The epidemiology of schistosomiasis in Egypt: Fayoum Governorate.

Abstract

Abstract. Health questionnaires and parasitologic examinations of urine and stool were performed upon a stratified random sample of 7,710 individuals from 1,109 households in 21 rural communities in Fayoum Governorate, Egypt in 1992 to investigate the prevalence of, risk factors for, and changing pattern of, infection with Schistosoma sp. in the governorate. A subset, every fifth household, or 1,038 subjects, had physical and ultrasound examinations to investigate prevalence of, and risk factors for, morbidity. The prevalence of S. haematobium ranged from 0% to 27.1% and averaged 13.7%. The geometric mean egg count (GMEC) was 10.0 eggs/10 ml of urine. Age-stratified prevalence and intensity of infection were 18-25% and 10-15 eggs/10 ml of urine in those 5-25 years of age. Schistosoma mansoni were detected in inhabitants of 13 communities, but 78.5% of the infections were focally present in a group of 4 satellite hamlets around a single village. The overall prevalence of S. mansoni in the governorate was 4.3% and the GMEC was 44.0 ova/g of stool. Risk factors for infection with either species were male gender, an age Ͻ20 years, living in smaller communities, and exposures to canal water by males. Histories of burning micturation, blood in the urine, or prior schistosomiasis and reagent strip-detected hematuria and proteinuria were risks for S. haematobium, but not for S. mansoni. Both urinary tract and higher grades of hepatic morbidity were rare. Obstructive uropathy was present in 6.3% of the subjects and was more common in males and older people. Ultrasonography-detected bladder lesions were present in 5.2% and correlated with S. haematobium only in younger subjects and in those with hematuria and proteinuria. The prevalences of hepatomegaly, splenomegaly, and periportal fibrosis (PPF) were associated with each other and increased with age and in males. Ultrasonography-detected hepatomegaly and splenomegaly were weakly associated with S. mansoni infections only in children. The prevalence of PPF was greater in the 4 communities with Ͼ25% S. mansoni infection rates in comparison with the 17 other villages and ezbas. Transmission of S. mansoni is focally well established in Fayoum, which also has the highest prevalence of S. haematobium in the governorates surveyed by the Epidemiology 1, 2, 3 Project. However, both urinary tract and hepatic morbidity are relatively rare in the governorate. This probably results from the long-standing schistosomiasis control program in Fayoum, which suppressed intensity more than prevalence of infection, leading to less community morbidity.El Fayoum, a large oasis in the Egyptian Western Desert 90-130 km southwest of Cairo, is supplied by water through a single canal (Bahr Youssef) from the Nile River (Figure 1 in Husein and others). 1 The governorate is inhabited by 1.2 million people who mainly work in agricultural and related industries. Irrigation is achieved through a system of open canals, with an estimated total length of 39,000 km, draining into Lake Quaroun, a salt lake,...

Irrigation and infection: The immunoepidemiology of schistosomiasis in ancient Nubia

“…As expected, the Wadi Halfa population had a higher prevalence than the Kulubnarti population. This follows the pattern of higher prevalence in populations living near annual irrigation schemes in modern populations (Kloos et al,1983; Abdel‐Wahab et al,2000; Steinmann et al,2006).…”

“…Schistosomiasis mansoni in Egypt is highest near the Nile Delta region and decreases upstream. Infections are rarely found in modern populations living along the Nile in Upper Egypt and Northern Sudan; only in the Fayoum governate did prevalence reach 4.3% (Abdel‐Wahab et al,2000). However, prevalence estimates between 40 and 50% have been made for populations living near recently implemented irrigation schemes in the region (El‐Sayed et al,1995).…”

“…Epidemiologic studies in modern populations typically find a higher prevalence of schistosomiasis among males than females (Watts et al,1998; Abdel‐Wahab et al,2000; El‐Khoby et al,2000; Klein,2004). This is likely the result of a gendered division of labor involving water contact.…”

“…The use of canal irrigation compounds the risk of exposure to schistosomiasis by increasing the available habitat for the aquatic snails necessary for transmission [Dougherty and Hall: (1995); Jobin: (1999)]. Studies have shown a clear link between contact with canal waters and exposure to schistosomiasis in modern Egyptian populations (Abdel‐Wahab et al: Am J Trop Med Hyg 62 (2000) 55–64) and throughout Africa (Steinmann et al: Lancet Infect Dis 6 (2006) 411–425). Meta‐analysis of numerous African schistosomiasis studies have shown that individuals living in irrigation schemes are as much as 23.0 times more likely to be infected with Schistosoma mansoni than individuals not living in those areas (Steinmann et al: Lancet Infect Dis 6 (2006) 411–425).…”

Bleeding Oesophageal Varices, Clinical Presentation and Outcome of Management in Wad Madani Teaching Hospital.

“…Alcohol consumption was not common in this study group. In other endemic areas schistosomiasis accounts for 22% as a cause of PPF (39) . There is therefore an increase need for schistosomiasis control programs, in addition to environmental and behavioral modifications.…”