Monday, August 2, 2010 - 2:10 PM

COS 9-3: Rubella meta-population dynamics and importance of spatial coupling in the risk of CRS in Peru

C. Jessica E. Metcalf, Princeton, Gerardo Chowell, Arizona State University, Cesar Munayco-Escate, Direccion General de Epidemiologıa, Bryan T. Grenfell, Princeton University, and Ottar Bjornstad, Pennsylvania State University.

Background/Question/Methods

Rubella is generally a mild childhood disease, but infection during early pregnancy may cause spontaneous abortion or congenital rubella syndrome (CRS), which can entail multiple birth defects. Consequently, understanding the age-structured dynamics of this infection has considerable public health value. A classic concern is the potential for vaccination without eradication to increase the average age of infection, thereby increasing numbers of susceptible individuals of childbearing age. A neglected aspect of the dynamics of this acutely immunizing infection is how the age incidence patterns may be moulded by the spatial dynamics inherent to epidemic metapopulations. Here, we use a uniquely detailed dataset from Peru to explore the implications of this for the burden of CRS. 
Results/Conclusions

Our results indicate that following vaccination campaigns, the burden of CRS may be particularly severe in small remote regions, a prediction at odds with expectations in the endemic situation. This outcome results directly from the meta-population context: the extinction – re-colonization dynamics are crucial because they allow for significant leakage of susceptible individuals into the older age classes.