Choi, S.; Chung, J.-W.; Chang, Y.J.; Lim, E.J.; Moon, S.H.; Do, H.H.; Lee, J.H.; Cho, S.-M.; Kwon, B.S.; Chung, Y.-S.; Park, S.Y. A Lesson from a Measles Outbreak among Healthcare Workers in a Single Hospital in South Korea: The Importance of Knowing the Prevalence of Susceptibility. Vaccines2023, 11, 1505.
Choi, S.; Chung, J.-W.; Chang, Y.J.; Lim, E.J.; Moon, S.H.; Do, H.H.; Lee, J.H.; Cho, S.-M.; Kwon, B.S.; Chung, Y.-S.; Park, S.Y. A Lesson from a Measles Outbreak among Healthcare Workers in a Single Hospital in South Korea: The Importance of Knowing the Prevalence of Susceptibility. Vaccines 2023, 11, 1505.
Choi, S.; Chung, J.-W.; Chang, Y.J.; Lim, E.J.; Moon, S.H.; Do, H.H.; Lee, J.H.; Cho, S.-M.; Kwon, B.S.; Chung, Y.-S.; Park, S.Y. A Lesson from a Measles Outbreak among Healthcare Workers in a Single Hospital in South Korea: The Importance of Knowing the Prevalence of Susceptibility. Vaccines2023, 11, 1505.
Choi, S.; Chung, J.-W.; Chang, Y.J.; Lim, E.J.; Moon, S.H.; Do, H.H.; Lee, J.H.; Cho, S.-M.; Kwon, B.S.; Chung, Y.-S.; Park, S.Y. A Lesson from a Measles Outbreak among Healthcare Workers in a Single Hospital in South Korea: The Importance of Knowing the Prevalence of Susceptibility. Vaccines 2023, 11, 1505.
Abstract
Background
Despite the high vaccination coverage rate, in-hospital transmission of measles continues to occur in South Korea. We present a measles outbreak in which two healthcare workers (HCWs) with presumptive evidence of measles immunity were infected by a patient with typical measles at a single hospital in South Korea. This facilitated the evaluation of measles seroprevalence in all HCWs.
Methods
In 2018, suspected patients and contacts exposed during a measles outbreak were investigated based on their medical histories and vaccination status. Cases were confirmed by the detection of measles-specific immunoglobulin M or RNA. After the measles outbreak, all HCWs underwent measles IgG testing for point-prevalence surveillance. In addition, we have routinely performed measles IgG tests on new HCWs since 2019. The measles vaccine was administered to HCWs who tested negative or equivocally negative for IgG antibodies.
Results
An index patient who returned from China with fever and rash was diagnosed with measles at a hospital in Korea. Two additional HCWs were revealed as measles cases: one was vaccinated with the 2-dose measles–mumps–rubella (MMR) vaccine, and the other, who was born in 1967, was presumed to have immunity from natural infection in South Korea. All three patients harbored the same D8 genotype. No additional measles cases were identified among the 964 contacts of secondary patients.
After the measles outbreak, 2,310 HCWs underwent measles IgG tests. The average age at the time of the test was 32.6 years, and 74.3% were female. The overall seropositivity of measles was 88.9% (95% confidence interval, 87.5 –90.1). Although the birth cohorts between 1985 and 1994 were presumed to have received the measles-rubella (MR) catch-up vaccination in 2001, 175 (89.3%) HCWs were born after 1985 among the 195 seronegative cases.
Conclusion
Despite high population immunity, imported measles transmission occurred among HCWs, with presumed immunity. This report underscores the importance of understanding the prevalence of measles susceptibility among newly employed HCWs. This is important for policymaking regarding hospital-wide vaccinations to prevent vaccine-preventable diseases.
Keywords
measles; outbreak; HCWs; vaccination; immunity
Subject
Public Health and Healthcare, Health Policy and Services
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
,
*
