Study of the malaria situation in forested foothill and nearby plain areas of Myanmar.

A longitudinal demographic-parasitological survey on malaria was conducted at 10 weekly intervals starting from September in one foothill village with the population of 1,095 and one epidemiologically comparable plain village with the population of 962 in Kyauktaga township, Bago division, 120 miles north of Yangon. The objective was to describe and analyse the current malaria situation in a forested foothill area and an adjacent plain area. Ten weekly blood film collections for malaria parasite examination, six monthly sera collections on filter paper for serological examination from the whole study population and ten weekly splenic measurements from 2-9 year children were done. The malaria parasite rate in the foothill area was invariably higher than that in the plain area in all age groups throughout the study period. Moreover, the parasite rate decreased with the increase in distance from the forested foothill area indicating that the deep forest malaria may have some influence on the foothill villages. The total age specific parasite rate in foothill villages was found to be highest in the 5-8 year age group and decreased as the age advanced which may be due to the increasing immunity. The study revealed the presence of local transmission in the foothill village. From these data it is evident that new village sites should be chosen at least 5 miles away from the forest fringe and the malaria control measures in the plain area should utilize chemoprophylaxis and effective chemotherapy focusing on the people who travel into the forest.