Emergence of Parechovirus-A3 as the Leading Cause of Central Nervous System Infection Surpassing Any Single Enterovirus Type in Children in Kansas City, USA from 2007-2016

Picornaviruses including Enterovirus species A-D (EV) and Parechovirus species A (PeV-A) are the leading reported causes of pediatric central nervous system infections in the United States. We investigated the molecular epidemiology of EV and PeV-A over 10 years, in cerebrospinal fluid (CSF) collected from children seen at Children’s Mercy -Kansas City (CMKC) during 2007 through 2016. The overall prevalence for EV was 16% (862/5362) and 7% (271/4016) for PeV. Among all picornavirus CSF detections EV was 76% and PeV-A was 24%. Multiple EV types co-circulated each year with a total of 31 EV types detected in the 10-year period; majority belonged to EV-B species (96%). Two PeV-A types were detected; PeV-A3 was the dominant PeV-A type (95%). Top five picornaviruses (PeV-A3, 26%; E30, 11%; E6 10%; E18 9%, E9 7%) in the CSF of infants accounted for two-third of all detections and PeV-A3 was the leading picornavirus detected. Routine testing and reporting of PeV-A in addition to EV, especially in children under 6 months old with acute febrile illnesses, could reduce hospital stays and antibiotic usage.

Multiplexed High-Throughput Serological Assay for Human Enteroviruses

Immunological assays detecting antibodies against enteroviruses typically use a single enterovirus serotype as antigen. This limits the ability of such assays to detect antibodies against different enterovirus types and to detect possible type-specific variation in antibody responses. We set out to develop a multiplexed assay for simultaneous detection of antibodies against multiple enterovirus and rhinovirus types encompassing all human infecting species. Seven recombinant VP1 proteins from enteroviruses EV-A to EV-D and rhinoviruses RV-A to RV-C species were produced. Using Meso Scale Diagnostics U-PLEX platform we were able to study antibody reactions against these proteins as well as non-structural enterovirus proteins in a single well with 140 human serum samples. Adults had on average 33-fold stronger antibody responses to these antigens (p < 10−11) compared to children, but children had less cross-reactivity between different enterovirus types. The results suggest that this new high-throughput assay offers clear benefits in the evaluation of humoral enterovirus immunity in children, giving more exact information than assays that are based on a single enterovirus type as antigen.

An outbreak of Coxsackievirus A6 infection in adults of a collective unit, China, 2019

Background: Outbreaks/epidemic caused by Coxsackievirus A6 have been reported continuously since 2008. However, outbreaks caused by Coxsackievirus A6 infection in adults of a collective unit have not been reported. Methods: The nasopharyngeal swab specimens were collected to extract the total nucleic acid (DNA/RNA). The pathogen was determined using 22 respiratory pathogen nucleic acid detection kits. The VP1 gene of this pathogen was amplified and sequenced. Sequence alignment and analysis were performed using Bioedit. The gene phylogenetic tree was constructed with MEGA software. Results: The factory emerged patients in succession from the February 14 and reached the peak on the 18th. The main symptoms were rash, ocular conjunctival hemorrhage, fever and sore throat. A total of 19 workers had symptoms in this factory up to March 31, 2019, giving an attack rate of 8.26%. The laboratory results showed that Coxsackievirus A6 was the enterovirus type causing this outbreak. The risk of illness was 7.37 times higher taking bath in bathroom than that of not taking bath (95% CI 1.67, 32.79). Conclusions: Epidemiologic and molecular data indicated Coxsackievirus A6 as the etiology of this outbreak of adults in a collective unit, a risk factor for the spread was taking bath in the bathroom of the factory.

EXTENDING THE UTILITY OF THE WHO RECOMMENDED ASSAY FOR DIRECT DETECTION OF ENTEROVIRUSES FROM CLINICAL SPECIMEN FOR RESOLVING POLIOVIRUS CO-INFECTION

ABSTRACTIn a polio-free world there might be reduced funding for poliovirus surveillance. There is therefore the need to ensure that enterovirologist globally, especially those outside the global polio laboratory network (GPLN), can participate in poliovirus surveillance without neglecting their enterovirus type of interest. To accomplish this, assays are needed that allow such active participation.In this light, we used 15 previously identified enterovirus isolates as reference samples for assay development. The first eight were enterovirus species B (EV-B). The remaining seven were EV-Cs; three of which were poliovirus (PV) 1, 2 and 3, respectively. A 16th sample was compounded; a mixture of two EV-Bs, three PVs and one nonPV EV-Cs (all part of the 15). In all, four samples contained PVs with the 16th consisting of mixture of the three PV types. All were subjected to the WHO recommended RT-snPCR assay, and five other modified (with substitution of the second round PCR forward primer) assays. The new primers included the previously described Species Resolution Primers (SRPs; 187and 189) and the Poliovirus Resolution Primers (PRPs: Sab 1, 2 and 3). All amplicons were sequenced and isolate identity confirmed using the Enterovirus Genotyping Tool.The PRPs detected PV types in only the four samples that contained PVs. In addition, it was able to show that the sample 16 (mixture) contained all the three PV types. On the other hand, though the SRPs and the WHO assay also detected the three singleton PVs, in sample 16, they both detected only one of the three PV types present.This study describes a sensitive and specific utility extension of the recently recommended WHO RT-snPCR assay that enables independent detection of the three poliovirus types especially in cases of co-infection. More importantly, it piggy-backs on the first round PCR product of the WHO recommended assay and consequently ensures that enterovirologists interested in nonpolio enteroviruses can continue their investigations, and contribute significantly and specifically to poliovirus surveillance, by using the excess of their first round PCR product.