Cost-effectiveness and sustainability of lambdacyhalothrin-treated mosquito nets in comparison to DDT spraying for malaria control in western Thailand.

The cost-effectiveness of lambdacyhalothrin-treated nets in comparison with conventional DDT spraying for malaria control among migrant populations was evaluated in a malaria hyperendemic area along the Thai-Myanmar border. Ten hamlets of 243 houses with 948 inhabitants were given only treated nets. Twelve hamlets of 294 houses and 1,315 population were in the DDT area, and another 6 hamlets with 171 houses and 695 inhabitants were in the non-DDT-treated area. The impregnated net program was most cost-effective (US$1.54 per 1 case of prevented malaria). Spraying with DDT was more cost-effective than malaria surveillance alone ($1.87 versus $2.50 per 1 case of prevented malaria). These data suggest that personal protection measures with insecticide-impregnated mosquito net are justified in their use to control malaria in highly malaria-endemic areas in western Thailand.

Differential diagnosis of schistosomiasis mekongi and trichinellosis in human.

An indirect (plate) ELISA and, a more convenient version, a dot-blot (membrane) ELISA have been developed using haemocyanin of a mollusk, Megathura crenulata, i.e. keyhole limpet haemocyanin (KLH) and purified, specific antigen of Trichinella spiralis (APTsAg) obtained from a monoclonal antibody-affinity column chromatography, for differential diagnosis of schistosomiasis mekongi and trichinellosis. Serum samples of patients with parasitologically confirmed trichinellosis were reactive to both antigens in both versions of ELISA while sera of patients with schistosomiasis mekongi were positive only to the KLH. Both ELISA were negative when used to test sera of normal controls and patients with gnathostomiasis, paragonimiasis and opisthorchiasis.

Cost and performance of malaria sector: a case study at Malaria Sector 11, Tak Province, Thailand.

The objective of this study was to assess the cost and performance of each operational unit at the malaria sector level and to calculate the unit cost of each activity accordingly. Data were collected at Malaria Sector No.11 situated at the western border of Thailand with Myanmar during the fiscal year of 1995. The unit cost was calculated by dividing the total cost of each activity by its output using appropriate units of analysis. The result showed that 67% of the total cost of malaria sector was labor cost and 45% of the total cost was allocated to diagnosis and treatment activities. Unit cost in terms of cost/visit, cost/case found, cost/case of falciparum malaria treated, cost/case of vivax malaria treated, cost/house spray and cost/impregnated net were US$1.85, 8.21, 10.07, 8.46, 2.24 and 1.54 respectively. The results of this study will provide important information as to the best use of limited available resources to determine which activities should be stopped, continued, increased or decreased at the malaria sector level.

Cost-effectiveness analysis of lambdacyhalothrin-treated nets for malaria control: the patients' perspective.

The present study was undertaken to evaluate the cost-effectiveness of lambdacyhalothrin-treated nets in comparison with conventional DDT-spraying as a method of malaria control according to the patients' perspective among migrant populations in a high-risk area along the Thai-Myanmar border in Thailand. Ten hamlets comprising 243 houses with 948 inhabitants were given only treated nets. Twelve hamlets comprising 294 houses and 1,315 inhabitants represented the DDT-treated area and another six hamlets with 171 houses and 695 inhabitants served as controls. Information as to consumer costs was obtained by interviewing 3,214 patients seeking care at all levels of the health care system in the study area. Analysis showed that the impregnated-net program was more cost-effective than the DDT-spraying program or surveillance alone (US$ 0.59 vs US$ 0.74 vs US$ 0.79 per 1 case of prevented malaria). We conclude that in a high-risk area such as along the Thai-Myanmar border in western Thailand, integrating the use of impregnated nets with large-scale primary health care programs is likely to constitute the most cost-effective method for controlling malaria according to the patients' perspective.

Maternal influence on the use of impregnated bednets in the protection of infantile malaria.

A cross-sectional survey of 184 mothers or caretakers was undertaken to investigate the effect of socio-behavioral background on decision making in relation to the use of impregnated bednets to prevent malaria for their children in Ratchaburi Province, Thailand. It was found that most mothers had knowledge of the cause, transmission and prevention of malaria. They perceived susceptibility and severity of malaria as a risk to their children, which might even cause death. They also perceived and had positive attitudes toward impregnated bednets as a protection for their children. Three-quaters (76.4%) of them used impregnated bednets regularly to protect their children whereas one-quarter (23.6%) used infrequently and few never used. Bivariate analysis showed that the use of impregnated bednets was significantly related to the factors such as knowledge of malaria prevention, perception of benefits of the use, the receipt of information about the impregnated bednets from malaria workers.

Behaviors in self-prevention of malaria among mobile population in east Thailand.

