Tuberculosis in Rural Vietnam | CDC EID

Volume 16, Number 9–September 2010
Dispatch
Tuberculosis Acquired Outside of Households, Rural Vietnam
Tran N. Buu, Dick van Soolingen, Mai N.T. Huyen, Nguyen N.T. Lan, Hoang T. Quy, Edine W. Tiemersma, Martien W. Borgdorff, and Frank G.J. Cobelens

Author affiliations: Pham Ngoc Thach Tuberculosis and Lung Disease Hospital, Ho Chi Minh City, Vietnam (T.N. Buu, M.N.T. Huyen, N.N.T. Lan, H.T. Quy); National Institute of Public Health and the Environment, Bilthoven, the Netherlands (D. van Soolingen); KNCV Tuberculosis Foundation, The Hague, the Netherlands (E.W. Tiemersma); and Academic Medical Centre, Amsterdam, the Netherlands (M.W. Borgdorff, F.G.J. Cobelens)

Suggested citation for this article

Abstract
Using population-based data from rural Vietnam, we assessed tuberculosis (TB) transmission within and outside of households. Eighty-three percent of persons with recent household TB were infected by different strains of Mycobacterium tuberculosis than were their household members. This result argues against the effectiveness of active TB case finding among household members.

Because of airborne transmission of Mycobacterium tuberculosis, persons who share a household with persons who have tuberculosis (TB) are at high risk for infection (1). In urban settings in South Africa, studies using DNA fingerprinting that found high TB transmission and HIV prevalence up to 5% suggested that more TB transmission occurs outside households than previously assumed (2,3). Few data exist for other settings that have a high incidence of TB, particularly rural areas in Asia where HIV prevalence is low.

In Vietnam, TB incidence is high; 70% of the population live in rural areas where the average HIV prevalence in adults is <0.5% (4). A recent survey showed TB prevalence to be higher than assumed, which suggests that case finding is inadequate (5). Improving TB case finding is thus a priority for TB control in Vietnam. To assess the value of active case finding among household contacts of patients with infectious TB, we studied within- and outside-household TB transmission, using data collected in a population-based study in rural southern Vietnam. The characteristics of the study site have been described elsewhere (6).

open here to see the full-text:
Tuberculosis in Rural Vietnam | CDC EID