CHALLENGES IN MEASURING MEASLES CASE FATALITY RATIOS IN SETTINGS WITHOUT VITAL REGISTRATION

Wednesday, 30th of November 2011

       ‘[W]e believe that accurate measles CFRs can be obtained from meticulously conducted    retrospective studies as we have outlined that take into account the unique characteristics of the disease.’ 

 CHALLENGES IN MEASURING MEASLES CASE FATALITY RATIOS IN SETTINGS WITHOUT VITAL REGISTRATION

K Lisa Cairns1*, Robin Nandy2, Rebecca F Grais3

Abstract below; full text is at

http://www.biomedcentral.com/content/pdf/1742-7622-7-4.pdf

Abstract

Measles, a highly infectious vaccine-preventable viral disease, is potentially fatal. Historically, measles case-fatality ratios (CFRs) have been reported to vary from 0.1% in the developed world to as high as 30% in emergency settings.

Estimates of the global burden of mortality from measles, critical to prioritizing measles vaccination among other health interventions, are highly sensitive to the CFR estimates used in modeling; however, due to the lack of reliable, up-to-date data, considerable debate exists as to what CFR estimates are appropriate to use.

To determine current measles CFRs in high-burden settings without vital registration we have conducted six retrospective measles mortality studies in such settings. This paper examines the methodological challenges of this work and our solutions to these challenges, including the integration of lessons from retrospective all-cause mortality studies into CFR studies, approaches to laboratory confirmation of outbreaks, and means of obtaining a representative sample of case-patients. Our experiences are relevant to those conducting retrospective CFR studies for measles or other diseases, and to those interested in all-cause mortality studies.