Analysis Of Epidemic Characteristics And Clinical Features Of Pertussis In 2012-2014

Objective:To provide basis for the diagnosis, treatment, prevention and control of pertussis through analysis of epidemic and clinical data from January 1,2012 to December 31,2014.Methods:Monitoring data of pertussis of the China Disease Prevention and Control Information System(CDC), Shandong Center for Disease Control and Prevention and Shandong Provincial Hospital Affiliated to Shandong University in 2012-2014 were collected, Serological test results (including outpatients and inpatients) of suspected cases and medical records diagnosed as pertussis (divided into severe group and non-severe group) in Shandong Provincial Hospital Affiliated to Shandong University from 2012 Jan 1st to 2014 Dec 31st were analyzed. This retrospective study was conducted to explore the epidemiological characteristics, clinical manifestations, image manifestations et al of pertussis in recent years.Result:The incidence of pertussis in the whole country and Shandong province was obviously higher than before, as well as our hospital,especially in summer and autumn.Pertussis mostly occurred to children under age of six, especially 3 months to 1 year old and 4 to 6 years old, there was a notable increasing trend in more than 6 years old in 2014, and pertussis infection increased significantly in more than 14 years old; the reported cases are far lower than the actual number of pertussis infection and incidence of pertussis was underestimated.The clinical manifestations were primarily spasmodic cough (79.01%,64/81 cases), cyanosis (60.491%,49/81 cases), vomiting after cough (35.801%,30/81 cases), conjunctiva haemorrhage (22.22%,18/81 cases) apnea or heart rate decrease (9.881%, 8/81 cases) whooping cough (7.411%,6/81 cases) et al; there were statistical significance (p<0.05) in age, paroxysmal cyanosis, elevated white blood cell count, and lymphocyte percentage increase compared severe group with non severe group; there was no statistical difference (p>0.05) in sex, season, spasmodic cough, whooping cough, conjunctiva hemorrhage and apnea etc; mixed infection with mycoplasma was most common, average time from onset to diagnosis was 15.5d.Imaging manifestations of pertussis were not specific, there could be no abnormal manifestation. Chest CT of some cases appeared light transmittance increases, "mosaic sign", ground glass opacity etc, some others could be manifested as patchy inflammatory infiltrates, consolidation even atelectasis.Conclusions:1.The morbidity of pertussis rises and atypical cases is increasing, infection of adolescents and adults should not be ignored.2.Severe cases are seen most frequently in small unimmunized infants, extremely elevated white blood cell count and lymphocyte percentage increase probably have prognostic significance.3.Mixed infection with mycoplasma is most common in pertussis, there is a necessity to differentiate.4.Improvement of standardized laboratory test methods and immune-prevention strategy still require large scale surveys and explore further.