Nurses and nurse practitioners who work with Mexican immigrant populations need to be aware of a new research study which suggests that Mexican-born adults living in the United States have a higher rate of susceptibility to varicella-more commonly known as chicken pox-than adults who were born in the U.S. Because chicken pox is a more serious illness in adults than in children, Mexican immigrant adults are at particularly high risk not only for catching varicella but for suffering severe complications from the disease.
The study, published in the December 1, 2004 issue of Clinical Infectious Diseases, investigated an outbreak of varicella among 18 Mexican-born adults in Alabama, many of whom lived in the same apartment complex and/or worked in the same factory. Five of these 18 patients had serious complications, including pneumonia and Guillain-Barré syndrome.The researchers, led by Dr. M. Carolina Danovaro-Holliday of the Centers for Disease Control and Prevention's National Immunization Program, interviewed both infected and non-infected persons from the apartment complex and the factory to assess their disease history. They also gave them blood tests to assess their susceptibility to the varicella virus. The results showed that one third of the apartment residents who did not have chicken pox were susceptible to the disease-and all but one of these people were born in Mexico. At the factory, Mexican-born workers were more than five times as likely to be susceptible to varicella than their U.S.-born co-workers (20% vs. 3%).
The good news is that chicken pox can be prevented by immunization. Therefore, the study's authors recommend that health care professionals serving immigrant populations "need to assess vaccination histories of [Mexican-born] persons, including adult workers" and "vaccinate unvaccinated persons (both children and adults) without history of disease whenever these persons come in contact with a health service." For adults who are already infected with varicella, the antiviral drug acyclovir can reduce the severity of the disease if it is given within 24 hours of the first appearance of the skin rash.