Evaluation of the factors affecting the influenza vaccination of the health care workers of dokuz Eylul University Hospital and the effecti̇veness of the vacci̇ne

INTRODUCTION AND AIM: İnfluenza is an acute respiratory infection caused by influenza viruses which circulate in all parts of the world. Influenza infects people from October to April. The disease is characterized by a sudden onset of fever, usually dry cough, headache , muscle pain, weakness, sore throat and runny nose. It is estimated that there are 3 to 5 million cases of severe influenza worldwide, inflicting approximately 290,000 to 500,000 influenza-related deaths. Vaccination is the most effective way to prevent disease. The aim of this study was to evaluate the factors affecting the influenza vaccination of the health care workers (HCWs) of Dokuz Eylül University (DEU) and the effectiveness of the influenza vaccine. METHOD: The research was carried out with prospective cohort method in HCWs of DEU Hospital. Sample size was calculated with 95% confidence interval 80% power, 1 exposed / 2 unexposed ratio, the incidence of influenza in vaccinated ones being 9.6%,and that of influenza in non-vaccinated ones being 18% as minimum of 596 persons. (181 exposed, 361 unexposed, %10 additional for nonresponse). Therefore it was aimed to reach 600 persons with 200 exposed and 400 unexposed. It is planned to gather the data of the vaccinated persons from DEU occupational health and safety Unit. It is planned that 400 people who are not vaccinated will be selected from the HCWs of DEU Hospital, the number of which is 4000, by simple random method and a baseline study will be carried out at this stage. Dependent variables are vaccination status and vaccine effectiveness. Independent variables were sociodemographic characteristics, occupational characteristics, presence of chronic disease, number of upper respiratory tract infections (URIs) per year, previous status of influenza vaccination and attitudes and behaviors towards influenza vaccination. The data were collected by face to face interviews using the questionnaire. Nasopharyngeal samples were obtained from the ones who had influenza-like symptoms during the flu season and tested in the Microbiology laboratory. RESULTS: 232 of 400 persons whose selected by simple random method participated in the baseline study. Participation rate is %58. 23 out of 232 people were found to be vaccinated. Vaccine coverage is 9.9%. 65 vaccinated people from DEU ISGB were included in the follow-up phase of the study and 88 vaccinated exposed people and 209 non-vaccinated unexposed people were followed up with 297 in total. When the characteristics of the vaccinated and non-vaccinated individuals were compared, it was found that the vaccinated individuals were younger and had a shorter working period. It was found that doctors were vaccinated more than the other occupational groups. HCWs who work in clinical departments tent to be vaccinated more than their non-clinical counterparts. The ones who has a regular wok day tent to be vaccinated less than those working shifts. In terms of the number of URIs per year, those who catched the disease more than 3 times throughout the year were more vaccinated than those who had less than 3 times. Those who have been vaccinated last year and earlier have been vaccinated more this season. When the attitudes and behaviors towards the vaccination are evaluated, those who find the vaccine useful and safe, who recommend it to others and who plan to have it next season have vaccinated more this season. In multiple regression analyses, the doctors had been vaccinated 5.32 times than the other occupational groups (p: 0.001 CI: 2.72-10.41). Those who had previously received influenza vaccination had 6.49 times more vaccination this season than those who had not (p: 0.001 CI: 3.45-12.18), and those who had more than 3 URIs per year were vaccinated 3.33 times more than those who had less than 3 URIs per year. 14 nasopharyngeal specimens was taken from people with influenza-like symptoms who contacted us. The results of 9 vaccinated people were 4 RV, 3 negative and 2 MPV, 5 unvaccinated were 4 RV and 1 negative. Effectiveness analyzes could not be performed because the number of specimens taken was insufficient. CONCLUSION: Influenza vaccine coverage was low in health care workers. In order to increase vaccine coverage, the vaccine should be provided in a timely and adequate amount, individual notifications should be provided and on-site vaccination should be performed. Special interventions are required for the group of nurses who have never vaccinated. In the future, vaccine effectiveness studies should be conducted in health workers and in the community as well. KEYWORDS: Adult immunization, influenza vaccine, health care workers