Seasonal variation of Pneumocystis jirovecii infection: analysis of underlying climatic factors

Abstract number: P1007

Sing A., Schmoldt S., Wildner M.

Objectives:Pneumocystis jirovecii pneumonia (PCP) represents a serious opportunistic infection in immunocompromised patients. However, the modes of transmission are still not completely elucidated. Seasonal changes of PCP incidence might be associated with climate changes. Therefore, we explored the relationship between PCP incidence and climatic factors.

Methods: Between April 1992 and December 2006, 576 microscopically confirmed cases of PCP were diagnosed at the Max von Pettenkofer-Institute serving the major hospitals in Munich, Germany, for laboratory diagnosis of P. jirovecii. The monthly incidence of PCP – both for the pre- and post-HAART area, respectively – were correlated with the three most important monthly weather data for Munich obtained from the German Weather Service., i.e. mean temperature (°C), height of precipitation as a measurement for rainfall activity (mm) and wind strength (Bft). Statistical methods used were bivariate graphical exploration and multiple linear regression modelling of the influence of weather parameters on the monthly incidence rates as dependent variable with adjustment for mean annual incidence and logarithmic transformation to achieve normal distribution.

Results: While there was a clear seasonal pattern in PCP incidence with two peaks in May and August, no significant correlation was found between PCP incidence and rainfall activity or wind strength. In contrast, PCP incidence was positively correlated with the mean monthly temperature. This correlation seems to be more pronounced in the post-HAART area than in the pre-HAART period.

Conclusion: To our knowledge, this is the first study using multiple linear regression statistics on monthly climatic data. In contrast to previous and more descriptive studies from Spain and the UK showing season-related PCP incidence patterns with maxima in the winter months – as it is known from other infectious respiratory diseases, we found an opposite incidence pattern with PCP incidence maxima in late spring and summer. Moreover, PCP incidence was positively correlated with the mean temperature. Possible explanations for this seasonal variety of PCP incidence will be discussed.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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