The epidemiology of typhoid fever in the Dong Thap Province, Mekong Delta region of Vietnam

A population-based surveillance for typhoid fever was conducted in three ru ral communes of Dong Thap Province in southern Vietnam (population 28,329) for a 12-month-period starting on December 4, 1995. Cases of typhoid fever were detected by obtaining blood for culture from residents with fever grea ter than or equal to 3 days. Among 658 blood cultures, 56 (8.5%) were posit ive for Salmonella typhi with an overall incidence of 198 per 10(5) populat ion per year. The peak occurrence was at the end of the dry season in March and April. The attack rate was highest among 5-9 year-olds (531/10(5)/year ), and lowest in > 30 year-olds (39/10(5)/year). The attack rate was 358/10 (5)/year in 2-4 year-olds. The isolation of S. typhi from blood cultures wa s highest (17.4%) in patients with 5 to 6 days of fever. Typhoid fever is h ighly endemic in Vietnam and is a significant disease in both preschool and school-aged children.