5. Measles

OBJECTIVES

  • Explain why measles infection can be so devastating in displaced populations.
  • Design a measles immunization campaign in an affected area and establish priority target populations for the provision of measles vaccine based on the availability of vaccine supplies and prior levels of measles vaccine coverage among the pediatric population.
  • Recognize Koplik spots and the classical measles rash; describe variations of the classical measles rash and the circumstances in which they are seen.
  • Describe the evolution of the clinical manifestation of classic measles over time and name the three complications of measles that contribute most to mortality.

What is the impact of measles?

A measles outbreak is potentially devastating in displaced populations. In many parts of the developing world measles is one of the leading causes of childhood morbidity and mortality: it is highly contagious and spreads through aerosolized particles from respiratory secretions containing the virus. Measles fatalities vary from 200,000 to 800,000 per year in developing countries (Black 2003; WHO 1999 and 2001; Murray 1996). While case fatality rates (CFR) for all measles infections are less than 0.1% in developed countries, in developing countries the rates exceed 1% to 2%. CFRs for hospitalized cases have been reduced by the use of vitamin A treatment.

Vitamin A deficiency increases measles associated morbidity and mortality.

In developing countries, mortality from measles is related to the intensity of the exposure and host’s nutritional and immunologic status. Secondary cases within a household are at greater risk than index cases. Knowing the level of measles vaccination coverage in the affected community and the frequency of measles cases diagnosed within the past few years is helpful. If measles cases have been diagnosed in the community within the past several years, plan a measles immunization campaign, regardless of the immunization coverage level.

Give measles vaccination high large displaced or refugee priority in a population because susceptible childr there may be enough en to cause an epidemic. Malnourished children living in crowded shelters following a disaster are especially vulnerable and at high risk for severe disease. Implement a surveillance system to identify possible measles cases in the camp or area. Educate medical staff about the clinical signs that suggest measles, such as fever, cough, conjunctivitis, and rash. Respiratory syndromes are often nonspecific; measles cases can be easily overlooked and other respiratory infections can be mistaken for measles.