An annoying enteric virus: A systematic review and meta-analysis of human astroviruses and gastrointestinal complications in children.

Human astroviruses (HAstVs) have frequently been detected in individuals with acute gastroenteritis (AGE). However, a precise estimate of the overall prevalence of the virus in children with AGE as well as the possible association of the virus with gastrointestinal complications is not available up to now. The present study estimated the overall prevalence of HAstVs in children with gastrointestinal complications as well as the association between the virus and symptoms. We systematically searched four international databases (PubMed, Scopus, Web of Science, and Google scholar) to find studies on the prevalence of HAstVs in people with AGE published between Jan 2000 and Sep 2021. Analysis of the 223 included studies presented a 4.2% (95% CI 3.8%-4.8%) prevalence of the virus in AGE individuals. Based on case-control studies, a significant association between these viruses and AGE was detected (OR: 2.059, 95% CI; 1.438-2.949). HAstV-1 and HAstV-VA-2 is the most and least common genotypes in the AGE patients, respectively (59.0%, 95% CI: 52.1%-65.6% vs. 4.9%, 95% CI: 2.6%-9.1%). Due to the statistically significant association between HAstV and gastrointestinal complications, more attention should be paid to these viruses in people with AGE and more studies should employ case-control design.

Astrovirus Infection in Cattle with Nonsuppurative Meningoencephalitis in South Korea.

Neurological diseases in cattle can be caused by several infectious agents. Astroviruses are increasingly recognized as the causative agent of encephalitis in various animals, including humans. In this study, a neuroinvasive astrovirus (BoAstV 20B05) was discovered in the brain tissues of an 81-month-old Korean native cattle with neurological symptoms. Lymphocyte infiltration and multifocal perivascular cuffing were observed in the cerebrum and brain stem, and viral antigens were also detected in the meninges. In particular, the concentration of the astroviral genome was high in the brain tissues. Korean BoAstV 20B05 was classified into the CH13/NeuroS1 clade and was closely related to the Neuro-Uy and KagoshimaSR28-462 strains. Our evolutionary analysis showed that Korean BoAstV 20B05 belongs to the sub-lineage NeuroS1 and evolved independently of BoAstV KagoshimaSR28-462. These results suggest that neuroinvasive astroviruses were first introduced in Korea. However, analysis is limited by the lack of reference astrovirus sequences reported in various countries within Asia, and further analysis should be performed using more strains. In this study, we identified a neuroinvasive astrovirus infection with neurological symptoms for the first time in South Korea and confirmed that BoAstV 20B05 may have been introduced in South Korea a long time ago.

Establishment of Duplex SYBR Green I-based Real-time PCR Assay for Simultaneous Detection of Duck Hepatitis A Virus-1 and Duck Astrovirus-3.

Duck viral hepatitis (DVH) mainly affects ducklings under 1 month of age, causes liver necrosis, enlargement, and hemorrhage, and is highly lethal, seriously jeopardizing the duck industry. The prevalence of duck hepatitis A virus (DHAV-1) and duck astrovirus type 3 (DAstV-3) is increasing, and coinfection is common. Moreover, the similar clinical characteristics of the DHAV-1 and DAstV-3 infections and the high frequency of coinfection make diagnosis difficult. In this study, to establish a method for the rapid, simultaneous detection of DHAV-1 and DAstV-3, two pairs of specific primers were designed according to their conserved gene regions. An SYBR® Green I-based qPCR assay was successfully established that can quickly and differentially detect the two viruses. Moreover, the assay is highly specific and does not show cross-reaction with other common viruses. The detection limit of the method is 7.34 × 101 copies/µl and 3.78 × 101 copies/µl for DHAV-1 and DAstV-3, respectively, indicating high sensitivity. A total of 34 clinical samples were tested using the established method; the positive rates for DHAV-1 and DAstV-3 were 14.71% and 8.82%, respectively, and that for coinfection was 2.94% (1/34), which was better than that obtained with conventional PCR. In summary, the SYBR Green I-based qPCR assay established in this study has high specificity, good sensitivity and accuracy, high feasibility, and is rapid. Thus, it can be a powerful tool for the coinfection detection of DHAV-1 and DAstV-3 and for future epidemiologic studies.

