Diversity of human parechoviruses isolated from stool samples collected from Thai children with acute gastroenteritis

Diversity of picornaviruses detected in diarrheal samples from children in Belém, Brazilian Amazon (1982-2019)

In this investigation, fecal specimens from children with diarrhea were collected from four community studies conducted between 1982 and 2019 in Belém, Brazilian Amazon. A total of 234 samples were tested by quantitative reverse transcription polymerase chain reaction (RT-qPCR) to detect infections by picornaviruses of the Enterovirus (EV), Parechovirus (HPeV), Cosavirus (HCoSV), Kobuvirus (Aichivirus - AiV) and Salivirus (SalV) genera. The positive samples were subjected to different amplification protocols of the VP1 region of the genome, such as nested PCR or snPCR, and were subsequently genotyped by sequencing VP1 and VP3 of the viral genome. Positivity was observed in 76.5% (179/234) of the samples tested using RT-qPCR for at least one virus, and co-infection was observed in 37.4% (67/179) of the cases. EV was detected in 50.8% (119/234), HPeV in 29.9% (70/234), HCoSV in 27.3% (64/234), and AiV/SalV in 2.1% (5/234) of the specimens tested by RT-qPCR. Using nested PCR and/or snPCR techniques, the positivity rates were 94.11% (112/119) for EV, 72.85% (51/70) for HPeV, and 20.31% (13/64) for HCoSV. It was not possible to amplify the samples that were positive for AiV/SalV. Sequencing revealed 67.2% (80/119) EV, 51.4% (36/70) HPeV, and 20.31% (13/64) HCoSV. Forty-five different types of EV were found among species A, B, and C; HCoSV identified five species, including a possible recombinant strain; all HPeV were identified as belonging to species A, in two samples a possible recombination involving three different strains was verified. This study demonstrated the high circulation and diversity of different types of picornaviruses in fecal samples, including those collected more than 30 years ago. This endorsed the evaluation of important points in the epidemiology of these viruses, such as the presence of co-infection and the possibility of knowing more about these agents, considering that some were recently described; therefore, their detection in older samples can provide more data about their ancestry.

Viral pathogens of acute gastroenteritis in Egyptian children: role of the parechovirus

BACKGROUND AND AIM

Human parechovirus (HPeV) has emerged as a pathogen associated with acute gastroenteritis (AGE).

AIM

To detect the presence of HPeV in the stool samples from Egyptian children with AGE seeking care and the possibility of its co-infection with other enteric viruses.

METHODOLOGY

One hundred stool samples were collected from children attending Mansoura University Children's Hospital with AGE. HPeV and astrovirus were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). At the same time, detection of rotavirus antigen and norovirus was achieved by enzyme-linked immunosorbent assay and rapid immunochromatographic method, respectively.

RESULTS

The most frequently detected virus was rotavirus (39%), followed by norovirus (27%), HPeV (19%), and astrovirus (12%). Interestingly, the single infection with HPeV was 5%. Among the 19 HPeV positive samples, the co-infection of HPeV with other enteric viruses was detected in 9(43.9%) for rotavirus, 7(36.8%) for norovirus, 2(10.5%) for astrovirus, in 3(15.8%) for rotavirus and norovirus and 1(5.3%) for norovirus and astrovirus. Regarding the clinical presentation, there was no significant difference between children infected with HPeV alone and those infected with viruses other than HPeV alone; fever (p = 0.3), vomiting (p = 0.12), abdominal pain (p = 0.12), and grades of severity (P = 0.82). HPeV alone infected children were of mild severity (60%), and their main presenting symptom was fever (60%).

CONCLUSIONS

Detection of HPeV as a single viral pathogen in the stool of some children with AGE showed that this virus could be a causative agent of AGE in Egyptian children. Therefore, HPeV could be included as one of the viruses screened for AGE diagnosis in children in Egypt.

Parechovirus A Infections in Healthy Australian Children During the First 2 Years of Life: A Community-based Longitudinal Birth Cohort Study

Background

Hospital-based studies identify parechovirus (PeV), primarily PeV-A3, as an important cause of severe infections in young children. However, few community-based studies have been published and the true PeV infection burden is unknown. We investigated PeV epidemiology in healthy children participating in a community-based, longitudinal birth cohort study.

Methods

Australian children (n = 158) enrolled in the Observational Research in Childhood Infectious Diseases (ORChID) study were followed from birth until their second birthday. Weekly stool and nasal swabs and daily symptom diaries were collected. Swabs were tested for PeV by reverse-transcription polymerase chain reaction and genotypes determined by subgenomic sequencing. Incidence rate, infection characteristics, clinical associations, and virus codetections were investigated.

Results

PeV was detected in 1423 of 11 124 (12.8%) and 17 of 8100 (0.2%) stool and nasal swabs, respectively. Major genotypes among the 306 infection episodes identified were PeV-A1 (47.9%), PeV-A6 (20.1%), and PeV-A3 (18.3%). The incidence rate was 144 episodes (95% confidence interval, 128–160) per 100 child-years. First infections appeared at a median age of 8 (interquartile range, 6.0–11.7) months. Annual seasonal peaks changing from PeV-A1 to PeV-A3 were observed. Infection was positively associated with age ≥6 months, summer season, nonexclusive breastfeeding at age <3 months, and formal childcare attendance before age 12 months. Sole PeV infections were either asymptomatic (38.4%) or mild (32.7%), while codetection with other viruses in stool swabs was common (64.4%).

Conclusions

In contrast with hospital-based studies, this study showed that diverse and dynamically changing PeV genotypes circulate in the community causing mild or subclinical infections in children.

Parechovirus can cause severe illnesses in children. However, studies focus mainly on hospitalized populations. True disease burden in the community remains largely unknown. From our community-based cohort, we found diverse parechovirus genotypes in the community, causing mild or subclinical infections in children.

