Integrated monitoring and evaluation and environmental risk factors for urogenital schistosomiasis and active trachoma in Burkina Faso before preventative chemotherapy using sentinel sites

Background: Over 1 billion of the world’s poorest inhabitants are afflicted by neglected tropical diseases (NTDs).
Integrated control programmes aimed at tackling these debilitating NTDs have been recently initiated, mainly
using preventative chemotherapy. Monitoring and evaluation (M&E) of these integrated programs presents
particular challenges over and above those required for single disease vertical programmes. We used baseline data
from the National NTD Control Programme in Burkina Faso in order to assess the feasibility of an integrated survey
design, as well as to elucidate the contribution of environmental variables to the risk of either Schistosoma
haematobium, trachoma, or both among school-aged children.
Methods: S. haematobium infection was diagnosed by detecting eggs in urine. A trachoma case was defined by
the presence of Trachomatous inflammation-Follicular (TF) and/or Trachomatous inflammation-Intense (TI) in either
eye. Baseline data collected from 3,324 children aged 7-11 years in 21 sentinel sites across 11 regions of Burkina
Faso were analyzed using simple and multivariable hierarchical binomial logistic regression models fitted by
Markov Chain Monte Carlo estimation methods. Probabilities of the risk of belonging to each infection/disease
category were estimated as a function of age, gender (individual level), and environmental variables (at sentinel
site level, interpolated from national meteorological stations).
Results: Overall prevalence at the sentinel sites was 11.79% (95% CI: 10.70-12.89) for S. haematobium; 13.30%
(12.14-14.45) for trachoma and 0.84% (0.53-1.15) for co-infections. The only significant predictor of S. haematobium
infection was altitude. There were significant negative associations between the prevalence of active trachoma
signs and minimum temperature, and air pressure. Conditional upon these predictors, these data are consistent
with the two pathogens being independent.
Conclusions: Urogenital schistosomiasis and trachoma constitute public health problems in Burkina Faso. Sentinel
site (at school level) surveys for these two NTDs can be implemented simultaneously. However, to support MDA
treatment decisions in Burkina Faso, the protocol used in this study would only be applicable to hypoendemic
trachoma areas. More research is needed to confirm if these findings can be generalized to West Africa and
beyond.