Artículo regular­Establecimiento de un ensayo dúplex de PCR en tiempo real basado en SYBR Green I para la detección simultánea del virus de la hepatitis A del pato-1 y del astrovirus del pato tipo 3. La hepatitis viral del pato (DVH) afecta principalmente a los patitos menores de 1 mes de edad, causa necrosis hepática, agrandamiento y hemorragia, y es altamente letal, lo que pone en grave peligro la industria del pato. La prevalencia del virus de la hepatitis A del pato (DHAV-1) y del astrovirus del pato tipo 3 (DAstV-3) está aumentando y la coinfección es común. Además, las características clínicas similares de las infecciones por el virus de la hepatitis A del pato y el astrovirus del pato tipo 3 así como la alta frecuencia de coinfección dificultan el diagnóstico. En este estudio, para establecer un método para la detección rápida y simultánea por el virus de la hepatitis A del pato y el astrovirus del pato tipo 3, se diseñaron dos pares de iniciadores específicos según sus regiones génicas conservadas. Se estableció con éxito un ensayo cuantitativo de PCR basado en SYBR® Green I que pudo detectar rápida y diferencialmente los dos virus. Además, el ensayo es muy específico y no muestró reacción cruzada con otros virus comunes. El límite de detección del método fue de 7.34 × 101 copias/µl y de 3.78 × 101 copias/µl para el virus de la hepatitis A del pato y para el astrovirus del pato tipo 3, respectivamente, lo que indica una alta sensibilidad. Se analizaron un total de 34 muestras clínicas utilizando el método establecido; las tasas positivas para el virus de la hepatitis A del pato y para el astrovirus del pato tipo 3 fueron del 14.71% y 8.82%, respectivamente y la de coinfección fue del 2.94% (1/34), que fue mejor que la obtenida con el método de PCR convencional. En resumen, el ensayo cuantitativo de PCR basado en SYBR Green I establecido en este estudio tiene alta especificidad, buena sensibilidad y precisión, alta viabilidad y es rápido. Por lo tanto, puede ser una herramienta poderosa para la detección de coinfecciones con el virus de la hepatitis A del pato y astrovirus del pato tipo 3 y para futuros estudios epidemiológicos.

Intra- and Cross-Species Transmission of Astroviruses.

Astroviruses are non-enveloped, single-stranded RNA viruses that infect mammalian and avian species. In humans, astrovirus infections are one of the most common causes of gastroenteritis in children. Infection has also been linked to serious neurological complications, especially in immunocompromised individuals. More extensive disease has also been characterized in non-human mammalian and avian species. To date, astroviruses have been detected in over 80 different avian and mammalian hosts. As the number of hosts continues to rise, the need to understand how astroviruses transmit within a given species as well as to new host species becomes increasingly important. Here, we review the current understanding of astrovirus transmission, the factors that influence viral spread, and the potential for cross-species transmission. Additionally, we highlight the current gaps in knowledge and areas of future research that will be key to understanding astrovirus transmission and zoonotic potential.

New insights on Avian orthoreovirus and Chicken astrovirus co-infection in an Italian broiler flock: preliminary biomolecular and pathological results.

Common pathogens of intensive poultry farms, either parasitic or bacterial, such as Coccidiaor Salmonella, are well known and strictly controlled by veterinary management. This case study reports an unusual case of runting stunting syndrome (RSS) observed on a Sicilian poultry farm of broiler chickens during 2019. The investigation was carried out on five chickens which present delayed in body weight and growth performance. Animals showed also difficulty in deambulation and diarrhea. At necropsy, intestinal lesions were detected in three of the five clinical cases. Gut samples were collected and analyzed to identify potential pathogens responsible for the RSS. Presence of viruses was detected by using quantitative reverse transcription PCR (RT­qPCR), while selected tissues were fixed and embedded in paraffin wax according to routine procedures. All histological sections were stained with hematoxylin­eosin. RT­qPCR successfully detected both Chicken astrovirus (CAstV) and Avian orthoreovirus (ARV). Histology evidenced severe specific lesions on the intestinal mucosa in liver and kidneys. Chicken astrovirus and Avian orthoreovirus RNA was also detected in cecal tonsils, kidney and liver, thus implying their possible primary role in inducing the disease. Further studies are needed to evaluate the role of other possible factors (low biosecurity measures, e.g.) and, most of all, the consequences in terms of economic losses and animal health impairment.

