Prevalence of asthma and asthma-like symptoms in Dalat Highlands, Vietnam.

INTRODUCTION: No data has been reported on the prevalence of asthma in highland rural areas of Vietnam. We attempt to determine the prevalence of asthma and asthma-like symptoms in Dalat, a Vietnamese city at 1,500 m altitude, and to learn about environmental influences, patient attitudes toward diagnosis and treatment, and the prevalent general knowledge about asthma. METHODS: Investigators were trained in the use of formal questionnaires. After an extensive publicity campaign by local television, the investigators randomly selected homes for interviews in 12 districts. When physician-diagnosed asthma or asthma-like symptoms were identified, all parts of the questionnaire were completed and a more detailed visit was arranged with the patients, for clinical examination, spirometry and skin tests for important allergens. RESULTS: 9,984 individuals were interviewed, of whom 243 were identified as having asthma or asthma-like symptoms, giving a prevalence of 2.4 percent. Average age was 48 +/- 27 years, age at onset of asthma was 25 +/- 22 years. Hospitalisation had been required in 18.3 percent of patients during 2003. Daily asthma treatment was used by only 17 percent of patients. 34 percent used inhalers and 6 percent used nebulisation. 52.3 percent had associated atopic features. Polyvalent positive prick tests were prevalent, but no one reacted to a pollen mixture. General knowledge about asthma was lacking. CONCLUSION: The prevalence of asthma and asthma-like symptoms in Dalat is low. Allergic cutaneous reactions to house mites predominate. Diagnosis and treatment of those afflicted with asthma appears to be suboptimal. The study highlights the need for further patient education and for preventative interventions for asthma sufferers in this region.

Control of malaria: a successful experience from Viet Nam.

OBJECTIVE: To follow malaria prospectively in an ethnic minority commune in the south of Viet Nam with high malaria transmission and seasonal fluctuation, during malaria control interventions using insecticide-treated bednets (ITBNs) and early diagnosis and treatment (EDT) of symptomatic patients. METHODS: From 1994 onwards the following interventions were used: distribution of ITBNs to all households with biannual reimpregnation; construction of a health post and appointment of staff trained in microscopic diagnosis and treatment of malaria; regular supply of materials and drugs; annual cross-sectional malaria surveys with treatment of all parasitaemic subjects, and a programme of community involvement and health education. Surveys were held yearly at the end of the rainy season. During the surveys, demographic data were updated. Diagnosis and treatment of malaria were free of charge. Plasmodium falciparum infection was treated with artesunate and P. vivax infection with chloroquine plus primaquine. FINDINGS: The baseline survey in 1994 recorded 716 inhabitants. Of the children under 2 years of age, 37% were parasitaemic; 56% of children aged 2-10 years, and 35% of the remaining population were parasitaemic. P. falciparum accounted for 73-79% of these infections. The respective splenomegaly rates for the above-mentioned age groups were 20%, 56%, and 32%. In 1999, the proportion of parasitaemic subjects was 4%, 7% and 1%, respectively, of which P.falciparum contributed 56%. The splenomegaly rate was 0%, 5% and 2%, respectively. CONCLUSIONS: A combination of ITBNs and EDT, provided free of charge, complemented by annual diagnosis and treatment during malaria surveys and community involvement with health education successfully brought malaria under control. This approach could be applied to other regions in the south of Viet Nam and provides a sound basis for further studies in other areas with different epidemiological patterns of malaria.