[Seroprevalence of pandemic influenza A (H1N1)pdm09 in two regions in Morocco following the 2010-2011 influenza season].

PURPOSES

To study and to compare the prevalence of infection with the virus A(H1N1)pdm 2009 in the population of two regions of Morocco compared to preexisting antibody levels.

PATIENTS AND METHODS

A total of 300 and 200 serum samples were collected in the region of Rabat and Meknes respectively. Samples were collected during March to April 2011. One hundred and fifty sera, collected in 2007 from blood donors, were recovered from the blood center. The research for antibodies to influenza A(H1N1)pdm09 was performed by hemagglutination inhibition assay.

RESULTS

The overall prevalence of antibodies inhibiting hemagglutination at the Rabat region (67%) is significantly higher than that of Meknes (53%) while the rate of cross-reactive antibodies was 7.3%. The subjects under 25 years from the Rabat region have infection rates as high with an odds ratio of 2.45. Individuals with comorbidities have the lowest prevalence with an odds ratio of 0.61. The rate of influenza A(H1N1)pdm09 vaccination in the Rabat region is 7%.

CONCLUSIONS

Immunization rates of the Moroccan population will prevent the occurrence of large outbreaks in the year 2011 to 2012 but the persistence of a naive population justifies the continuation of vaccination against A(H1N1)pdm09.