THE ECOLOGY OF ANOPHELES ARABIENSIS AND INSECTICIDE RESISTANCE/ SUSCEPTIBILITY STATUS IN KASSALA AREA, EASTERN SUDAN
Objectives: The study was carried out to investigate the ecology of A. arabiensis and their susceptibility to insecticides in Kassala area, eastern Sudan.
Methods: Both adult anopheline mosquitoes and immature stages were sampled monthly following the standard WHO procedures during the period November 2000 through January 2002. The susceptibility of A. arabiensis to insecticides was conducted using the WHO standard technique.
Results: A. arabiensis was the main malaria vector; its density fluctuated throughout the year with bimodal peaks during the rainy (6.1 females/room and 56.1 larvae/dip) and the cool dry seasons (4.8 females/room and 47.5 larvae/dip). The difference was not statistically significant (P>0.05). An indication of partial aestivation of A. arabiensis to adapt the harsh environmental conditions of the dry season was confirmed in the area. Adult populations like to cluster around breeding sites in an area of less than 200 m. The susceptibility to DDT and fenitrothion was 88.3% and 100% respectively.
Conclusion: A. arabiensis is the sole malaria vector in Kassala area and it was highly susceptible to the insecticides tested and these should be considered for malaria vector control in the area.
2. EL-Gaddal A A. The experience of Blue Nile Health Project in control of malaria and other water associated diseases. In: Malaria in Africa. Geneva: WHO; 1990. p. 51 - 58.
3. Petrarca V, Nugud AD, El karim Ahmad MA, Haridi AM, Dideco MA, Cluzzi M. Citogenetics of the A. gambiae complex in Sudan, with spécial reference to A. arabiensis: relationships with East and West Africa populations. Méd Vet Ent 2000; 14: 149-16.
4. Marshal K (1998) Malaria disaster in Africa. Lancet 1998; 352: 924.
5. A global strategy for malaria control. Bull World Health Org 1993; 71: 281-284.
6. Haridi AM. Inheritance of DDT. Résistance in species A and B of the Anopheles gambiae complex. Bull World Health Org 1972 ; 47: 619-626.
7. Abdelrahman AA. The integrated pest management strategy and its expected environnemental and economical impact in Sudan. Albuhuth 1994 ; 4: 164-175.
8. Himeidan YE, Dukeen MY, El-Rayah E, and Adam I. Anopheles arabiensis: abundance and insecticide resistance in an irrigated area of eastern Sudan. East Mediterr Health J; in press.
9. Hamad AA, Nugud AD, Arnot DE, Giha HA et al. A marked seasonality of malaria transmission in two rural sites in eastern Sudan. Acta Tropica 2002; 83: 71- 82.
10. Manual on practical entomology in malaria: off-set publication. Geneva: WHO; 1975. No.13, part 11. p. 191.
11. Gillies MT, DeMeillon B. The Anopheline of Africa South of the Sahara. Johannesburg, Publications of South Africa Institute Medical Research; 1968.
12. Annex of Twenty-second Report of the WHO Expert Committee on Insecticide-Resistance of Vectors and Reservoirs of diseases. Geneva: WHO; 1976. (WHO Technical Report Series, No. 585).
13. El-Gaddal AA, Haridi AM, Hassan FT, Hussein H. Malaria control in Gezira Managil Irrigated Scheme of the Sudan. J Trop Med Hyg 1985; 88:153-159.
14. Mwangi RW, Mukiama TK. Irrigation scheme or mosquito hazard: a case study in Mwea Irrigated Scheme. Hydrobiologia 1992; 232: 19-22.
15. Craig MH, Snow RW, Le Sueur D. A climate-based distribution model of malaria transmission in sub-Saharan Africa. Parasitology 1999; 15:105-111.
16. Molineaux L et al. The epidemiolgy of malaria and its measurement. In: Wernsdorfer WH, Mc Gregor I, editors. Malaria: Principle and Practice of malariology. London: Churchill Living Stone Press; 1988. p. 999-1090.
17. Omer, S.M. & Cloudsely-Thompson, J.L. (1970). Survival of female Giles through the 9 month dry season in Sudan. Bull World Health Org, 42, 319-330.
18. Macdonald G. The epidemiology and control of malaria. London: Oxford University Press; 1957.
19. Service MW, Joshi GB, Pradhan GD. A survey of Anopheles gambiae (species A) and Anopheles arabiensis (species B) of the Anopheles gambiae complex in the Kisumu area of Kenya following insecticidal spraying with OMS –43 (fenitrothion). Ann Trop Med Parasitol 1978; 72: 377-386.
20. Fontenille D, Lochouarn L, Diagne N, et al. High annual and seasonal variations in malaria transmission by anopheline and vector species composition in Dielmo, Senegal. Americ. J. Trop. Med. Hyg. 1997; 56: 247-253.