The study investigated preventive behaviors among mobile villagers in Chanthaburi and Trat Provinces where the slide positive rates (SPR) of malaria in 1987 were 10.3 and 11.1%, respectively. The study was conducted in four villages namely Wang Thong, Khao Thong in Chanthaburi, and Manow and Khow in Trat by using a cross-sectional survey. Household and in-depth interviews with the movers were done together with field observations. The sizes of the villages were 52, 180, 184 and 209 households and the movement rates were 23.1, 12.2, 37.5 and 28.7%, respectively. The population involved in short term migration was 729 villagers living in 153 households or 23.7% of the total. Malaria prevalence rates in the four villages were 7.5%, 5.9%, 7.3% and 2.2%, respectively. The results indicate that the mobile population had a moderate 40% rating score of knowledge about malaria. Apparently, the rating score of preventive behaviors of the disease appeared to be as small as 20%. After six months of field investigations, 1,083 thick blood smears collected from the mobile population, there were 657 episodes (60.7%) of malaria that could be categorized with age specific prevalence of 60.3% in 19-29 years, 80.8% in 30-39 years, 54.8% in 40-49 years, 38.6% in 50-59 years and 35.7% in 60 years and over. Villagers aged between 30-39 years with frequent movement into the forest had the highest impact of malaria risk. Moderate levels of knowledge and attitude scores did not appear to enable the people to protect themselves against malaria.

Maternal practices and risk factors for dehydration from diarrhoea in young children: a case-control study in central Thailand slums.

To determine factors related to dehydration from diarrhoea, we conducted a hospital-based, case-control study in children aged 24 months or younger who had acute watery diarrhoea and attended Chonburi Regional Hospital in central Thailand during November 1988 through May 1989. The study compared 48 cases who had moderate or severe dehydration with 48 controls who had no dehydration. Both cases and controls belonged to low socioeconomic families and were living in urban slum areas. They had adequate health care facilities and access to ORS packets. Overall, 56% of the mothers used ORS solution at home. None of the mothers knew how to administer ORS, i.e. the fluid was not given at the onset of diarrhoea to prevent dehydration, and they gave no more than 60 ml over a 24-hour period to their dehydrated children. They also did not use home fluids. Multivariate analysis of data showed two factors significantly associated with dehydration: children's dirty fingernails that indicated inadequate maternal hygiene-related behaviour (Odds Ratio 6.4; 95% Confidence Intervals 1.5-27.6, p < 0.01), and frequency of vomiting in the 24 hours before rehydration (Odds Ratio 1.3; 95% Confidence Intervals 1.1-1.6, p < 0.001). Cases and controls had similar aetiologic agents and nutritional status. Providing proper education to mothers about oral rehydration therapy with special emphasis on the volume of ORS to be given, along with guidance to improve their personal hygiene should be considered important interventions in reducing the risk of dehydration and deaths from diarrhoea in these children.

Malaria-related social and behavioral risk factors in Thailand: a review.

A review of the social and behavioral risk factors that have been implicated in malaria infection in Thailand was done as a basis for designing a conceptual framework in formulating recommendations of strategies and research needs to ensure better implementation and/or maximization of the effectiveness of existing malaria control measures in the country. These factors can be broadly divided into three categories: (1) social and behavioral risk factors favoring increased occurrence and transmission, ie population movements, irregular use or non-use of mosquito nets, partial or non-conformance with residual DDT house spraying, etc, (2) behavioral risk factors predisposing to occurrence of severe and complicated malaria, not clearly known, probably delayed treatment, (3) behavioral risk factors related to occurrence of drug resistance, ie treatment-seeking patterns, practices of drug utilization and population movements. Recommendations on research needs as well as strategies for a more effective control program are given.

Social, behavioural, housing factors and their interactive effects associated with malaria occurrence in east Thailand.

This retrospective case-control study was carefully designed to investigate the principal factors that had effects on malaria occurrence. The findings of this study showed that malaria occurs less frequently among persons who have lived in the area for a long period of time, who have obtained education, who have a sizable annual family income. Malaria occurs more frequency among persons who work in or near the forest and persons who move into the forest frequently or occasionally as well as among persons whose houses are in close proximity of vector breeding sites.

Migration and disease problems: a study of pattern of migration in an endemic area of malaria in Thailand.

The preliminary results of a study of rural-rural migration in an endemic area of malaria is reported. The study on socio-economic status of migrant workers was made during the post planting season of sugarcane plantation in Tambon Nong Rhee Kanchanaburi Province. Among 9,311 population in four villages of this Tambon, 15.4% were migrants and 45.5% were from the northeast provinces of Thailand. Almost half of the migrant population came to the area for the first time and stayed for six months mostly during the sugarcane cutting season. No significant difference in experience with malaria (as recognized by the people not from blood examination) between the local population and the migrants was observed from the interview. However, the duration of migration seemed to relate with the risk of contracting malaria.