SETTING: Douala, the economic capital of Cameroon,
with a network of 20 diagnostic and treatment centres
for tuberculosis (TB).
OBJECTIVE: To describe the spatial distribution of
smear-positive pulmonary tuberculosis (PTB) cases in
Douala, Cameroon, and to evaluate links between PTB
incidence and patients’ socio-economic status (SES).
DESIGN: Between May 2011 and April 2012, demographic
clinical characteristics and global positioning
system coordinates for the residence of each consenting
PTB case were collected. Spatial scan statistic was used
to identify spatial clusters of tuberculosis. SES data were
collected by interview during home visits. PTB patients’
SES data were compared with those available for the
whole urban population from a recent demographic and
health survey. The correlation between PTB incidence
and the mean SES of the PTB patients was examined by
health area (HA).
RESULTS: In total, 2132 (84%) diagnosed PTB cases
were identified and interviewed. Three statistically significant
spatial clusters were identified. High PTB incidence
was predominantly found in HAs characterised
by low SES.
CONCLUSION: There is evidence of clustering of PTB
cases in Douala. Clusters are mainly found in neighbourhoods
of low SES. Systematic use of cluster detection
techniques for regular TB surveillance in Cameroon
might aid in the effective deployment of National TB
Programme resources.