Malaria control with residual fenitrothion in Central Java, Indonesia: an operational-scale trial using both full and selective coverage treatments.

An operational-scale trial, using residual fenitrothion, for control of malaria was carried out in Central Java, Indonesia, from 1980 to 1982. Two areas, each comprising about 70 km(2) and a population of about 50 000, were treated with fenitrothion (40% water dispersible powder) at a target dosage of 2 g/m(2) for 3 cycles at 6-monthly intervals. One area was treated with full coverage (i.e., the interiors of houses and cattle shelters were sprayed to a height of 3 m) for 2 cycles, followed by a third cycle with selective coverage (i.e., the interiors of houses were sprayed with one 75 cm horizontal swath between 10 cm and 85 cm from the floor while the cattle shelters were sprayed to a height of 3 m). The other area was treated for 3 cycles with only selective coverage. While both treatment methods reduced malaria rates and vector populations to very low levels, the full coverage treatment was more rapidly effective and also reduced the Plasmodium falciparum index. However, the selective coverage treatment was 68% less expensive than full coverage and greatly reduced the degree of cholinesterase depressions among the spraymen. The trial also showed that a dosage of 1 g/m(2) with full coverage was nearly as effective as the 2 g/m(2) dosage.