Epidemiological and Clinical Characteristics of Human Metapneumovirus-Associated Acute Respiratory Tract Infection Cases in the Pudong New Area, Shanghai, from 2014 to 2023.

Abstract

Background: This study characterized Human metapneumovirus (HMPV) infection epidemiology and clinical features in patients with acute respiratory infections (ARIs) in Pudong New Area, Shanghai, China, compared by pre- and post-COVID-19 periods.

Methods: Between January 2014 and December 2023, the basic and clinical information, as well as respiratory tract specimens from ARIs, were collected at 14 sentinel hospitals in Shanghai Pudong. Specimens were tested for HMPV and other respiratory pathogens. The positivity rates were analyzed by age, period (pre- and post-COVID-19), season, and case type. Clinical characteristics of HMPV-infected versus non-infected cases were compared.

Results: 14,488 ARI patients were enrolled, with a 1.77% HMPV-positive rate (257/14,488). Among the age groups, the highest positive rate was 5.39% (11 /204) in the 6-11-month age group, and all the HMPV-positive cases in the 6-11-month-old age group were inpatients. Among the < 6 months old, 1-2 years old, 3-5 years old, 6-14 years old, 15-64 years old, and ≥ 65 years old groups, the positivity rates were 1.92% (6/313), 2.92% (23/788), 2.21% (33/1494), 1.08% (25/2311), 1.46% (94/6443) and 2.21% (65/2935), respectively. HMPV-positive patients showed higher proportions of cough (p < 0.001), runny nose (p = 0.048), and sore throat (p = 0.0175) than HMPV-negative patients in children. Compared to HMPV-negative patients, there was a significant difference in pneumonia diagnosis in both children and adults (p < 0.001, p = 0.004). Before COVID-19, HMPV infection peaks occurred mainly in February and March. In October 2023, a significant peak (4.37%, 10/229) was observed.

Conclusions: Young children and elderly individuals are at higher risk for HMPV infection, with a reversal of seasonal patterns observed post-COVID-19. Surveillance of HMPV in children and the elderly is crucial for future epidemic Preparedness.