The potential to transmit Mycobacterium tuberculosis at a South African tertiary teaching hospital

Abstract

Objectives To assess the risk of nosocomial transmission by confirmed pulmonary tuberculosis (PTB) patients in a high TB/HIV incidence environment. Methods Between November 2006 and April 2007, we carried out a cross-sectional survey of PTB patients with positive smears or cultures at an academic tertiary hospital in the Western Cape, South Africa. Results Of 394 confirmed PTB patients, only 199 (50.5%) had a known HIV status, of whom 107 (53.8%) were HIV-co-infected. Sensitivity testing for Mycobacterium tuberculosis (TB) was done in 49.3% of patients with available cultures (140/284). Of these patients, 9.3% (13/140) had multidrug-resistant (MDR) TB strains. The turnaround times (TAT) for culture and susceptibility testing were delayed: mean TAT for cultures was 27 days (range 63 days) and for susceptibility testing was 42 days (range 63 days). One fifth of PTB patients (82/394) were diagnosed from wards that do not deal with TB on a daily basis. PTB inpatients were hospitalized for an average of 13 days and were on average transferred twice. Only 14.2% of all PTB patients were notified to the South Africa Provincial Department of Health. Throughout their hospitalization, PTB patients were potentially infectious. Conclusions The potential for nosocomial TB transmission in a setting of high TB and HIV co-infection with a high MDR prevalence, inconsistent infection prevention and control measures, and delayed diagnosis cannot be ignored. Barriers to TB infection control must urgently be addressed.