+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Early outbreak of 2009 influenza A (H1N1) in Mexico prior to identification of pH1N1 virus

Early outbreak of 2009 influenza A (H1N1) in Mexico prior to identification of pH1N1 virus

Plos One 6(8): E23853

In the aftermath of the global spread of 2009 influenza A (pH1N1) virus, still very little is known of the early stages of the outbreak in Mexico during the early months of the year, before the virus was identified. We fit a simple mathematical model, the Richards model, to the number of excess laboratory-confirmed influenza cases in Mexico and Mexico City during the first 15 weeks in 2009 over the average influenza case number of the previous five baseline years of 2004-2008 during the same period to ascertain the turning point (or the peak incidence) of a wave of early influenza infections, and to estimate the transmissibility of the virus during these early months in terms of its basic reproduction number. The results indicate that there may have been an early epidemic in Mexico City as well as in all of Mexico during February/March. Based on excess influenza cases, the estimated basic reproduction number R₀ for the early outbreak was 1.59 (0.55 to 2.62) for Mexico City during weeks 5-9, and 1.25 (0.76, 1.74) for all of Mexico during weeks 5-14. We established the existence of an early epidemic in Mexico City and in all of Mexico during February/March utilizing the routine influenza surveillance data, although the location of seeding is unknown. Moreover, estimates of R₀ as well as the time of peak incidence (the turning point) for Mexico City and all of Mexico indicate that the early epidemic in Mexico City in February/March had been more transmissible (larger R₀) and peaked earlier than the rest of the country. Our conclusion lends support to the possibility that the virus could have already spread to other continents prior to the identification of the virus and the reporting of lab-confirmed pH1N1 cases in North America in April.

Please choose payment method:

(PDF emailed within 1 workday: $29.90)

Accession: 052761565

Download citation: RISBibTeXText

PMID: 21909366

Related references

Identification of influenza A pandemic (H1N1) 2009 variants during the first 2009 influenza outbreak in Mexico City. Journal of Clinical Virology 48(1): 36-39, 2010

Inside the outbreak of the 2009 influenza A (H1N1)v virus in Mexico. Plos One 5(10): E13256, 2011

Outbreak of swine-origin influenza A (H1N1) virus infection - Mexico, March-April 2009. Mmwr. Morbidity and Mortality Weekly Report 58(17): 467-470, 2009

Humans and ferrets with prior H1N1 influenza virus infections do not exhibit evidence of original antigenic sin after infection or vaccination with the 2009 pandemic H1N1 influenza virus. Clinical and Vaccine Immunology 21(5): 737-746, 2014

Influenza-like illness in a community surrounding a school-based outbreak of 2009 pandemic influenza A (H1N1) virus-Chicago, Illinois, 2009. Clinical Infectious Diseases 52 Suppl 1: S94-101, 2011

MS2 Coliphage as a Surrogate for 2009 Pandemic Influenza A (H1N1) Virus (pH1N1) in Surface Survival Studies on N95 Filtering Facepiece Respirators. Journal of the International Society for Respiratory Protection 21(1): 14-22, 2014

A preliminary analysis of the epidemiology of influenza A(H1N1)v virus infection in Thailand from early outbreak data, June-July 2009. Euro Surveillance 14(31), 2009

Comparison of the efficacy of a commercial inactivated influenza A/H1N1/pdm09 virus (pH1N1) vaccine and two experimental M2e-based vaccines against pH1N1 challenge in the growing pig model. Plos One 13(1): E0191739, 2018

Prior infection with classical swine H1N1 influenza viruses is associated with protective immunity to the 2009 pandemic H1N1 virus. Influenza and Other Respiratory Viruses 4(3): 121-127, 2010

Influenza virus A(H1N1)2009 antibody-dependent cellular cytotoxicity in young children prior to the H1N1 pandemic. Journal of General Virology 97(9): 2157-2165, 2017

2009 pandemic influenza A (H1N1) virus outbreak and response--Rwanda, October, 2009-May, 2010. Plos One 7(6): E31572-E31572, 2012

Rapid multiplex reverse transcription-PCR typing of influenza A and B virus, and subtyping of influenza A virus into H1, 2, 3, 5, 7, 9, N1 (human), N1 (animal), N2, and N7, including typing of novel swine origin influenza A (H1N1) virus, during the 2009 outbreak in Milwaukee, Wisconsin. Journal of Clinical Microbiology 47(9): 2772-2778, 2009

Household transmission of 2009 influenza A (H1N1) virus after a school-based outbreak in New York City, April-May 2009. Journal of Infectious Diseases 201(7): 984-992, 2010

Lack of evidence for pre-symptomatic transmission of pandemic influenza virus A(H1N1) 2009 in an outbreak among teenagers; Germany, 2009. Influenza and Other Respiratory Viruses 5(6): E499-E503, 2012

Non-pharmaceutical interventions during an outbreak of 2009 pandemic influenza A (H1N1) virus infection at a large public university, April-May 2009. Clinical Infectious Diseases 52 Suppl 1: S138-S145, 2011