1.5 Snail sutvey and control
In Barong Dalig, Pola, a two-year-old child was found to be egg-positive. A snail breeding site with a high snail density (618 snails/man/hr) was then found in a boggy area located near the shore of the Lake Naujan. Out of 200 snails examined 6 (3%) were infected with S. japonicum. Clearing followed by mollusciciding with niclosamide and drainage operations will be conducted soon by the team and 20-30 volunteers from the barangay.
Another search for snails was done by the team in Javier Swamp, San Narciso, and Malabo forest and Malibaguhan creek, Malabo. A number of snails (37/man/hr) were collected in Javier swamp, while few snails were collected in Malabo forest (2/man/hr) and Malibaguhan creek(1/man/hr). Out of 37 snails collected in Javier Swamp 0ne (1) was seen to be infected. No infection was observed in snails from Malabo forest and Malibaguhan creek. Clearing with 2 sets of mowing machines was thoroughly carried out in Malabo forest for 2 days. Seven laborers were temporary employed for the operations.
2. Bohol
2.1. Snail survey
Snail surveys were conducted twice, on 31 July and 4 August, at Omaguin palawan II (seepages, pockets, and man-made canal) and Bunaos palawan (seepage) in San Roque, and Apao palawan (Canas boggy and lowers), Gaspar boggy, Troceno boggy, and Kanggabok creek (rice field) in San Vicente. No Oncomelania quadrasi was found except Boncales boggy in which a few snails (2.0 snails/hour/man) were collected only on 31 July by 5 well-trained workers. No schistosome infection was Seen in 3 snails collected from Boncales boggy. The long spel of dry weather for the past 7 months in Bohol did considerable damage to snails.
It was a matter of regret that a poor maintenance was observed in Casilion cement-lined creek in Sto. Tomas.
2.2 Snail control
Niclosamice is now out of stock in Bohol. Only vegetation removal operations were thoroughly carried out in Boncales bogg on 5 August. The boggy is about 100 meters long, and has average width of 20 m. The source of its water is the seepage on its upperportions. Pesigan et al.(1958) studied the effect of clearing alone in Leyte. During the time of their experiments the uncleared areas showed an over-all increase in snail density, whereas the population in the cleared areas never regained its original density, and averaged 25.6% of that in uncleared areas.
