Evidence of previous but not current transmission of chikungunya virus in southern and central Vietnam: Results from a systematic review and a seroprevalence study in four locations

摘要

In recent years, the reemergence of chikungunya has gained global attention and threatened to become a global outbreak. Although the epidemiology of chikungunya is known globally, the viral activity in Vietnam has not been thoroughly investigated. In this paper, we used information from a systematic review and serological survey to understand the past activity of chikungunya in Vietnam. In the serological survey, we tested age -stratified population serum samples in the central and southern parts of Vietnam from 2015 for chikungunya IgG, which is indicative of past exposure to chikungunya. Our results show almost no positive individuals below the age of 30 years old, indicating very low to no virus transmission for the last 30 years. In individuals over 30 years old, there were more positive individuals, and we estimate widespread transmission with an average of 2–4% of the population infected each year. Because of the lack of recent transmission in these locations, the susceptible population is increasing and is now high, suggesting Vietnam is vulnerable to future outbreaks if chikungunya is reintroduced. Hence, chikungunya surveillance along with surveillance for other arboviruses, such as dengue, should be conducted in Vietnam.