Genetic diversity of Parechovirus A in infants and children with acute gastroenteritis in Japan during 2016-2018

Parechovirus A (PeV-A), previously known as human parechovirus, is a common pathogen in children that can cause respiratory and gastrointestinal diseases as well as severe neurological disease. Take advantage of our previous findings on the genetic diversity of PeV-A circulating in Japanese children with acute gastroenteritis (AGE), this study was conducted to investigate the genetic diversity of PeV-A isolated from children with AGE in Japan as well as their clinical symptoms. Of 1070 stool samples collected from Japanese infants and children with AGE during the 2-year period from July 2016 to June 2018, 76 were positive for PeV-A by multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) and were subjected to genotyping based on viral protein 1 (VP1) sequences. Five different PeV-A genotypes including PeV-A1B, -A2, -A3, -A4, and -A6 were detected with predominant of PeV-A1 clade B genotype. This study revealed a high genetic diversity of PeV-A circulating in Japanese infants and children with AGE and the PeV-A2, a rare genotype, was detected for the first time in Japan in patients with AGE. The clinical symptoms observed in these patients included diarrhea, vomiting, fever, cough, rhinorrhea, and dehydration.

Viral Etiology of Acute Gastroenteritis in <2-Year-Old US Children in the Post-Rotavirus Vaccine Era

BACKGROUND

The rotavirus disease burden has declined substantially since rotavirus vaccine was introduced in the United States in 2006. The aim of this study was to determine the viral etiology of acute gastroenteritis (AGE) in US children aged <2 years.

METHODS

The New Vaccine Surveillance Network (NVSN) of geographically diverse US sites conducts active pediatric population-based surveillance in hospitals and emergency departments. Stool samples were collected from children aged <2 years with symptoms of AGE (n = 330) and age-matched healthy controls (HCs) (n = 272) between January and December 2012. Samples were tested by real-time reverse-transcriptase polymerase chain reaction assays {adenovirus (type 40 and 41), norovirus, parechovirus A, enterovirus, sapovirus, and astrovirus} and an enzyme immunoassay (rotavirus). All samples that tested positive were genotyped.

RESULTS

Detection rates of pathogens in children with AGE versus those of HCs were, respectively, 23.0% versus 6.6% for norovirus (P < .01), 23.0% versus 16.0% for adenovirus (P = .08), 11.0% versus 16.0% for parechovirus A (P = .09), 11.0% versus 9.0% for enterovirus (P = .34), 7.0% versus 3.0% for sapovirus (P = .07), 3.0% versus 0.3% for astrovirus (P = .01), and 3.0% versus 0.4% for rotavirus (P = .01). A high prevalence of adenovirus was detected at 1 surveillance site (49.0% for children with AGE and 43.0% for HCs). Norovirus GII.4 New Orleans was the most frequently detected (33.0%) norovirus genotype. Codetection of >1 virus was more common in children with AGE (16.0%) than in HCs (10.0%) (P = .03).

CONCLUSIONS

Norovirus, astrovirus, sapovirus, and rotavirus were detected significantly more in children with AGE than in HCs, and norovirus was the leading AGE-causing pathogen in US children aged <2 years during the year 2012.

Highly sensitive parechovirus CODEHOP PCR amplification of the complete VP1 gene for typing directly from clinical specimens and correct typing based on phylogenetic clustering

PURPOSE

Human parechoviruses (HPeVs), particularly type 3, can cause severe neurological disease and neonatal sepsis in infants. HPeV3 lacks the receptor-binding motif arginine-glycine aspartic acid (RGD), and is proposed to use a different receptor associated with severe disease. In contrast, HPeV1, which contains the RGD motif, is associated with mild disease. Rapid characterization of the presence/absence of this motif is essential for understanding their epidemiology and differential disease profiles. Current HPeV typing assays are based on partial capsid genes and often do not encompass the C-terminus where the RGD region is localized/absent. In addition, these assays lack sensitivity to enable characterization within low viral-load samples, such as cerebral spinal fluid.

METHODOLOGY

We developed a highly sensitive HPeV CODEHOP PCR, which enables typing of parechoviruses directly from clinical samples while generating a complete VP1 gene, including the C-terminus.

RESULTS

The assay was HPeV-specific and has a sensitivity of 6.3 TCID50 ml^-1 for HPeV1 and 0.63 TCID50 ml^-1 for HPeV3. Analysis of the complete VP1 gene in comparison to partial VP1 fragments generated by previously published PCRs showed homologous clustering for most types. However, phylogenetic analysis of partial VP1 fragments showed incongruent typing based on the 75  % homology classification rule. In particular, the strains designated as type 17 were found to be either type 3 or 4 when using the (near-) complete VP1 fragment.

CONCLUSION

While enabling sensitive characterization of HPeVs directly from clinical samples, the HPeV CODEHOP PCR enables the characterization of RGD and non-RGD strains and correct HPeV typing based on the complete VP1.

Molecular epidemiology and genetic diversity of human parechoviruses in children hospitalized with acute diarrhea in Thailand during 2011-2016

Little is known about human parechovirus (HPeV) infection in Thailand. The genotype distribution of HPeV strains in children admitted to hospitals with acute gastroenteritis was investigated using polymerase chain reaction (PCR) and nucleotide sequencing of the VP1 region as the detection and genotype identification methods, respectively. Of a total of 2,002 stool samples, 49 (2.4%) were positive for HPeV. Of these, HPeV-1 was the most predominant genotype (40.8%), followed by HPeV-3 (16.3%) and HPeV-14 (16.3%), while HPeV-5, -6, -2, -4, and -8 strains were less frequently detected, at 10.2%, 8.2%, 2%, 2%, and 2%, respectively. HPeV infections were detected throughout the year with the biannual peaks of infection in the rainy (Jun-Jul-Aug) and winter (Nov-Dec-Jan) months in Thailand. Based on VP1 amino acid sequence alignment, the arginyl-glycyl-aspartic acid (RGD) motif was found in HPeV-1, -2, -4, and -6 strains. Additionally, an amino acid insertion at the N-terminus of VP1 was observed in HPeV-4 and HPeV-5 strains. Phylogenetic analysis revealed that small clades of HPeV-1 and HPeV-3 strains emerged in 2016 and 2015, respectively, and dominated in the year of their emergence. The HPeV strains detected in Thailand in this study were most closely related to reference strains from Asia and Europe. The evolutionary rate of HPeV strains was 2.87 × 10^-4 (95% highest posterior density (HPD) 0.10-6.14 × 10^-4) substitutions/site/year. These findings provide information about the genetic diversity and evolutionary dynamics of HPeV genotypes circulating in pediatric patients with acute gastroenteritis in Thailand.

