Case-fatality rate during a measles outbreak in eastern Niger in 2003

Clin Infect Dis. 2006 Feb 1;42(3):322-8. doi: 10.1086/499240. Epub 2005 Dec 19.

Abstract

Background: The World Health Organization (WHO) estimates that the case-fatality rate (CFR) for measles in West Africa is 4%-6%. In Niger, 50,138 measles cases and 201 deaths (CFR, 0.4%) were reported in 2003. We conducted an investigation to determine the epidemiology and the true CFR of measles in the Mirriah district in Niger.

Methods: Twenty-two villages from the Mirriah district that reported measles cases in 2003 were included in the investigation. A comprehensive household search for measles cases and deaths was conducted, and serum samples from 12 villages were collected for laboratory confirmation. A measles case was defined as illness characterized by fever, rash, and either cough, coryza, or conjunctivitis, with rash onset during the period from 1 January 2003 to 15 April 2003. Deaths occurring within 30 days after rash onset were attributed to measles unless they were obviously due to other causes.

Results: Measles was confirmed serologically in all villages from which samples were collected. Of 945 case patients identified, 900 (95.2%) were aged <15 years, 114 (12.3%) were vaccinated, and 789 (83.5%) sought treatment at a health care facility. A total of 92 deaths were attributed to measles (CFR, 9.7%; 95% confidence interval, 7.9%-11.5%). The CFR was highest in infants aged <1 year (15.6%). Households with >or=2 case patients had a higher CFR (10.8%) than that of households with only 1 case patient (6.0%). Households consisting of >or=8 members had a CFR of 12.8%, whereas the CFR of smaller households was 7.1%.

Conclusions: This investigation suggests that the measles CFR in the Mirriah district may be 2-fold higher than the WHO regional estimate and 20-fold higher than the estimate derived from routine surveillance. Reducing measles mortality in Niger will require wide-age-range vaccination campaigns, improvement in routine immunization services, and periodic "follow-up" campaigns.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Aging
  • Child
  • Child, Preschool
  • Disease Outbreaks / statistics & numerical data*
  • Female
  • Humans
  • Infant
  • Male
  • Measles / drug therapy
  • Measles / mortality*
  • Measles / prevention & control
  • Measles Vaccine / immunology
  • Niger / epidemiology
  • Retrospective Studies
  • Risk Factors
  • Time Factors
  • Vitamin A / therapeutic use

Substances

  • Measles Vaccine
  • Vitamin A