Human astroviruses have been recognized as one of the important causes of viral gastroenteritis in infants and young children. In the present work, we reviewed the progress of astrovirus infections in humans, focusing on the serotypes molecular biological, characteristics of disease, pathogenic mechanism, epidemiology and detection methods, and concluded that there were multiple astroviruses circulating in the world, and several novel astroviruses were discovered in recent years. Human astrovirus 1 was the most prevailing serotype. Which caused intestinal and parenteral infections, and the characteristics of infections were similar to other diarrheal viruses. However, the pathogenic mechanism remained unknown. Only limited data was available about the correlation between the novel astroviruses and diseases, and the laboratory detection methods needed to be established.
Animals ; Astroviridae Infections ; diagnosis ; epidemiology ; pathology ; Cell Line ; Genome, Viral ; genetics ; Humans ; Mamastrovirus ; classification ; genetics ; pathogenicity ; physiology ; Virus Replication

Human astrovirus (HAstV) is one of the leading causes of actue virual diarrhea in infants. HAstV-induced epithdlial cell apoptosis plays an important role in the pathogenesis of HAstV infection. Our previous study indicated that HAstV non-structural protein nsPla C-terminal protein nsPla/4 was the major apoptosis functional protein and probably contained the main apoptosis domains. In order to screen for astrovirus encoded apoptotic protien, nsPla/4 and six turncated proteins, which possessed nsPla/4 protein different function domain ,were cloned into green fluorescent protein (GFP) vector pEG-FP-N3. After 24-72 h transfection, the fusion protein expression in BHK21 cells, was analysis by fluorescence microscope and Western blot. The results indicated seven fusion proteins were observed successfully in BHK21 cell after transfected for 24 h. Western blot analysis showed that the level of fusion protein expressed in BHK21 cells was increased significantly at 72h compared to 48h in transfected cells. The successful expression of deletion mutants of nsPla/4 protein was an important foundation to gain further insights into the function of apoptosis domains of nsPla/4 protein and it would also provide research platform to further confirm the molecule pathogenic mechanism of human astrovirus.
Amino Acid Motifs ; Astroviridae Infections ; virology ; Humans ; Mamastrovirus ; genetics ; metabolism ; Mutation ; Sequence Deletion ; Transfection ; Viral Nonstructural Proteins ; chemistry ; genetics ; metabolism

Objective: To study the complete genome characterization of Human Astrovirus (HAstV) in Shandong Province. Methods: Stool samples from acute flaccid paralysis (AFP) surveillance in Shandong Province from 2020 to 2022 were collected, and HAstV nucleic acid was examined by real-time quantitative PCR (qPCR). Next-generation sequencing (NGS) was conducted for the positive samples to obtain complete genome sequences and identify the genotype. Homology comparison and phylogenetic analysis were performed by using BioEdit and Mega software. Results: A total of 667 samples were examined by qPCR, of which 14 were HAstV-positive (2.1%), including HAstV-1 (n=6), MLB1 (n=6), MLB2 (n=1), and VA2 (n=1). The complete genome sequences were obtained from 11 samples. The six HAstV-1 sequences of this study had 98.2% to 99.9% nt similarities with each other and 87.6% to 98.6% with those from other regions. The four MLB1 sequences of this study had 99.1% to 99.9% nt similarities with each other and 92.2% to 99.4% with those from other regions. The VA2 sequence of this study had 96.0% to 96.3% nt similarities with those from other regions. Phylogenetic analysis based on ORF2 region showed that the local HAstV-1 sequences were most closely related to Japanese strains, and had distinct topology with phylogenies based on ORF1a and ORF1b regions. Conclusion: The complete genome sequences of 11 HAstV strains are obtained, and the VA2 complete genome is found.
Humans ; Mamastrovirus/genetics* ; Phylogeny ; Astroviridae Infections/epidemiology* ; Feces ; Sequence Analysis, DNA ; Genotype ; Real-Time Polymerase Chain Reaction

Objective: To study the complete genome characterization of Human Astrovirus (HAstV) in Shandong Province. Methods: Stool samples from acute flaccid paralysis (AFP) surveillance in Shandong Province from 2020 to 2022 were collected, and HAstV nucleic acid was examined by real-time quantitative PCR (qPCR). Next-generation sequencing (NGS) was conducted for the positive samples to obtain complete genome sequences and identify the genotype. Homology comparison and phylogenetic analysis were performed by using BioEdit and Mega software. Results: A total of 667 samples were examined by qPCR, of which 14 were HAstV-positive (2.1%), including HAstV-1 (n=6), MLB1 (n=6), MLB2 (n=1), and VA2 (n=1). The complete genome sequences were obtained from 11 samples. The six HAstV-1 sequences of this study had 98.2% to 99.9% nt similarities with each other and 87.6% to 98.6% with those from other regions. The four MLB1 sequences of this study had 99.1% to 99.9% nt similarities with each other and 92.2% to 99.4% with those from other regions. The VA2 sequence of this study had 96.0% to 96.3% nt similarities with those from other regions. Phylogenetic analysis based on ORF2 region showed that the local HAstV-1 sequences were most closely related to Japanese strains, and had distinct topology with phylogenies based on ORF1a and ORF1b regions. Conclusion: The complete genome sequences of 11 HAstV strains are obtained, and the VA2 complete genome is found.
Humans ; Mamastrovirus/genetics* ; Phylogeny ; Astroviridae Infections/epidemiology* ; Feces ; Sequence Analysis, DNA ; Genotype ; Real-Time Polymerase Chain Reaction