Genetic diversity of human parechoviruses in stool samples, Germany

Human parechoviruses (HPeV) are ubiquitous and mainly occur in early infancy. They are known to cause various clinical manifestations including acute gastroenteritis. To gain insight into the diversity of circulating HPeV genotypes, stool samples from patients (n = 539) with clinical signs of infectious gastroenteritis which showed negative results for other common viral and bacterial enteric pathogens were obtained during three years, 2008 to 2010. Real-time RT-PCR showed HPeV RNA in 34 (6.3%) of the samples. The HPeV detection rate was highest (8.8%) in samples derived from infants and young children under the age of two years. Genotyping was based on VP3/VP1 junction nucleic acid sequences and revealed predominant HPeV-1B (n = 16) and HPeV-3 (n = 12) strains. Those prevailed minor HPeV-6 (n = 3) as well as HPeV-2, -4 and -5 (n = 1, each) strains. To ascertain the assigned HPeV-2 genotype of uncommon strain LPZ04-2008, analysis of complete coding sequences was performed. In complete VP1 analysis strain LPZ04-2008 showed 81.2% nucleic acid identity with HPeV-2 reference strain Williamson. In phylogenetic analysis VP1 of strain LPZ04-2008 clustered with a recent HPeV-2 strain from the UK. Regarding clinical manifestations, severe disease occurred HPeV-1B, -3 and - 6 infections. In conclusion, this paper a high genetic diversity of HPeV in stool samples, including rare strains. The investigation adds data on the whole coding sequences of the rare HPeV-2 strain. Genotyping results confirm previously reported association of more severe illness with HPeV-3 and HPeV-1B strains.

Parechovirus A3 (PeV-A3)-associated myalgia/myositis occurs irrespective of its genetic cluster: a longitudinal molecular epidemiology of PeV-A3 in Yamagata, Japan between 2003 and 2016

No longitudinal molecular epidemiology of parechovirus A3 (PeV-A3) over a decade is available and PeV-A3-associated myalgia/myositis has been reported only in Japan. Thus, we aimed to clarify the longitudinal molecular epidemiology of PeV-A3 with a major focus on the strains detected from PeV-A3-associated myalgia/myositis cases. We performed sequence and phylogenetic analysis for the VP1 region of PeV-A3 strains in Yamagata, Japan, between 2003 and 2016. The phylogenetic analysis indicated that PeV-A3 strains caused PeV-A3-associated myalgia/myositis as well as a variety of infectious diseases, ranging from mild to severe, in subjects ranging from neonates to adults, irrespective of genetic cluster or variations. PeV-A3 strains are causative agents of a variety of human diseases, irrespective of their genetic cluster. Furthermore, we consider that PeV-A3-associated myalgia/myositis may occur, not only in Japan, but also in other countries, as closely related PeV-A3 strains have been circulating around the world.

Microfluidic PCR Amplification and MiSeq Amplicon Sequencing Techniques for High-Throughput Detection and Genotyping of Human Pathogenic RNA Viruses in Human Feces, Sewage, and Oysters

Detection and genotyping of pathogenic RNA viruses in human and environmental samples are useful for monitoring the circulation and prevalence of these pathogens, whereas a conventional PCR assay followed by Sanger sequencing is time-consuming and laborious. The present study aimed to develop a high-throughput detection-and-genotyping tool for 11 human RNA viruses [Aichi virus; astrovirus; enterovirus; norovirus genogroup I (GI), GII, and GIV; hepatitis A virus; hepatitis E virus; rotavirus; sapovirus; and human parechovirus] using a microfluidic device and next-generation sequencer. Microfluidic nested PCR was carried out on a 48.48 Access Array chip, and the amplicons were recovered and used for MiSeq sequencing (Illumina, Tokyo, Japan); genotyping was conducted by homology searching and phylogenetic analysis of the obtained sequence reads. The detection limit of the 11 tested viruses ranged from 10⁰ to 10³ copies/μL in cDNA sample, corresponding to 10¹–10⁴ copies/mL-sewage, 10⁵–10⁸ copies/g-human feces, and 10²–10⁵ copies/g-digestive tissues of oyster. The developed assay was successfully applied for simultaneous detection and genotyping of RNA viruses to samples of human feces, sewage, and artificially contaminated oysters. Microfluidic nested PCR followed by MiSeq sequencing enables efficient tracking of the fate of multiple RNA viruses in various environments, which is essential for a better understanding of the circulation of human pathogenic RNA viruses in the human population.

Analysis of Human Parechovirus Genotypes in Yokohama District from 2000 to 2016

Human parechovirus (HPeV) infections in Yokohama City, Japan, were surveyed from 2000 to 2016. The sequence of the VP1 region of HPeVs was used to construct a phylogenetic tree and to reveal the putative amino acid (aa) sequences. Phylogenetic analysis showed the presence of 3 genotypes in Yokohama City: HPeV1 (25 specimens), HPeV3 (86 specimens), and HPeV4 (2 specimens). HPeV1 was detected nearly every year, with the highest number detected in 2014. HPeV3 was not detected until 2005, but was detected over a 1- or 3-yr period thereafter. HPeV1 was most prevalent from July to November, whereas HPeV3 peaked in July and August each year. HPeV1 was mainly detected in patients with infectious gastroenteritis or respiratory tract infections. In contrast, 87% of HPeV3-positive cases were in patients less than 2 months of age with a viral-induced fever. An analysis of the aa sequence of VP1 revealed a divergence within the same HPeV genotype, which was useful in analyzing the emergence and re-emergence of HPeV infections during the survey period. These findings suggest that molecular analysis of HPeVs may contribute to a better understanding of its epidemiology.

