Impact of cattle keeping on human biting rate of anopheline mosquitoes and malaria transmission around Ziway, Ethiopia.
OBJECTIVE
To assess the impact of livestock keeping on the human biting rate (HBR) of anopheline mosquitoes and malaria transmission around Ziway in the middle course of the Ethiopian Rift Valley.


METHODS
As a passive experiment, man landing captures were done in homesteads with mixed dwelling, separate cattle shed and without livestock; and as an active experiment, captures were in experimental tukuls (huts) of cattle, goats, and without livestock. Parasite and spleen rates of children were compared among those residents under variable living conditions mentioned for passive experiment.


METHODS
For entomological study, human-baits were used for man-landing captures of mosquitoes. Study subjects for parasitological and clinical studies were children below 10 years old.


METHODS
Human-biting rate (HBR) of anopheline mosquitoes; and the parasite and spleen rates of the study subjects in different living conditions.


RESULTS
In the passive experiment, the mean HBR of Anopheles arabiensis in mixed dwelling, separate cattle shed and without livestock was 8.45, 4.64 and 5.97, respectively. Similarly, the HBR of An. pharoensis was 2.88, 1.79 and 1.61, respectively. In the active experiment, the mean HBR of An. arabiensis in tukuls with cattle, goats, and without livestock was 3.50, 3.38 and 1.43 respectively; while that of An. pharoensis was 0.37, 0.70 and 0.55 respectively. Parasitologically, mean parasite rates of 26.67%, 15.05% and 23.85% were, respectively, recorded from children living under the above conditions stated for passive experiment. Similarly, the mean spleen rates of 50.0%, 26.9%, and 47.37% were recorded, respectively.


CONCLUSIONS
These observations in the present study indicate that the presence of cattle in homesteads tends to increase the man biting rate of An. arabiensis, although differences in the mean HBR of vector mosquitoes were not statistically significant for all groups. In contrast, cattle keeping in separate cattle sheds outside of the human dwellings tends to reduce the man biting rate of An. arabiensis and malaria transmission in the study area.
Seyoum
A
A
Institute of Pathobiology, Faculty of Medicine, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
Balcha
F
F
Balkew
M
M
Ali
A
A
Gebre-Michael
T
T
D000328:Adult; D000822:Animal Husbandry / Q000706:statistics & numerical data*; D000818:Animals; D000829:Animals, Domestic; D000852:Anopheles / Q000469:parasitology* / Q000502:physiology; D002417:Cattle; D002648:Child; D019353:Endemic Diseases / Q000706:statistics & numerical data; D005002:Ethiopia / Q000453:epidemiology; D005247:Feeding Behavior; D006041:Goats; D006798:Housing / Q000706:statistics & numerical data; D006799:Housing, Animal / Q000706:statistics & numerical data; D006801:Humans; D007299:Insect Bites and Stings / Q000150:complications* / Q000453:epidemiology*; D007303:Insect Vectors / Q000469:parasitology* / Q000502:physiology; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission*; D016780:Malaria, Vivax / Q000453:epidemiology / Q000469:parasitology* / Q000635:transmission*; D012621:Seasons; D013163:Splenomegaly / Q000453:epidemiology / Q000469:parasitology; D018881:Suburban Health / Q000706:statistics & numerical data