Cluster of human parechovirus infections as the predominant cause of sepsis in neonates and infants, Leicester, United Kingdom, 8 May to 2 August 2016

Clinical Spectrum and Epidemiology of Human Parechovirus Infections in Infants: A Retrospective Study in the Western Part of Sweden

Background

Human parechovirus (HPeV) infections can cause sepsis and meningoencephalitis in infants. To improve our knowledge of the consequences of HPeV infections in young children, the incidence, clinical spectrum, and short-term outcome among infants infected with HPeV were investigated retrospectively.

Methods

The presence of HPeV RNA was investigated by polymerase chain reaction in cerebrospinal fluid from 327 children aged 0 to 12 months sampled between 2014 and 2017. Eighty-one were infected with HPeV and included in the study. These infants were divided into 3 groups based on clinical assessment: HPeV was the presumed cause of disease (n = 35); HPeV could have contributed to or been considered the cause of disease (n = 24); and HPeV was not considered the cause of disease (n = 22).

Results

Infection with HPeV type 3 was common in all groups (n = 54), and most children were younger than 3 months (n = 63). The children in the first group (HPeV as presumed cause) had meningoencephalitis (n = 20), viral sepsis (n = 9), or non-severe viral infection (n = 6). The youngest were more prone to develop meningoencephalitis, while the slightly older children had symptoms of viral sepsis or nonsevere viral infection (P < .05). Eleven had symptom onset within 2 days after birth. Two infants diagnosed with sudden infant death syndrome were HPeV infected when tested postmortem.

Conclusions

HPeV infections were identified in 25% of children with suspected central nervous system infection. The clinical presentation of those infected with HPeV varied with age. HPeV infections may be associated with sudden infant death syndrome, although this is not well studied. The results suggest that HPeV infections may be underdiagnosed in young infants.

Myeloid-associated differentiation marker is an essential host factor for human parechovirus PeV-A3 entry

Human parechovirus (PeV-A) is an RNA virus that belongs to the family Picornaviridae and it is currently classified into 19 genotypes. PeV-As usually cause mild illness in children and adults. Among the genotypes, PeV-A3 can cause severe diseases in neonates and young infants, resulting in neurological sequelae and death. In this study, we identify the human myeloid-associated differentiation marker (MYADM) as an essential host factor for the entry of six PeV-As (PeV-A1 to PeV-A6), including PeV-A3. The infection of six PeV-As (PeV-A1 to PeV-A6) to human cells is abolished by knocking out the expression of MYADM. Hamster BHK-21 cells are resistant to PeV-A infection, but the expression of human MYADM in BHK-21 confers PeV-A infection and viral production. Furthermore, VP0 capsid protein of PeV-A3 interacts with one extracellular domain of human MYADM on the cell membrane of BHK-21. The identification of MYADM as an essential entry factor for PeV-As infection is expected to advance our understanding of the pathogenesis of PeV-As.

Year-Round, Routine Testing of Multiple Body Site Specimens for Human Parechovirus in Young Febrile Infants

OBJECTIVES

To test our hypothesis that routine year-round testing of specimens from multiple body sites and genotyping of detected virus would describe seasonal changes, increase diagnostic yield, and provide a better definition of clinical manifestations of human parechovirus (PeV-A) infections in young febrile infants.

STUDY DESIGN

PeV-A reverse-transcriptase polymerase chain reaction (RT-PCR) analysis was incorporated in routine evaluation of infants aged ≤60 days hospitalized at Nationwide Children's Hospital for fever and/or suspected sepsis-like syndrome beginning in July 2013. We reviewed electronic medical records of infants who tested positive for PeV-A between July 2013 and September 2016. Genotyping was performed with specific type 3 RT-PCR and sequencing.

RESULTS

Of 1475 infants evaluated, 130 (9%) tested positive for PeV-A in 1 or more sites: 100 (77%) in blood, 84 (65%) in a nonsterile site, and 53 (41%) in cerebrospinal fluid (CSF). Five infants (4%) were CSF-only positive, 31 (24%) were blood-only positive, and 20 (15%) were nonsterile site-only positive. PeV-A3 was the most common type (85%) and the only type detected in CSF. Although the majority (79%) of infections were diagnosed between July and December, PeV-A was detected year-round. The median age at detection was 29 days. Fever (96%), fussiness (75%), and lymphopenia (56%) were common. Among infants with PeV-A-positive CSF, 77% had no CSF pleocytosis. The median duration of hospitalization was 41 hours. Four infants had bacterial coinfections diagnosed within 24 hours of admission; 40 infants had viral coinfections.

