Transmission indices of malaria infection in Chanchaga Local Government Area of Niger State, Minna

Abstract

ABSTRACT Despite of intensive control measures and intervention in Nigeria, malaria remains a major public health threat. The dearth of information on the diversity and distribution of Anopheline mosquito species, a prerequisite to successful malaria control, informed this study. Indoor adult mosquito populations were sampled using Pyrethrum Spray Catches (PSC).Two hundred and seventy six (276) human individuals were examined for malaria parasites using Giemsa staining techniques.All individuals were screened for the presence of malaria parasite and classified into four (4)age groups: < 5 years, 6 – 10 years, 11 – 15 years and >16 years. A total of one thousand five hundred and sixteen (1516) mosquitoes were collected and identifiedas follows; Anopheles species 371 (24.47%) and Culex species 1145 (75.53%). Mosquitoes collected per location was as follows F-layout 399 (26.31%), Tunga 406 (26.28%), Chanchaga 361 (23.81%) and Sauka-Kahuta 350 (23.08%). The distribution of mosquitoes per location showed a significant difference at p<0.05. Six species of Anopheles mosquitoes were identified. These are Anopheles gambiae, 235 (63.34%), Anopheles funestus, 111 (29.92%), Anopheles coustani,10 (2.69%), Anopheles nili, 6 (1.62%), Anopheles squamosus, 6 (1.62%) and Anopheles moucheti,3 (0.81%). Tunga had the highest number of Anopheles mosquitoes of 116 (31.27%), followed by F-layout 93 (25.07%) while Sauka-Kahuta had the least number of Anopheles mosquitoes collected 74 (19.95%). The collected mosquitoes were subsequently dissected for sporozoite infection rate (54.56%) and parity (egg laying status) rate (62.5%) using standard procedures.These were not statistically significant a p>0.05. Out of the 276 human blood specimens examined, 178 (64.49%) were positive for Plasmodiumfalciparum. Individuals of age group 6 – 10 years had highest infection rate of 40 (78.43%), followed by 16 years 87 (63.50%) while age group 0 – 5 years, had the least infection rate of 6 (56%). Males were more infected 91 (67.91%) with malaria than females 87 (61.27%) which also showed a significant difference at p<0.05. This study demonstrated the complex distribution of Anopheles mosquito and the considerable variations in the intensity of malaria transmission in Chanchaga Local Government and its environs. The study indicates abundances of malaria vectors in the study area, hence the need to intensify control strategies to eliminate larva sources of the vectors.