Some recent studies suggested that dengue remains an imported disease in China but these studies used small datasets. The first comprehensive genomic analysis of the dengue virus in China has revealed that the disease has become endemic and diverse in the country and may survive the year-round in southern parts of the nation.
The study provides evidence that China may be at an increased risk for more frequent and severe dengue fever outbreaks similar to the 2014 outbreak in Guangdong Province that sickened more than 40,000 people.
Rubing Chen, evolutionary virologist at University of Texas Medical Branch- Galveston, said, "We now have compelling evidence that dengue can persist in China - in some cases up to six to eight years. We found a surprisingly complex and diverse mix of viral subtypes represented in China, a factor that can mean greater risk of epidemic dengue in the future."
The researchers evaluated all dengue virus sequences from China available in the public database GenBank. They found 50 individual variants and multiple variants during the 2014 Guangdong outbreak.
Chen said, "Even within the same year, a person can catch dengue more than once if distantly related variants are circulating in the same region."
The authors said, "Regardless of the exact transmission pattern China is facing a substantial dengue threat, with potential invasion into broader areas of the country. Sporadic cases have been identified in several provinces in recent years. The combination of a hot, humid climate ideal for breeding mosquitoes and large population centers in southern China combine to make this area a particular concern for public health officials."
The research appeared in the Journal of Tropical Medicine and Hygiene.