Outbreak of H3N2 Influenza at a US Military Base in Djibouti during the H1N1 Pandemic of 2009

PLoS One

John D. Klena¹  Remington L. Nevin²  Guillermo Pimentel³  Peter J. Sebeny⁴  Michael T. Cosby⁵  Ehab Amir⁵  Salwa Fouad Ahmed⁵  Mary Younan⁵  Robert Browning⁶ 

[1] Emerging Infectious Diseases Program, China Office, United States Centers for Disease Control and Prevention, Beijing, China;Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America;Naval Medical Research Center (NMRC) – Frederick, Fort Detrick, Maryland, United States of America;Naval Medical Research Center (NMRC), Silver Spring, Maryland, United States of America;United States Naval Medical Research Unit No. 3 (NAMRU-3), Cairo, Egypt;Walter Reed National Military Medical Center, Bethesda, Maryland, United States of America

关键词: Influenza;    Infectious disease surveillance;    RNA extraction;    Influenza A virus;    Phylogenetic analysis;    DNA sequence analysis;    Military personnel;    Sequence analysis;   

DOI  :  10.1371/journal.pone.0082089

学科分类：医学（综合）

来源: Public Library of Science

【 摘 要 】

Background Influenza pandemics have significant operational impact on deployed military personnel working in areas throughout the world. The US Department of Defense global influenza-like illness (ILI) surveillance network serves an important role in establishing baseline trends and can be leveraged to respond to outbreaks of respiratory illness. Objective We identified and characterized an operationally unique outbreak of H3N2 influenza at Camp Lemonnier, Djibouti occurring simultaneously with the H1N1 pandemic of 2009 [A(H1N1)pdm09]. Methods Enhanced surveillance for ILI was conducted at Camp Lemonnier in response to local reports of a possible outbreak during the A(H1N1)pdm09 pandemic. Samples were collected from consenting patients presenting with ILI (utilizing a modified case definition) and who completed a case report form. Samples were cultured and analyzed using standard real-time reverse transcriptase PCR (rt-RT-PCR) methodology and sequenced genetic material was phylogenetically compared to other published strains. Results rt-RT-PCR and DNA sequencing revealed that 25 (78%) of the 32 clinical samples collected were seasonal H3N2 and only 2 (6%) were A(H1N1)pdm09 influenza. The highest incidence of H3N2 occurred during the month of May and 80% of these were active duty military personnel. Phylogenetic analysis revealed that sequenced H3N2 strains were genetically similar to 2009 strains from the United States of America, Australia, and South east Asia.Conclusions This outbreak highlights challenges in the investigation of influenza among deployed military populations and corroborates the public health importance of maintaining surveillance systems for ILI that can be enhanced locally when needed.

【 授权许可】

CC BY