Healthcare-associated parechovirus-A infection in hospitals with neonatal units in Japan: a nationwide survey.

Objective: To determine the scope and characteristics of healthcare-associated parechovirus-A infection (HA-PI). Design: Cross-sectional survey. Setting: Hospitals with neonatal units in Japan. Participants: Patients with parechovirus-A infection in 2023 in Japan. Methods: A 2-step questionnaire survey included the primary survey ascertaining the number of patients with HA-PI in 2023, followed by the secondary survey investigating the details of the patients with HA-PI. Results: Of the 408 hospitals, 226 (55.4%) responded. Seven sporadic patients were reported from 6 (2.7%) hospitals between May and September 2023, diagnosed as having sepsis (n = 5) or sepsis-like illness (n = 2). The median gestational age was 37.7 weeks (IQR, 36.2-38.3). They were second-born (n = 6) or third-born (n = 1), without first-born. The median days of onset of illness were 7 days (IQR, 6-15). The locations were the newborn nursery (n = 3), growth care (n = 3), or neonatal intensive care units (n = 1). No sequelae were found at least 10 months in all patients. Parechovirus-A genotype analyses demonstrated A3 (n = 6) and unknown (n = 1). The identified sources of infection were from the mother (n = 5) or unknown (n = 2). Among the 5 mothers, 2 were symptomatic. Notably, the siblings of patients in 3 asymptomatic mothers, who had no direct contact with the patients, were all symptomatic. Conclusions: This nationwide survey in Japan demonstrated HA-PI can occur in neonatal units, with potential risks for nosocomial outbreaks. Suspecting HA-PI and preventive measures are critical in neonatal units.