PREVALENCE OF MEASLES IGG ANTIBODIES AMONG HEALTHCARE WORKERS IN BULGARIA

Background: Healthcare workers are at greater risk of acquiring measles than the general population. Transmission occurs from infected patients to staff and from infected staff to patients and colleagues. In inpatient and outpatient settings, susceptible patients suffering from other conditions, especially the elderly and severely ill patients in intensive care units are at a high risk of severe disease or death if infected with measles. The most effective preventive measure against measles is vaccination with two doses of a measles-containing vaccine. Aim: To perform a serological assessment of the presence of measles IgG antibodies among healthcare workers. Materials and Methods: The present study involves serological testing performed on samples from persons working in hospitals and Regional Health Inspectorates in the country. Screening started in connection with a reported measles outbreak in Bulgaria in 2019, and continued into early 2020. An indirect ELISA assay for the detection of specific measles IgG antibodies in serum samples was used. Results: The tested 152 healthcare workers were from 5 regions of the country, i.e. Sofia-capital (n=87), Burgas (n=6), Blagoevgrad (n=5), Dobrich (n=8) and Pazardzhik (n=46). Anti-measles IgG antibodies were detected in 85.5% of the participants (130/152). Negative results, indicating a possible lack of protective immunity against measles, were obtained primarily in samples from persons younger than 40 years of age. Conclusion: Screening to identify healthcare workers who lack presumptive evidence of protective immunity against measles should be reinforced, especially among younger healthcare workers, in order to minimize the risk of measles both among healthcare workers and among patients.