Epidemiological and molecular characteristics of HPEV infection in children<6 months hospitalized with symptoms of sepsie-like illness, northen Italy, 2015-2018

BACKGROUND. Human parechoviruses (HPeVs) are widespread pathogens belonging to the Picornaviridae family and currently divided into 19 genotypes. HPeV infections can be associated with severe clinical manifestations, such as sepsis-like illness, particularly in youngest children. The epidemiological and molecular characteristics of HPeV infections observed in children <6 months hospitalized with symptoms of sepsis-like illness were investigated. METHODS. From January 1st, 2015, to December 31st, 2018, clinical samples (cerebrospinal fluid samples and/or blood samples) were collected for diagnosis of HPeV infection from 193 patients (median age: 21 days, range: 1 day - 6 months) hospitalized with symptoms of sepsis-like illness, in two hospitals of Northern Italy. HPeV-RNA was detected by real-time RT-PCR (target 5\u2019UTR) and a portion of HPeV VP3/VP1 junction (nt. 2159\u20132458) was sequenced for typing and molecular characterization. RESULTS. 14% (27/193) of patients with symptoms of sepsis-like illness tested HPeV-positive. 26/27 (96.3%) HPeV-cases were <3 months and 20/27 (74.1%) <1 month. HPeV-positive cases were detected throughout the study period, mainly (12/27; 44.4%) during the summertime (June-August). 17/27 (63%) HPeV-positive samples were molecularly characterized: 16 resulted HPeV-3 and 1 HPeV-5. CONCLUSIONS. HPeV infection was identified in 14% of children <6 months with symptoms of sepsis-like illness. Almost all HPeV infections were detected in children <3 months and mainly during the summertime; almost all molecularly characterized HPeV belonged to type 3. Including HPeV molecular detection in routine diagnostic tests would allow estimating the burden of HPeV infection and improving clinical management of pediatric patients