Incidence of TB and HIV in Prospectively Followed Household Contacts of TB Index Patients in South Africa

Cari Van Schalkwyk,Alex Welte,Neil Martinson,Limakatso Lebina,Modiehi Rakgokong,Adrienne E Shapiro,Ebrahim Variava,Katlego Masonoke,Robert J Wilkinson

doi:10.1371/journal.pone.0095372

Abstract

ObjectiveTo report the incidence rates of TB and HIV in household contacts of index patients diagnosed with TB.DesignA prospective cohort study in the Matlosana sub-district of North West Province, South Africa.MethodsContacts of index TB patients received TB and HIV testing after counseling at their first household visit and were then followed up a year later, in 2010. TB or HIV diagnoses that occurred during the period were determined.ResultsFor 2,377 household contacts, the overall observed TB incidence rate was 1.3 per 100 person years (95% CI 0.9–1.9/100py) and TB incidence for individuals who were HIV-infected and HIV seronegative at baseline was 5.4/100py (95% CI 2.9–9.0/100py) and 0.7/100py (95% CI 0.3–1.4/100py), respectively. The overall HIV incidence rate was 2.2/100py (95% CI 1.3–8.4/100py).ConclusionsIn the year following a household case finding visit when household contacts were tested for TB and HIV, the incidence rate of both active TB and HIV infection was found to be extremely high. Clearly, implementing proven strategies to prevent HIV acquisition and preventing TB transmission and progression to disease remains a priority in settings such as South Africa.

Highlights

South Africa has an estimated annual tuberculosis (TB) incidence rate of 1.0 per 100 population [1]
In the year following a household case finding visit when household contacts were tested for TB and human immunodeficiency virus (HIV), the incidence rate of both active TB and HIV infection was found to be extremely high
Implementing proven strategies to prevent HIV acquisition and preventing TB transmission and progression to disease remains a priority in settings such as South Africa

Summary

Introduction

South Africa has an estimated annual tuberculosis (TB) incidence rate of 1.0 per 100 population (95% CI 0.8–1.2) [1]. There are several studies from high burden countries describing the prevalence of HIV and TB in contacts of TB index cases, but few describe TB incidence over a prospective follow up period, and none, that we are aware of, where HIV incidence was determined simultaneously [3,4,5,6] Incidence measures of both TB and HIV are important for those planning or implementing household-based active case finding strategies, which have shown some promise in controlling TB [7,8], and for policy makers to base decisions on the utility of a second or third visit to the household of an index TB patient. This study describes the incidence of TB and HIV in household contacts of TB index patients in a very high TB and HIV burden setting

Methods

Results

Conclusion