Epidemiology and genetic diversity of human parechoviruses circulating among children hospitalised with acute gastroenteritis in Pune, Western India: a 5-years study

Human parechoviruses (HPeVs) are known to cause various clinical manifestations including acute gastroenteritis. Although HPeV infections and their genotypes have been detected in human patients worldwide, no such reports are available from India to ascertain the association of HPeVs in acute gastroenteritis. The present study was conducted to determine the clinical features and genetic diversity of HPeVs detected in children hospitalised for acute gastroenteritis. Stool specimens (n= 979) collected from children aged ⩽5 years hospitalised for acute gastroenteritis in Pune, western India during January 2006–December 2010 were included. HPeV RNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) (5′UTR) followed by genotyping using VP1 gene-based PCR and phylogenetic analysis. HPeV was detected in 13·9% (136/979) of the cases, co-infections with other enteric viruses were found in 43·4%. HPeV was more frequent in children ⩽1 year age with infections reported throughout the year. A total of 102/136 (75%) HPeV strains were genotyped, which comprised 13 different HPeV genotypes. Of these, HPeV1 was the most predominant genotype detected and phylogenetically clustered with the Harris strain which is rarely reported. The study documents circulation of heterogeneous HPeV genotypes. Two variant strains of HPeV4 and ‘RGD absent’ HPeV5 and 6 strains were also detected. This is the first report of HPeV with diversified genotypes identified in acute gastroenteritis patients from India.

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.

First report of human parechovirus type 3 infection in a pregnant woman

Human parechovirus type 3 (HPeV3) can cause serious conditions in neonates, such as sepsis and encephalitis, but data for adults are lacking. The case of a pregnant woman with HPeV3 infection is reported herein. A 28-year-old woman at 36 weeks of pregnancy was admitted because of myalgia and muscle weakness. Her grip strength was 6.0kg for her right hand and 2.5kg for her left hand. The patient's symptoms, probably due to fasciitis and not myositis, improved gradually with conservative treatment, however labor pains with genital bleeding developed unexpectedly 3 days after admission. An obstetric consultation was obtained and a cesarean section was performed, with no complications. A real-time PCR assay for the detection of viral genomic ribonucleic acid against HPeV showed positive results for pharyngeal swabs, feces, and blood, and negative results for the placenta, umbilical cord, umbilical cord blood, amniotic fluid, and breast milk. The HPeV3 was genotyped by sequencing of the VP1 region. The woman made a full recovery and was discharged with her infant in a stable condition.

Detection of gastroenteritis viruses among pediatric patients in Hiroshima Prefecture, Japan, between 2006 and 2013 using multiplex reverse transcription PCR-based assays involving fluorescent dye-labeled primers

Multiplex reverse transcription (RT)-polymerase chain reaction (PCR)-based assays involving fluorescent dye-labeled primers were modified to detect 10 types of gastroenteritis viruses by adding two further assays to a previously developed assay. Then, these assays were applied to clinical samples, which were collected between January 2006 and December 2013. All 10 types of viruses were effectively detected in the multiplex RT-PCR-based assays. In addition, various viral parameters, such as the detection rates and age distributions of each viral type, were examined. The frequency and types of mixed infections were also investigated. Among the 186 virus-positive samples, genogroup II noroviruses were found to be the most common type of virus (32.7%), followed by group A rotaviruses (10.6%) and parechoviruses (10.3%). Mixed infections were observed in 37 samples, and many of them were detected in patients who were less than 2 years old. These observations showed that the multiplex RT-PCR-based assays involving fluorescent dye-labeled primers were able to effectively detect the viruses circulating among pediatric acute gastroenteritis patients and contributed to the highly specific and sensitive diagnosis of gastroenteritis. J. Med. Virol. 89:791-800, 2017. © 2016 Wiley Periodicals, Inc.

Human parechovirus type 3 infection: Cause of apnea in infants born prematurely

Four infants born prematurely presented with multiple apnea episodes caused by human parechovirus type 3 (HPeV3) infection. All patients required oxygen supplementation, and one patient required mechanical ventilation. HPeV3 infection might be included in the differential diagnosis of apnea in neonates and young infants, especially those born prematurely.

Detection of Human Parechoviruses in Clinical and Municipal Wastewater Samples in Miyagi, Japan, in 2012-2014

In order to study the epidemiology of human parechovirus (HPeV) infections and to evaluate the feasibility of environmental surveillance, we analyzed 281 stool samples, 265 nasopharyngeal swab samples, and 79 municipal wastewater samples for HPeV. The samples were collected in Miyagi Prefecture, Japan, between April 2012 and March 2014. HPeV was detected by reverse-transcription-PCR targeting the partial 5'-untranslated region and was genotyped by sequencing the capsid VP1 region. Seven stool samples (2.5%) and 1 nasopharyngeal swab sample (0.4%), all of which were from children under 2 years old, and 14 wastewater samples (18%) were positive for HPeV. Clear seasonality was observed: all positive samples were collected between July and December during the study period. All strains detected in the stool and wastewater samples had genotype HPeV1, and the strain from the nasopharyngeal swab sample had genotype HPeV6. A phylogenetic analysis revealed that all HPeV1 strains from the stool samples cluster together with those from the wastewater samples, indicating that the HPeV1 strains circulating in human populations can also be detected in municipal wastewater.

