Seroprevalence of IgG antibodies against measles in health care workers of the Strakonice Hospital.

AIM

Due to mandatory vaccination introduced in the Czech Republic since 1969, only few measles cases were reported annually until recently. However, a rapid increase of cases has been recorded in last two years. In contrast to the pre-vaccination era, in recent measles outbreaks, many cases have been reported among vaccinated adults. Health care workers (HCWs) are particularly at high risk of contact with measles. Therefore, to minimize transmission in health care settings, many hospitals evaluate measles immune status of their HCWs and offer free vaccination to those with too low anti-measles antibody levels. The aim of this study was to evaluate the seroprevalence of IgG antibodies against measles in all HCWs of the Strakonice Hospital.

MATERIALS AND METHODS

Anti-measles IgG serum levels were measured using quantitative ELISA.

RESULTS

Almost all HCWs born before 1969, when the mandatory vaccination started, showed high levels of IgG antibodies (93.5%). Contrarily, among previously vaccinated individuals, only 64.8% were seropositive. A high percentage of seronegative or borderline samples was observed even in the age groups who were previously vaccinated with two doses.

CONCLUSIONS

In total, 25.4% of all HCWs of the Strakonice Hospital had too low anti-measles IgG levels, and most of them were immunized with one dose of MMR vaccine. Prioritized vaccination substantially decreased the number of staff at higher risk of measles acquisition and, at the same time, of those who would need to be quarantined after exposure.