To investigate the clinical characteristics in patients with pertussis in Xi’an, and to provide a scientific reference for treatment of pertussis.

The medical records of children with pertussis were in Xi’an from 2015 to 2016 reviewed, which were divided few groups according to age, vaccination and severity. The epidemiological and clinical characteristics were performed in every groups, and were analyzed and compared, retrospectively.

Among the 857 patients with pertussis, the gender ratio (male︰female) was 1.21︰1, with the median age of 5.8 (3.1, 12.1) months. The cases with pertussis occur throughout the year, particularly peaking from June to September, 492 cases (57.4%) were exposed to those who coughed in their family. Compared with those older than 6 months, various symptoms such as spasmodic cough, crow-like echo, apnea and severe pertussis, severe pneumonia and respiratory failure were more common in those younger than 6 months, and had a prolonged hospital stay, with significant differences (χ² = 26.517, 29.939, 25.632, 30.740, 15.046, 4.476, t = 4.940; all P < 0.05). Compared with the vaccination group, various symptoms such as spasmodic cough, cyanosis, apnea, severe pneumonia and severe pertussis were more common in cases of the non-vaccination group with a prolonged median hospital stay, with significant differences (χ² = 4.160, 17.747, 10.058, 10.257, 39.463, t = 4.559; all P < 0.05). The incidences of chicken-like echogenicity and pertussis complicated with cerebropathy between cases in the two groups were without significant difference (χ² = 0.389, 1.989; both P > 0.05). Compared with cases with ordinary pertussis, severe children were younger, with higher proportion of uninoculated DTP, higher incidence of fever and pneumonia, larger increase of white blood cells in routine blood detection, and longer length of hospitalization, with significant differences (χ² = -5.713, 47.214, 53.394, 7.993; t = 7.938, -8.060; all P < 0.01). Among all the children, there were 515 (60.1%) cases with spasmodic cough disappeared within one week of hospitalization, 198 (23.1%) cases with significant remission; there were no death. The median number of hospitalization period was 8 (6, 10) days.

The cases of pertussis occur throughout the year in Xi’an, particularly peaking from June to September. A higher incidence was reported particularly in those who were younger than 6 months and with incomplete DTP vaccination, and suffered from severe conditions, most had good prognosis with active treatments. Severe-type pertussis was mostly found in children with significantly increased count of leukocytes in routine blood detection and those without inoculation of DTP vaccine.