Rhinovirus Delayed the Circulation of Pandemic Influenza A (H1N1) 2009 Virus in France

[Pathfinder]

Clin Microbiol Infect. 2010 Jan 28. [Epub ahead of print]
RHINOVIRUSES DELAYED THE CIRCULATION OF PANDEMIC INFLUENZA A(H1N1) 2009 VIRUS IN FRANCE.

Casalegno JS, Ottmann M, Bouscambert Duchamp M, Escuret V, Billaud G, Frobert E, Morfin F, Lina B.

Hospices Civils de Lyon, National Influenza Centre (South of France), Laboratory of Virology - B?t A3, 59 Boulevard Pinel, F-69677 Bron Cedex, France.

Background: In contrast with other European countries, the onset of the A(H1N1)2009 influenza virus epidemic was unexpectedly slow in France during the first part of Autumn 2009. Objectives: To test the hypothesis that intense circulation of rhinoviruses might have reduced the probability of infection by A(H1N1)2009 virus at the beginning of autumn 2009. Study design: Systematic analysis for the detection of A(H1N1)2009 (H1N1) and human rhinovirus (HRV) was performed by RT-PCR from week 36 to 48 on respiratory samples sent to the diagnostic laboratory by the paediatric hospital (n=2121). Retrospective analysis of the obtained data, using 2x2 contingency tables with Fisher's exact test, revealed evidence of an inverse relationship between HRV and H1N1 detection. Results: Between weeks 36 to 48 of 2009, both HRV and H1N1 were detected but in different time frames. HRV dispersed widely during early September peaking at the end of the month whereas the H1N1 epidemic began during mid-October and was still active at the end of this survey. During the co circulation period of these two respiratory viruses (weeks 43 to 46), HRV detection appeared to reduce the likelihood of H1N1 detection in the same sample (OR=0.08 to 0.24 p<0.0001). Conclusion: These results support the hypothesis that HRV infections can reduce the probability of A(H1N1) infection. This viral interference between respiratory viruses could have affected the spread of the H1N1 viruses and delayed the influenza pandemic at the beginning of autumn in France (Xavier, is this a possible approach for disease control, ie identify the mechanism of interference -interferon??- and use it to reduce the risk of influenza onset!!).

PMID: 20121829 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/pubmed/20121829?dopt=Abstract

 

[gsgs]

Re: Rhinovirus Delayed the Circulation of Pandemic Influenza A (H1N1) 2009 Virus in France

it didn't help much, though, only delay.
The peak came later and was bigger than in neighbor countries.

Why did neighbor countries have no HRV-wave at that time ?

 

[Pathfinder]

Re: Rhinovirus Delayed the Circulation of Pandemic Influenza A (H1N1) 2009 Virus in France

I remember France staying at Level 5 when WHO declared a Level 6 pandemic, their health officer saying "we are well protected". I always thought that this statement was said in reference to antiviral drugs.

Projections from a past study has concluded that taking antiviral would delay H1N1. This study was published on September 14, 2009.

So, is it rhino virus or a larger scale of the population taking Tamiflu that delayed the infection?

Excerpt:

"Results show that the use of antiviral drugs for treatment of 30% of the cases would result in a delay of the epidemic peak of approximately 4 weeks. This delay would be extremely valuable in providing the necessary time for the implementation of the mass vaccination program."


Delay effect induced by the use of antiviral drugs for treatment with 30% case detection and drug administration.

http://www.gleamviz.org/2009/09/projections-for-the-activity-peaks-of-the-h1n1-pandemic-in-the-fall/

See also:
http://www.gleamviz.org/2009/09/us-winter-projections-mitigation-effect-of-antiviral-treatment/