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Schistosomiasis Mansoni in Yemen: A Review

1992; King Faisal Specialist Hospital and Research Centre; Volume: 12; Issue: 3 Linguagem: Inglês

10.5144/0256-4947.1992.294

0975-4466

Jamal Sallam, Stephen G. Wright,

Trypanosoma species research and implications

Original ArticlesSchistosomiasis Mansoni in Yemen: A Review Jamal A. Sallam and MB, BcH, DTMH, MSc Stephen G. WrightMRCP Jamal A. Sallam Address reprint requests and correspondence to Dr. Sallam: G.I. Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, United Kingdom. From the Department of Gastroenterology, London. and Stephen G. Wright From the Western General Hospital, Edinburgh, and London School of Hygiene and Tropical Medicince, London. Published Online:1 May 1992https://doi.org/10.5144/0256-4947.1992.294SectionsPDFCite ToolsAdd to favoritesTrack citations ShareShare onFacebookTwitterLinked InRedditEmail AboutABSTRACTABSTRACTSchistosomiasis is a major public health problem in Yemen. In 1922 Schistosoma 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 the 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 finding and treatment an important part of schistosomiasis control. Control of the disease also requires field studies followed by mollusciciding, improvement of water supply and sanitation and, perhaps most importantly, health education.IntroductionIn 1922, Greval [1] first reported the presence of Schistosoma mansoni in two Yemeni patients in a hospital located in Aden, South Yemen. One patient was from Usaifira, North Taiz, and the other from Makatrira, West Taiz. In 1951, the first surveys were carried out when the United States Naval Medical Research Unit No. 3 (NAMRU3) examined snails taken from three different locations: (a) San'a, 7,200 feet above sea level, (b) Taiz, 4,100 feet and (c) Hodeidah on the Red Sea coast. In Taiz, the survey revealed the presence of Biomphalaria biossyi arabica of which 35% of the snails examined were heavily infected with S. mansoni. In San'a, Biomphalaria spp. were not infected and in Hodeidah, no snails were found. However, few infections among the population were found in the last two cities.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 [3]. Kuntz et al [3] found that the majority of patients infected with S. mansoni in San'a and Hodeidah had come from Taiz. To investigate the presence of helmenthic infection, fecal and urine specimens were obtained from 218 persons living in Taiz which revealed 56% S. mansoni.Between December 1951 and February 1952 [4] a small study carried out in three public schools in San'a, Taiz and Hodeidah showed that in Taiz, 14 of 20 stools examined for S. mansoni ova were positive (70%). All the infected people came to Taiz from surrounding regions. The individuals included in this study were a mixture from primary, secondary, and orphanage schools as well as adult staff between the ages of 9 to 35 years. However, in San'a and Hodeidah, S. mansoni infection was much less frequent than in Taiz.In 1972, Arfaa [6] showed schistosomiasis as being one of the most important public health problems in Yemen. He estimated the total number of people in Yemen infected with S. mansoni and/or S. hematobium to be more than one million out of a total population of 5 to 6 million [6]. The southern parts of Yemen Arab Republic showed the highest prevalence of S. hematobium while both species were found in a patchy distribution in all areas visited except Hodeidah. In Hajjah, North San'a, the prevalence of S. hematobium was found to be much greater than the prevalence of S. mansoni (76% and 15% respectively), while in Hujariah and Rahidah, South Taiz, the prevalence of S. mansoni was more than that of S. hematobium (40% and 30%, respectively).Warren et al [7] reported the endemnicity of S. mansoni in Yemeni immigrants living in the San Joaquin Valley in California, USA. Two hundred eighteen Yemeni workers were investigated and 56% were positive for S. mansoni. The life span of the Yemeni strains of S. mansoni was estimated to be five to ten years.The effect of S. mansoni infection on the liver and spleen was reported by Mount [5] in 1953. In Taiz, 76 (38.2%) people under 21 years had hepatomegaly and 60.6% in the same group had splenomegaly (Table 1).Table 1. Effects of S. mansoni infection on the liver and the spleen of Yemeni patients in 1951.Table 1. Effects of S. mansoni infection on the liver and the spleen of Yemeni patients in 1951.A combined Yemen/WHO project set up in 1973 to control schistosomiasis in Yemen, reported the presence of S. mansoni and S. hematobium in most parts of the YAR and estimated that 25% of the population were infected with one or both species [8,9]. A malacological survey showed that Biomphalaria, the snail intermediate host of S. mansoni, is common in Taiz and Ibb. In 1988, surveys [8] showed that both species of schistosome were found in San'a, Saada, and Hajja. Both species were found to be endemic in Taiz, Ibb, Thamaar, and Al-Mahweet with S. mansoni being the most common. It seems, however, that the disease is not a public health problem in other parts of the country such as Hodeidah, Al-Beidah, Mareb and Al-Gouff.Schistosomal hepatofibrosis with consequent portal hypertension and esophageal varices with a high risk of hematemesis is a major clinical problem in Yemen. Between 1985 and 1988, during work being done in the Department of Medicine and in the Gastrointestinal Endoscopy Unit in Al-Thawra Modern General Hospital, it was found that severe upper gastrointestinal bleeding from ruptured