OBJECTIVETo study the epidemiology and strain variations of astrovirus infection among children under 5 years of age, hospitalized for acute diarrhea in China.

METHODSInpatients under 5 years of age with acute diarrhea in hospitals of seven provinces between 1998 and 2005 were enrolled in the study Stool specimens were collected and tested for astrovirus using the Dako Amplified IDEIA Astrovirus kits or reverse-transcription polymerase chain reaction (RT-PCR). Genetic identities of the strains were determined using RT-PCR with serotype-specific primers and confirmed by sequencing of the RT-PCR products.

RESULTSA total of 1668 diarrheal stool samples tested for both rotavirus and calicivirus negative were examined. The detection rate of astrovirus infection was 5.5% (91/1668) and the diarrhea cases caused by astrovirus infection could be found in any season of the year but mainly occurred in cold season from October to next January. Astrovirus detection-rates were: 7.4% among infants aged 9-11 months followed by 6.1% in 12-17 month-olds, and 6-8 months 5.6% & 0-2 months 5.6% before 8 months. Over 95% of astrovirus infections occurred in children before 2 years of age. Among 49 strains, typed, serotype 1(45/91) was most commonly seen while serotype 5 was in two cases and serotype 3 and 8 were detected in only one case respectively.

CONCLUSIONAstrovirus seemed an important etiologic agent in young children with acute diarrhea in China and Serotype 1 was the most prevalent one.

Acute Disease ; Astroviridae ; classification ; isolation & purification ; Astroviridae Infections ; complications ; epidemiology ; Child, Preschool ; China ; epidemiology ; DNA, Viral ; analysis ; Diarrhea ; virology ; Humans ; Infant ; Infant, Newborn ; Inpatients ; Reverse Transcriptase Polymerase Chain Reaction ; Seasons ; Serotyping

BACKGROUNDThis study was to assess certain epidemiological and clinical characteristics of astrovirus infection in children with diarrhea below 5 years old hospitalized at the Beijing Children's Hospital.

METHODSFrom September 1999 to August 2001, a total of 288 children with diarrhea below 5 years old hospitalized at Beijing Children's Hospital were studied. Fecal specimens collected from each patient were tested for astrovirus by using enzyme immunoassay (EIA) and further serotyped by reverse-transcription polymerase chain reaction (RT-PCR) using serotype-specific primers.

RESULTSAstrovirus antigen was positive in 9.0% of the patients, and the rate of coinfection with rotavirus was 19.2% among the astrovirus positive patients. The patients with astrovirus infection were at the age of 7 days to 17 months, most (92.3%) of them were less than 12 months. Astrovirus infection occurred mainly between October and March of the following year. Main symptoms included watery stool, vomiting, fever, and dehydration. Increased activity of myocardial enzyme was seen in 4 patients. Of the 22 astrovirus positive specimens, 14 were successfully serotyped by RT-PCR and they were all serotype 1.

CONCLUSIONSThe overall incidence of astrovirus infection in young children with diarrhea hospitalized at the Beijing Children's Hospital was 9.0%. The predominant serotype was type 1. Astrovirus may play an important role in viral diarrhea in young children in Beijing, China.

Astroviridae Infections ; diagnosis ; epidemiology ; China ; epidemiology ; Diarrhea ; virology ; Feces ; virology ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Mamastrovirus ; immunology ; isolation & purification ; Serotyping

Currently, there are a few reports on viral coinfection that causes an acute watery diarrhea in Korean children. So, to evaluate the features of coinfectious viral agents in children with acute watery diarrhea, we enrolled 155 children with acute watery diarrhea from July 2005 to June 2006. Fecal samples were collected and evaluated for various viral infections such as rotavirus, norovirus, adenovirus and astrovirus. The mean (+/-standard deviation) age of the children was 2.71+/-2.37 yr. The detection rate of viral agents was most common in children between the ages of 1 and 3 yr. Rotavirus was detected in 63 children (41.3%), norovirus in 56 (36.2%), adenovirus in 11 (7.1%), and astrovirus in 1 (0.6%). Regarding rotavirus, there were 38 (60.3%) cases with monoinfection and 25 (39.7%) with coinfection. For norovirus, there were 33 (58.9%) cases with monoinfection and 23 (41.1%) with coinfection. Coinfection with rotavirus and norovirus was most common, and occurred in 20/155 cases (12.9%) including coinfection with adenovirus. So, rotavirus and norovirus were the most common coinfectious viral agents in our study population with acute watery diarrhea.
Acute Disease ; Adenovirus Infections, Human/epidemiology ; Astroviridae Infections/epidemiology ; Caliciviridae Infections/epidemiology ; Child ; Child, Preschool ; Diarrhea/epidemiology/*virology ; Feces/virology ; Humans ; Infant ; Korea/epidemiology ; Norovirus/isolation & purification ; Rotavirus Infections/epidemiology ; Virus Diseases/complications/*epidemiology/virology

OBJECTIVETo understand the major viral pathogens for infant diarrhea in Chizhou, Anhui.

