Potential for nosocomial transmission of multidrug-resistant (MDR) tuberculosis in a South African tertiary hospital

Abstract

Tuberculosis (TB) is a major health problem in the Western Cape, with an incidence exceeding 900 per 100 000 people. Nosocomial transmission of TB, and particularly drug-resistant TB, is a potential risk that may be undetected. Rapid diagnosis and rapid institution of effective anti-TB treatment, combined with appropriate infection control measures, are essential to prevent nosocomial transmission of TB. To estimate the potential for nosocomial transmission, we aimed to determine the in-hospital delays in diagnosis and treatment of patients with multidrug-resistant (MDR)-TB at a tertiary care hospital. A descriptive study, based on retrospective review of patient records and laboratory data, including all adult patients (>13 years) where TB culture and susceptibility testing confirmed MDR- TB on specimens submitted to Tygerberg Hospital's National Health Laboratory Service (NHLS) laboratory in 2007. Thirty-one patients with MDR-TB were identified. The median laboratory turnaround time (TAT) from collection of specimen to confirmation of MDR-TB was 40 days, while the median time from the time of first presentation at Tygerberg Hospital to institution of MDR treatment was 44 days. Twenty patients were considered infectious during their hospital stay, generating 345 inpatient infectious days. The study suggests that there is an ongoing substantial risk for nosocomial transmission of MDR-TB at Tygerberg Hospital. We propose improvements, including the use of rapid drug susceptibility testing. The consistent application of infection control measures to prevent nosocomial spread of TB, including MDR-TB, remains vital.