Risk of Mycobacterium tuberculosis transmission in an antiretroviral therapy clinic.

Objective: The risk of transmission of Mycobacterium tuberculosis in antiretroviral therapy (ART) clinics is recognized, particularly, when HIV and tuberculosis services are unified, but the degree of potential exposure to patients with infectious tuberculosis has not been measured. We aimed to quantify this clinic exposure.

Methods: Over 1 year, we recorded all visits to a clinic in northern Malawi that offers HIV testing and counselling, HIV care, ART, and TB diagnostic and treatment services.

Association between socioeconomic position and tuberculosis in a large population-based study in rural Malawi.

Setting: There is increasing interest in social structural interventions for tuberculosis. The association between poverty and tuberculosis is well established in many settings, but less clear in rural Africa. In Karonga District, Malawi, we found an association between higher socioeconomic status and tuberculosis from 1986-1996, independent of HIV status and other factors.

Monitoring the impact of decentralised chronic care services on patient travel time in rural Africa--methods and results in Northern Malawi.

Background: Decentralised health services form a key part of chronic care strategies in resource-limited settings by reducing the distance between patient and clinic and thereby the time and costs involved in travelling. However, few tools exist to evaluate the impact of decentralisation on patient travel time or what proportion of patients attend their nearest clinic. Here we develop methods to monitor changes in travel time, using data from the antiretroviral therapy (ART) roll-out in a rural district in North Malawi.

Very early anthropometric changes after antiretroviral therapy predict subsequent survival, in karonga, Malawi.

Background: Antiretroviral (ART) scale-up in Malawi has been achieved on a large scale based mainly on clinical criteria. Simple markers of prognosis are useful, and we investigated the value of very early anthropometric changes in predicting mortality.

Principal Findings: Adult patients who initiated ART in Karonga District, northern Malawi, between September 2005 and August 2006 were included in a prospective cohort study, and followed for up to one year.

What happens to ART-eligible patients who do not start ART? Dropout between screening and ART initiation: a cohort study in Karonga, Malawi.

Background: Routine ART programme statistics generally only provide information about individuals who start treatment. We aimed to investigate the outcome of those who are eligible but do not start ART in the Malawi programme, factors associated with this dropout, and reasons for not starting treatment, in a prospective cohort study.

Methods: Individuals having a first screening visit at the ART clinic at Karonga District Hospital, northern Malawi, between September 2005 and July 2006 were interviewed.

Declining child mortality in northern Malawi despite high rates of infection with HIV.

Objective: To determine whether routine surveys, such as the Demographic and Health Surveys (DHS), have underestimated child mortality in Malawi.

Methods: Rates and causes of child mortality were obtained from a continuous-registration demographic surveillance system (DSS) in Malawi for a population of 32 000. After initial census, births and deaths were reported by village informants and updated monthly by project enumerators.

Child mortality in rural Malawi: HIV closes the survival gap between the socio-economic strata.

Background: As HIV-related deaths increase in a population the usual association between low socioeconomic status and child mortality may change, particularly as death rates from other causes decline.

Methods/principal Findings: As part of a demographic surveillance system in northern Malawi in 2002-6, covering a population of 32,000, information was collected on socio-economic status of the households. Deaths were classified as HIV/AIDS-related or not by verbal autopsy.

Implication of new WHO growth standards on identification of risk factors and estimated prevalence of malnutrition in rural Malawian infants.

Background: The World Health Organization (WHO) released new Child Growth Standards in 2006 to replace the current National Center for Health Statistics (NCHS) growth reference. We assessed how switching from the NCHS to the newly released WHO Growth Standards affects the estimated prevalence of wasting, underweight and stunting, and the pattern of risk factors identified.

Methodology/principal Findings: Data were drawn from a village-informant driven Demographic Surveillance System in Northern Malawi.

Assessment and evaluation of contact as a risk factor for tuberculosis in rural Africa.

Setting: A rural district in Malawi.

Objective: To determine the effect of inaccurate recall on estimates of the proportion of tuberculosis (TB) cases attributable to contact with identifiable prior cases.

Design: Case-control study of laboratory-confirmed TB cases and community controls, comparing family, household and area contacts identified from a database of TB cases with those named at interview.

Population-level effect of HIV on adult mortality and early evidence of reversal after introduction of antiretroviral therapy in Malawi.

Background: Malawi, which has about 80,000 deaths from AIDS every year, made free antiretroviral therapy available to more than 80 000 patients between 2004 and 2006. We aimed to investigate mortality in a population before and after the introduction of free antiretroviral therapy, and therefore to assess the effects of such programmes on survival at the population level.

Methods: We used a demographic surveillance system to measure mortality in a population of 32,000 in northern Malawi, from August, 2002, when free antiretroviral therapy was not available in the study district, until February, 2006, 8 months after a clinic opened.

Ascertainment of childhood vaccination histories in northern Malawi.

Objective: To assess factors related to recorded vaccine uptake, which may confound the evaluation of vaccine impact.

Methods: Analysis of documented vaccination histories of children under 5 years and demographic and socio-economic characteristics collected by a demographic surveillance system in Karonga District, Malawi. Associations between deviations from the standard vaccination schedule and characteristics that are likely to be associated with increased mortality were determined by multivariate logistic regression.

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.

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.

Tuberculosis: associations with HIV and socioeconomic status in rural Malawi.

Tuberculosis (TB) is associated with human immunodeficiency virus (HIV) infection, increasing age and male sex, but less is known about other risk factors in developing countries. As part of the Karonga Prevention Study in northern Malawi, we conducted a retrospective cohort study in the general population to assess risk factors for the development of TB. Individuals were identified in 1986-89 and TB cases diagnosed up to 1996 were included.