Dengue virus serotype-4 during the 2015-2017 epidemic: emergence of a novel genotype IIa of DENV-4 in the Philippines

• Published in: Japanese Journal of Infectious Diseases p. JJID.2019.208
• Main Authors: Mark Anthony de Vera Luz, Nabeshima, Takeshi, Moi, Meng Ling, Dimamay, Maria Terrese Alonzo, Pangilinan, Lady-Anne Suarez, Dimamay, Mark Pierre Sijo, Matias, Ronald Roll, Mapua, Cynthia Abad, Buerano, Corazon Cerilla, Guzman, Ferdinand de, Tria, Edith Sangalang, Natividad, Filipinas Florendo, Maria Luisa de Guzman Daroy, Takemura, Taichiro, Hasebe, Futoshi, Morita, Kouichi
• Format: Journal Article
• Language: English
• Published: National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee 20-09-2019
• Subjects: Dengue; emergence; genotype; Philippines; serotype 4
• ISSN: 1344-6304; 1884-2836
• DOI: 10.7883/yoken.JJID.2019.208

Dengue remains a major public health problem in the Philippines. Here, we determined the circulating serotypes in the Philippines during the 2015-2017 outbreaks by using a total of 678 serum samples that were collected from 537 individual dengue patients. Following an increase in the percentage of DENV-4 patients in recent years, we conducted a comprehensive molecular epidemiology analysis on the DENV-4 strains isolated recently in the Philippines. While two genotypes of DENV-4 have been isolated in the Philippines since 1956, the GI and GIIa which were the DENV-4 strains isolated in this study were closely related to a distinct group of GIIa strains that were isolated from the Philippines since 2004. A majority of the isolates of this sub-group has been identified in the Philippines, suggesting that the lineage may have been introduced and evolved in the Philippines to form the distinct sub-group within GIIa strains. The increase in DENV-4 activity also coincided with the appearance of GIIa sub-group and the phasing-out of GI lineage in the Philippines. Overall, our study demonstrates a shift in DENV-4 genotype and epidemic dynamics in a hyperendemic region, suggesting the importance of DENV genetic evolution in establishing and sustaining transmission.