Distribution of human fascioliasis by age and gender among rural population in the Nile Delta, Egypt.

The number of cases of human fascioliasis reported in Egypt, has increased drastically during the past years. Most of the newly infected cases were children and adolescents. In the year 2000, the Egyptian Ministry of Health and Population implemented a cross-sectional survey in four endemic foci of Behera Governorate, in the Nile Delta. The aim of the study was to define prevalence and intensity of human fascioliasis, by age and gender, in order to plan appropriate control measures in endemic areas. The field assessments involved 1331 subjects and utilized the Kato-Katz thick-smear technique, on a double preparation, for quantitative diagnosis of intestinal helminths. A total of 72 positive cases were detected, the majority of them (n = 51, 71 per cent) in subjects below 19 years of age. The highest prevalence and intensity of infection was reported in the 9-11 years age group. Women were more affected then men, but not at a significant level. Primary schoolchildren appeared to be more at risk of contracting the infection and should be considered the main target for control measures. Further studies are needed to identify new ways of infections and possible risk factors responsible for the higher transmission among schoolchildren and women.

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.

Specific IgG avidity in acute and chronic human fascioliasis.

The detection of IgG avidity in sera is potentially useful in the diagnosis of acute and chronic infection. We studied IgG avidity in 31 patients with fascioliasis, with the aim of evaluating the clinical application of this test to confirm the diagnosis of incubating cases and to distinguish between acute and chronic cases. Of the 31 cases, 13 were incubating and had a mean avidity index of 57.28 +/- 5.79%. The 18 chronic cases had an avidity index of 68.80 +/- 8.92%. The difference was highly significant. We conclude that IgG avidity is a reliable means of identifying the stage of fascioliasis and suggest a cut-off point of 59.90% to distinguish between acute and chronic infection.

Epidemiology of human fascioliasis: a review and proposed new classification.

The epidemiological picture of human fascioliasis has changed in recent years. The number of reports of humans infected with Fasciola hepatica has increased significantly since 1980 and several geographical areas have been described as endemic for the disease in humans, with prevalence and intensity ranging from low to very high. High prevalence of fascioliasis in humans does not necessarily occur in areas where fascioliasis is a major veterinary problem. Human fascioliasis can no longer be considered merely as a secondary zoonotic disease but must be considered to be an important human parasitic disease. Accordingly, we present in this article a proposed new classification for the epidemiology of human fascioliasis. The following situations are distinguished: imported cases; autochthonous, isolated, nonconstant cases; hypo-, meso-, hyper-, and holoendemics; epidemics in areas where fascioliasis is endemic in animals but not humans; and epidemics in human endemic areas.