Jul 15, 2014, 9:00 AM, Posted by Audrey Dorélien
Audrey Dorélien, PhD, is a 2012-2014 Robert Wood Johnson Foundation (RWJF) Health & Society Scholar studying demography, infectious diseases, and maternal and child health.
Reoccurring outbreaks of measles and other vaccine-preventable diseases are a major killer of children, particularly in sub-Saharan Africa. In 2012, more than 226,000 cases of measles were reported worldwide, with a little less than half of those in Africa. For the World Health Organization to meet its global measles eradication goal and implement more effective supplemental vaccination programs, public health officials will need a better understanding of the mechanism driving seasonal and episodic outbreaks.
Infectious disease ecologists have demonstrated the importance of human demography, and in particular the influence of the birth rate on the dynamics of acute childhood immunizing (ACI) diseases. For instance in London, in the few years prior to 1950, the city experienced annual measles epidemics, but the dynamics changed to biennial epidemics as a result of a decline in the birth rate between 1950 and 1968. How can the birth rate influence disease outbreaks? An outbreak can only occur when the fraction of the susceptible population exceeds a critical threshold. In the case of ACI disease, the majority of the susceptible population are young children; therefore the birth rate influences the rate at which the pool of susceptibles is replenished.