Clinical signs and household characteristics associated with human fascioliasis among rural population in Egypt: a case-control study

The symptomatology associated with human fascioliasis has been studied mostly in hospitalised subjects. Very little is known about clinical signs and symptoms associated with infections in human endemic zones, as well as on possible new ways of transmission which might be responsible for the increased number of human cases reported in recent years. This information is of great importance to facilitate diagnosis and plan effective control measures. With the objective to identify clinical signs, blood tests, household characteristics and hygienic habits associated with human fascioliasis, a cross-sectional case-control study was implemented among the rural population of three endemic foci in the Nile Delta, Egypt. Clinical history was collected from 53 cases of fascioliasis and the same number of individually matched controls. They received a complete clinical examination and a range of blood tests was performed on them. Information on socio-economic conditions, dietary and hygienic habits was also collected. The most important complaints, associated with the infection, were right abdominal pain (Odds Ratio 20, P = 0.005), epigastric burning (o.r. 16, P = 0.007) and nausea (o.r. 8, P = 0.05). Blood analyses reported a marked increase in blood eosinophils (o.r 1.3, P = 0.001) among cases. The presence of cows (o.r 3.2), buffaloes (o.r 3.0) and goats (o.r 2.6) in the household was closely associated with the infection together with the habit to bring those animals to the canal for bathing and/or drinking (o.r. 3.2). Among dietary habits investigated, eating raw seeds was more common in cases than controls (o.r. 9, P = 0.03) and emerged as a possible new way of infection.