Etiology of acute gastroenteritis among children less than 5 years of age in Bucaramanga, Colombia: A case-control study.

BACKGROUND: Acute gastroenteritis (AGE) is a major cause of morbidity and mortality in children aged less than 5 years in low- and middle-income countries where limited access to potable water, poor sanitation, deficient hygiene, and food product contamination are prevalent. Research on the changing etiology of AGE and associated risk factors in Latin America, including Colombia, is essential to understand the epidemiology of these infections. The primary objectives of this study were to describe etiology of moderate to severe AGE in children less than 5 years of age from Bucaramanga, Colombia, a middle-income country in Latin American, and to identify the presence of emerging E. coli pathotypes. METHODOLOGY/PRINCIPAL FINDINGS: This was a prospective, matched for age, case-control study to assess the etiology of moderate to severe AGE in children less than 5 years of age in Bucaramanga, Colombia, South America. We tested for 24 pathogens using locally available diagnostic testing, including stool culture, polymerase chain reaction, microscopy and enzyme-linked immunoassay. Adjusted attributable fractions were calculated to assess the association between AGE and each pathogen in this study population. The study included 861 participants, 431 cases and 430 controls. Enteric pathogens were detected in 71% of cases and in 54% of controls (p = <0.001). Co-infection was identified in 28% of cases and in 14% of controls (p = <0.001). The adjusted attributable fraction showed that Norovirus GII explained 14% (95% CI: 10-18%) of AGE, followed by rotavirus 9.3% (6.4-12%), adenovirus 3% (1-4%), astrovirus 2.9% (0.6-5%), enterotoxigenic Escherichia coli (ETEC) 2.4% (0.4-4%), Cryptosporidium sp. 2% (0.5-4%), Campylobacter sp. 2% (0.2-4%), and Salmonella sp.1.9% (0.3 to 3.5%). Except for Cryptosporidium, all parasite infections were not associated with AGE. Three emergent diarrheagenic E. coli pathotypes were identified in cases (0.7%), including an enteroaggregative/enterotoxigenic E.coli (EAEC/ETEC), an enteroaggregative/enteropathogenic E.coli (EAEC/EPEC), and an emergent enteroinvasive E. coli with a rare O96:H19. No deaths were reported among cases or controls. CONCLUSIONS/SIGNIFICANCE: Norovirus and rotavirus explained the major proportion of moderate to severe AGE in this study. Higher proportion of infection in cases, in the form of single infections or co-infections, showed association with AGE. Three novel E. coli pathotypes were identified among cases in this geographic region.

Goose astrovirus infection affects uric acid production and excretion in goslings.

In 2018, a new goose astrovirus (GAstrV) was reported in China, which causes 2 to 20% deaths in 4- to 16-day-old goslings causing great damages to the livestock industry. Gout is the typical feature of GAstrV infection in goslings. However, the mechanism of gout formation remains unclear. In the present study, 2-day-old goslings were infected intramuscularly with GAstrV for 14 D. One quarter of the infected goslings died, and typical gout pathological changes were found in the dead infected goslings. Pathological changes were observed in the morphology of the kidney and liver, such as degeneration, necrosis, and inflammatory cell infiltration. Accordingly, a high virus load was found in both organs. The serum level of uric acid in the inoculated goslings was higher, whereas no differences were found in levels of creatinine, calcium, and phosphorus. Moreover, the xanthine dehydrogenase (XOD) and adenosine deaminase (ADA) activities and the mRNA levels of xanthine dehydrogenase, adenosine deaminase, phosphoribosyl pyrophosphate amidotransferase, and phosphoribosyl pyrophosphate synthetase 1 in livers increased, wheres the multidrug resistance-associated protein 4 mRNA level and Na-K-ATPase activity in the kidneys decreased. These results showed that GAstrV infection could cause lesions on the liver and kidney and then increase the expression or activity of enzymes related to uric acid production in the liver and decrease renal excretion function, which contribute to hyperuricemia and gout formation.