CONCLUSIONS

Although most frequent in summer and fall, PeV-A infections were encountered in every calendar month within the 3-year period of study. More than one-half of patients had PeV-A detected at more than 1 body site. Coinfections were common. PeV-A3 was the most common type identified and the only type detected in the CSF.

Parechovirus infection as a cause of necrotising enterocolitis in a premature neonate

Parechovirus is becoming increasingly recognised as a cause of morbidity in the neonatal population. It is widely known to cause sepsis, encephalitis and myocarditis. We report a case of parechovirus as a possible cause of necrotising enterocolitis in a premature neonate. The infant, who was born at 28 weeks’ gestation, deteriorated at 1 month of life with fever and abdominal distension and had evidence of intramural bowel gas on imaging. Parechovirus was subsequently isolated from naso-oropharyngeal and rectal swabs, and he was managed medically with antibiotics and cessation of enteral feeds.

Epidemiology of Human Parechovirus Type 3 Upsurge in 2 Hospitals, Freiburg, Germany, 2018

In 2018, a cluster of pediatric human parechovirus (HPeV) infections in 2 neighboring German hospitals was detected. Viral protein 1 sequence analysis demonstrated co-circulation of different HPeV-3 sublineages and of HPeV-1 and -5 strains, thereby excluding a nosocomial outbreak. Our findings underline the need for HPeV diagnostics and sequence analysis for outbreak investigations.

Enterovirus and parechovirus meningitis in infants younger than 90 days old in the UK and Republic of Ireland: a British Paediatric Surveillance Unit study

OBJECTIVES

This study aimed to prospectively collect detailed clinical information for all enterovirus (EV) and human parechovirus (HPeV) meningitis cases in infants aged <90 days in the UK and Ireland.

PARTICIPANTS, DESIGN AND SETTING

Prospective, active national surveillance during July 2014 to July 2015 through the British Paediatric Surveillance Unit. Reporting paediatricians completed questionnaires requesting information on clinical presentation, investigations, management and outcomes at hospital discharge and after 12 months.

MAIN OUTCOME MEASURES

To describe the clinical burden of EV and HPeV meningitis in infants aged <90 days.

RESULTS

During the 13-month surveillance period, 703 cases (668 EV, incidence0.79/1,000 live- births; 35 HPeV, 0.04/1,000 live-births) were identified. The most common clinical presentations were fever (EV: 570/668(85%); HPeV: 28/35(80%)), irritability (EV: 441/668(66%); HPeV: 23/35(66%)) and reduced feeding (EV: 363/668(54%); HPeV 23/35(66%)). Features of circulatory shock were present in 27% (182/668) of EV and 43% (15/35) of HPeV cases. Overall, 11% (76/668) of EV and 23% (8/35) of HPeV cases required intensive care support. Nearly all cases (678/703, 96%) were confirmed by cerebrospinal fluid (CSF) PCR, with 52% (309/600) having normal CSF white cell count for age. Two infants with EV meningitis died (2/668, 0.3%) and four survivors (4/666, 0.6%) had long-term complications at 12 months' follow-up. Infants with HPeV meningitis survived without sequelae. Overall 189 infants had a formal hearing test and none had sensorineural hearing loss.

CONCLUSION

The incidence of laboratory-confirmed EV/HPeV meningitis in young infants is more than twice that for bacterial meningitis. Less than 1% will develop severe neurological complications or die of their infection. Further studies are required to formally assess long-term neurodevelopmental sequelae.

Infant identical triplets' presentation of human parechovirus Type 3

Introduction

Human parechovirus (HPeV) infections appear common across age groups, and transmission is likely fecal-oral and through respiratory secretions. Cyclical and seasonal patterns have been described; however, HPeV has likely been previously underdiagnosed due to lack of commercially available diagnostic testing.

Presentation of Case

We present identical triplets contracting HPeV Type 3.

Discussion

The clinical presentation, similar to echoviruses, is broad and includes asymptomatic shedding, severe pulmonary and neurologic disease, and disseminated intravascular coagulation. Neonates and young infants are particularly susceptible. In neonates, distinctive MRI brain findings have been described that, when combined with clinical presentation, suggest HPeV. Infection clusters have been described, and neonates with older siblings may be a risk factor.

