Schistosomiasis in patients in the Sultanate of Oman.

BACKGROUND: Following an intensive public health eradication program, the focus of schistosomiasis mansoni at Salalah in Southern Oman (the only focus of schistosomiasis in Oman), appeared to have been eradicated in 1994. Since the vector snails for Schistosoma mansoni (and also for S. haematobium) were widely endemic in freshwater springs at Salalah, and reintroduction of infection (or introduction in the case of S. haematobium) was possible, we undertook a prospective study in 1995 for schistosomiasis in patients at the Sultan Qaboos University Hospital (SQUH), and to obtain evidence of visits by these patients to Salalah. PATIENTS AND METHODS: From May 1995 to May 2000, Omani and expatriate patients presenting at SQUH were evaluated for possible schistosomiasis (residence in an endemic region, suggestive clinical features) by a search for ova in stool, urine, or in tissue biopsies, or when ova were absent, by serodiagnosis. A retrospective survey of schistosomiasis patients diagnosed in SQUH from 1990 to April 1995 was also performed. Ministry of Health (MOH) data on reports of schistosomiasis (a notifiable disease) in Oman from 1991 to 2000, were obtained. RESULTS: Thirty patients with schistosomiasis were identified, 10 retrospectively and 20 in the prospective study. Patients were aged 9 to 60 years, and 25 of them (10 Omanis, 14 Egyptians, 1 Sudanese) contracted the infection in Africa, while 5 Omanis became infected in Salalah (3 in 1999). Twelve patients had schistosomiasis mansoni, 6 had schistosomiasis haematobia, and in the rest, infection by both parasites was confirmed or possible. The most common presentation (23%) was hepatosplenic schistosomiasis with portal hypertension. No patient admitted to contaminating freshwater with excreta in Salalah. MOH data revealed 3 to 14 cases of schistosomiasis were reported annually between 1991 and 2000, and that all schistosomiasis cases reported from 1994 to 1998 originated from Africa. CONCLUSION: Schistosomiasis remains an important health problem in Oman. Many doctors are unfamiliar with the clinical features and methods of diagnosis, thereby frequently causing delays in diagnosis. Because vector snails are endemic in Salalah, schistosomiasis patients must be detected and treated early. At infested freshwater sites at Salalah, mollusciciding should continue indefinitely, and notices should warn visitors not to contaminate the spring water.

Use of whole-gut lavage to measure intestinal immunity in healthy Sierra Leonean children.

In view of the potential roles of intestinal immunodeficiency and hypersensitivity in the infection/diarrhea/malnutrition cycle, we need a safe and ethical method to study intestinal immunity of children in the developing world. Work in adults has shown that the fluid obtained by whole-gut lavage (WGLF), essentially a gut perfusate, can be used to assess intestinal immunity, inflammation, and gut losses of protein and blood. Gut lavage was successfully performed in 24 of 25 "normal" children aged 6-9 years, from Freetown, Sierra Leone, with parental informed consent. WGLF was treated with protease inhibitors, stored at -20 degrees C, and transferred to Edinburgh for laboratory studies. These showed that no child had occult blood loss but four had evidence of protein-losing enteropathy. Compared with values for Scottish adults, WGLF from the Sierra Leonean children had significantly higher concentrations of IgA and IgM and of IgA and IgM antibodies to dietary antigens and to Salmonella typhi lipopolysaccharide. In three children, very low levels of IgA and IgA antibody were present: Two of these were the only cases with detectable sIL2R in lavage fluid, indirect evidence of intestinal T cell activation; tumor necrosis factor was not detectable. Substantial information on childrens' intestinal immunity can be obtained by the method described.

Schistosomiasis mansoni in Yemen: A review.

Schistosomiasis is a major public health problem in Yemen. In 1922 Schistosomiasis mansoni was first reported to be found in Yemeni patients. In 1951 the first population survey was carried out in Taiz and revealed the presence of Biomphalaria biossyi arabica where 35% of the snails were heavily infected with S. mansoni and in San'a no snails were infected. Although S. mansoni and S. hematobium infections have been found in most parts of Yemen Arab Republic (YAR) it seems that the disease is not a public health problem in some parts of the country such as Hodeidah, Al-Beidah, Mareb, and Al-Gouff. The source of S. mansoni and S. hematobium in Yemen was attributed to the continual migration of infected persons from Eritrea and other countries of East Africa to Yemen. The prevalence of infection is higher in rural than in urban areas. The complications of S. mansoni, notably portal hypertension, esophageal varices, and hematemesis have become a major clinical problem. The availability of Praziquantel as a safe and effective treatment makes case findings and treatment an important part of schistosomiasis control. Control of the disease also requires field studies followed by mollusciding, improvement of water supply and sanitation and, perhaps most importantly, health education.