Childhood tuberculosis (TB) is due to recent M. tuberculosis infection, and is regarded as a marker of ongoing transmission. Antiretroviral therapy (ART) in HIV+ persons decreases TB risk. This study was conducted to characterize the spatiotemporal distribution of TB in pediatric cases < 5 years old presenting to the TB clinic in central Durban. We hypothesized that following the introduction of ART there would be changes in the spatiotemporal distribution indicating reduced TB transmission.
Using routinely collected data from the Prince Cyril Zulu Centre for Communicable Diseases (PCZCDC) between 2000 and 2012, we mapped cases of pediatric TB (< 5 years old) in central Durban. Address data enabled street level referencing. Cases were mapped by era (pre-ARV, 2000 – 2005 vs post-ARV, 2006 – 2012) and HIV co-infection status.
We georeferenced 557 cases of childhood TB to 313 addresses. Of the 135 cases (28%) with HIV results, 59% were co-infected with HIV. Of all cases 93% had pulmonary TB. TB cases were identified in all 6 Durban central suburbs, 2 of which had an aggregation of TB cases. Between 2000 and 2005, 217 TB cases were mapped to 154 addresses, 36 of which had multiple TB cases. Between 2006 and 2012, 340 TB cases were mapped to 225 addresses, 62 of which had multiple TB cases. HIV co-infected patients were identified at 21 addresses in the pre-ARV era and 53 addresses in the post-ARV era.
We present evidence of increased pediatric TB cases at specific geographic locations, as well as multiple cases of TB at single addresses in central Durban. An understanding of the spatial distribution of TB data will inform targeted interventions to more effectively control ongoing TB transmission. An increase in TB cases post-ART was not consistent with our hypothesis. The etiology behind the apparent increase in multiple TB cases per address between eras is unclear, but suggests ongoing transmission and warrants further investigation.