Changes in the viral distribution pattern after the appearance of the novel influenza A H1N1 (pH1N1) virus in influenza-like illness patients in Peru.

Autor: Victor Alberto Laguna-Torres, Jorge Gómez, Patricia V Aguilar, Julia S Ampuero, Cesar Munayco, Víctor Ocaña, Juan Pérez, María E Gamero, Juan Carlos Arrasco, Irmia Paz, Edward Chávez, Rollin Cruz, Jaime Chavez, Silvia Mendocilla, Elizabeth Gomez, Juana Antigoni, Sofía Gonzalez, Cesar Tejada, Gerardo Chowell, Tadeusz J Kochel, Peru Influenza working group
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Zdroj: PLoS ONE, Vol 5, Iss 7, p e11719 (2010)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0011719
Popis: BACKGROUND: We describe the temporal variation in viral agents detected in influenza like illness (ILI) patients before and after the appearance of the ongoing pandemic influenza A (H1N1) (pH1N1) in Peru between 4-January and 13-July 2009. METHODS: At the health centers, one oropharyngeal swab was obtained for viral isolation. From epidemiological week (EW) 1 to 18, at the US Naval Medical Research Center Detachment (NMRCD) in Lima, the specimens were inoculated into four cell lines for virus isolation. In addition, from EW 19 to 28, the specimens were also analyzed by real time-polymerase-chain-reaction (rRT-PCR). RESULTS: We enrolled 2,872 patients: 1,422 cases before the appearance of the pH1N1 virus, and 1,450 during the pandemic. Non-pH1N1 influenza A virus was the predominant viral strain circulating in Peru through (EW) 18, representing 57.8% of the confirmed cases; however, this predominance shifted to pH1N1 (51.5%) from EW 19-28. During this study period, most of pH1N1 cases were diagnosed in the capital city (Lima) followed by other cities including Cusco and Trujillo. In contrast, novel influenza cases were essentially absent in the tropical rain forest (jungle) cities during our study period. The city of Iquitos (Jungle) had the highest number of influenza B cases and only one pH1N1 case. CONCLUSIONS: The viral distribution in Peru changed upon the introduction of the pH1N1 virus compared to previous months. Although influenza A viruses continue to be the predominant viral pathogen, the pH1N1 virus predominated over the other influenza A viruses.
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