Geographical Distribution And Seasonal Fluctuation Of Snails And Their Intermediate Hosts In The Blue Nile STATE, SUDAN
Abstract
The present study was carried out at the Blue Nile State to assess the distribution of snails in freshwater canals especially the intermediate hosts of Schistosoma and their epidemiology. Snails were collected by the standard scooping method, from small water bodies and canals. The snails’ habitats were critically studied. Collected aquatic forms were transferred to the prepared laboratory, where snails were cleaned from the vegetation cover and the attached debris, the snails were then counted and sorted to species and separated in labelled plastic bowls
The study recorded the presence of the Prosobrancha (Melanoides.tuberculata, Lanistus.carinatus and Cleopatra. bulimoides) which are of no medical importance and the Pulmonate (Bulinus.truncatus, Bulinus.forskalii and Biomphalaria pfeifferi) of which Bulinus.for skalii is of no medical importance. The dominated snail was Melanoides.tuberculata. The density of all snails dropped during the flood season, except for Melanoides.tuberculata which is able to protect its soft tissues inside the snails by the operculum. A significant relation (p < 0.05) was found between the physical (turbidity and temperature), chemical and biological (decaying matter) characteristics of the water bodies and reproduction of snails. The density of the snails was negatively affected by distance of the site from the point of water entrance into the canal, season, abundance and density of vegetation.
The results showed infectivity of Bulinus.truncatus in water sites frequently visited by the people indicating that schistosomiasis is endemic in the area. The results showed that Bulinus.truncatus is highly susceptible to S. haematobium infection.
هذه الدراسة نفذت في ولاية النيل الأزرق لتحديد توزيع الحلزونات في قنوات الماء العذب خصوصاً العائل الوسيط للشستوسوما ووبائيته . أجريت المسوحات الحلزونية لفترة 12 شهر خلال الفترة من مايو 2009 الى أبريل 2010 مستخدمين في ذلك المجرفة. أما بيئة الحلزونات فقد دُرست بشكل بالغ الأهمية فكل الأشكال المائية التي جمعت نقلت الى المعمل المحضر لذلك ، حيث تم نظافة الحلزونات مِنْ غطاءِ النباتاتَ والحطامَ الملحقَ، ثمّ حسابَ وتصنّيفَ الحلزونات إلى النوعِ المحدد وفُصِلَها في طاساتَ بلاستيكيةَ موضح عليها أسماء الحلزونات .وجدت ستة أنواع من الحلزونات في قنوات هذه الولاية هي الحلزونات الرئوية ذات الأهمية الطبية للعائل الوسيط للبلهارسيا التي تصيب الإنسان والتي تنقل بلهارسيا المجاري البولية وبلهارسيا الامعاء على التوالي . Bulinus truncatus (بولاينس ترنكاتس) Biomphalaria pfeifferi, (بيومفالاريا فيفراى) و Bulinus forskalii (بولاينس فورسكالي) الذي ليس له أهمية طبية . بينما الحلزونات غير الرئوية مثل Melanoides tuberculata, (ميلانويدز تيوبركيوليتا) كان له السيطرة علي الحلزونات الأخرى و Cleopatra bulimoides (كليوباترا بوليمويدز) و Lanistus.carinatus (لانستس كارينيتس) وهذه ليست ذات أهمية طبية .
كثافة كل الحلزونات إنخفضت خلال موسم الفيضان ما عدا Melanoides tuberculata (ميلانويدز تيوبركيوليتا) الذي يحمي الأنسجة الداخلية بغطاء ولا يتأثر بتعكير الماء. هنالك علاقة هامة (p < 0.05) وجدت بين الخصائص الفيزيائية والكيميائية والإحيائية للأجسام المائية وتكاثر أو توالد الحلزونات . كثافة الحلزوناتِ تتأثر سلبياً بمسافةِ الموقعِ مِنْ نقطةِ مدخلِ الماءِ إلى القناةِ والفصلِ من السنة ووفرةِ وكثافةِ النباتاتِ . أثبتت النَتائِجُ قابليةَ اصابة Bulinus truncatus (بولاينس ترنكاتس) في مواقعِ الماءِ التي تزارَ بشكل متكرّر مِن قِبل الناسِ مما يُشيرُ بأنّ مرض البلهارسيا مستوطنُ في المنطقةِ. كما أثبتت النَتائِجُ أيضاً بأن Bulinus truncatus (بولاينس ترنكاتس) إلى حدٍ كبير معرّض للعدوى ببلهارسيا المجاري البولية .
