MORBID: Morbidity Operational Research for Bilharziasis Implementation Decisions (Pilot)

Research question

A pilot study to identify meaningful and measurable targets for detecting the control of schistosomiasis-related morbidity in Africa. The overall study is designed to answer the following primary evaluation questions:

  • What are the infection levels of Schistosoma mansoni and S. haematobium below which there is little, or no, detectable schistosomiasis-associated morbidity?
  • What are the optimal morbidity markers for S. mansoni and S. haematobium?
  • What are the optimal species-specific morbidity goals for which schistosomiasis control programs should be aiming?

Outcomes

 Individuals in low prevalence villages were significantly less likely to test positive for microhaematuria. In both low and high village settings, of those who tested positive for microhaematuria, the greatest proportion had a high level of severity of infection.

·       Individuals in the low prevalence villages were significantly less likely to test positive for proteinuria than those in high prevalence villages.

·       There was no significant association between anthropometric measures (stunting, wasting) and S. haematobium across age-groups and high and low prevalence villages.

·       Prevalence of mild, moderate and severe anaemia were marginally higher in the high prevalence villages than the low prevalence villages across all age groups; whereas malaria prevalence was higher in PSAC and adolescent age groups in the low prevalence villages. There were no statistical associations in these observations.  

·       Minimal bladder wall abnormalities and upper urinary tract abnormalities were detected by ultrasound. There was no difference between high and low prevalence villages 

·       When looking across all study villages (high and low) a strong linear association with microhaematuria, and good but non-linear association with proteinuria and a weak linear association with bladder ultrasound morbidity were observed when plotted against infection prevalence. No other morbidities showed associations worth exploring further. 

Study sites

Notes

The pilot study will be conducted in Malawi (endemic for S. haematobium) and Kenya (endemic for S. mansoni) based on previous experience working in these areas and confidence in their ability to carry out the work.

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