Conclusion

This case suggests that HPeV has been under-recognized in the United States, and HPeV Type 3 prevalence is likely underestimated. The case highlights variation in presentation, including lack of fever and rash, which were previously documented as common HPeV symptoms.

Comparing the Clinical Severity of Disease Caused by Enteroviruses and Human Parechoviruses in Neonates and Infants

Comparison of children hospitalized with enterovirus or human parechovirus (HPeV) detected in their cerebrospinal fluid revealed that HPeV infections presented with more persistent fever, irritability and feeding problems, more frequent leukopenia and lymphopenia and higher admission rates to high dependency or intensive care units. Few HPeV cases were followed up, further studies on long-term outcomes are needed.

Human Parechovirus 3 in Infants: Expanding Our Knowledge of Adverse Outcomes

BACKGROUND

Human parechovirus particularly genotype 3 (HPeV3) is an emerging infection affecting predominantly young infants. The potential for neurologic sequelae in a vulnerable subset is increasingly apparent. A review of 2 epidemics of human parechovirus (HpeV) infection in 2013 and in 2015 in Queensland, Australia, was undertaken, with an emphasis on identifying adverse neurodevelopmental outcome.

METHODS

All hospitalized cases with laboratory-confirmed HPeV infection between October 2013 June 2016 were identified. Clinical, demographic, laboratory and imaging data were collected and correlated with reported developmental outcome.

RESULTS

Laboratory-confirmed HPeV infections were identified in 202 patients across 25 hospitals; 86.6% (n = 175) were younger than 3 months 16.3% (n = 33) received intensive care admission. Of 142 cerebrospinal fluid samples which were HPeV polymerase chain reaction positive, all 89 isolates successfully genotyped were HPeV3. Clinical information was available for 145 children; 53.1% (n = 77) had follow-up from a pediatrician, of whom 14% (n = 11) had neurodevelopmental sequelae, ranging from hypotonia and gross motor delay to spastic quadriplegic cerebral palsy and cortical visual impairment. Of 15 children with initially abnormal brain magnetic resonance imaging, 47% (n = 7) had neurodevelopmental concerns, the remainder had normal development at follow-up between 6 and 15 months of age.

CONCLUSIONS

This is the largest cohort of HPeV3 cases with clinical data and pediatrician-assessed neurodevelopmental follow-up to date. Developmental concerns were identified in 11 children at early follow-up. Abnormal magnetic resonance imaging during acute infection did not specifically predict poor neurodevelopmental in short-term follow-up. Continued follow-up of infants and further imaging correlation is needed to explore predictors of long-term morbidity.

Increased detection of human parechovirus infection in infants in England during 2016: epidemiology and clinical characteristics

BACKGROUND

Human parechovirus (HPeV), like enteroviruses, usually causes mild self-limiting respiratory and gastrointestinal symptoms. In infants, HPeV can occasionally cause serious illnesses, including sepsis-like syndrome and encephalitis. In summer 2016, Public Health England (PHE) received increasing reports of severe HPeV infections nationally. We, therefore, reviewed all infants with confirmed HPeV across England during 2016.

METHODS

HPeV cases in infants aged <12 months reported to PHE during 2016 were followed up using a clinical questionnaire. Additional cases identified by clinicians completing the questionnaire were also included.

RESULTS

We identified 106 infants with confirmed HPeV infection during 2016. The disease peaked during early summer. Most infants (98/106, 92%) were aged <90 days, and 43% (46/106) were neonates. Fever was the most commonly reported symptom (92%) and signs of circulatory shock were present in 53%. Eighteen infants (18%) required paediatric intensive care admission. Most infants had normal or low C reactive protein concentrations (<10 mg/dL in 75%, <50 mg/dL in 98%). A lumbar puncture was performed in 98% of cases; 92% (33/36) of neonates and 93% (53/57) of older infants had normal white cell count in the cerebrospinal fluid (CSF). Nearly all reported cases (98%) were confirmed by CSF PCR. All infants survived, but five had ongoing seizures after hospital discharge.

CONCLUSIONS

HPeV is an important cause of febrile illness in infants and can have severe clinical presentations. Early diagnosis may help reduce antimicrobial use, unnecessary investigations and prolonged hospitalisation. While prognosis remains favourable, some infants will develop long-term complications-paediatricians should ensure appropriate follow-up after discharge.