Diversity of human parechoviruses in Bulgaria, 2011: Detection of rare genotypes 8 and 10

Human parechovirus (HPeV) infections are commonly asymptomatic but are also found in association with symptoms of the gastrointestinal and respiratory tract, or central nervous system. In order to study their distribution and genetic diversity in Bulgaria, specimens from 229 children aged <5years old hospitalized due to neurological manifestations (n=104) and acute gastroenteritis (n=125) were analyzed. Stool samples were tested using reverse transcription followed by real-time polymerase chain reaction toward the 5'UTR region, and the HPeVs detected were identified by PCR directed to VP1 followed by sequencing. HPeV infection rates of 1.9% and 7.2% were found in children presented with neurological symptoms or with acute diarrhea, respectively. Four different HPeV genotypes, HPeV-3 (n=2), HPeV-5 (n=2), HPeV-8 (n=1) and HPeV-10 (n=1) were identified. All but two HPeVs were detected in acute diarrheal cases, while a single HPeV-3 strain and an HPeV-8 strain were detected in association with facial palsy and encephalitis, respectively. This is the first report of HPeV-8 and HPeV-10 in Europe.

Epidemiology of gastroenteritis viruses in Japan: Prevalence, seasonality, and outbreak

Acute gastroenteritis has been recognized as one of the most common diseases in humans and continues to be a major public health problem worldwide. Several groups of viruses have been reported as the causative agents of acute gastroenteritis, including rotavirus, norovirus, sapovirus, human astrovirus, adenovirus, and an increasing number of others which have been reported more recently. The epidemiology, prevalence, seasonality, and outbreaks of these viruses have been reviewed in a number of studies conducted in Japan over three decades. Rotavirus and norovirus were the two most common viruses detected almost equally in children under 5 years of age who were suffering from acute gastroenteritis. Like many other countries, the main rotavirus strains circulating in pediatric patients in Japan are G1P[8], G2P[4], G3P[8], and G9P[8]. Norovirus GII.4 was involved in most outbreaks in Japan and found to be associated with the emergence of new variants Sydney_2012. The classic human astrovirus, MLB, and VA clades astroviruses were also commonly found in pediatric patients with acute diarrhea. The sapovirus and adenovirus have been identified as the minor viral causative agents for acute gastroenteritis in Japan.

Human Parechovirus 3: The Most Common Viral Cause of Meningoencephalitis in Young Infants

Human parechoviruses (HPeVs) were initially classified as echoviruses. HPeVs occur worldwide, comprising up to 17 genotypes. HPeV1 and HPeV3 are most common. Clinical disease varies somewhat among genotypes. HPeV1 causes mostly gastrointestinal infections. HPeV3's prominence is due to its causing sepsis syndromes and central nervous system (CNS) infections in young infants. Currently, HPeV3 is the most common single cause of aseptic meningitis/meningoencephalitis in infants less than 90 days old in North America, usually with biannual summer-fall seasonality. HPeV3 CNS infections usually lack cerebrospinal fluid pleocytosis. Mortality and sequelae are uncommon, usually accompanying initially severe or neurologically complicated acute illnesses.

A child with acute encephalopathy associated with quadruple viral infection

Pediatric acute encephalopathy (AE) was sometimes attributed to virus infection. However, viral infection does not always result in AE. The risk factors for developing infantile AE upon virus infection remain to be determined. Here, we report an infant with AE co-infected with human herpesvirus-6 (HHV-6) and three picornaviruses, including coxsackievirus A6 (CVA6), Enterovirus D68 (EV-D68), and human parechovirus (HPeV). EV-D68 was vertically transmitted to the infant from his mother. CVA6 and HPeV were likely transmitted to the infant at the nursery school. HHV-6 might be re-activated in the patient. It remained undetermined, which pathogen played the central role in the AE pathogenesis. However, active, simultaneous infection of four viruses should have evoked the cytokine storm, leading to the pathogenesis of AE.

CONCLUSION

an infant case with active quadruple infection of potentially AE-causing viruses was seldom reported partly because systematic nucleic acid-based laboratory tests on picornaviruses were not common. We propose that simultaneous viral infection may serve as a risk factor for the development of AE.

Viral etiologies of acute dehydrating gastroenteritis in pakistani children: confounding role of parechoviruses

Despite substantial interventions in the understanding and case management of acute gastroenteritis, diarrheal diseases are still responsible for a notable amount of childhood deaths. Although the rotavirus is known to cause a considerable burden of pediatric diarrheal cases, the roles of other viruses remain undefined for the Pakistani population. This study was based on tertiary care hospital surveillance, from January 2009 to December 2010, including the detection of rotavirus, norovirus, astrovirus, and human parechovirus in children under the age of five using serological or molecular assays. Rotavirus, human parechovirus, norovirus, and astrovirus were detected in 66%, 21%, 19.5%, and 8.5% subjects, respectively. Human parechovirus genotypes, determined through analysis of VP1 gene sequences, showed a great diversity among co-circulating strains. Eighty percent of hospitalized children had dual or multiple viral infections, while 98% parechovirus positive cases were co-infected with rotavirus. The remarkable diversity of viruses associated with the childhood diarrhea in Pakistan calls for large-scale epidemiological surveys, coupled with case control studies, to ascertain their role in clinical manifestations. In addition, these findings also highlight the need for the implementation of up-to-date health interventions, such as the inclusion of a rotavirus vaccine in routine immunization programs for the improvement of quality in child health care.

Human parechovirus infections and child myositis cases associated with genotype 3 in Osaka City, Japan, 2014

Human parechovirus (HPeV) infects humans early in life and typically causes asymptomatic or mild diseases such as gastrointestinal and respiratory illness but sometimes leads to more serious consequences in neonates and young infants. In 2014, we detected HPeV from 38 patients by real-time reverse transcription-PCR in Osaka City, Japan, and 33 HPeV strains were genotyped based on their VP1 sequences. HPeV genotype 3 (HPeV-3) was the most prevalent and accounted for 22 cases (66.7%) followed by nine HPeV-1 (27.3%), one HPeV-2 (3.0%) and one HPeV-4 (3.0%). Phylogenetic analysis revealed that detected HPeV-3 strains were divided into three genetically distinct groups. One was characterized by a novel single amino acid deletion mutation at the N terminus of the 2A protein as well as the VP1 sequence, whereas the others were closely related to HPeV-3 strains detected in Japan in either 2008 or 2011. These HPeV-3 groups were detected from patients with various symptoms including three myositis cases. Recent papers have demonstrated that HPeV-3 was the aetiological agent for epidemic myalgia exclusively among adults from Yamagata Prefecture in Japan. Here, we provide clinical details and episodes of three myositis patients including an adult and two children in Osaka City, Japan. Our results suggest that HPeV-3 is a causative agent of myositis not only in adults but also in children.

