Gebre-Michael Teshome (PhD)Ali Ahmed (PhD)Woyessa Adugna2018-06-132023-11-092018-06-132023-11-092001-05http://etd.aau.edu.et/handle/123456789/803To elucidate malaria transmission and determine its prevalence in a highland-fringe urban area, Akaki, parasitological and entomological investigations were conducted between October 1999 and October 2000. Review of malaria cases was using records of the Addis Ababa and Akaki health institutions for the years between 1993 and 2000. Parasitological survey was conducted, during a peak malaria transmission season, October through December 1999. A total of 712 persons (264 males and 448 females) were examined for three consecutive months (Oct.-Dec. 1999). Using different mosquito sampling methods a monthly collection of larvae and adult mosquitoes was conducted for 1 year from October 1999 to October 2000. The review of 6 Zonal Health Department records in Addis Ababa indicated that malaria is one of the major causes of outpatient consultation. A significant increase in malaria prevalence was noted after 1996 reaching a peak in 1998. The records do not show the geographical origin of the cases but most of them are believed to be internally imported. This however, can not rule out the possibility of its importation from the peripheral Towns like Akaki, with active malaria transmission considered. The occurrence of malaria outbreak during 1997/98 with its peak in October through November in Akaki and their sharing Plasmodiulll vivax as the dominant species both in Addis Ababa and Akaki suggest the likely hood. A total of2136 blood films were examined, 78 (3.7 %) persons were malaria positive of which 54 (69%) were due to Plaslllodium vivax and only 24 (31 %) due to P. jalcipa/'lIll1. Parasitological surveys done in this study in Akaki Town shows 30 (4.2%) were malaria positive with predominance of P. jalcipal'lIl1l (70%); in the second survey, 48(6.7%) wcre positive with a predominance of P. vivax (93.7%); no case was detected in the last survey. Although prevalence increased with age, the detection of cases in children below the age of 5 years suggested autochthonous malaria transmission in Akaki area. Two Anopheles species were encountered in the larval collection. Anopheles christyi (9\,7%), An. galllbiae s. 1., (presumably An. arabiensis, 6.7%) and An. cinereus (\.6%). In the adult collection, four species of were recorded: An. arabiensis, An. christyi, An. pharoensis and An. coustani. Anopheles arabiensis and An. christyi were the dominant manbiting species in the area. They were both more exophagic and active in the early evening unlike An. pharoensis that showed an endophagic tendency. The dissection of 49 An. christyi, 43 An. arabiensis, 2 An. pharoensis and a single specimen of An. COl/stani turned negative for sporozoites. Anopheles arabiensis might be the major vector in the area. However, further and detailed investigations are required to asceltain the relative importance of An. arabiensis and the other man-biting species (pmticularly An. christyi) in the transmission of malaria in Akaki and surrounding areas to design appropriate control strategy. The findings are discussedenBiologyThesis