On the Spread of the Novel Influenza A (H1N1) Virus in Mexico

Abstract

A novel influenza A H1N1 virus of swine origin is responsible for the influenza epidemic affecting Mexico, the United States of America (USA), and 39 other countries. While the origin of this emerging pathogen remains uncertain, an increase in the reported incidence of respiratory diseases was noted during March 2009 at the town of La Gloria, in the southeastern state of Veracruz, Mexico. So far, this is the first community in which a case of novel influenza A H1N1 virus has been identified. Further cases were rapidly detected in other areas of Mexico and elsewhere. Initially, the atypical respiratory disease outbreak caused great uncertainty posing a challenge to the Mexican health system. Control measures such as social distancing, timely medical care, and personal hygiene have so far proven effective in containing the outbreak, resulting in a decline of the number of new cases. To the best of our knowledge, it appears that the virus might not be as virulent or contagious as previously thought. Here we provide a description of the influenza epidemic spread in Mexico. As the virus disseminates worldwide, there is concern about the possibility of a new reassortment resulting in a more pathogenic strain that will pose a threat for every country. The influenza epidemic provided lessons that underscore the importance of epidemiologic surveillance and preparedness. Further investigation to address questions about this new virus and conditions for its spread is warranted.

Ten lessons for the next influenza pandemic—an English perspective

“…The maximum incidence in patients presenting in the WRS during the 1969/70 pandemic was in age groups 45-64 and 15-44: in 1989/90, the impact was particularly strong in children 0-4 and exceeded that 12 By April 24, confirmation was obtained that a genetically similar virus had been identified in several cases from Mexico where a sharp increased incidence of acute respiratory infections had been noted since March 2009. 13 The delay between the initial outbreak of illness and detection of a novel virus provides the first lesson and is an immediate challenge to the prospect of pandemic containment by 'saturation' prophylaxis in an infected area.…”

Start of a Pandemic: Influenza A H1N1 Virus

“…The spread was fast and it was extended to many countries. On April 30th, the World Health Organization called officially an "H1N1/09 Pandemic Virus" (Dawood et al, 2009;Garten et al, 2009;López-Cervantes et al, 2009;Updated 2009;Vaillant et al, 2009;WHO, 2009). So, on June 11th, the WHO declared a pandemic.…”

“…The international nomenclature used to describe the different influenza virus is to appoint the following characteristics: a) gender of the virus A, B or C; b) host type is ignored when it comes from human c) place of isolation; d) case number in the laboratory; e) year of isolation; f) HA and NA subtype of the virus which is written in parentheses. An example of a human virus isolated in Mexico in 2009 was described as "A / Mexico / INDRE / 4487 / 2009 (H1N1)" (Dawood et al, 2009;López-Cervantes et al, 2009;WHO, 2009a).…”

Pandemic (H1N1) 2009 Surveillance in Marginalized Populations, Tijuana, Mexico

“…The first declared influenza pandemic in 40 years likely originated in March 2009 in La Gloria, Veracruz, a small rural town in southern Mexico ( 1 ). The virus responsible for the outbreak, identified as a novel influenza A (H1N1) virus, now referred to as pandemic (H1N1) 2009, spread quickly.…”