Objective: To elucidate the immune status of representative infectious diseases among Japanese youth, we retrospectively investigated serum antibody levels in university students, partly comparing these to immunization records and infectious disease histories confirmed by the maternal and child health (MCH) handbooks.
Materials and methods: In total, 168 Japanese female university students, aged 20-21 years, were included. Data were collected from examinations of antibody titers against measles, rubella, varicella-zoster (VZ), mumps, and hepatitis B (HB) and C (HC) viruses, and from QuantiFERON®-TB Gold tests, between 2011 and 2015. Records of immunization and infectious disease histories were available from MCH handbooks for students who agreed with the use of their data for this study (n=23).
Results: All students had positive antibodies, detected by enzyme immunoassay (EIA), against measles, rubella, VZ, and mumps; however, seroprevalences within the range of seroprotective antibody levels were 38.1% (64/168), 67.9% (114/168), 95.9% (141/147), and 89.8% (132/147), respectively. The students had probably not been infected with HB, HC, or tuberculosis at the time of the examinations.
Discussion: The study indicated that a two-dose vaccine for measles and rubella (MR) might not be sufficient to produce antibodies at seroprotective levels. Therefore, we propose that health care workers, including students, should receive an additional MR vaccine, even if they have received two doses of MR vaccine or if they have unknown histories of immunizations or infectious diseases. Further investigations in these areas will be needed.
Keywords: enzyme immunoassay (EIA); health care worker; seroprotective.