Characteristics of the mosaic genome of a human parechovirus type 1 strain isolated from an infant with pneumonia in China

Human parechoviruses (HPeVs) belong to the Parechovirus genus of the large and growing family of Picornaviridae with a non-enveloped, single-stranded and positive-sense RNA. An HPeV strain was isolated from the nasopharyngeal aspirate specimen of a 2 months old infant hospitalized with pneumonia in Beijing, China and nominated as BJ-37359 followed the code of the specimen. Strain BJ-37359 was identified as HPeV1 by whole genome sequencing. The full genome of strain BJ-37359 consisted of 7336 nucleotides (nt), excluding a poly (A) tail and contained an ORF of 6537 nt flanked by 5'UTR of 709 nt and 3'UTR of 90 nt. Phylogenetic analyses revealed that strain BJ-37359 were clustered together with HPeV1 strains in the structural capsid protein region, while uncoupling in the non-structural gene regions. Analyses with Simplot and Bootscan indicated that multiple recombination events occurred in the non-structural region and VP0 region of strain BJ-37359 with other HPeV1, and other types might have contributed to the recombination, especially HPeV6 and HPeV7 strains. Recombination analyses indicated that strain BJ-37359 may have a mosaic genome with new genomic recombination breakpoints.

Epidemiology of human parechovirus, Aichi virus and salivirus in fecal samples from hospitalized children with gastroenteritis in Hong Kong

BACKGROUND

Emerging human picornaviruses, including human parechovirus (HPeV), Aichi virus (AiV) and salivirus (SalV) were found to be associated with gastroenteritis, but their roles in enteric infections are not fully understood. In addition, no report on the circulation of these viruses in Hong Kong is available. The objective of this study was to investigate the prevalence and genetic diversity of HPeV, AiV and SalV in fecal samples from hospitalized children with gastroenteritis in Hong Kong.

METHODS

Fecal samples from hospitalized children with gastroenteritis were subject to detection of HPeV, AiV and SalV by RT-PCR using consensus primers targeted to their 5'UTRs. Positive samples were subject to capsid and/or 3CD region analysis for genotype determination. The epidemiology of HPeV, AiV and SalV infections was analyzed.

RESULTS

Among 1,708 fecal samples subjected to RT-PCR using primers targeted to 5'UTR of HPeV, AiV and SalV, viruses were detected in 55 samples, with 50 positive for HPeV only, 3 positive for AiV only, 1 positive for both HPeV and AiV, and 1 positive for both HPeV and SalV. Phylogenetic analysis of the partial VP1 gene of the 33 HPeV strains revealed the presence of genotypes of HPeV- 1, 3, 4, 5, 7, 10, among which HPeV-1 was the predominant genotype circulating in our population. The peak activity of HPeV infection was in fall. Of the 3 children with AiV infection, the 3 AiV strains were found to belong to genotype A based on the phylogenetic analysis of their partial VP1 and 3CD regions. The genotype of a SalV strain detected in this study could not be determined. Co-detection of different pathogens was observed in 24 samples (43.6%) of 55 fecal samples positive for HPeV, AiV and SalV.

CONCLUSIONS

HPeV, AiV and SalV were detected in fecal samples of hospitalized children with gastroenteritis in Hong Kong, with the former having the highest prevalence. HPeV-1 was the predominant genotype among HPeVs, while genotype A was the predominant genotype among AiVs in this study.

Detection of diarrheal viruses circulating in adult patients in Thailand

A total of 332 fecal specimens collected during January-December 2008 from adult patients with diarrhea were screened for group A and C rotaviruses, noroviruses GI and GII, sapovirus, Aichi virus, human parechovirus, enterovirus, adenovirus and astrovirus by RT-multiplex PCR. The detection rate for diarrheal viruses was 4.2 %. Adenovirus and enterovirus were equally detected as the most predominant viruses, with prevalence of 1.2 %, followed by Aichi virus (0.9 %) and norovirus GII (0.6 %). Mixed infection with norovirus GII and human parechovirus was also detected (0.3 %). This study provides epidemiological data for a wide variety of diarrheal viruses circulating in adult patients with diarrhea in Chiang Mai, Thailand.

Human parechovirus genotypes -10, -13 and -15 in Pakistani children with acute dehydrating gastroenteritis

Human parechoviruses are known to cause asymptomatic to severe clinical illness predominantly respiratory and gastroenetric infections. Despite their global prevalence, epidemiological studies have not been performed in Pakistan. In this study, we retrospectively analyzed 110 fecal specimen and found 26 (24%) positive for viral RNA with HPeV-10 (n = 3, 23%), HPeV-13 (n = 4, 31%) and HPeV-15 (n = 6, 46%) genotypes. Clinical features of patients with different HPeV genotypes were compared. All HPeV positive children were aged ≤4 years (mean 13.92 months). The male-to-female ratio was 1: 1.17 (46.2 vs 53.8%) with significant association (p = .031) to HPeV infectivity. HPeV-10 and -13 were found during summer while HPeV-15 was only detected during late winter season. Disease symptoms were more severe in children infected with HPeV-10 and -13 as compared to HPeV-15. Fever and vomiting were observed in 100% cases of HPeV-10 and -13 while only 17% patients of HPeV-15 had these complaints. Phylogenetic analyses showed that HPeV-10, -13 and -15 strains found in this study have 9-13%, 16.8% and 21.8% nucleotide divergence respectively from the prototype strains and were clustered to distinct genetic lineages. This is the first report of HPeV-15 infection in humans although first identified in rhesus macaques. The arginine-glycine-aspartic acid (RGD) motif present at the C-terminal of VP1 responsible for the viral attachment to cellular integrins was not found in all of these strains. In conclusion, these findings enhance our knowledge related to the epidemiology and genetic diversity of the HPeV in Pakistan and support the need for continued laboratory based surveillance programs especially in infants and neonatal clinical settings. Further, the parechovirus pathogenesis, cross-species transmission and disease reservoirs must be ascertained to adopt better prevention measures.

