Epidemiological profile of meningitis in Iran before pentavalent vaccine introduction.

BACKGROUND: No reliable and comprehensive study has been published on the incidence and epidemiological profile of meningitis in Iran from 2008 to 2014, before pneumococcal conjugate vaccine (PCV) and pentavalent vaccine (DTPw-Hep B-Hib (PRP-T) vaccine (pentavac) (adsorbed)) introduction. The present study aimed to portray the epidemiological profile of meningitis in Iran from 2008 to 2014. METHODS: Data on meningitis cases aged from 1 day to 110 years were extracted from national notifiable diseases surveillance system from March 2008 to December 2014 in Iran. A total number of 48,006 cases of suspected meningitis were identified and 1468 cases of which met the criteria for diagnosis-confirmed meningitis. Of 1468 cases, 1352 patients were included in the study. RESULTS: The great number of cases reported from urban areas. Moreover, males were more predominant than females (58.51% vs. 33.81%) in total. The estimated annual incidence rate of meningitis varied from 0.28/100000 in 2008 to 0.09/100000 in 2014. Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis were the most leading pathogens causing bacterial meningitis, accounted for 266(23.44%), 145(12.78%), 95(8.37%) of cases, respectively. Each of the three bacterial species showed a descending trend. The majority of infected subjects are children under five years. CONCLUSIONS: Unlike the decreasing trend of meningitis and high percentage of cultures with negative results, according to World Health Organization recommendation PCV introduction into routine immunization is evident. Implementing an enhanced surveillance system to provide high quality data on epidemiological profile of meningitis in Iran is necessary.

Adverse events following immunization with pentavalent vaccine: experiences of newly introduced vaccine in Iran.

BACKGROUND: The most important factors that affect the incidence of vaccine-related complications are the constituent biological components of the vaccine, injection site reactions, age and sex. The aim of this study is to determine the incidence rate of adverse events following immunization with pentavalent vaccine (DTPw-Hep B-Hib (PRP-T) vaccine (pentavac) (adsorbed) is manufactured by Serum Institute of India ltd), which was introduced in Iran in November 2014. It is important to monitor vaccine-related adverse events because of the role of vaccine safety in immunization program success. METHODS: This study was a mixed cohort study that included 1119 children less than 1 year of age. In 2015, the children were referred to Hamadan health centers to receive pentavalent vaccine at 2, 4 and 6 months of age. The data were collected from the parents of the children using a questionnaire that was administered either face-to-face or by telephone. The cumulative incidence of side effects and risk ratio was reported with 95% confidence intervals (CI). Chi-squared tests and logistic regressions were used to investigate the association between the variables. RESULTS: The cumulative incidence rate of pentavalent-related adverse events during 48 h following immunization was estimated to be 15.8% for swelling, 10.9% for redness, 44.2% for pain, 12.6% for mild fever, 0.1% for high fever, 20.0% for drowsiness, 15.0% for loss of appetite, 32.9% for irritability, 4.6% for vomiting and 5.5% for persistent crying. There is no evidence for the occurrence of convulsion and encephalopathy among children who receive pentavalent vaccines. CONCLUSION: Further large studies with long time follow up are required to address rare events include convulsions, encephalopathy or persistent crying. However, Findings urge immunization programs to use pentavalent vaccinations and to continue implementing the current immunization program in children under 1 year of age.