Distribution and molecular characterization of saffold virus and human cosavirus in children admitted to hospitals with acute gastroenteritis in Thailand, 2017-2022.

Saffold virus (SAFV) and human cosavirus (HCoSV) are emerging viruses of the Picornaviridae family. They have been shown to associate with gastrointestinal infection and more recently these viruses have also been demonstrated to associate with other clinical infections such as the respiratory tract, cardiovascular system, and the cerebral ventricular system. In this study, 2459 stool specimens collected from pediatric patients admitted to hospitals with acute gastroenteritis from January 2017 to December 2022, were screened for SAFV and HCoSV utilizing reverse transcription-polymerase chain reaction. Positive samples were then characterized into genotypes via nucleotide sequencing and bioinformatic analysis. Of the 2459 samples, 21 and 39 were positive for SAFV (0.9%) and HCoSV (1.6%), respectively. Three genotypes of SAFV were identified-SAFV-1 (38%), SAFV-2 (24%), and SAFV-3 (38%). Two genetic groups of HCoSV were identified-HCoSV-C (97%) and HCoSV-A (3%), demonstrating a large increase of HCoSV-C as compared to those reported previously from the same geographical region in Thailand. This study provides the prevalence of SAFV and HCoSV genotypes in Chiang Mai, Thailand during a period of 6 years from 2017 to 2022.

Near-complete genome of cosavirus A from a child hospitalized with acute gastroenteritis, Brazil.

Acute gastroenteritis (AG) is responsible for 525,000 deaths worldwide in children under-5-years and is caused by the Human Cosavirus (HCoSV; family Picornaviridae, Genus Cosavirus). Although its health importance, a significant percentage of diarrhea cases (≈ 40 %) still of unknown etiology. In Brazil, few studies have reported HCoSV-A sequences analyzing partial 5' UTR. This study characterized the first near-complete genome of a Cosavirus A (strain AM326) from a child hospitalized with AG in Amazonas state, Northern Brazil. High throughput sequencing (HTS) was performed using the HiSeq™ 2500 platform (Illumina) in one fecal specimen collected from the Surveillance of Rotavirus Network of the Evandro Chagas Institute collected in 2017. Sequence reads were assembled by the De Novo approach using three distinct algorithmic (IDBA-UD, Spades, and MegaHit). The final contig was recovered from the HCoSV-AM326 sample revealing 7,735 nt in length (SRA number SRR12535029; GenBank MT023104) and the genetic characterization, as well as phylogenetic analysis demonstrated a new variant strain from Brazil, highlighting the association of HCoSV-A as a possible causative agent of AG. This finding demonstrates the importance of the metagenomic approach to elucidate cases of diarrhea without a defined etiology, as well as providing a better understanding about the virus genetics, evolution and epidemiology.

Molecular detection of enteric viruses in the stool samples of children without diarrhea in Bangladesh.

A number of molecular epidemiological studies reported the detection of enteric viruses in asymptomatic children. The role of these viruses in an asymptomatic infection remains unclear. This study investigated the enteric viruses in the stool samples collected from children without diarrhea. Stool samples were collected during June to October 2016, from 227 children who lived in Matlab, Bangladesh. Seventeen enteric viruses, including rotavirus A, B, and C (RVA, RVB, and RVC), norovirus GI (NoV GI), norovirus GII (NoV GII), sapovirus (SaV), adenovirus (AdV), human astrovirus (HAstV), Aichivirus (AiV), human parechovirus (HPeV), enterovirus (EV), human bocavirus (HBoV), Saffold virus (SAFV), human cosavirus (HCoSV), bufavirus (BufV), salivirus (SalV), and rosavirus (RoV), were investigated by RT-PCR method. One hundred and eighty-two (80.2%; 182/227) samples were positive for some of these viruses, and 19.8% (45/227) were negative. Among the positive samples, 46.7% (85/182) were a single infection, and 53.3% (97/182) were coinfection with multiple viruses. The HCoSV was the most prevalent virus (41.4%), followed by EV (32.2%), NoV GII (25.6%), HPeV (8.8%), RVA (6.2%), AdV (5.7%), AiV (5.3%), SAFV (4.4%), and SaV (2.6%). Each of NoV GI, HAstV, HBoV, and BufV was detected at 0.4%. However, RVB, RVC, SalV, and RoV were not detected in this study. Phylogenetic analysis showed that diverse HCoSV species and genotypes were circulating in Bangladesh, and four strains of species A are proposed to be new genotypes. The data indicated that non-diarrheal Bangladeshi children were asymptomatically infected with wide varieties of enteric viruses.

Occurrence and Genetic Diversity of Human Cosavirus in Sewage in Italy.

Human Cosavirus (HCoSV) is a newly discovered virus whose role in human enteric diseases is still unknown. In Italy, the prevalence and genetic diversity of HCoSV are unexplored. One hundred forty-one raw sewage samples collected throughout Italy were screened for HCoSV by RT-nested PCR. HCoSV was detected in 25.5% of samples. Species A, C, and D, and a potentially new species were detected. Our results show a significant circulation and heterogeneity of HCoSV in Italy.