Human astrovirus infection associated with encephalitis in an immunocompetent child: a case report.

BACKGROUND: Until today, classic human astroviruses have not been associated with central nervous system infections in immunocompetent patients. CASE PRESENTATION: A 16-month-old Caucasian girl presented with repetitive generalized seizures with a 4-day history of watery diarrhea, which had already gradually improved. Initially, the prolonged seizures ceased after systemic midazolam treatment and were thought to be fever associated. However, her mental status remained altered, and after seizure recurrence, she was transferred to our pediatric intensive care unit. Seizure control was achieved by a combination of high-dose levetiracetam and phenobarbital, but she remained unconscious. An electroencephalogram at this time revealed generalized high voltage theta activity. All laboratory analyses, including extended blood and cerebrospinal fluid analyses, and a brain magnetic resonance imaging were normal. On day 4, the child gradually became conscious, but was very agitated and not able to walk. Since an electroencephalogram at this time still revealed generalized high voltage theta activity, although she had not received sedative medications for 72 hours, she was diagnosed as having encephalopathy. At that time, results of diagnostic testing of the stool sample were positive for classic astrovirus infection, and we decided to analyze the initially obtained cerebrospinal fluid for astrovirus as well. Cerebrospinal fluid was also found positive for human astrovirus. Sequencing analysis revealed a classic astrovirus genotype 1 with exactly the same nucleotide sequence as in the feces. Clinically, the child gradually improved and was discharged on day 9. CONCLUSIONS: Whereas the new human astrovirus subtypes have been recently associated with central nervous system infection, this is the first case of encephalitis in an immunocompetent child due to classic human astrovirus. Considering that classic human astroviruses are the third most common etiological agents of viral gastroenteritis in children, we believe that human astroviruses as causative agents for central nervous system infections should be considered more often, especially in children and infants with preceding gastroenteritis.

Persistent Infections with Diverse Co-Circulating Astroviruses in Pediatric Oncology Patients, Memphis, Tennessee, USA.

Human astroviruses are a major cause of pediatric gastroenteritis, especially in immunocompromised children. We conducted a retrospective study to demonstrate that diverse astrovirus genotypes can co-circulate in pediatric oncology patients. A subset of cases is associated with long-term virus shedding (range 17-183 days).

Acute encephalopathy in an immunocompromised boy with astrovirus-MLB1 infection detected by next generation sequencing.

We report a case of an immunodeficient 4-year-old boy with acute encephalopathy possibly related to human astrovirus-MLB1 infection. The astrovirus-MLB1 genome was identified in his stool, serum, cerebrospinal fluid, urine, and throat swabs by next generation sequencing. We present additional evidence showing human astroviruses are important infectious agents, regardless of their clades, involving the central nervous system in immunocompromised hosts.

Prevalence of human astrovirus in patients with acute gastroenteritis.

The prevalence of human astroviruses was tested in patients with acute gastroenteritis by using conventional duplex reverse transcription (RT)-PCR and electrophoresis. Diarrheal fecal samples were collected from 9,597 patients at local hospitals in Seoul. The prevalence of astroviruses was 1.0% (94/9,597 patients; mostly infants), and that of sapoviruses was 0.1% (14/9,597 patients). Age- and gender-wise analyses were carried out on 29 astrovirus-positive patients having complete information on file regarding their age, gender, and other particulars. The results were higher in patients of ages 0 to 14 yr, and 69.0% of the astrovirus-positive patients were females, of which 69.2% were infants (0 to 12 months), and 61.5% were 1-4 yr old. Notably, in the case of 5 to 78-yr-old acute gastroenteritis patients, 100% were females.

