Clinical characteristics and mortality risk factors among hospitalized infants and children with pertussis in China: a retrospective study

Shuhan Zheng¹Feng Luo²Ying Su²Rongrong Dai¹Xuan Deng³Yao Zhu³Yang Zhou³Hanqing He^3,4*Chun Zhen Hua^5*Hangjie Zhang^6*

• ¹School of Public Health, Hangzhou Medical College, Hangzhou, China
• ²School of Public Health, Zhejiang Chinese Medical University, Hangzhou, China
• ³Department of Immunization Program, Zhejiang Center for Disease Control and Prevention (Zhejiang CDC), Hangzhou, China
• ⁴Zhejiang Key Lab of Vaccine, Infectious Disease Prevention and Control, Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
• ⁵Children’s Hospital, Zhejiang University School of Medicine, Hangzhou, China
• ⁶Department of Prevention and Control of Infectious Disease, Zhejiang Center for Disease Control and Prevention (Zhejiang CDC), Hangzhou, China

Background: The resurgence of pertussis has emerged as a significant global public health threat. Severe pertussis primarily affects infants and children and is often associated with serious complications or death. Methods: We retrospectively evaluated the clinical data of 197 hospitalized children with pertussis admitted to Children's Hospital, Zhejiang University School of Medicine, from 2019 to 2024. Patients were categorized into severe and mild cases groups based on their admission ward. Multivariate logistic model was applied to explore associated factors. Results: Among the 197 hospitalized children, those born prematurely or younger than 3 months were more likely to be admitted to the pediatric intensive care unit (PICU). All patients admitted to the PICU were infants who were either unvaccinated or incompletely vaccinated against pertussis. The most common clinical symptoms among hospitalized children were pneumonia, paroxysmal cough, and flushing. The severe cases group exhibited significantly higher levels than the mild cases group in length of stay, duration of antibiotic treatment, white blood cell (WBC) count, pneumonia, respiratory failure, and tachypnea (P<0.05). Multivariate logistic regression analysis identified cefuroxime usage (odds ratio [OR]=0.10, 95% confidence interval [CI]=0.01–0.92), high WBC count (OR=0.79, 95% CI=0.69–0.91), and high neutrophil percentage (OR=1.49, 95% CI=1.22–1.82) as independent risk factors for PICU admission (P<0.05). Conclusions: Infants younger than 3 months and children who are unvaccinated or incompletely vaccinated for pertussis are more susceptible to developing severe pertussis. Common clinical features of severe pertussis include pneumonia, respiratory failure, elevated WBC count, and decreased neutrophil percentage. Pediatricians should prioritize early recognition and treatment of these clinical indicators to prevent the progression of severe pertussis.