Surveillance and Molecular Characterization on Dengue Viruses in Taiwan, 2013

Cheng-Fen Yang, Chien-Ling Su, Tung-Chien Hsu, Li-Yu Chen, Pei-Yun Shu

2014 Vol.30 NO.19

Correspondence Author： Pei-Yun Shu

Abstract：

       We present our surveillance results on imported and indigenous dengue cases in Taiwan in 2013. A total of 264 imported dengue patients were identified. Among them, 113 (42.8%) cases were identified by fever screening at airports. The travelers were infected in 16 countries, including India, China, Brazil, and those located in Southeast Asia and South Pacific islands. Most of these imported cases were infected in Indonesia, next in Thailand, the Philippines, and Malaysia. The main dengue virus serotype was DENV-1 in all countries, with the exception of the Philippines and India in which DENV-4 and DENV-2 were the main serotypes, respectively. Molecular epidemiologic study showed that six different strains of DENV were co-circulated in southern Taiwan.
       The first dengue outbreak occurred in Chunri Township, Pingtung County and was caused by a strain of DENV-1 which was also responsible for epidemics in Tainan City in 2011 and 2012. The second outbreak occurred in Xinyuan Township, Pingtung County and was caused by a strain of DENV-3 imported from Indonesia. The third outbreak which caused by a strain of DENV-2 imported from Indonesia began in Chaozhou Township, Pingtung County and later some sporadic cases were reported in Xinpi Township and Zhutian Township. The forth outbreak caused by a different strain of DENV-2 also imported from Indonesia. This large-scale outbreak began in Pingtung City and later spread to Pingtung County, Kaohsiung City, and Tainan City. In addition, a different strain of DENV-1 which likely introduced from Malaysia caused few sporadic cases in Xinpi Township, Pingtung County, Taipei City, and New Taipei City. Finally, a DENV-2 strain most closely related to Singapore strain caused only one case in North District, Tainan City. These results provide an updated view of geographic distributions and dynamic transmission of DENV strains circulating in Taiwan and in Southeast Asian countries.