Changes in human parechovirus profiles in hospitalized children with acute gastroenteritis after a three-year interval in Lanzhou, China

The changing profile of infection over time for Human Parechoviruses (HPeVs) is not well known and no detailed study has been reported to date in China. This investigation on HPeV infection in hospitalized children in Lanzhou, China revealed variations in epidemiological characteristics after a three-year interval. To assess the changes that had occurred, epidemiological and clinical characteristics of HPeVs were characterized and compared with previously reported data by our group. A comparable positivity rate (25.3%, 73/289) was revealed after the three-year interval with the majority of the infected children (95.9%, 70/73) being younger than two years of age. While a temporal change in the seasonal distribution was noted in the current study, HPeVs were more frequently detected during July to November compared to September to December in the previous study. Changes in HPeV genotypes patterns, a temporal change in the prevalence of HPeV1, a younger susceptible age to HPeV3 compared with HPeV1 and a tendency of older children to be infected with HPeV4 are in contrast to our previous report. HPeV2, a rarely reported genotype, was identified for the first time in China. In addition, an exclusive trinucleotide (GAT) insertion in the HPeV4 nucleotide sequence was identified. However, the profiles of co-infection with other enteric related viruses were similar to our previous findings. In summary, these data suggest temporal variation in the seasonal distribution of HPeV and changing patterns of HPeV genotypes over time in the study region.

Two cases of sepsis-like illness in infants caused by human parechovirus traced back to elder siblings with mild gastroenteritis and respiratory symptoms

Sepsis and sepsis-like illness in neonates and infants are serious emergencies. Recently, human parechovirus type 3 (HPeV-3) has been identified as a further etiologic agent of these conditions. We report two unlinked cases of infant HPeV-3 sepsis-like illness whose sources could be traced back to elder siblings with mild gastroenteritis and respiratory symptoms.

Prevalence of human parechoviruses in central nervous system infections in children: a retrospective study in Shanghai, China

Human parechoviruses (HPeV) are associated with central nervous system (CNS) infections and sepsis-like illnesses. However, data from China are not available. The aim of this study was to determine the prevalence, age, and seasonal distributions and genotypes of HPeV infections in children with CNS related disease in Shanghai, China. Of 776 cerebrospinal fluid (CSF) samples collected from children with CNS-related diseases under the age of 16 years during the years 2008-2011, 68 (9%) were identified to be HPeV positive. The annual prevalence varied remarkably: 1% (2/153) in 2008, 7% (12/177) in 2009, 15% (23/153) in 2010, and 11% (31/293) in 2011. The virus was detected in all age groups of children ranging from 2 days to 13 years and the median age was 14 months. Of the 31 positive samples that were genotyped successfully, 28 were HPeV1 and 3 were HPeV3. This study provided data on the molecular epidemiology of HPeV infections in CNS-related diseases in Shanghai, China and suggest that the screening for HPeV by PCR should be included in the routine viral testing of CSF.

Identification of human parechovirus genotype, HPeV-12, in a paralytic child with diarrhea

BACKGROUND

New genotypes of human parechoviruses have been readily identified after improvement of diverse diagnostic tools. We hereby report the detection of a new genotype, HPeV 12, from a child presented with diarrhea and paralysis.

OBJECTIVES

The genetic variability of human parechoviruses has recently expanded defining 16 genotypes however data available covers only 11 genotypes. The present study was designed to determine the genetic characterization of human parechovirus identified in a child with gastroenteritis and acute flaccid paralysis (AFP).

STUDY DESIGN

Stool samples are referred to Virology Department, NIH-Pakistan for the routine detection of enteroviruses and polioviruses through cell culture and RT-PCR. Five of isolates showing cytopathic effect on L20B cell line but negative for poliovirus were further explored for human parechovirus using multiple cell lines and RT-PCR.

RESULTS

Human Coxsackie A virus type 2, 3, 6 and 20 were found in four samples whereas the fifth sample contained human parechovirus genotype 12. Efficient growth of human parechovirus was found on L20B cells while Vero and LLC-MK2 cells showed no apparent cytopathic effect.

CONCLUSIONS

This study describes the detection of a new human parechovirus genotype (HPeV-12) in a paralytic child with diarrhea. Human parechoviruses are now considered as potential pathogens that may cause a number of serious clinical complications especially in infants and young children. These findings emphasize to conduct large scale epidemiological surveys in the country to understand their association with clinical diseases especially gastroenteritis, respiratory and neurological disorders.

Human Parechovirus and Other Enteric Viruses in Childcare Attendees in the Era of Rotavirus Vaccines

OBJECTIVE

We studied the prevalence of enteric viruses, including rotavirus, enterovirus, norovirus, adenovirus, and human parechovirus (HPeV), in stool samples of childcare attendees. The prevalence of enteric viruses was described in children with and those without gastroenteritis.

METHODS

Children aged 1-19 months were recruited from 2 childcare centers in Tacoma, Washington, from October 2008 through June 2009. Stool samples were obtained at enrollment and during diarrheal illnesses for enteric virus testing. A symptom diary was completed by parents.

RESULTS

One hundred six children (mean age, 10 months) were followed for an average of 170 days. At enrollment, 78 asymptomatic children had stool samples available. Forty-eight illnesses with acute diarrhea (stool samples were available for 24 illnesses) occurred in 37 children. Rotavirus was not detected in samples from symptomatic or asymptomatic children. HPeV was present in 21% and adenovirus in 46% of symptomatic children. At least 1 virus was detected in 78% of samples from asymptomatic children, including HPeV in 27% and adenovirus in 55%. No differences were found in symptom prevalence between HPeV-positive and HPeV-negative diarrheal illnesses. Molecular analysis revealed a diversity of HPeV types.

