Incidence of snakebites in 3 different geographic regions in Thua Thien Hue province, central Vietnam: Green pit vipers and cobras cause the majority of bites.

Background: The annual incidence of snakebites in Vietnam is not known and only few publications about snakebite envenoming and medically relevant snakes can be found in English language literature. The present community-based surveys provide data on incidence of snakebites in three different geographic regions of Thua Thien Hue (TT Hue) province, central Vietnam and snake species responsible for bites in this region.

Methodology/results: The cross-sectional community based surveys were conducted from March to July 2017. Multistage cluster sampling was applied and snakebite incidence was calculated at 58 snakebites per 100,000 person-years for the entire province, and 172, 69 and 10 snakebites per 100,000 person-years in the mountainous, coastal and urban region of TT Hue province, respectively. Thirty-one snakebite victims interviewed during the surveys reported 18 (58%) green pit viper bites (Trimeresurus species), 5 (16%) cobra bites (Naja kaouthia, Naja siamensis), 2 (7%) krait bites (Bungarus candidus, Bungarus fasciatus), 2 (7%) red-necked keelback bites (Rhabdophis subminiatus) and 4 bites from unidentified snakes (13%). The outcome was favourable for 28 snakebite victims (90%), two (6%) had minor sequelae and one (3%) victim died after a Malayan krait bite. Two hundred and twenty-one snakebite patients were treated in 9 district hospitals and one central hospital in TT Hue between 2014 and 2016. Eighty green pit vipers (84%), 12 cobras (13%) and 3 kraits (3%) were responsible for bites in 95 patients where snake identification was documented.

Conclusions: Incidence of snakebites is surprisingly low in TT Hue province in central Vietnam in comparison to other regions in Asia, particularly to neighbouring Lao PDR. However, snakebites are still a significant health problem in the mountainous region and green pit vipers and cobras cause the vast majority of bites.