Distribution and ecology of breeding sites of Simulium damnosum s.l. in south-eastern primary health zone of Nigeria

Abstract

Entomological studies were undertaken in the primary health Zone A of Nigeria to ascertain the distribution and ecology of
breeding sites of Simulium damnosuim complex. A total of 29 sites were prospected for immature stages of Simulium in seven
[7] states in the zone: Akwa Ibom [5], Cross River [4], Imo [12], Abia [4], Enugu [1], Ebonyi [11], and Benue [4]. Ten of
these breeding sites were positive for pre-imaginal stages of S.damnosum complex: Atan and Akpan-Ikpong (in Cross River
State), Ibii (Umulolo), Imo, Ibii (Aku), Ibu, Ugbi and Iyi-aka) in Imo State; Idodo (in Enugu State; and Oturkpo (in Benue
State). Three cytospecies of the complex were breeding in the study sites (S. damnosum s.s; S.squamnosum, and S. yahense).
In addition to S. damnosum complex, other Simulium (though not vectors of human onchocerciasis) that were found breeding
in some of these breeding sites included S. adersi, S .alcoki, S. auresimile, S. colasbelcouri, S. hargreavesi, S. mamahoni, S.
unicornitum, S. vorax and S. walshi. Water temperature and pH were not significant (p>0.05) while dissolved oxygen and
water velocity of the breeding sites of S. damnosum were significantly higher than the other sites.

Keywords: Simulium damnosum complex, S. squamosum. S. yahense, onchocerciasis, south-eastern Nigeria.

Nigerian Journal of Parasitology Vol. 28 (1) 2007: pp. 32-38