A novel type of cosavirus from children with nonpolio acute flaccid paralysis.

Human cosavirus (HCoSV) is a genus recently identified in the family Picornaviridae, which contains important pathogens to human health. Here, a novel type of HCoSV strain, cosavirus-zj-1 (GenBank no. KX545380), was identified in the fecal sample of a child with nonpolio acute flaccid paralysis (AFP) in China. Phylogenetic and sequence analyses suggested that this virus strain belonged to a new genotype in HCoSV B species. Our data show that surveillance of HCoSV is necessary for detecting viral agents in children with AFP, despite being the low detection rate.

Detection and molecular characterization of human cosavirus in a pediatric patient with acute gastroenteritis, Japan.

Human cosavirus (HCoSV) is a genus recently identified in the family Picornaviridae, which includes important pathogens in human health. The pathogenicity of HCoSV remains unclear. This study reports that an HCoSV strain, 10928/2012/JPN, was identified and collected from the stool sample of a child with acute gastroenteritis in Japan, with the detection rate of 0.16%. The patient was not co-infected with other common diarrhea-causal viruses, suggesting HCoSV as a causal pathogen in this pediatric patient. Phylogenetic and sequence analyses exhibited that the virus strain was classified as a new genotype in HCoSV A species, and this study is first to detect HCoSV in a clinical specimen collected in Japan. These results showed that surveillance of HCoSV is important for detecting viral agents in children with diarrhea, despite being the low detection rate.

Cytopathic effect of Human cosavirus (HCoSV) on primary cell cultures of human embryonic lung MRC5.

Human cosaviruses (HCoSVs) are newly discovered viruses in Picornaviridae family. Until now, most published studies reported HCoSV detection using molecular techniques and genetic characterization of the virus. Nevertheless, no laboratory has yet reported the replication of these viruses in cultured cell lines. In the present work, the propagation of HCoSV strains isolated from human fecal specimens in MRC5 cell line and their induced cytopathic effects (CPE) was studied. The first sign of virus growth was observed 24-48h after inoculation. The cells rounded up and clumped together rapidly; empty areas became visible and, on the third day of CPE, a remarkable decrease in live cells was observed. This represents the first report on in vitro model of HCoSV replication which opens up opportunities for future investigations of these new viruses.

Occurrence of Human Cosavirus in Wastewater and River Water in Japan.

Human cosavirus was detected using reverse transcription-quantitative polymerase chain reaction in 71 % of raw sewage and 29 % each of secondary-treated sewage and river water samples in the Kofu Basin, Japan. The highest concentration was 2.80 × 10(6) copies/l. Nucleotide sequence analysis revealed multiple genotypes of the virus in wastewater.

Persistent human cosavirus infection in lung transplant recipient, Italy.

Human cosavirus is a novel picornavirus recently identified in feces from children in southern Asia. We report infection with human cosavirus in a patient in the Mediterranean area. The patient was an adult double lung transplant recipient who had chronic diarrhea associated with persistent infection with human cosavirus.

Genetic diversity of cosaviruses in nonpolio acute flaccid paralysis cases of undefined etiology, Northern India, 2010-2011.

BACKGROUND: No cases of wild poliovirus have been reported for more than one and a half years from India. Cases of acute flaccid paralysis (AFP) of undefined etiology continue to occur in the region. Despite the recent discovery of the human Cosavirus (HCoSV) in the feces of children from developing countries, there have been no studies of cosavirus infection in India. OBJECTIVES: To detect and characterize HCoSVs in stool specimens of nonpolio AFP cases by RT-PCR followed by sequencing. STUDY DESIGN: A total of 387 fecal samples collected from AFP cases in Uttar Pradesh, India, between May 2010 and April 2011, tested negative on cell culture according to WHO algorithm, were subjected to 5'-UTR region specific RT-PCR followed by sequencing to detect HCoSV. Molecular characterization of HCoSV strains was done by sequencing followed by phylogenetic analysis. RESULT: 123 (32%) samples tested positive for cosaviruses and 87 (70.7%) were identified for genetic variants by sequencing a 316-nucleotide interval in the partial 5'-UTR region. Cosavirus strains were characterized as putative species HCoSV-A (n=70; 82%), HCoSV-B (n=7; 8%), HCoSV-C (n=1; 1.1) and HCoSV-D (n=4; 4.5%) while 5 (5%) strains remain uncharacterized. The cosavirus infection appeared highest (63.5%) in younger children, and showed a distinct seasonality, with a late summer peak and winter low. CONCLUSION: This study demonstrates a diversity of cosavirus strains in circulation, and reports the first investigation of HCoSV infection in children with nonpolio acute flaccid paralysis in India. Currently, this study provides baseline data for further studies of HCoSV infections in children with common enteric infections in India.