Objective: We investigated measles immunization coverage and the actual situation of immunization in Niigata Pref.
Method: We distributed questionnaires to all parents of pediatric outpatients who went to hospitals and clinics in Niigata Pref. from January 20 to 31. In the questionnaire, we asked parents about the measles immunization status of not only patients but also their sisters and brothers in each household, reasons for their immunization failure, and sources of information on immunization. We were able to collect 4,840 questionnaires from the parents who lived in Niigata Pref. and analyzable data obtained from 9,783 children. Furthermore we compared these with data from official annual reports of public health centers in Niigata Pref.
Result: Our survey showed that around 90% of the children who had been born since 1979 to 1993 had received measles vaccine, while the official annual reports indicated low immunization coverage (around 70%). The age at which children received measles vaccine was one year old (38.2% of the vaccinated) and two years old (37.5%), and finally 93.6% of children were immunized by three years old. The primary reason for failure to receive immunization was that he or she was infected with measles before immunization (30.4%). Around 53% of these were infected with measles by 2 years old. With regard to sources of information on immunization, public announcements and letters were the greatest sources, whereas the contribution of doctors and paramedical staffs which was expected to be the main providers of the information to parents was quite low.
Conclusions: 1) It was shown that there was a difference of measles immunization coverage between our results (90%) and the official record (70%), indicating that the current coverage survey method does not reflect the actual situation of immunization. Since more than 90% of children were immunized by three years old, we recommend that measles immunization coverage should be surveyed through interviews and data in maternity record book at the health examination for three year-old children which is operated by the government and has good attendance. 2) More than 50% of children who were infected with measles before immunization were infected by two years old, suggesting further promotion of measles immunization before two years old. 3) The main source of information on immunization was public announcements and publications. Further participation of doctors and paramedical staffs in disseminating information and providing education activities is desired.