Incidence of Pertussis in Anbar Province, West of Iraq, during 2009-2019

Pertussis (whooping coughalso called100-day cough) is an extremely infectious bacterial illness caused by Bordetella pertussis. B. pertussis spreads by coughs and sneezes of sick patients. The present study aimed to investigate the pertussis incidence, and thereafter, decide whether it is necessary to import a vaccine for this disease in Anbar province, Iraq. This descriptive cross-sectional study was performed by using the electronic archives of Pertussis patients in Anbar Governorate hospitals during a period of 10 years from 2009 to 2019. The incidence rate of pertussis has been calculated by dividing the annual cases number of infections by the size of the population at risk multiplied by 100,000. From 608 patients with pertussis registered at Anbar province hospitals, 315 (51.8%) and 293 (48.2%) of them were males and females, respectively, with an average age of 11.1±3 years old. The incidence rates of pertussis in 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 were 0.014, 2.770, 1.427, 1.375, 3.421, 0.228, 0.00, 0.00, 21.321, 4.242, 0.604 in 100,000 people per year. The annual incidence ratio was 13.620/100,000 people per year. There was no statistically significant difference between males and females (P-value =0.130). There was one peak in the annual incidence rate of pertussis from 2009-2019 which happened in 2017. Lack of pertussis incidence during 2015-2016 was due to population displacement. Incidence of pertussis was more prevalent in the age group of 1-4 years old, compared to the1-year-old group. The incidence of pertussis decreased sharply during the last 2 years in Anbar province.