STABILITY OF THE AGE DISTRIBUTION OF MEASLES CASES OVER TIME DURING OUTBREAKS IN BANGLADESH, 2004-2006.

Tuesday, 6th of August 2013

[source]Journal of Infectious Diseases[|source]

Following wide-age measles vaccination campaigns, the occurrence of measles is documented to have declined by about 74% in the last decade. In the  same time period, measles epidemiology is also been observed to have shifted. Does measles epidemiolgy also change in outbreak settings? If yes, does it then require that measles outbreak response immunization be adaptive and tailored to the changing epidemiology, even in the same country/context? Exciting story available at:  http://jid.oxfordjournals.org/content/204/suppl_1/S414.long 

 

 Abstract

Despite WHO Recommendations to conduct measles outbreak response vaccination campaigns based on the age distribution of cases at the beginning of an outbreak, few data exist to specifically examine whether the age distribution of cases remains constant over time in a measlesoutbreak. This analysis explores this question with use of measles outbreak surveillance data from Bangladesh from the period 2004-2006. Pearson χ(2) tests were conducted of age distributions over 2 periods during 41 large laboratory-confirmed measles outbreaks. Statistically significant changes in age distribution over time were observed in 24% of the outbreaks. No single pattern was detected in the shifts in age distribution; however, an increase in the proportion of cases occurring among infants <9 months of age was evident in 6 outbreaks. These findings suggest a need to consider the possibility of a shift in the age distribution over time when planning an outbreak response vaccination campaign.