China faces uphill battle against escalating dengue infections

China faces increasing challenges to control the spread of dengue fever, together with the increasing global incidences of the disease over the past two decades, according to recent research.

Dengue is the most widespread arbovirus and causes the highest number of arboviral disease cases globally. From 2005 to 2023, 117,892 dengue cases were reported in China, with significant fluctuation in annual reported cases, according to the report released on China CDC Weekly, a national public health bulletin and an academic platform set up by the Chinese Center for Disease Control and Prevention, on Oct 11.

Global dengue circulation over the past two decades has markedly increased the risk of virus importation by viremic travelers into China, it said.

Factors contributing to local transmission include high mosquito populations, susceptibility to circulating dengue virus serotypes and favorable environmental conditions — such as air temperature, precipitation and humidity — that affect mosquito reproduction, feeding patterns and the virus incubation period, according to the report.

Regional outbreaks most likely occurred in China's southwestern, southeastern coastal and inland areas between June and November, generally peaking in September or October.

No significant gender or occupational differences were observed in the reported cases. It could be supposed that susceptibility to dengue might mainly depend on the proximity to the source of infection and the chance of being bitten by infected mosquitoes in China, it said.

Proactive prevention and control interventions should be deployed, and staff training and mobilization should be carried out before June for timely responses to regional outbreaks in the Chinese mainland, according to the research.