LESSONS AND CHALLENGES FOR MEASLES CONTROL FROM UNEXPECTED LARGE OUTBREAK, MALAWI.

Monday, 11th of August 2014

[source]Emerging Infectious Diseases[|source]

Despite Malawi s measles control successes during the past 2 decades, a large outbreak occurred in 2010, with as many cases as in the 1980s. Response vaccinations were conducted in children 9–59 months of age in some districts in epidemiologic weeks 10–14 (March–April), epidemiologic weeks 18–26 (May–June) and a nationwide vaccination campaign targeting children 9months to 14 years in epidemiologic weeks 33–34 (August).

In this report, the authors describe this epidemic and outcomes from outbreak response vaccination and document that timeliness and choice of the target population for outbreak response immunizations are the critical drivers of success. More details and recommendations are accessible at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3559033/#!po=10.0000

 

ABSTRACT

Despite high reported coverage for routine and supplementary immunization, in 2010 in Malawi, a large measles outbreak occurred that comprised 134,000 cases and 304 deaths. Although the highest attack rates were for young children (2.3%, 7.6%, and 4.5% for children <6, 6–8, and 9–11 months, respectively), persons >15 years of age were highly affected (1.0% and 0.4% for persons 15–19 and >19 years, respectively; 28% of all cases). A survey in 8 districts showed routine coverage of 95.0% for children 12–23 months; 57.9% for children 9–11 months; and 60.7% for children covered during the last supplementary immunization activities in 2008. Vaccine effectiveness was 83.9% for 1 dose and 90.5% for 2 doses. A continuous accumulation of susceptible persons during the past decade probably accounts for this outbreak. Countries en route to measles elimination, such as Malawi, should improve outbreak preparedness. Timeliness and the population chosen are crucial elements for reactive campaigns.