Phylogeographic analysis of human influenza A and B viruses in Myanmar, 2010-2015

PLoS One. 2019 Jan 10;14(1):e0210550. doi: 10.1371/journal.pone.0210550. eCollection 2019.

Abstract

We investigated the circulation patterns of human influenza A and B viruses in Myanmar between 2010 and 2015 by analyzing full HA genes. Upper respiratory tract specimens were collected from patients with symptoms of influenza-like illness. A total of 2,860 respiratory samples were screened by influenza rapid diagnostic test, of which 1,577 (55.1%) and 810 (28.3%) were positive for influenza A and B, respectively. Of the 1,010 specimens that were positive for virus isolation, 370 (36.6%) were A(H1N1)pdm09, 327 (32.4%) were A(H3N2), 130 (12.9%) B(Victoria), and 183 (18.1%) were B(Yamagata) viruses. Our data showed that influenza epidemics mainly occurred during the rainy season in Myanmar. Our three study sites, Yangon, Pyinmana, and Pyin Oo Lwin had similar seasonality and circulating type and subtype of influenza in a given year. Moreover, viruses circulating in Myanmar during the study period were closely related genetically to those detected in Thailand, India, and China. Phylogeographic analysis showed that A(H1N1)pdm09 viruses in Myanmar originated from Europe and migrated to other countries via Japan. Similarly, A(H3N2) viruses in Myanmar originated from Europe, and disseminated to the various countries via Australia. In addition, Myanmar plays a key role in reseeding of influenza B viruses to Southeast Asia and East Asia as well as Europe and Africa. Thus, we concluded that influenza virus in Myanmar has a strong link to neighboring Asian countries, Europe and Oceania.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dogs
  • Humans
  • Influenza A Virus, H1N1 Subtype / genetics
  • Influenza A Virus, H1N1 Subtype / isolation & purification
  • Influenza A Virus, H3N2 Subtype / genetics
  • Influenza A Virus, H3N2 Subtype / isolation & purification
  • Influenza A virus / genetics*
  • Influenza A virus / isolation & purification
  • Influenza B virus / genetics*
  • Influenza B virus / isolation & purification
  • Influenza, Human / diagnosis
  • Influenza, Human / epidemiology*
  • Influenza, Human / virology*
  • Madin Darby Canine Kidney Cells
  • Myanmar / epidemiology
  • Phylogeny
  • Phylogeography
  • RNA, Viral / genetics
  • RNA, Viral / isolation & purification

Substances

  • RNA, Viral

Grants and funding

This work was supported by the International Development Strategy Program for Infectious Diseases Research (J-GRID) of AMED (Japan Medical Research and Development Organization) (15fm0108009h0001 to RS), JSPS Core-to-core Program, B to RS. Asia-Africa Science Platforms, and Kakenhi (Grants-in-Aid for Scientific Research), sourced from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), and Health and Labor Sciences Research Grant, Ministry of Health, Labor and Welfare, Japan.