Journal of Water, Sanitation and Hygiene for Development Vol 3 No 2 pp 134–143 2013 doi:10.2166/washdev.2013.042
Risk factor analysis of diarrhoeal disease incidence in faecal sludge-applying farmers’ households in Tamale, Ghana
Razak Seidu, Owe Löfman, Pay Drechsel and Thor Axel Stenström
Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, Postboks 5003, N-1432 Ås, Norway E-mail: razaks@umb.no
International Water Management Institute, P.O. Box 2075, Colombo, Sri-Lanka
Swedish Institute for Infectious Disease Control, 171 82 Solna, Sweden and Stockholm Environment Institute, Kräftriket 2B, 106 91 Stockholm, Sweden
ABSTRACT
This study assesses the effect of risk factors and their inter-related mediation on diarrhoeal disease incidence in households applying faecal sludge in agricultural fields in Tamale, Ghana. Risk factors were assigned to three inter-related blocks: distal socio-economic, proximal public and domestic domains. The study involved 1,431 individuals living in 165 faecal sludge-applying households followed bi-weekly for 12 months. The incidence rate of diarrhoeal disease in the sludge-applying households was 1.09 (95% CI: 0.78–1.23) diarrhoeal episodes per person year at risk. Risk factors for diarrhoeal disease transmission in the public domain included sludge drying time (population attributable fraction (PAF) of 6%) and distance covered to collect water (PAF = 18%). The main distal socio-economic risk factor was wealth status (PAF = 15%).
In the domestic domain, the risk factor significantly associated with diarrhoeal disease transmission was, not washing hands with soap after defecation (PAF = 18%). About 17% of the effect of sludge drying time (including distance to water facilities) was mediated by the domestic domain risk factors. The study recommends risk management strategies in sludge-applying households that address public and domestic domain risk factors in addition to specific farm level interventions.
