A marked seasonality of malaria transmission in two rural sites in eastern Sudan

TY - JOUR

T1 - A marked seasonality of malaria transmission in two rural sites in eastern Sudan

AU - Hamad, Amel A

AU - Nugud, Abd El Hamid D

AU - Arnot, David E

AU - Giha, Haider A

AU - Abdel-Muhsin, Abdel Muhsin A

AU - Satti, Gwiria M H

AU - Theander, Thor G

AU - Creasey, Alison M

AU - Babiker, Hamza A

AU - Elnaiem, Dia Eldin A

N1 - Keywords: Animals; Anopheles; Humans; Incidence; Malaria, Falciparum; Plasmodium falciparum; Rural Population; Seasons; Sudan

PY - 2002

Y1 - 2002

N2 - The ecology of Anopheles arabiensis and its relationship to malaria transmission was investigated in two villages in eastern Sudan. Seasonal malaria case incidence was compared with the number of vectors detected and with climatic variables. Following the end of the short rainy season in October the number of A. arabiensis detected dropped gradually until February when neither outdoor human bait trapping nor indoor spray catches revealed any mosquitoes. Vectors re-appeared in June as humidity rose with the onset of rain. Despite the apparent absence of the vector at the height of the long, hot dry season between February and May, sporadic asymptomatic malaria infections were detected in the two villages. The low endemicity of malaria in the area was reflected by the relatively low total September-December parasite and sporozoite rates (15 and 1.4%, respectively) measured in the villages. The entomological inoculation rate (EIR) was estimated to be around two to three infective bites per person per year, although heterogeneity in the transmission indices of malaria between the two villages was observed. The implications of these patterns of anopheline population dynamics for the epidemiology and control of malaria in eastern Sudan are considered.

AB - The ecology of Anopheles arabiensis and its relationship to malaria transmission was investigated in two villages in eastern Sudan. Seasonal malaria case incidence was compared with the number of vectors detected and with climatic variables. Following the end of the short rainy season in October the number of A. arabiensis detected dropped gradually until February when neither outdoor human bait trapping nor indoor spray catches revealed any mosquitoes. Vectors re-appeared in June as humidity rose with the onset of rain. Despite the apparent absence of the vector at the height of the long, hot dry season between February and May, sporadic asymptomatic malaria infections were detected in the two villages. The low endemicity of malaria in the area was reflected by the relatively low total September-December parasite and sporozoite rates (15 and 1.4%, respectively) measured in the villages. The entomological inoculation rate (EIR) was estimated to be around two to three infective bites per person per year, although heterogeneity in the transmission indices of malaria between the two villages was observed. The implications of these patterns of anopheline population dynamics for the epidemiology and control of malaria in eastern Sudan are considered.

M3 - Journal article

C2 - 12062795

SN - 0001-706X

VL - 83

SP - 71

EP - 82

JO - Acta Tropica

JF - Acta Tropica

IS - 1

ER -