, but the mechanisms responsible are unknown. We examined the impact of age on memory and naive CD4(+) T cell entry and progression through the cell cycle using acridine orange to identify cell cycle stage. For both subsets, fewer stimulated cells from old donors were able to enter and progress through the first cell cycle, with an increased number of cells arrested in G(0) and fewer cells in post G(0) phases.

Gut overgrowth with abnormal flora: the missing link in parenteral nutrition-related sepsis in surgical neonates.

Background And Aims: Patients receiving parenteral nutrition are at risk of septicaemia. Intestinal dysmotility and impaired gut immunity due to parenteral nutrition promote bacterial overgrowth. Gut overgrowth with aerobic Gram-negative bacilli (AGNB) impairs systemic immunity.

The long-term impact of HIV and orphanhood on the mortality and physical well-being of children in rural Malawi.

Objective: To assess the influence of maternal HIV status and orphanhood on child mortality and physical well-being.

Design: Retrospective cohort study with > 10 years of follow-up.

Methods: From population-based surveys in Karonga District, Malawi in the 1980s, 197 individuals were identified as HIV-positive.

Early evolution of the human immunodeficiency virus type 1 subtype C epidemic in rural Malawi.

We have tracked the early years of the evolution of the human immunodeficiency virus type 1 (HIV-1) epidemic in a rural district of central east Africa from the first documented introductions of subtypes A, D, and C to the present predominance of subtype C. The earliest subtype C sequences ever reported are described. Blood samples were collected on filter papers from 1981 to 1984 and from 1987 to 1989 from more than 44,000 individuals living in two areas of Karonga District, Malawi.

The evolving epidemiology of HIV infection and tuberculosis in northern Thailand.

Objectives: To examine the association between HIV infection and tuberculosis (TB) and the proportion of TB attributable to HIV in Chiang Rai province, northern Thailand, in response to a rapidly changing incidence of HIV infection.

Methods: Case-control study covering the period 1990 to 1998. Cases were all new TB patients seen at Chiang Rai Hospital.

Worldwide occurrence of Beijing/W strains of Mycobacterium tuberculosis: a systematic review.

Strains of the Beijing/W genotype family of Mycobacterium tuberculosis have caused large outbreaks of tuberculosis, sometimes involving multidrug resistance. This genetically highly conserved family of M. tuberculosis strains predominates in some geographic areas.

Long-term follow-up of HIV-positive and HIV-negative individuals in rural Malawi.

Objective: To measure the effect of HIV on survival in rural Africa.

Design: A retrospective cohort study with more than 10 years follow-up.

Methods: Individuals with known HIV status in the 1980s were identified from previous population surveys in Karonga District, northern Malawi.

Educational attainment and HIV-1 infection in developing countries: a systematic review.

Objectives: To assess whether educational status is associated with HIV-1 infection in developing countries by conducting a systematic review of published literature.

Methods: Articles were identified through electronic databases and hand searching key journals. Studies containing appropriately analysed individual level data on the association between educational attainment and HIV-1 status in general population groups were included.

HIV-1 and recurrence, relapse, and reinfection of tuberculosis after cure: a cohort study in South African mineworkers.

Background: The proportion of recurrent tuberculosis cases attributable to relapse or reinfection and the risk factors associated with these different mechanisms are poorly understood. We followed up a cohort of 326 South African mineworkers, who had successfully completed treatment for pulmonary tuberculosis in 1995, to determine the rate and mechanisms of recurrence.

Methods: Patients were examined 3 and 6 months after cure, and then were monitored by the routine tuberculosis surveillance system until December, 1998.

Comparison of two versus three smears in identifying culture-positive tuberculosis patients in a rural African setting with high HIV prevalence.

Setting: Karonga district, northern Malawi.

Objective: To compare the sensitivity and specificity of two versus three smears for the diagnosis of pulmonary tuberculosis in a setting with high HIV prevalence.

Design: A total of 1992 pulmonary tuberculosis suspects with three sputum smears taken over a 2-7 day period and at least one culture result were studied.

Field-based random sampling without a sampling frame: control selection for a case-control study in rural Africa.

Selection bias, particularly of controls, is common in case-control studies and may materially affect the results. Methods of control selection should be tailored both for the risk factors and disease under investigation and for the population being studied. We present here a control selection method devised for a case-control study of tuberculosis in rural Africa (Karonga, northern Malawi) that selects an age/sex frequency-matched random sample of the population, with a geographical distribution in proportion to the population density.

Condom use and its association with HIV/sexually transmitted diseases in four urban communities of sub-Saharan Africa.

Objectives: To estimate rates of condom use in four urban populations in sub-Saharan Africa and to assess their association with levels of HIV infection and other sexually transmitted diseases (STDs).

Methods: Data were obtained from a multicentre study of factors that determine the differences in rate of spread of HIV in four African cities. Consenting participants were interviewed on sexual behaviour, and also provided blood and urine samples for testing for HIV infection and other STDs.

Why do young women have a much higher prevalence of HIV than young men? A study in Kisumu, Kenya and Ndola, Zambia.

Objective: To examine the factors responsible for the disparity in HIV prevalence between young men and women in two urban populations in Africa with high HIV prevalence.

Design: Cross-sectional survey, aiming to include 1000 men and 1000 women aged 15-49 years in Kisumu, Kenya and Ndola, Zambia.

Methods: Participants were interviewed and tested for HIV and other sexually transmitted infections.

Interpreting sexual behaviour data: validity issues in the multicentre study on factors determining the differential spread of HIV in four African cities.

Background: The main conclusion of the multicentre study on factors determining the differential spread of HIV in four African cities was that differences in sexual behaviour could not, by themselves, explain the differences in HIV prevalence between the four cities. The present paper examines three potential sources of bias that could invalidate this conclusion: (1) changes in sexual behaviour since the start of the HIV epidemics; (2) bias due to the low response rates of men; and (3) bias in reported sexual behaviour.

Methods: To assess whether there have been any changes in sexual behaviour over time, selected parameters of sexual behaviour were compared between different age groups in the four cities.