An Emerging Human Parechovirus Type 5 Causing Sepsis-Like Illness in Infants in Australia.

Human parechovirus (HPeV), particularly type 3 (HPeV3), is an important cause of sepsis-/meningitis-like illness in young infants. Laboratory records identified a total of ten HPeV-positive cases in Southeastern Australia between January and July 2019. The HPeV present in these cases were typed by Sanger sequencing of the partial viral capsid protein 1 (VP1) region and selected cases were further characterised by additional Sanger or Ion Torrent near-full length virus sequencing. In seven of the ten cases, an HPeV type 5 (HPeV5) was identified, and in the remaining three cases, an HPeV type 1 was identified. The HPeV5-positive cases were infants under the age of 3 months admitted to hospital with fever, rash, lethargy and/or sepsis-like clinical signs. Near full-length virus sequencing revealed that the HPeV5 was most likely a recombinant virus, with structural genes most similar to an HPeV5 from Belarus in 2018, and a polymerase gene most similar to an HPeV3 from Australia in 2013/14. While HPeV5 is not typically associated with severe clinical signs, the HPeV5 identified here may have been able to cause more severe disease in young infants through the acquisition of genes from a more virulent HPeV.

Rhinoviruses and Their Receptors.

Human rhinoviruses (RVs) are picornaviruses that can cause a variety of upper and lower respiratory tract illnesses, including the common cold, bronchitis, pneumonia, and exacerbations of chronic respiratory diseases such as asthma. There are currently > 160 known types of RVs classified into three species (A, B, and C) that use three different cellular membrane glycoproteins expressed in the respiratory epithelium to enter the host cell. These viral receptors are intercellular adhesion molecule 1 (used by the majority of RV-A and all RV-B types), low-density lipoprotein receptor family members (used by 12 RV-A types), and cadherin-related family member 3 (CDHR3; used by RV-C). RV-A and RV-B interactions with intercellular adhesion molecule 1 and low-density lipoprotein receptor glycoproteins are well defined and their cellular functions have been described, whereas the mechanisms of the RV-C interaction with CDHR3 and its cellular functions are being studied. A single nucleotide polymorphism (rs6967330) in CDHR3 increases cell surface expression of this protein and, as a result, also promotes RV-C infections and illnesses. There are currently no approved vaccines or antiviral therapies available to treat or prevent RV infections, which is a major unmet medical need. Understanding interactions between RV and cellular receptors could lead to new insights into the pathogenesis of respiratory illnesses as well as lead to new approaches to control respiratory illnesses caused by RV infections.

Molecular Epidemiology of the Human Rhinovirus Infection in Mongolia during 2008-2013.

Rhinovirus infections are common in all age groups world-wide, and they occur throughout the year. In this study, we examined 2,689 nasopharyngeal swabs collected in Mongolia during 2008-2013. Human rhinoviruses (HRVs) were detected in 295 (11.0%) samples, and 85 (28.8%) patients were co-infected with other respiratory viruses. HRV was co-detected with bocavirus, human coronavirus, and respiratory syncytial virus in 21 (24.7%), 17 (20.0%), and 14 (16.5%), respectively. We tested 170 (57.6%) of the 295 HRV-positive samples: 117 HRV strains were typed by using the VP4/VP2 method and 53 by using 5' UTR method. We found HVR-A, HVR-C, and HVR-B infections in 80 (47.1%), 76 (44.7%), and 14 (8.2%) samples, respectively.

Clinical relevance of positive human parechovirus type 1 and 3 PCR in stool samples.

Human parechoviruses (HPeV) cause symptoms ranging from severe neonatal infections to mild gastrointestinal and respiratory disease. Use of PCR and genotyping has markedly improved the detection rate of HPeV but has simultaneously raised questions about the clinical relevance of positive tests. This retrospective study correlates positive HPeV1 or HPeV3 PCR tests in stools from children with their symptoms to determine clinical relevance. Children with HPeV1- or HPeV3-positive stool samples, as detected by real time RT-PCR and direct genotyping, between 2004 and 2008 were selected. Clinical data were retrospectively collected from the patient's files and results were compared. One hundred and thirty-eight children with positive HPeV1 (n = 112) or HPeV3 (n = 26) stool samples were identified. Significantly more HPeV3-infected children were neonates or infants younger than 6 months of age. Meningitis or sepsis-like illnesses were diagnosed most frequently and were found in significantly younger children. Almost half of HPeV1-infected children had an underlying disease. Mild gastrointestinal disease was seen most frequently in these children. There was no clear correlation between viral load (Ct value) and severity of symptoms. In conclusion, HPeV3 detected by PCR in stool samples is associated with clinically relevant disease. For HPeV1, a positive stool sample is mainly associated with symptoms in children with underlying disease.