METHODSFecal specimens were collected from 428 infants hospitalized with diarrhea in People's Hospital of Chizhou, Anhui between January 2005 and December 2006. Enzyme immunoassay (EIA) and enzyme-linked immunosorbent assay (ELISA) were performed to detected specific antigens of rotavirus, astrovirus, adenovirus or calicivirus. For rotavirus, specimens were tested for typing by serum virology and reverse transcription PCR (RT-PCR).

RESULTSThe positive test rates for rotavirus, calicivirus and adenovirus were 29.2%, 10.5% and 2.4%, respectively, in infants with diarrhea from Chizhou, Anhui. Among them, 3 cases (2.4%) were infected with two or more viruses. Forty-four fecal specimens were tested with ELISA and RT-PCR for rotavirus, and the results showed that the two methods got consistency of 97.7%. Another 48 rotaviruses of serotype G were further typed as serotype I (3 cases), II (1 case), III (35 cases) and IX (2 cases), with 7 cases untyped. Among the cases that could be typed, 26 cases were collected from 2005, and 15 from 2006. RV type ml was the major pathogens for infant diarrhea, with 24 from 2005 and 11 from 2006. Among the 8 rotaviruses of type P, 7 were type as G3P8 and one G9P8. The epidemic of rotavirus showed significant season privilege, with a high prevalence in winter-spring, while the prevalence of calicivirus was prone to be high in Fall.

CONCLUSIONRotavirus was the major viral pathogen accounting for infant diarrhea in Chizhou, Anhui, followed by calicivirus and adenovirus Type G3 was the main rotavirus, especially type G3P8.

Adenoviridae ; genetics ; isolation & purification ; Adenoviridae Infections ; virology ; Astroviridae Infections ; virology ; Caliciviridae ; genetics ; isolation & purification ; Child, Hospitalized ; Child, Preschool ; China ; Diarrhea, Infantile ; virology ; Feces ; virology ; Female ; Humans ; Infant ; Male ; Rotavirus ; genetics ; isolation & purification ; Rotavirus Infections ; virology ; Seasons

To investigate epidemiologic feature and genetic variance of Sapovirus among children in China, fecal specimens were collected from children under 5 years old with acute diarrhea from Feb 2006 to Jan 2007 in nine provinces including Anhui, Fujian et al. A total of 1,110 fecal samples were detected for Sapovirus by reverse transcriptase-PCR (RT-PCR). Ten samples (0.9%) were positive for Sapovirus. The PCR products were then sequenced and analysed by phylogenetic tree. The results indicated that the detected Sapovirus strains were classified into two genogroups and three genotypes, including G I/1, G I/3, G II/3.
Astroviridae Infections ; epidemiology ; etiology ; genetics ; Base Sequence ; Caliciviridae Infections ; epidemiology ; China ; epidemiology ; Diarrhea ; classification ; virology ; Feces ; virology ; Gastroenteritis ; epidemiology ; etiology ; virology ; Genetic Variation ; Humans ; Molecular Sequence Data ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Sapovirus ; classification ; genetics

A molecular study of intestinal samples from 21 broiler flocks with a history of enteritis revealed that 23.8% and 14.3% were positive for chicken astrovirus (CAstV) and avian rotavirus (ARV), respectively. CAstV and group A ARV were simultaneously detected in only one broiler flock. Birds in this group developed the significant intestinal lesions characterized by frothy contents, paleness, and thin intestinal walls. In this report we present an unusual case of runting stunting syndrome (RSS) with a history of high mortality and growth retardation in broiler chickens. We also make the first identification of CAstV and group A ARV in broiler chickens in Korea.
Animals ; Astroviridae Infections/diagnosis/epidemiology/*veterinary/virology ; Avastrovirus/classification/*genetics/isolation & purification/metabolism ; *Chickens/growth & development ; Enteritis/diagnosis/pathology/veterinary/virology ; Intestines/pathology/virology ; Molecular Sequence Data ; Phylogeny ; Poultry Diseases/*diagnosis/epidemiology/virology ; Republic of Korea/epidemiology ; Rotavirus/classification/*genetics/isolation & purification/metabolism ; Rotavirus Infections/diagnosis/epidemiology/*veterinary/virology