Entomological and epidemiological investigations of XXXX transmission in relation to population movements in forest areas of north-west Thailand.

@entity5461 @entity1 @entity3964 @entity311 @entity579
Transmission of forest-related @entity311 was observed entomologically and epidemiologically for 2 transmission seasons in 1990 and 1991 in 5 villages of Mae Sariang district, Mae Hong @entity5461 Province, north-west Thailand. The entomological study included collections of mosquitos and determination of infection rate by using enzyme-linked immunosorbent assay in the residential villages and the farm huts. The epidemiological study included fortnightly visits to 30% of the households to interview and record movement activities and illness of villagers. Circumsporozoite proteins, in most cases of @entity3964 , were detected in Anopheles minimus species A, An. dirus s.l., An. maculatus s.s. and An. sawadwongporni in residential villages and/or farm huts, suggesting transmission could occur there. Movement of @entity1 away from their residences occurred throughout the year for several reasons with a sharp peak in July for agricultural activity, mainly ploughing and planting for @entity579 cultivation. The relative risk of infection for @entity1 engaged in agricultural activity was 3 times that of @entity1 living in the residential villages. Although a higher biting density of vectors was generally evident at the farm huts, the estimated inoculation rates in the 2 settings were similar. Movement for forest activity increased after harvesting @entity579 in the cool dry season and carried the highest @entity311 risk, suggesting different epidemiological and probably entomological conditions which need further investigation. The significance is discussed of discrepancies between the case classification system used by this study and that used by @entity311 sector staff.