Prevalence of Human Astrovirus in Patients with Acute Gastroenteritis

The prevalence of human astroviruses was tested in patients with acute gastroenteritis by using conventional duplex reverse transcription (RT)-PCR and electrophoresis. Diarrheal fecal samples were collected from 9,597 patients at local hospitals in Seoul. The prevalence of astroviruses was 1.0% (94/9,597 patients; mostly infants), and that of sapoviruses was 0.1% (14/9,597 patients). Age- and gender-wise analyses were carried out on 29 astrovirus-positive patients having complete information on file regarding their age, gender, and other particulars. The results were higher in patients of ages 0 to 14 yr, and 69.0% of the astrovirus-positive patients were females, of which 69.2% were infants (0 to 12 months), and 61.5% were 1-4 yr old. Notably, in the case of 5 to 78-yr-old acute gastroenteritis patients, 100% were females.

[Astroviral infection in Russian Federation].

The astroviral infections are considered among the most common pathogens of gastroenteritis in children. The incidence, molecular epidemiology and clinical manifestations of the astrovirus infection in children hospitalized with acute gastroenteritis, in various areas of the Russian Federation from 2004 to 2010 was determined.

Divergent astrovirus associated with neurologic disease in cattle.

Using viral metagenomics of brain tissue from a young adult crossbreed steer with acute onset of neurologic disease, we sequenced the complete genome of a novel astrovirus (BoAstV-NeuroS1) that was phylogenetically related to an ovine astrovirus. In a retrospective analysis of 32 cases of bovine encephalitides of unknown etiology, 3 other infected animals were detected by using PCR and in situ hybridization for viral RNA. Viral RNA was restricted to the nervous system and detected in the cytoplasm of affected neurons within the spinal cord, brainstem, and cerebellum. Microscopically, the lesions were of widespread neuronal necrosis, microgliosis, and perivascular cuffing preferentially distributed in gray matter and most severe in the cerebellum and brainstem, with increasing intensity caudally down the spinal cord. These results suggest that infection with BoAstV-NeuroS1 is a potential cause of neurologic disease in cattle.

Importance of viral pathogens in children with acute gastroenteritis in the south of Iran.

BACKGROUND AND OBJECTIVES: Different types of viruses are the leading cause of acute diarrhea among infants and young children worldwide. Epidemiological surveillance of viral agents is critical for the develop.ment of effective preventive measures, including vaccines. This study aimed to determine the prevalence of the four major enteropathogenic viruses-rotavirus, norovirus, adenovirus and astrovirus-in children over 7 years of age. DESIGN AND SETTING: A cross-sectional descriptive study conducted on stool specimens of children with acute gastroenteritis admitted to the Pediatrics Unit of 17 Shahrivar Hospital in Borazjan, Iran from October 2008 to September 2010. PATIENTS AND METHODS: Acute gastroenteritis was defined as >=3 loose watery stools per 24 hours. A total of 375 stool samples were collected from hospitalized children aged < 7 years old with acute gastroenteritis. All samples were investigated by using enzyme-linked immunosorbent assay for the presence of viral antigens. RESULTS: Rotavirus was detected in 91 (24.3%) of the patients whereas the prevalence of norovirus, adenovirus and astrovirus was 12.5%, 5.1% and 2.4%, respectively. On average, 75.9% of children with viral diarrhea were younger than 2 years old (P=.023). All the strains of viral gastroenteritis studied peaked in the autumn, except for adenovirus which peaked in spring (P=.015). The most common clinical symptoms included diarrhea (92.2%), vomiting (68.7%), abdominal cramp (60.8%) and moderate dehydration (57.2%). CONCLUSION: Since nearly half of gastroenteritis cases (44.3%) were due to viral agents, testing for the viral antigens may guide the clinical approach to those patients with acute diarrhea particularly in the case of children less than 2 years old, and during cold seasons.

Mixed infection by Feline astrovirus and Feline panleukopenia virus in a domestic cat with gastroenteritis and panleukopenia.

