Institute of Tropical Medicine, Nagasaki University
Abstract
Cases of "Acute Encephalitis Syndrome (AES)" and deaths were reported annually in all 17 provinces in the South of Vietnam. The highest morbidity of 936 patients was recorded in 1980, while highest mortality of 339 deaths in 1977. The lowest figures of morbidity was 197 cases in 1990 and lowest mortality was 34 deaths in 1985. Sporadic cases were reported throughout the year but small outbreaks with low peaks were seen in February and July annually. Twenty five strains of Japanese encephalitis (JE) virus were isolated during 1978-1992: 8 from patients\u27 blood, 5 from cerebrospinal fluid (CSF), 9 from Culex quinquefasciatus, 3 from Aedes aegypti. Serologically confirmed JE cases were not many, because most of the human sera sent to us for testing were used for differential diagnosis of pernicious malaria. The anti-JE antibody prevalence among healthy human in 11/17 provinces was found to be extremely high, especially in adults. The antibody positive rate among swine to JE was found to be high: 82% with GMT 65.2 in 189 sera taken at My Tho-Tien Giang province in March 1978 and 77.4% with GMT 49.7 in 261 sera taken in the vicinity of Ho Chi Minh City in September 1992. From the above data, the Southern part of Vietnam is an endemo-epidemic area of JE virus infection