Varicella among immigrants from the tropics, a health problem.

The incidence of varicella in Tamil refugees in Denmark was evaluated. Of 256 Tamils, 44% developed varicella infection in the first few months after arrival, representing 38% of the adults, and 68% of the children. During approximately four months' observation in Denmark, 75% of the refugees with no history of varicella developed a typical infection whereas only 2% of those with a history of varicella developed the disease. Tropical refugees with a negative history of varicella must therefore be considered nonimmune. Nine of 44 fertile women were pregnant. Two acquired the varicella infection during the first-trimester, none in relation to delivery. By organizing a health-check on arrival, prophylactic measures can reduce the health hazard of varicella infection in refugees from the tropics.