Parechovirus A prevalence in adults in The Netherlands

Emerging Meningococcal B Meningitis in Japan: A Case Report of a 50-Year-Old Japanese Man with Diabetes

BACKGROUND Meningococcal meningitis is rare in Japan; however, when outbreaks do occur, they predominantly involve domestically infected cases rather than those contracted overseas. CASE REPORT A Japanese man with diabetes in his 50s experienced fever and loss of consciousness, with no history of international travel. In our hospital, gram-negative diplococci were detected in the cerebrospinal fluid (CSF) of the patient by Gram staining, although the rapid agglutination test and cultures of blood and CSF were negative. Multiplex polymerase-chain reaction (PCR) testing returned positive results for meningococcus and parechovirus. Brain MRI revealed a finding of meningitis, but there were no indications of encephalitis. To determine the serotype and genotype, we sent the sample to the National Institute of Infectious Diseases, which identified the serogroup and sequence type (ST) as type B and 2057, respectively. Despite the unknown antimicrobial susceptibility, the patient responded well to empirical treatment with ceftriaxone at 2 g every 12 h, and was discharged with remaining symptoms of dizziness, headache, difficulty hearing in the left ear, and tinnitus in the left ear. CONCLUSIONS In Japan, vaccines covering serogroups A, C, and W/Y are available but not routinely administered. According to epidemiological surveillance reports, serogroup B is the second most common cause of meningococcal meningitis in Japan, yet there is no corresponding vaccine available in the country. This case has prompted a review of the epidemiology of meningococcus in Japan, encompassing strategies for vaccination and hospital infection control to prevent droplet transmission, which includes post-exposure prophylaxis when no prior measures have been implemented.

First parechovirus reported case in Saudi Arabia in hospitalized immunocompromised adult patient

Human parechovirus, a member of the Picornaviridae family (PeVs), can lead to severe infections, including severe meningitis, meningoencephalitis, and sepsis-like syndrome. We report a case of human parechovirus-related encephalitis in a 52-year-old woman diagnosed with glioblastoma multiforme. She underwent surgical resection in June 2022. Unfortunately, her disease recurred, and she underwent a second resection in August 2022, followed by radiation therapy and Temozolomide therapy. She presented to the hospital with acute confusion followed by seizures, necessitating intubation for airway support. A cerebrospinal fluid (CSF) sample was obtained and processed using the Biofire FilmArray, which reported the detection of HSV-1. Despite being on Acyclovir, the patient did not show signs of improvement. Consequently, a second CSF sample was obtained and sent for next-generation sequencing (NGS), which returned a positive result for Parechovirus. In this presented case, the patient exhibited symptoms of an unknown infectious cause. The utilization of NGS and metagenomic analysis helped identify Parechovirus as the primary pathogen present, in addition to previously identified HSV. This comprehensive approach facilitated a thorough assessment of the underlying infection and guided targeted treatment. In conclusion, the application of NGS techniques and metagenomic analysis proved instrumental in identifying the root cause of the infection.

Recombinant parechovirus A3 possibly causes various clinical manifestations, including myalgia; findings in Yamagata, Japan in 2019

BACKGROUND

Parechovirus A3 was first reported in 2004 and has been recognized as a causative agent of mild and severe infections in children. Since we first reported an outbreak of adult parechovirus A3-associated myalgia in Yamagata, Japan in 2008, this disease has since been recognized across Japan, but has not yet been reported from other countries.

AIM

We analysed 19 cases of parechovirus A3 infections identified in Yamagata in 2019 to further clarify the epidemiology of this disease.

METHODS

We performed phylogenetic analyses of parechovirus A3 isolates and analysed the clinical manifestations and the genomic clusters.

RESULTS

There were two clusters, with cluster 2019B replacing 2019 A around October/November. Phylogenetic analysis revealed that 2019B cluster strains and Australian recombinant strains, which appeared between 2012 and 2013, were grouped in one cluster at non-structural protein regions, suggesting that the ancestor to these regions of 2019B cluster strains were Australian recombinant lineage strains. The strains from both clusters caused various infections in children including myalgia. These findings strongly support that parechovirus A3 strains cause myalgia and other paediatric infections irrespective of the virus strains involved, including recombinant strains.　　.

CONCLUSIONS

We have reported repeatedly sporadic cases of myalgia and here showed that recombinant strains also cause myalgia. We hope our experiences will help better understand these infections and possibly result in detection of more cases in the world.

Parechovirus A Infection of the Intestinal Epithelium: Differences Between Genotypes A1 and A3

Human parechovirus (PeV-A), one of the species within the Picornaviridae family, is known to cause disease in humans. The most commonly detected genotypes are PeV-A1, associated with mild gastrointestinal disease in young children, and PeV-A3, linked to severe disease with neurological symptoms in neonates. As PeV-A are detectable in stool and nasopharyngeal samples, entry is speculated to occur via the respiratory and gastro-intestinal routes. In this study, we characterized PeV-A1 and PeV-A3 replication and tropism in the intestinal epithelium using a primary 2D model based on human fetal enteroids. This model was permissive to infection with lab-adapted strains and clinical isolates of PeV-A1, but for PeV-A3, infection could only be established with clinical isolates. Replication was highest with infection established from the basolateral side with apical shedding for both genotypes. Compared to PeV-A1, replication kinetics of PeV-A3 were slower. Interestingly, there was a difference in cell tropism with PeV-A1 infecting both Paneth cells and enterocytes, while PeV-A3 infected mainly goblet cells. This difference in cell tropism may explain the difference in replication kinetics and associated disease in humans.

Human parechovirus are emerging pathogens with broad spectrum of clinical syndromes in adults

Parechoviruses are emerging pathogens of humans often affecting the pediatric age group, with a growing line of evidence implicating them as agents of a broad spectrum of clinical syndromes in adults. However, because many clinicians are not familiar with the manifestation of the infections, they are not included in the list of diagnostic pathogens. Furthermore, due to the indistinguishable feature of the infection compared with other common pathogens, a large number of cases are likely to go unchecked. Some may develop asymptomatic infection and recover without overt clinical disease. In this manuscript, we reviewed available literature on parechovirus infection in adult and summarized information relating to epidemiology, clinical manifestation, laboratory diagnosis, and therapeutics. The information provided should help in early case detection and support an evidence-based clinical decision.

Detection of Parechovirus A1 with Monoclonal Antibody against Capsid Protein VP0

Parechovirus A (PeV-A; human parechovirus) causes mild infections and severe diseases such as neonatal sepsis, encephalitis, and cardiomyopathy in young children. Among the 19 types of PeV-A, PeV-A1 is the most common type of infection. We have previously established an immunofluorescence assay for detecting multiple PeV-A types with a polyclonal antibody against the conserved epitope of VP0. Although the polyclonal antibody is useful for PeV-A diagnosis, it could not distinguish the PeV-A genotypes. Thus, the development of a specific monoclonal antibody for identifying the common infection of PeV-A1 would be beneficial in clinical diagnosis practice. In this study, the recombinant full-length PeV-A1 VP0 protein was used in mouse immunization; a total 10 hybridomas were established. After evaluation by immunoblotting and fluorescence assays, six hybridoma clones with monoclonal antibody (mAb) production were confirmed. These mAbs, which specifically recognize viral protein PeV-A1 VP0 without cross-reactivity to PeV-A3, will prove useful in research and PeV-A1 diagnosis.