Culture confirmed multidrug resistant tuberculosis: diagnostic delay, clinical features, and outcome

To determine the delay in diagnosis of multidrug resistant (MDR) tuberculosis (TB), the correlation between drug susceptibility patterns of adult-child contact pairs, the effectiveness of treatment, and the outcome in these children.

MDR M tuberculosis culture results of children were prospectively collected during a four year period in the Western Cape Province of South Africa, an area with a TB incidence of 589/100 000 population, and a new MDR TB rate of 0.94%. Folder reviews were done to retrieve clinical information. Children not already on treatment at our MDR TB clinic or TB hospital were recalled and appropriate treatment was started. Follow up was done for as long as possible.

Thirty nine children, median age 4.5 years at first TB diagnosis and 6.2 years on MDR culture confirmation, were seen. Delay in starting appropriate MDR treatment after TB diagnosis was a median of 2 days if MDR TB source cases were taken into account, but 246 days if the drug susceptibility pattern of the source case was not considered, and 283 days if there was no known tuberculosis source case. Correlation between the drug susceptibility results of the child's and adult source case's isolates was 68%. Seventeen children had smear positive tuberculosis, of whom 13 had cavitatory pulmonary disease. Eight children had central nervous system TB. Thirty six children were treated for MDR tuberculosis, of whom four died.

Obtaining a detailed contact history is essential as a delay in starting appropriate MDR antituberculosis treatment has potentially serious consequences.