Outcome of routine cerebrospinal fluid screening for enterovirus and human parechovirus infection among infants with sepsis-like illness or meningitis in Cornwall, UK

Enteroviruses (EV) and human parechoviruses (HPeV) are known and emerging cause of sepsis-like illnesses in infants; however, testing is not yet routine. We retrospectively evaluated the number of diagnosed EV/HPeV infections in children under the age of 5 years who presented with sepsis-like illness or meningitis in Cornwall, UK, before and after routine implementation of viral screening of cerebrospinal fluid samples. During the 4-year period prior to routine testing, we identified 20 cases of EV meningitis and no cases of HPeV. In the year after introduction of routine screening, 27 cases of EV and 14 cases of HPeV were identified in 1 year. The majority of EV/HPeV infections occurred among children under 3 months old between May and August. Clinical and laboratory characteristics of EV and HPeV infections were mostly indistinguishable. We found that CSF pleocytosis and biochemistry-based testing strategy could miss 48.1 and 78.5% of EV and HPeV cases, respectively. With routine viral screening, the mean length of hospital stay (3.8 vs 5.9 days, P < 0.001) and antibiotic days (2.8 vs 4.7 days, P < 0.001) were significantly reduced in EV/HPeV-positive cases compared to a similar cohort without any detectable microbial aetiology.

CONCLUSION

Routine EV and HPeV testing of CSF samples in children has the potential to reduce length of stay and antibiotic use. What is Known: • EV and HPeV are frequent cause of meningitis and sepsis-like illness among young children. • There is increasing evidence supporting routine EV and HPeV testing of paediatric CSF. What is New: • Outcome of routine EV and HPeV testing in Cornwall, UK. • The value of testing all paediatric CSF without any screening criteria. • A rapid diagnosis of EV/HPeV can significantly reduce length of hospital stay and unnecessary antibiotics.

Echovirus 30 and coxsackievirus A9 infection among young neonates with sepsis in Iran

BACKGROUND AND OBJECTIVES

Human enteroviruses (EV) are the most common causes of neonatal sepsis-like disease. The frequencies of EV including coxsackievirus A, coxsackievirus B and Echovirus serotypes have been studied in young infants (younger than three months) with sepsis. So far, the role of enteroviruses among neonates with sepsis was not determined in Ahvaz, Iran. Therefore, this study was aimed to evaluate the frequency of EV among hospitalized young infants with clinical signs and symptoms of sepsis in Ahvaz.

MATERIALS AND METHODS

Blood specimens from 128 neonates (younger than 90 days), including 56 (43.75%) girls and 72 (56.25%) boys, were collected from hospitalized neonates with clinical signs and symptoms of sepsis-like symptoms. All blood samples were negative for bacterial culture. RNA was extracted from all sera and tested for detection of 5'UTR (Untranslated Region) of the EV by RT-PCR. To determine specific strains of EV, positive 5'UTR samples were further tested for detection of the VP1 region of EV by RT-PCR.

RESULTS

Overall, 50/128 (39.06%) specimens, including 24 (48%) girls and 26 (52%) boys, were positive for EV. 21/50 (42%) specimens were positive for the VP1 region. Randomly, 8 positive VP1 were selected and sequenced. Analysis of sequencing data showed 7/21 (33.33%) samples were positive for Echovirus 30 and 1/21 (4.76%) samples were positive for CVA9.

CONCLUSION

The results of this survey indicate high prevalence of 39.06% of EV among young neonates with sepsis. A high prevalence of 33.3% Echoviruses 30 and a low rate of 4.76% coxsackievirus A9 infection has been observed in neonatal patients with viral sepsis. This outbreak is probably one of the first Enterovirus outbreaks to be reported in Ahvaz, Iran. The results of this survey will help to minimize unneeded use of antimicrobial drugs and reduce unnecessary hospitalization.