esophageal varices was a common problem. Although the patients who were investigated about the cause of the esophageal bleeding gave a history of S. mansoni infection, one cannot be certain whether this bleeding is due to schistosomal hepatofibrosis or due to hepatitis B related cirrhosis which is also common in Yemen [11]. A further study to find out the definitive cause of the esophageal varices is indicated.CONCLUSION AND RECOMMENDATIONSSchistosomiasis caused by S. mansoni as well as S. hematobium is a major public health problem in Yemen. Epidemiologically, the prevalence of infection is higher in rural than in urban areas, due mostly to the improvement of water supplies to urban areas. The size of the problem is likely to become more prominent considering that more than 90% of the population of YAR live in the rural areas. Schemes to control the spread of Schistosomiasis involve case findings and treatment, control of snail intermediate hosts, improvement of water supplies, prevention of contact with snail-infested water and, perhaps most importantly, health education. In 1983 [8] Praziquantel (Biltricide) was introduced into the control scheme. Praziquantel is distributed free of charge by the project staff to patients proved to be positive for schistosomiasis. The availability of praziquantel as a safe and effective chemotherapeutic agent makes case findings and treatment an important part of schistosomiasis control. Regular surveillance of communities, i.e., active case findings and treating infected persons will not only decrease the risk of developing schistosomal disease, but will rapidly decrease the intensity and prevalence of infection [10]. Continuous mollusciciding of water sources of suspected areas has been found to be very effective according to the WHO report on schistosome infected snails in the area surrounding the Mareb Dam (northeast YAR). In 1988, this area was found to be free of snails after using molluscicides in 1987 when both Biomphalaria and Bulinus snails were found in large numbers. Other methods of snail control include elimination of pools, removal of vegetation, prevention of pollution, increasing the rate of water flow and changing the level of water in dams [10]. Improvement of water supplies that have taken place in recent years will also help to reduce the risk of infection. Finally, health education and health promotion are of major importance in the control of schistosomiasis in Yemen.ARTICLE REFERENCES:1. Greval SDS. "Schistosomiasis (Bilharziasis) in Arabia" . Ind J Med Research. 1922; 10:943–7. Google Scholar2. Kuntz RE. "Schistosomiasis mansoni and Schistosomiasis haematobium in the Yemen, Southwest Arabia: with a report of an unusual factor in the epidemiology of Schistosoma mansoni" . J Parasitology. 1952; 38:24–8. Google Scholar3. Kuntz RE, Malakatis GM, Lawless DK, et al.. "Medical mission to the Yemen, Southwest Arabia, 1951. II. A cursory survey of the intestinal protozoa and helminth parasites in the people of the Yemen" . Am J Trop Med Hyg. 1953; 2:13–9. Google Scholar4. Naguib A. "Bilharziasis survey in British Somaliland, Eritrea, Ethiopia, Somalia, Sudan and Yemen" . WHO Bull. 1956; 41:1–7. Google Scholar5. Mount RA. "Medical mission to the Yemen, Southwest Arabia, 1951: geomedical observation" . Am J Trop Med Hyg. 1953; 2:1–12. Google Scholar6. Arfaa F. "Studies on Schistosomiasis in the Yemen Arab Republic" . Am J Trop Med Hyg. 1972; 21:421–4. Google Scholar7. Warren KS, Mahmoud AAF, Cummings P, et al.. "Schistosomiasis mansoni in Yemenis in California: duration of infection, presence of disease, therapeutic management" . Am J Trop Med Hyg. 1974; 23:902–9. Google Scholar8. Daffalla A. "Schistosomiasis control project in Y.A.R. Assignment Report Sept 1988" . WHO office, San'a. Google Scholar9. Arfaa F. "Schistosomiasis control: Southern Uplands Rural Development Project" . Y.A.R. Assignment Report January 1980. WHO office, San'a. Google Scholar10. Webbe G, Jordan P. In: Jordan P, Webbe G, eds. Schistosomiasis epidemiology, treatment and control. London: William Heinemann Medical Books, Ltd. 1982;293–349. Google Scholar11. Scott DA, Burans JP, Al-Quzeib HD, et al.. "A seroepidemiological survey of viral hepatitis in the Yemen Arab Republic" . Trans R Soc Trop Med Hyg. 1990; 84:288–91. Google Scholar Previous article Next article FiguresReferencesRelatedDetailsCited by Al-Delaimy A (2022) The Prospective Effects of Climate Change on Neglected Tropical Diseases in the Eastern Mediterranean Region: a Review, Current Environmental Health Reports, 10.1007/s40572-022-00339-7, 9:2, (315-323), Online publication date: 1-Jun-2022. Gray G, Kassira E, Rodier G, Myers M, Calamaio C, Gregory M, Nagi M, Kamal K, Botros B, Soliman A, Hassan N, Gregory R, Arunkumar B, Cope A and Hyams K (2016) Remote Village Survey for Agents Causing Hepatosplenic Disease in the Republic of Yemen, Tropical Doctor, 10.1177/004947559902900408, 29:4, (212-219), Online publication date: 1-Oct-1999. Guneid A, Gunaid A, O'Neill A, Zureikat N, Coleman J and Murray‐Lyon I (2005) Prevalence of hepatitis B, C, and D virus markers in yemeni patients with chronic liver disease, Journal of Medical Virology, 10.1002/jmv.1890400413, 40:4, (330-333), Online publication date: 1-Aug-1993. Cited by Literature Volume 12, Issue 3May 1992 Metrics History Accepted26 May 1991Published online1 May 1992 ACKNOWLEDGMENTWe are grateful to Miss Leyly the secretary of WHO office in San'a for providing us with the WHO Assignment Reports needed for our review.InformationCopyright © 1992, Annals of Saudi MedicinePDF download