Sustainability of a successful malaria surveillance and treatment program in a Runggus community in Sabah, east Malaysia.

The district of Kudat has one of the highest and most persistent malaria transmission levels in Sabah, Malaysia, with annual parasite incidence of 102 per 1,000 inhabitants per year. Due to this situation and the failure of DDT spraying to control malaria, a community participation health program (Sukarelawan Penjagaan Kesihatan Primer or SPKP) was developed as an adjunct to current anti-malarial measures during 1987-1991. SPKP is made up of unpaid community workers known as village health volunteers (VHVs). VHVs are selected by a village development and security committees training and supervision a member of the Vector-Borne Diseases Control Program (VBDCP). The beneficiaries of SPKP consisted primarily of Runggus people and other remote, and mobile populations who visit the home of a VHV for diagnosis and treatment. This group of febrile patients and their children who attend a participating school submit finger prick blood and personal details to the VHV. and receive a presumptive treatment for malaria. Thick and thin blood smears are examined by a VBDCP microscopist who then prepare and forward a radical or curative treatment to the VHV so that it can be administered to the microscopically-positive patient free of charge. Between June 1987 to June 1991, VHVs from 32 kampungs (villages) and 22 schools collected 56,245 slides representing 24.7% of total slide collection compared to 74.9% collected by passive case detection (PCD) posts in health centers and district hospital. The average volunteer treated 11.8 (range 10.4-13.4) and 31.4 (range 26-49) patients per month in kampungs and schools respectively. In contrast, non-SPKP posts in a district hospital, health centers and flying doctor service treated an average of 616.3 patients per month (range 134.8-1032.8). The slide positivity rate of blood smears taken by VHVs was 8.43% compared with 7.37% for non-SPKP posts. Average slide collection and slide positivity rates varied considerably from one community to another, despite their close geographic proximity. The monthly number of VHV-diagnosed patients from the school and kampungs communities and the monthly number of true malaria patients in the two groups were significantly correlated. Sustainability of SPKP was linked to an ongoing process of social change which involved co-operative networking between the government health sector and the community. This in turn provided a stimulus for malaria abatement efforts. When Runggus people themselves control and maintain ownership of community-based malaria programs, the function of SPKP as a malaria surveillance system and an antimalarial drug distribution network is vastly improved.

Enzyme polymorphism of the malaria vector, An. balabacensis (Diptera: Culicidae) revisited--why sample natural populations?

Two separate observations from recent electrophoretic studies of the systematics and population genetics of laboratory-reared populations which had a long history of colonization in various laboratories, were found to be inconsistent with the present study which used wild-caught populations from East Malaysia. Reanalysis of the two data sets generally indicated a low amount of genetic variation in laboratory colonies. The latter is characterized by higher frequency of monomorphic loci, low average heterozygosity values and, in one extreme case, no variability at two loci. However, natural populations of An. balabacensis and An. leucosphyrus showed more protein variability by the use of polyacrylamide gel electrophoresis. Since laboratory-maintained mosquitoes are genetically and phenotypically different from those in the field, results of laboratory studies on the systematics and population genetics of Anopheles species complexes may be biased.