Surveillance of dengue hemorrhagic fever cases in Thailand.

A long-term surveillance system is necessary for planning and evaluation of hemorrhagic fever control Dry blood collection and using one dengue 2 antigen have been proved to be an efficient method to detect low and high level of HI antibody, determined to prove dengue infection. The percentage of dengue infection serologically proved from cases reported throughout a 3 year study was 52%. Dengue infected cases were reported outside epidemic period with lowest incidence in January. The majority of dengue proven cases occur at age 6 years. For chikungunya infection, studied in Bangkok metropolis and in this study in 72 provinces shows similar result indicating that chikungunya virus shows no significance in clinical and laboratory study in the surveillance programme. This study provides definite information for the planning and evaluation of hemorrhagic fever control.

Surveillance of Japanese encephalitis cases in Thailand.

This surveillance study reveal the incidence of Japanese encephalitis cases throughout the year with an increase during the rainy-seasons. JEV attacks all ages, but with a high incidence found in age group between 8 to 14 years determined from the studies in 1974, 1975 and 1976 and records of distribution in 40 provinces of Thailand. The severity of infection is high to warrant virus surveillance by the Ministry of public Health.