HIV and the risk of tuberculosis due to recent transmission over 12 years in Karonga District, Malawi☆

Received 6 March 2009; received in revised form 11 March 2009; accepted 12 March 2009.

Summary

Tuberculosis (TB) patients with strains common to other recent cases (‘clustering’) suggest recent transmission. HIV status and age may affect proportions clustered. We investigated TB clustering by HIV and age in a population-based study in Malawi. Among 746 patients, HIV infection increased the proportion clustered. Sex-period-adjusted odds ratios for the association of HIV and clustering were 1.26 (95% CI 0.4–4.1) for ages 15–25 years, 1.40 (0.9–2.3) for 25–50 years and 10.44 (2.3–47.9) for >50 years and remained stable over two periods examined. These results suggest that HIV increases the proportion of TB due to recent transmission in the elderly.

Keywords: HIV, Tuberculosis, Mycobacterium tuberculosis, Molecular epidemiology, Transmission, Malawi

a Karonga Prevention Study, Malawi

b Infectious Disease Epidemiology Unit, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK

c Pathogen Molecular Biology Unit, London School of Hygiene and Tropical Medicine, London, UK

d Mycobacterium Reference Unit, Health Protection Agency, London, UK

Corresponding author. Tel.: +44 20 7927 2668; fax: +44 20 7637 4314.

☆ Based on a presentation to the Royal Society of Tropical Medicine & Hygiene Research in Progress meeting on 18 December 2008. This oral presentation was awarded third prize at the meeting.

✠ Deceased.

PII: S0035-9203(09)00099-6

doi:10.1016/j.trstmh.2009.03.013

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