Hepatitis A bifásica en niños colombianos: reporte de nueve casos y revisión de la literatura / Biphasic hepatitis A in colombian children: report of nine cases and literature review

La hepatitis A tiene una prevalencia o incidencia en los países en desarrollo de 50 a 100 por cada 100000 personas. La presentación atípica de la hepatitis A bifásica, es rara. El objetivo es presentar 9 casos de niños con hepatitis A bifásica. Se estudiaron nueve niños de edades comprendidas entre los 7 y 13 años (edad media 8,6 años); 5 varones con antecedentes de fiebre, vómito, ictericia, dolor abdominal y coluria de 3 a 5 días de evolución, e IgM para la hepatitis A (IgM VHA) positivo. Después de un mes de evolución asintomáticos, se volvieron a presentar iguales manifestaciones clínicas del primer episodio, con la presencia de IgM VHA positiva otra vez. La media de las pruebas de función hepática en el segundo cuadro fueron: ALT 1258 U/L,AST 986 U/l, bilirrubina directa 5,87 mg/dl, y fosfatasa alcalina 580 U/L. En ninguno se informó anomalías a la ecografía abdominal y la serología de hepatitis autoinmune fue negativa. No hubo morbilidad en los niños. La hepatitis agudaApuede tener entre un 3% a 20% de casos con más de un pico de aminotransferasas, que se eleva entre las 2 y 8 semanas después del primer cuadro. Las hipótesis para explicar ello, son fenómenos de reinfección y autoinmunes. En general, la evolución es satisfactoria.

Hepatitis A has a prevalence or incidence in developing countries from 50 to 100 per 100,000 people. The atypical presentation of biphasic hepatitis A, is rare. The objective was to report 9 cases of children with biphasic hepatitis A. We studied 9 children aged between 7 and 13 years (mean age 8.6 years), including 5 males with a history of fever, vomiting, jaundice, abdominal pain, and coluria for about 3 to 5 days of evolution, and IgM to hepatitisA(IgMVHA) positive. After a mean month evolution asymptomatic, again showed the same clinic manifestations for the second time in the presence of IgM VHA positive again. The median liver function tests in the second frame were ALT 1258 U/L, AST 986 U/L, direct bilirubin 5.87 mg/dL, FA 580 U/L. In all reported no abdominal ultrasound abnormalities and autoimmune hepatitis serology was negative. There was no morbidity in children. Acute hepatitisAcan take on 3%-20% of cases with more than 1 peak of aminotransferases, which can be raised between 2 and 8 weeks after the first frame. Hypotheses to explain this, are reinfection and autoimmune phenomena. In general, evolution is satisfactory.

Isolation and characterization of novel human parechovirus from clinical samples.

Using Vero cells, we isolated a virus (NII561-2000) from a cerebrospinal fluid specimen of a 1-year-old girl with Reye syndrome. The determined amino acid sequence of the virus indicated that the isolate was a human parechovirus (HPeV), a member of Picornaviridae. Neutralization test showed that the NII561-2000 virus had distinct antigenicity to HPeV-1, HPeV-2, and HPeV-3, and that the sequence was distinct from these types as well as from HPeV-4 and HPeV-5. Thus, we propose the virus (NII561-2000) as the prototype of HPeV-6. We isolated 10 NII561-2000-related viruses, 14 HPeV-1, 16 HPeV-3, and 1 HPeV-4 of 41 HPeVs from various clinical samples collected in Niigata, Japan. Clinical symptoms of the persons infected with the NII561-2000-related viruses were infectious gastroenteritis, rash, upper respiratory tract infection, and paralysis, in addition to Reye syndrome in the 1-year-old girl.