Prevention of Measles Outbreaks Among Displaced Persons

For protection against the elements and for basic nutrition many people have congregated in displaced persons camps. Past experience has shown that due to their high population density, displaced persons camps are at high risk for outbreaks of infectious diseases, including measles. Moreover, the recent influx of large numbers of disaster personnel into Central America increases the risk of measles virus importations. Indeed many of the public health workers now entering the region are coming from parts of the world where measles remains endemic.

Extremely high measles-associated mortality rates have been previously reported from displaced persons camps. Mortality from measles is, however, preventable, and immunization against the disease must be a high priority in emergency relief programs. Efforts are clearly needed to prevent measles outbreaks among camps of displaced persons.

The group at highest risk for dying from measles are children less than 1 year of age. Maternal measles antibody generally wanes between 6 and 9 months of age. It is, thus, recommended that the age of measles vaccination be reduced to 6 months of age in these camps. Infants vaccinated before 12 months of age should receive a second dose of measles-containing vaccine after their first birthday.

While most persons in Central America between 2 and 20 years of age have probably been previously vaccinated in the measles eradication efforts, some may have escaped vaccination and others have been vaccinated, yet for one reason or another, failed to respond to the vaccine and thus remain susceptible to the disease. The recent large measles outbreak in Brazil suggests that there may be a relatively large number of young adults in Latin America who remain susceptible to measles. Young adults living in the conditions of a displaced persons camp may be at high risk for coming into contact with measles virus. Most persons born before 1960, however, likely had natural measles disease and do not need to be vaccinated. For the above reasons, it would seem reasonable to indiscriminately administer measles vaccine to infants, children, adolescents and young adults residing in displaced persons camps.

Based on the above information, the following specific recommendations are made:

1. Relief programs need to be based on sound health and nutrition information and should focus on the provision of adequate shelter, food, water, sanitation, and public health programs that prevent morbididty and mortality from diarrhea, measles, and other communicable diseases, especially among young children and women.
   
2. To prevent measles outbreaks. all persons 6 months-35 years of age who are living in displaced persons camps should receive measles-containing vaccine. Vaccine should be administered as soon as they enter an organized camp or settlement. Having previously been vaccinated or having a history of measles disease are not contraindications receiving the vaccine.
   
3. Emergency public health personnel, both national and international, should be routinely vaccinated against measles, regardless of age.
   
4. The vaccine of choice is either measles-rubella (MR) vaccine or measles-mumps-rubella (M-M-R) vaccine. If neither of the above vaccines are available then single-antigen measles vaccine may be administered.
   
5. The occurrence of measles in a displaced persons camp is not a contraindication to conducting an immunization campaign. In addition, mortality and morbidity in children with clinical measles can be reduced by administering high doses of vitamin A.
   

Contact
John Fitzsimmons
PAHO/WHO Special Program for Vaccines and Immunization
E-mail: fitzimmj@paho.org