Comparing Seasonal Pattern of Laboratory Confirmed Cases of Pertussis with Clinically Suspected Cases.

During recent decades, there has been limited attention on the seasonal pattern of pertussis within a high vaccine coverage population. This study aimed to compare the seasonal patterns of clinical suspected pertussis cases with those of laboratory confirmed cases in Iran.
METHODS:
The current study was conducted using time series methods. Time variables included months and seasons during 2011-2013. The effects of seasons and months on the incidence of pertussis were estimated using analysis of variance or Kruskal-Wallis.
RESULTS:
The maximum average incidence of clinically confirmed pertussis was 23.3 in July (p = 0.04), but the maximum incidence of clinical suspected pertussis was 115.7 in May (p = 0.6). The maximum seasonal incidences of confirmed and clinical pertussis cases were reported in summer (average: 12, p = 0.004), and winter (average: 108.1; p = 0.4), respectively.
CONCLUSION:
The present study showed that the seasonal pattern of laboratory confirmed pertussis cases is highly definite and different from the pattern of clinical suspected cases.

Authors:Ghorbani GR1, Zahraei SM2, Moosazadeh M3, Afshari M4, Doosti F2.
Journal:Osong Public Health Res Perspect. 2016
Link:http://www.ncbi.nlm.nih.gov/pubmed/27169013