Estimating the Infection Burden of the pH1N1/2009 Virus in Reunion Island
Author Information
Author(s): Dellagi Koussay, Rollot Olivier, Temmam Sarah, Salez Nicolas, Guernier Vanina, Pascalis Hervé, Gérardin Patrick, Fianu Adrian, Lapidus Nathanael, Naty Nadège, Tortosa Pablo, Boussaïd Karim, Jaffar-Banjee Marie-Christine, Filleul Laurent, Flahault Antoine, Carrat Fabrice, Favier Francois, de Lamballerie Xavier
Primary Institution: GIS CRVOI, Centre de Recherche et de Veille sur les Maladies Emergentes dans l'Océan Indien, Saint-Denis, La Réunion
Hypothesis
What is the attack rate of the pH1N1/2009 virus in Reunion Island and what are the risk factors for infection?
Conclusion
The study found that the seroincidence of pH1N1/2009v infection was three times higher than clinical estimates, with younger individuals being the most affected.
Supporting Evidence
- Seroprevalence was 29.8% in individuals under 20 years of age.
- Seroconversion rates were highest in children and adolescents at 63.2%.
- Pre-epidemic titers ≥1/40 were found to prevent seroconversion.
Takeaway
The study shows that many people in Reunion Island got the pH1N1/2009 virus without knowing it, especially kids, and that some had protection from getting sick.
Methodology
A serosurvey was conducted with paired sera collected from individuals during and after the pandemic wave to assess infection rates.
Potential Biases
Potential bias due to the timing of serum collection coinciding with the epidemic progression.
Limitations
The study could not collect strictly pre-epidemic sera, which may overestimate baseline immunity.
Participant Demographics
The cohort included 2,164 individuals from 772 households, with a slight excess of females and an older age distribution compared to the general population.
Statistical Information
P-Value
p<0.0001
Confidence Interval
95% CI: 37.4%–49.6%
Statistical Significance
p<0.0001
Digital Object Identifier (DOI)
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