CONCLUSIONS

Our study highlights the high level of HPeV circulation in childcare. The lack of rotavirus detected in this study supports the impact of rotavirus vaccine and emphasizes the need for a greater focus on the epidemiology of non-rotavirus etiologies of gastroenteritis.

Detection of human rhinovirus C in fecal samples of children with gastroenteritis

Background

Despite recent discovery of the novel human rhinovirus species, HRV-C, little is known about the association of HRV-C in diseases other than respiratory tract infections.

Objectives

To investigate the presence of HRV-C in fecal samples of children with gastroenteritis.

Study design

734 fecal samples from hospitalized children with gastroenteritis were subject to picornavirus detection by RT-PCR of the conserved 5′-NCR. Positive samples were subject to VP4 and 3D^pol gene analysis for species determination. The clinical and molecular epidemiology of HRV-C and other picornaviruses was analyzed.

Results

Picornaviruses were detected in 113 (15.4%) of 734 fecal samples from children with gastroenteritis by RT-PCR of 5′-NCR, with 58 containing potential HRVs and 55 containing other enteroviruses. PCR of the VP4 and 3D^pol regions was positive in 21 and 19 samples respectively (both regions positive in 8 samples). Sequencing analysis showed the presence of HRV-C in four samples, and diverse picornaviruses including HRV-A (n = 2), HEV-A (n = 2), HEV-B (n = 2), HEV-C (n = 21) and HPeV (n = 2) in other samples, with co-detection of HRV-C and HPeV in one sample. Of the four children with HRV-C detected in fecal samples, three presented with diarrhea in the absence of respiratory symptoms, while one also had acute bronchiolitis. The four HRV-C strains from fecal samples belonged to the existing clade of diverse HRV-C genotypes, indistinguishable from previous respiratory strains.

Conclusions

HRV-C can be detected in fecal samples of children with gastroenteritis, in the absence of respiratory symptoms. This study also represented the first to detect HPeV in our population.

Molecular epidemiology, genome characterization, and recombination event of human parechovirus

Human Parechovirus (HPeV), a member of the Picornaviridae family, is an infectious agent mostly affecting children. There are 16 recognized genotypes which have globally spread. This study incorporated a total of 2957 nasopharyngeal (NP) swab and 759 fecal samples that were collected from different parts of Thailand. The NP of HPeV was detected in 0.4% of NP swab and 6.1% of fecal samples. The majority of HPeV infections occur in infants below the age of 2 years, while infections were detected in children above the age of 10 years as well. Various genotypes comprising 1A, 1B, 2, 3, 4, 5, 6, 10 and 14 have been characterized. This study revealed recombination events in 16 samples in which HPeV1B was shown as the highest frequency. In conclusion, HPeV can be detected in both the respiratory and GI tract. Moreover, HPeV which circulates in Thailand is highly diverse and subject to recombination.

Introduction of a novel parechovirus RT-PCR clinical test in a regional medical center

BACKGROUND

Although data documenting the severity and frequency of human parechovirus (HPeV) infections have been published, detection of HPeV is not routinely performed in most clinical virology laboratories.

OBJECTIVE

To describe diagnostic yield, epidemiology and clinical characteristics of patients infected with HPeV during the first year using a new HPeV reverse transcription (RT)-PCR.

STUDY DESIGN

We introduced an HPeV RT-PCR for the routine testing of cerebrospinal fluid (CSF) and blood samples submitted to our clinical laboratory for detection of human enteroviruses (HEV). Prospective testing of samples with retrospective analysis of medical charts was performed.

RESULTS

Of the 499 clinical samples received between May, 2009 and May, 2010, 9.6% (46 patients) had HEV detected and 3.4% (15 patients) had HPeV detected. All patients infected by HPeV were <3 months old, hospitalized between June and October 2009, and all typed viruses were HPeV3. Clinical characteristics of HPeV and HEV infected infants were similar. However, patients infected with HPeV were more likely to have a normal leukocyte count in their CSF (p<0.001). One HPeV3-infected infant developed encephalitis and another developed hepatitis.

CONCLUSION

In our institution, the HPeV RT-PCR was useful to diagnose a novel pathogen in infants with sepsis-like disease.

Human parechovirus 3 causing sepsis-like illness in children from midwestern United States

BACKGROUND

: Human parechovirus (HPeV) infections of the central nervous system (CNS) in children can be associated with severe outcomes such as neonatal sepsis-like illness, meningitis, or paralysis. We sought to determine the prevalence of HPeV CNS infections and clinical presentation in children from the United States.

METHODS

: Frozen nucleic acid extracts from enterovirus-negative cerebrospinal fluid (CSF) obtained at the Children's Mercy Hospitals and Clinics, in Kansas City from 2006 (n = 242), 2007 (n = 324), and 2008 (n = 218) were tested by 2-step HPeV real-time reverse transcription polymerase chain reaction. HPeV genotype was determined by sequencing the VP3/VP1 junction. Demographic and clinical data were abstracted from medical records.

RESULTS

: Overall HPeV was detected in 58/780 (7%) of tested CSF samples; 4/218 (2%) in 2006, 54/320 (17%) in 2007, and 0/242 (0%) in 2008. HPeV (17%) and enterovirus (20%) detection were comparable in 2007. HPeV-3 genotype was detected in 52/53 specimens successfully sequenced. Detection was seasonal (June-October). HPeV-3-CNS-infection occurred at a mean age of 6.6 ± 4.4 weeks and predominantly in males (71%). The most common clinical presentation was sepsis-like syndrome (66%). The most common symptoms were irritability (98%), fever (95%), and nonspecific rash (58.6%), while neurologic manifestations were rare (5%).

CONCLUSIONS

: To our knowledge, this is the first multiyear prevalence report of HPeV CNS infection in the United States. HPeV CNS infection was detected mostly in male infants with sepsis-like illness during the late summer/autumn season. Routine seasonal CSF testing in infants for HPeV plus enterovirus may improve etiologic detection and clinical management of infantile sepsis-like presentations.