References
2. Ahmed, A. A; Babiker, A; El Tash, L.A. and Shiff, C.J. (2002). Development of a modified baited trap for detection of schistosome cercariae using natural oils rich in polyunsaturated fatty acids in Sudan. Acta Tropica (82): 363 - 368.
3. Ahmed, E. S. (1994). Infection, disease and transmission patterns in human schistosomiasis in the White Nile Province, Sudan. Ph. D. Thesis. University of Khartoum.
4. Ahmed, R. F. M. (1999). Distribution of freshwater snails and transmission pattern of Schistosoma mansoni in a low endemic area, Gezira irrigated scheme, Sudan. M. Sc. thesis, Department of Zoology, Faculty of Science, University of Khartoum.
5. Amin, M. A. (1972). Large scale assessment of the molluscicides copper sulphate and N-trityl morpholine (Frescon) in the north group of the Gezira irrigated area, Sudan. Journal of Tropical Medicine and Hygiene, 75:169-175.
6. Appleton, C. C. (1977). The influence of temperature on the life- cycle and distribution of Biomphalaria pfeifferi in South Eastern Africa. International Journal of Parasitology, 7: 335- 346.
7. Babiker, A. (1987). Transmission and control of Schistosoma mansoni in the Gezira irrigated area of the Sudan. Ph. D. Thesis, Department of Zoology, Faculty of Science, University of Khartoum.
8. Babiker, S. M.; Blankespoor, H. D.; Wassila, M.; Fenwick, A. and Daffalla, A. A. (1985 a). Transmission of Schistosoma haematobium in North Gezira, Sudan. Journal of Tropical Medicine and Hygiene, 88: 65- 73.
9. Babiker, S. M.; Fenwick, A.; Daffala, A. A. and Amin, M. A. (1985 b). Focality and seasonality Schistosoma mansoni transmission in the Gezira Irrigated Area, Sudan. Journal Tropical Medicine and Hygiene, 88: 57 – 63.
10. Blue Nile State, Ministry of Health, Development and Planning Management, (2011).
11. Dazo, B. C.; Hairston, N. G. and Dawood, I. K. (1966). The ecology of Bulinus truncatus and Biomphalaria alexandrina and its implications for the control of bilharziasis in Egypt-49 Project area. Bulletin of the World Health Organization, 35: 339-356.
12. Demian, E. S and Kamil, E. G. (1972). Growth and population dynamics of Bulinus trancatus under semi – field conditions in Egypt. Proc. Egypt. Acad. Sci, 25: 37 – 60.
13. Ecological Footprint in Arab States, (2012). The Arab Forum for Environment and Development. AFED, Beirut, 14 December 2012
14. El Emam, M. A. and Madsen, H. (1982). The effect of temperature, darkness, starvation and various food types on growth, survival and reproduction of Helisoma duryi, Biomphalaria alexandrina and Bulinus truncates. Hydrobiologia, 88: 265- 275.
15. El Gaddal, A. A. (1985). The Blue Nile Health Project: a comprehensive approach to the prevention and control of water-associated diseases in irrigated scheme of the Sudan. Journal of Tropical Medicine and Hygiene, 88: 47-56.
16. Elias, E. E. (1992).Transmission of urinary schistosomiasis in the Rahad irrigation scheme, Sudan. Ph.D. Thesis. Department of Zoology, Faculty of Science, University of Khartoum.
17. Ferguson, F. F. (1977). The role of biological agents in the control of schistosome-bearing snails. U. S. Department of health, education and Welfare, Public Health Services, Centers for disease control, Atlanta Georgia.
18. Gasm El-Seed, N. M. (1998). Fresh water snails in El-Genaid Sugar Farm and Laboratory Evaluation of Anew Method for Molluscicide Application, Sudan. M. Sc. Thesis. Medical Parasitology, Department of Pathology, Faculty of Medicine, University of Gezira, Sudan.
19. Hilali A. M. H.; Madsen, H.; Daffalla, A. A.; Wasilla, M. and Christensen, N. O. (1995). Infection and transmission pattern of Schistosoma mansoni in the Managil irrigation scheme, Sudan. Annals of Tropical Medicine and Parasitology, 89 (3): 279-86.
