Repellent efficacy of DEET, MyggA, neem (Azedirachta indica) oil and chinaberry (Melia azedarach) oil against Anopheles arabiensis, the principal malaria vector in Ethiopia.
BACKGROUND
In Ethiopia, Anopheles arabiensis is the main vector responsible for the transmission of malaria in the country and its control mainly involves application of indoor residual spraying (IRS) and use of insecticide-treated bed nets (ITNs).


OBJECTIVE
Although the role of repellents for reducing man-vector contact is documented in the literature, the response of An. arabiensis to repellents was not previously evaluated under field conditions in Ethiopia.


METHODS
The trial was conducted in Sodere village assessing the repellent activities of four repellents, of which, two of them were commercially available DEET (N, N-diethyl-1,3-methylbenzamide) and MyggA (p-methane diol) and the other two were laboratory- produced, 20% neem oil and 20% chinaberry oil. A 6 by 6 Latin square design was employed by involving six volunteers who received rotated treatments of repellents and the Ethiopian Niger seed, noog abyssinia (Guizotia abyssinia), and locally called as noog oil (diluents to the two plant oils). Each volunteer also served as control. Volunteers were positioned at a distance of 20-40 m from each other and each was treated with one of the repellents, Niger seed/noog/ oil or untreated. Landing mosquitoes were collected from dusk to down using tests tubes. The tests were done in three replicates.


RESULTS
Both DEET and MyggA provided more than 96% protection. The mean protection time for DEET was 8 hrs while the time for MyggA was 6 hrs. Protection obtained from neem oil and chinaberry oil was almost similar (more than 70%), however, the complete protection time for neem was 3 hrs, while that of chinaberry oil was one hour.


CONCLUSIONS
The commercial products and laboratory-produced repellents can be utilized by individuals to avoid contact with An. arabiensis in Ethiopia.
The Carter Center Ethiopia, North Wollo Zone Health Department, Malaria and Trachoma project office, PO Box 69, Woldia, Northeast Amhara region, Ethiopia. ephremabiy1@gmail.com.
Ephrem
E
Abiy
Aklilu Lemma Institute of Pathobiology, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia. teshomegm@gmail.com.
Teshome
T
Gebre-Michael
Aklilu Lemma Institute of Pathobiology, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia. meshesha_b@yahoo.com.
Meshesha
M
Balkew
Aklilu Lemma Institute of Pathobiology, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia. gtmedhin@yahoo.com.
Girmay
G
Medhin
D000328:Adult; D000818:Animals; D000852:Anopheles; D002648:Child; D003671:DEET; D005002:Ethiopia; D005989:Glycerides; D006801:Humans; D007302:Insect Repellents; D007303:Insect Vectors; D008288:Malaria / Q000517:prevention & control*; D008297:Male; D031586:Melia azedarach / Q000737:chemistry; D009032:Mosquito Control; D010938:Plant Oils; D013729:Terpenes; D055815:Young Adult
D005989:Glycerides; D007302:Insect Repellents; D010938:Plant Oils; D013729:Terpenes; D003671:DEET; C002443:neem oil