Pertussis resurgence in a highly vaccinated population, Mazandaran, North of Iran 2008-2011: an epidemiological analysis.
OBJECTIVE
To describe the epidemiological characteristics of pertussis cases reported to Mazandaran Center for Diseases Control and Prevention (P-CDC) during the years 2008-2011 in Mazandaran, North of Iran.


METHODS
The patients included were those who fulfilled the WHO definition for pertussis or those clinically diagnosed by physicians. The demographic features of cases, their vaccination status, the incidence rate per 100,000 population, the relative proportion of cases for each age group, and their relation to vaccination status of the patients were all determined.


RESULTS
During the study period, a total of 518 cases of pertussis were reported; of which 43 were confirmed. The highest incidence rate and the largest proportion were 135.5 cases/100,000 and 37.7 %, respectively, observed in infants <12 mo of age. Almost 35.7 % of the cases were under vaccinated, however 54.4 % of them were fully vaccinated.


CONCLUSIONS
Pertussis infection has re-emerged in Mazandaran. It has caused a significant health problem in the susceptible young infants, and also among completely vaccinated children. Implementing strategies to protect these vulnerable infants and studies to evaluate the immunogenicity and efficacy of pertussis vaccine in Iran is recommended. It was difficult to confirm pertussis in the majority of cases, therefore, providing and improving laboratory diagnostic methods seems to be an urgent requirement.
Pediatric Infectious Diseases Unit, Department of Pediatrics, Mazandaran University of Medical Sciences, Sari, Iran.
Mohammad Jafar
MJ
Saffar
Gholamreza
G
Ghorbani
Ahmad
A
Hashemi
Mohammad Sadegh
MS
Rezai
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007492:Iran / Q000453:epidemiology; D008297:Male; D010567:Pertussis Vaccine / Q000008:administration & dosage*; D014611:Vaccination / Q000706:statistics & numerical data*; D014917:Whooping Cough / Q000453:epidemiology*; D055815:Young Adult
D010567:Pertussis Vaccine