Enterovirus D68 epidemic, UK, 2018, was caused by subclades B3 and D1, predominantly in children and adults, respectively, with both subclades exhibiting extensive genetic diversity

A review of enterovirus-associated hand-foot and mouth disease: preventive strategies and the need for a global enterovirus surveillance network

Enterovirus (EV)-associated hand, foot, and mouth disease (HFMD) is a significant public health issue worldwide, commonly occurring in children five years of age or younger. The leading causes of most HFMD cases are EVs, which are members of the Picornaviridae family. The typical clinical manifestations of EV-associated HFMD are febrile presentations with mucosal herpangina, oral ulcerations, and skin rashes on the hands and feet. The majority of HFMD cases resolve without consequence; however, a subset progresses to severe neurological and cardiopulmonary complications, which can be fatal. In the past two decades, EV-associated HFMD has received significant attention. In this review, we organize published papers and provide updates on epidemiology, pathogenesis, surveillance, and vaccine developments for EV-associated HFMD. The impact of EV-associated HFMD is increasing globally. Developing efficacious vaccines has become a priority for preventing EV infections without adequate treatment. Simultaneously, emerging EV infections (including EV-D68, EV-A71, Coxsackieviruses, and echoviruses) are increasing, highlighting the need to create a vigilant surveillance system for EV infections worldwide.

Enterovirus virus-like-particle and inactivated poliovirus vaccines do not elicit substantive cross-reactive antibody responses

Human enteroviruses are the most common human pathogen with over 300 distinct genotypes. Previous work with poliovirus has suggested that it is possible to generate antibody responses in humans and animals that can recognize members of multiple enterovirus species. However, cross protective immunity across multiple enteroviruses is not observed epidemiologically in humans. Here we investigated whether immunization of mice or baboons with inactivated poliovirus or enterovirus virus-like-particles (VLPs) vaccines generates antibody responses that can recognize enterovirus D68 or A71. We found that mice only generated antibodies specific for the antigen they were immunized with, and repeated immunization failed to generate cross-reactive antibody responses as measured by both ELISA and neutralization assay. Immunization of baboons with IPV failed to generate neutralizing antibody responses against enterovirus D68 or A71. These results suggest that a multivalent approach to enterovirus vaccination is necessary to protect against enterovirus disease in vulnerable populations.

Off-season circulation and characterization of enterovirus D68 with respiratory and neurological presentation using whole-genome sequencing

To explore an off-season enterovirus D68 (EV-D68) upsurge in the winter season of 2019/2020, we adapted a whole-genome sequencing approach for Nanopore Sequencing for 20 hospitalized patients with accompanying respiratory or neurological presentation. Applying phylodynamic and evolutionary analysis on Nextstrain and Datamonkey respectively, we report a highly diverse virus with an evolutionary rate of 3.05 × 10^-3 substitutions per year (entire EV-D68 genome) and a positive episodic/diversifying selection with persistent yet undetected circulation likely driving evolution. While the predominant B3 subclade was identified in 19 patients, one A2 subclade was identified in an infant presenting with meningitis. Exploring single nucleotide variations using CLC Genomics Server showed high levels of non-synonymous mutations, particularly in the surface proteins, possibly highlighting growing problems with routine Sanger sequencing for typing enteroviruses. Surveillance and molecular approaches to enhance current knowledge of infectious pathogens capable of pandemic potential are paramount to early warning in health care facilities.