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To the Editor: The picornaviruses constitute a large, diverse family of positive-sense RNA viruses, which comprise 8 genera: Enterovirus, Aphthovirus, Cardiovirus, Hepatovirus, Parechovirus, Erbovirus, Kobuvirus, and Teschovirus (1). The genus [...]

To establish an animal model for the newly identified Marmota Himalayana hepatovirus, MHHAV, so as to develop a better understanding of the infection of hepatitis A viruses. Five experimental woodchucks (Marmota monax) were inoculated intravenously with the purified MHHAV from wild woodchuck feces. One animal injected with PBS was defined as a control. Feces and blood were routinely collected. After the animals were subjected to necropsy, different tissues were collected. The presence of viral RNA and negative sense viral RNA was analyzed in all the samples and histopathological and in situ hybridization analysis was performed for the tissues. MHHAV infection caused fever but no severe symptoms or death. Virus was shed in feces beginning at 2 dpi, and MHHAV RNA persisted in feces for ~2 months, with a biphasic increase, and in blood for ~30 days. Viral RNA was detected in all the tissues, with high levels in the liver and spleen. Negative-strand viral RNA was detected only in the liver. Furthermore, the animals showed histological signs of hepatitis at 45 dpi. MHHAV can infect M. monax and is associated with hepatic disease. Therefore, this animal can be used as a model of HAV pathogenesis and to evaluate antiviral and anticancer therapeutics. [ABSTRACT FROM AUTHOR]

GII.2[P16] noroviruses (NoV) reemerged and rapidly became the main epidemic strain in acute gastroenteritis (AGE) outbreaks in Asian countries since 2016. The current GII.2 [P16] NoV showed the same antigenicity to the ones before 2016, but several unique amino acid substitutions existed in the RNA dependent RNA polymerase (RdRp) and other non-structural proteins, and the viral load of the current GII.2[P16] NoV was higher than those of other genotypes, it was estimated that the viral replication ability may have improved. However, other genotypes, such as GII.1 and GII.3, also had recombination with the novel RdRp, were not prevalent in AGE-outbreaks; thus, it was inferred that the capsid proteins also played an important role in the enhanced replication process. The viral infection could also be affected by other factors, such as the population genetic background, the climate and environment, and people's lifestyles. Continued surveillance on genetic diversity and evolutionary pattern for the GII.2[P16] NoV is necessary., (Copyright and License information: Editorial Office of CCDCW, Chinese Center for Disease Control and Prevention 2022.)

Porcine sapoviruses (SaVs), which belong to the family Caliciviridae, have been considered potential zoonotic agents for human infection, and several cases have been reported in Asian countries. In this study, a total of 200 porcine fecal samples collected from Lulong county of China were tested. Among 200 samples, porcine sapoviruses were detected by RT-PCR in 17 samples (8.5%) showing their circulation in China. 14 out of 17 positive sapovirus strains were genetically related to the genogroup III (GIII) and were further divided into three different clusters or genotypes according to the phylogenetic analysis. In addition, the remaining three sapovirus strains belonged to GVII (one strain) and a potential novel genogroup (two strains) according to the phylogenetic analysis and the nucleotide identity and amino acid identity. These data suggested the genetic diversity of porcine sapoviruses in China.

From November 2008 to January 2009, a sharp increase of diarrhea in children in Guangdong province appeared, we randomly collected 53 stool specimens from out-patient children with dirrhea in 3 major hospitals (Guangzhou City Children's Hospital, Shenzhen Baoan District Maternal and Child Health Hospital, First Affiliated Hospital of Shantou University). Rotavirus and calicivirus were screened by ELISA and RT-PCR. We found 29 cases of rotavirus infection with diverse serotypes. Only four cases were identified as calicivirus infection. The result indicated that rotavirus was a major pathogen of this high incidence of diarrhea from November 2008 to January 2009 in Guangdong Province.

Objective: To sequence the complete sequence of bocavirus I with sequence independent single primer amplification (SISPA-PCR)., Methods: To exclude the co-effection samples, all clinical samples of diarrhea cases were screened with special primers of rotavirus, astrovirus, adenovirus, calicivirus and bocavirus I. The virus were enriched through ultracentrifugation. Other nucleic acids, such as human and bacteria genomes, were degradated by DNase I and RNase. DNA of bocavirus was Amplificated with SISPA-PCR, then purificated, cloned and sequenced. The sequences were alighmented in nr with blastn and assembled with DNAstar., Results: A 4834bp sequence of bocavirus I were assembled., Conclusion: SISPA-PCR is an economical and efficient technique for sequence a virus complete genome.

Objective: To detect human parechovirus (HPeV) from stool samples of hospitalized children for acute gastroenteritis of undetectable etiology., Methods: We conducted a real-time PCR to detect HPeV., Result: The results showed that 24 of 99 (24%) children with gastroenteritis of undetectable etiology were detected with HPeV. Four known HPeV types (HPeV1, 3, 4, 6) were detected in the present study. HPeV1 (50%) was frequently identified as the predominant strain and follow by HPeV3 (25%), HPeV4 (8.3%) and HPeV6 (4.2%). We were unable to type 3 samples., Conclusion: HPeV was prevalent in hospitalized children for acute gastroenteritis of undetectable etiology in China. Further study is needed for clarifying the role of HPeV in gastroenteritis.

Two Rotavirus G9P[8] strains (LL52696 and LL52727) were recognized during a sentinel-based survey in Lulong, China. Phylogenetic analysis of the VP7 gene showed that both strains isolated constituted a divergent genetic cluster distinct from the other G9 strains isolated in China. Analysis of VP4, VP6, and NSP4 genes revealed that these strains were closely related to Lulong strains. We hold that two strains were reassortant between G9 and Lulong predominant strains.

Objective: To analyze epidemiological characters of an outbreak of rotavirus diarrhea in Daxing County, Guangxi Province., Methods: Rotavirus-positive specimens were identified by ELISA kit. G/P typing assays were confirmed with multiplex seminested RT-PCR. Full-length VP7 genes of 4 positive specimens were amplified and analyzed., Results: 30 cases of Rotavirus-positive were identified from 64 specimens. The attack rate was 46.9%, and G/P typing was G1P[8]. A change of VP7 amino acid residue is at positions 68., Conclusion: G1P[8] rotavirus is the etiologic agents of this diarrhea outbreak. In addition, adults were included in this outbreak.

To construct a helper-dependent adenoviral vector expressing human respiratory syncytial virus (RSV) subgroup A F gene, and finish large scale preparation, purification and identification of the vector. F gene under the control of CMV promoter was subcloned into a shutle vector pSC11, and then cloned into HADd plasmid pSC15B. The HDAd/F genome was liberated by removing the bacterial sequences from the resulting plasmid pSC15B/F digested with restriction enzyme Pme I, and then the linear HDAd/F DNA was transfected into 293Cre4 cells with calcium phosphate transfection method. The cells were infected by helper virus 16 hours after transfection. HDAd/F was amplified by serial coinfection of 293Cre4 cells by helper virus and the crude lysates from previous passage until it reached plateau of amplification by BFU staining of parallel amplified control vector pSC9A. HDAd/F was purified by CsCl gradient ultracentrifugation and expression of F protein was identified by RT-PCR and Western blot. HDAd/F was constructed, purified successfully. The expression of F protein was detected. The successful construction and preparation of HDAd/F is the foundation for the further investigation of potential immune protection in vivo and opens a new window for the RSV vaccine research.