20. Hilali, A. M. H; Desougi, L. A; Wasilla, M; Daffalla, A. A; and Fenwick. A. (1985). Snails and aquatic vegetation in Gezira irrigation canals. Journal of Tropical Medicine and Hygiene, 88: 75-81.
21. Hilali, A.H. (1992). Transmission of Schistosoma mansoni in the Managil area, Sudan. Ph. D. Thesis, Department of Zoology, Faculty of Science, University of Khartoum.
22. Jordan, P. and Webbe, G. (1982). Schistosomiasis Epidemiology, treatment and control, William Heineman Medical Books, London pp 16-23. Journal of Tropical Medicine and Hygiene, 31: 490-498.
23. Kardaman, M. W.; Amin, M. A.; Fenwick, A.; Cheesmonde, A. K. and Dixon, H. G. (1982). A field trial using Praziquantel to treat Schistosoma mansoni and Schistosoma haematobium infection in Gezira, Sudan. Annals of Tropical Medicine and Parasitology, 77 (3): 297-304.
24. Karoum, K. O. A. (1988). Trials on biological control of intermediate hosts of Schistosomiasis in the Gezira Agricultural scheme by competitor snail species. Ph.D. Thesis, University of Khartoum.
25. Klumpp, R. K.; Chu, K. Y. and Webbe, G. (1985). Observations on the growth and population dynamics of Bulinus rohlfsi in an outdoor Laborotary at Volta Lake, Ghana. Annals of Tropical Medicine and Parasitology, 79: 635- 642.
26. Malek, E. A. (1962). Bilharziasis control in pump schemes near Khartoum, Sudan, and evaluation of the efficiency of chemical and mechanical barriers. Bulletin of the World Health Organization, 27: 41-58.
27. Marti, H. P. (1986). Field observations on the population dynamics of Bulinus globosus, the intermediate host of Schstosoma haematobium in the Ifakara area, Tanzania. Journal of Parasitology, 72(1): 119- 124.
28. Ministry of Irrigation and Water Resources, 1992
29. Shiff, C. J. (1964). Studies on Bulinus (Physopsis) globosus in Rhodesia. I. The influence of temperature on the intrinsic rate of natural increase. Annals of Tropical Medicine and Parasitology, 58: 94-105.
30. Sturrock, R. F.(1966). The influence of temperature on biology of Biomphalaria pfeifferi (Krauss). A intermediate host of Schistosoma mansoni . Annals of Tropical Medicine and Parasitology, 60: 100-152.
31. Sudan Ministry of Finance and Economic Planning (SMFEP). (2000). Annuals Reports.
32. Taha, M. K. (1998). Distribution of snails in El-Seilate irrigated agricultural scheme, East Nile Province, Khartoum State, Sudan. M. Sc. (Qualifying), Department of Zoology, Faculty of Science, University of Khartoum.
33. Taha, M. K. (2002). Studies on the Ecology of snails and transmission of schistosomiasis in the Gezira scheme. Sudan. M. Sc. Thesis. Department of Zoology, Faculty of Science, University of Khartoum.
34. Taha, M. K. (2013). Transmission of Schistosomiasis in the Blue Nile State, Sudan. Ph.D. Thesis. Department of Zoology, Faculty of Science, University of Khartoum.
35. Thomas, D. and Tait, A. I. (1984). Control of the snail hosts of schistosomiasis by environmental manipulation: a field and laboratory appraisal in the Ibadan area, Nigeria. Philosophical Transactions of the Royal Society, London, B 305: 201-253.
36. Thomas, J. D.; Greedly, B. and Fennel, C. F. (1983). The effect of varing quality of various plankton feeding and growth of Biomphalaria glabrata. OIKOS, 41: 77-90, Copenhagen.
37. Webbe, G. and Msangi, A. S. (1958). Observation on the three species of Bulinus on the east coast of Africa. Annals of Tropical Medicine and Parasitology, 52: 302-314.
38. World Health Organization (1979). Workshop on the human-water-contact in Schistosomiasis transmission, St. Lucia, 28 May – 1 June. TDR/SER – HNC/79.3.
39. World Health Organization. (2003). Action against worms, Report Series, Issue 1.