Astroviruses are important pathogens of human beings and animals. Feline astroviruses have been identified by electron microscopy in the feces of either asymptomatic or symptomatic cats, and experimental infection with one isolate was shown to induce enteric clinical signs and virus excretion, thus suggesting a possible role as enteric pathogen. However, due to the lack of specific diagnostic assays, feline astroviruses are not included in the diagnostic algorithms of feline infectious diseases, and their role as feline pathogens remains unclear. The present report describes a dual infection by Feline astrovirus and Feline panleukopenia virus in a 4-month-old cat with severe gastroenteritis and panleukopenia. Upon sequence analysis, the Feline astrovirus strain was found to be genetically related to astroviruses identified in human beings and felids.

Human astrovirus infection in a patient with new-onset celiac disease.

Many diseases with unknown etiology may be caused by unidentified viruses. Sequence-independent amplification revealed a new astrovirus, similar to VA1, in a 4-year-old male diagnosed with celiac disease. This expands the geographic range of this virus to include Europe and may associate astrovirus infection with the onset of celiac disease.

Clinical characteristics of viral intestinal infection in preterm and term neonates.

The clinical presentation of the viral enteric pathogens in newborn infants has not been adequately examined. The aim of this study was to evaluate the clinical characteristics of viral intestinal infections in newborn infants. Clinical data of all term and preterm infants admitted to our tertiary neonatal intensive care unit from 1998 to 2007 with clinical signs of gastroenteritis (GE) or necrotizing enterocolitis (NEC) were retrospectively reviewed and compared between infants with different viral enteric pathogens in stool specimens. In 34 infants with signs of GE or NEC, enteropathogenic viruses were found in stool specimens. Rotavirus was detected in 12 cases, of which two infants had NEC. Compared with infants with rotavirus or norovirus, infants with astrovirus more frequently suffered from NEC (p<0.05). In addition, an acute systemic inflammatory response was significantly more common in patients with astrovirus infection (astrovirus vs. rotavirus and astrovirus vs. norovirus, p < 0.01 and p < 0.05, respectively). Of eight children infected with norovirus, one infant had a systemic acute inflammatory response and NEC. This study demonstrates that in newborn infants, intestinal rotavirus, norovirus, and astrovirus infections may be associated with severe illness such as hemorrhagic enteritis resulting in bloody diarrhea or even NEC.

Genetic diversity of norovirus, sapovirus, and astrovirus isolated from children hospitalized with acute gastroenteritis in Chiang Mai, Thailand.

Norovirus (NV), sapovirus (SV), and human astrovirus (HAstV) are important causes of acute gastroenteritis in infants and young children. This study investigated the prevalence of NV, SV, and HAstV infections in children hospitalized with acute gastroenteritis in Chiang Mai, Thailand from May 2000 to March 2002. Fecal specimens were tested for NV, SV, and HAstV by reverse transcription polymerase chain reaction (RT-PCR) using degenerate specific primers. These viruses were characterized further by sequence and phylogenetic analyses of the partial capsid gene. From 296 fecal specimens tested, 13.5% (40 of 296) were positive for NV, SV, and HAstV. Of these, NV most predominant, with a prevalence of 60% (24 of 40), of which 17.5% were NVGI and 42.5% were NVGII. Of note, one specimen was positive for both NVGI and SV. SV was detected in 25%, while HAstV was detected in 17.5%. Analysis of nucleotide and amino acid sequences revealed that NVGI strains comprised GI/3, GI/4, GI/6, GI/7, and GI/13 genotypes. Among NVGII strains, approximately half of them belonged to genotype GII/4 (Lordsdale virus cluster), followed by GII/3, GII/10, GII/1, GII/6, GII/8, and GII/15. Analysis of SV sequences revealed that SVGI (Manchester virus) was more common than SVGII (London virus). The SV genotypes detected in this study belonged to SVGI/1, SVGI/4, SVGI/5, SVGII/1, and SVGII/2, whereas the HAstV belonged to genotypes HAstV-1, HAstV-2, HAstV-3, and HAstV-5. The findings suggest that NV, SV, and HAstV are important enteric viruses cocirculating among hospitalized children in Chiang Mai, Thailand.