Analysis of enterovirus types in patients with symptoms of aseptic meningitis in 2014 in Shandong, China

We reviewed the epidemiological and clinical characteristics of 927 aseptic meningitis patients in Shandong in 2014, and the phylogeny of predominant enterovirus (EV) types causing this disease was analyzed. A total of 209 patients that were positive for EV were identified by both cell culture and a reverse transcription-seminested PCR in cerebrospinal fluid samples. The positive patients were most likely to be children within 15 years of age, had symptoms such as fever, vomiting and nausea (P＜ .05). The 209 EV sequences belonged to 11 types, and coxsackievirus B5, echovirus types 6 and 30 were predominant types. VP1 analysis exhibited multiple lineages were co-circulating. The significance of the study could come from the fact that surveillance is important to monitor the prevalence of EV types in population, which shows enterovirus meningitis maintains an important public health problem in China.

Neonatal nonpolio enterovirus and parechovirus infections

Nonpolio enteroviruses and parechoviruses are frequent causes of neonatal infection. Clinical manifestations of infection range from asymptomatic infection to mild infection without sequelae to septic shock with muiltiorgan failure. Neonates with clinically apparent infection typically have mothers and/or other contacts with recent symptoms consistent with a viral illness. Severe neonatal infection with nonpolio enterovirus or parechovirus cannot be differentiated clinically from serious bacterial infection. The preferred method for diagnosing neonatal nonpolio enterovirus or parechovirus infection is PCR as it is rapid, sensitive, specific, and commercially available for the detection of virus from various clinical specimens. Investigational agents such as the capsid inhibitors pleconaril and pocapavir show promise for treatment of neonatal enterovirus infections, and other investigational agents are being developed. This review focuses on the epidemiology, diagnosis, and treatment of neonatal nonpolio enterovirus and parechovirus infections.

Clinical features and seasonality of parechovirus infection in an Asian subtropical city, Hong Kong

BACKGROUND

The epidemiology of human parechovirus (HPeV) in Asia remains obscure. We elucidated the prevalence, seasonality, type distribution and clinical presentation of HPeV among children in Hong Kong.

METHODS

A 24-month prospective study to detect HPeV in children ≤36 months hospitalized for acute viral illnesses.

RESULTS

2.3% of the 3911 children examined had HPeV infection, with most (87.5%) concentrated in September-January (autumn-winter). 81.3% were HPeV1 and 12.5% were HPeV4, while HPeV3 was rare (2.5%). HPeV was a probable cause of the disease in 47.7% (42/88), mostly self-limiting including acute gastroenteritis, upper respiratory tract infection and maculopapular rash. A neonate developed severe sepsis-like illness with HPeV3 as the only pathogen detected. A high proportion (60.0%) of children coinfected with HPeV and other respiratory virus(es) had acute bronchiolitis or pneumonia. Six children with HPeV coinfections developed convulsion / pallid attack. Most rash illnesses exhibited a generalized maculopapular pattern involving the trunk and limbs, and were more likely associated with HPeV4 compared to other syndrome groups (36.4% vs. 3.1%, p = 0.011).

CONCLUSIONS

In Hong Kong, HPeV exhibits a clear seasonality (autumn-winter) and was found in a small proportion (2.3%) of young children (≤36 months) admitted with features of acute viral illnesses. The clinical presentation ranged from mild gastroenteritis, upper respiratory tract infection and febrile rash to convulsion and severe sepsis-like illness. HPeV3, which is reported to associate with more severe disease in neonates, is rare in Hong Kong. HPeV coinfection might associate with convulsion and aggravate other respiratory tract infections.

Human parechovirus type 3 infection: An emerging infection in neonates and young infants

Human parechoviruses (HPeVs) are RNA viruses that have characteristics similar to those of enteroviruses and usually cause mild respiratory or gastrointestinal symptoms. Human parechovirus type 3 (HPeV3), first reported in 2004, is exceptional because it can provoke sepsis and meningoencephalitis leading to neurological sequelae, and even death, in neonates and young infants. Pediatricians and researchers are increasingly aware that HPeV3 is responsible for serious disease in neonates and young infants. Retrospective studies and several reports of epidemics of HPeV3 infection have provided data on epidemiology, clinical symptoms and signs, laboratory findings, and outcomes. However, the pathogenesis of HPeV3 infection remains unclear, which explains the lack of specific antiviral therapy and effective prevention measures. Maternal antibodies are important in protection against severe HPeV3-related disease, and this may be a clue regarding its pathogenesis. HPeV3 epidemics are likely to continue, and because the clinical manifestations of HPeV3 are severe, determining the pathogenesis of HPeV3 infection and establishing specific antiviral therapies are important goals for future research.