Molecular study of human astrovirus in Egyptian children with acute gastroenteritis

Worldwide prevalence and genotype distribution of human astrovirus in gastroenteritis patients: A systematic review and meta-analysis

AIM

Human astrovirus (HAstV) is an important causative agent of gastroenteritis in humans, which mainly infects young children and the elderly. The goal of this study was to conduct a meta-analytic review of the prevalence of HAstV amongst patients with gastroenteritis, and to shed light on the connection between HAstV infection and gastroenteritis.

METHODS

Systematic literature searches were conducted to identify all potentially relevant studies recorded up to April 8th, 2022. For study weighting, the inverse variance method was employed and the random-effects model was applied to evaluate data. For case-control studies, the pooled odds ratio (OR) and 95% confidence interval (CI) were calculated to establish the relationship between HAstV infection and gastroenteritis.

RESULTS

Among 302423 gastroenteritis patients from 69 different countries, the overall pooled prevalence of HAstV infection was 3.48% (95% CI: 3.11%-3.89%). Case-control approach was used in 39 investigations, and the overall prevalence of HAstV infection among the 11342 healthy controls was 2.01% (95% CI: 1.40%-2.89%). Gastroenteritis and HAstV infection were associated with a pooled OR of 2.16 (95% CI: 1.72-2.71; P < 0.0001; I² = 33.7%). The most commonly found HAstV genotypes in gastroenteritis patients were HAstV1 (62.18%), HAstV7 (33.33%), and HAstV-MLB1 (17.43%).

CONCLUSION

The frequency of HAstV infection was the highest in children under the age of five, and in developing countries. The prevalence rate of HAstV was not influenced by gender. Semi-nested and nested RT-PCR were highly sensitive assays for detecting HAstV infections.

High Burden of Co-Infection with Multiple Enteric Pathogens in Children Suffering with Diarrhoea from Rural and Peri-Urban Communities in South Africa

Infectious diarrhoea contributes to high morbidity and mortality in young children from sub-Saharan Africa. The aim of this study was to assess the prevalence of single and multiple diarrhoeal-causing pathogen combinations in children suffering from diarrhoea from rural and peri-urban communities in South Africa. A total of 275 diarrhoea stool specimens were collected between 2014 and 2016 from Hospitals and Primary Health Care clinics. The BioFire^® FilmArray^® Gastrointestinal panel was used to simultaneously detect 22 diarrhoea pathogens (viruses, bacteria, parasites) known to cause diarrhoea. A total of 82% (226/275) enteric pathogens were detected in the stool specimens. The two most detected bacterial, viral and parasitic pathogens each included: EAEC (42%), EPEC (32%), Adenovirus F40/41 (19%), Norovirus (15%), Giardia (8%) and Cryptosporidium (6%), respectively. Single enteric pathogen infections were recorded in 24% (65/275) specimens with EAEC, and Norovirus was found in 26% (17/65) and 14% (9/65) of the specimens, respectively. Multiple enteric pathogen combinations were recorded in 59% (161/275) of the stool specimens with 53% (85/161) containing two pathogens, 22% (35/161) containing three pathogens and 25% (41/161) containing four or more pathogens. The results from this study demonstrated the complex nature of pathogen co-infections in diarrhoeal episodes which could have an impact on treatment effectiveness.

Viral pathogens of acute gastroenteritis in Egyptian children: role of the parechovirus

BACKGROUND AND AIM

Human parechovirus (HPeV) has emerged as a pathogen associated with acute gastroenteritis (AGE).

AIM

To detect the presence of HPeV in the stool samples from Egyptian children with AGE seeking care and the possibility of its co-infection with other enteric viruses.

METHODOLOGY

One hundred stool samples were collected from children attending Mansoura University Children's Hospital with AGE. HPeV and astrovirus were detected by reverse transcriptase-polymerase chain reaction (RT-PCR). At the same time, detection of rotavirus antigen and norovirus was achieved by enzyme-linked immunosorbent assay and rapid immunochromatographic method, respectively.

RESULTS

The most frequently detected virus was rotavirus (39%), followed by norovirus (27%), HPeV (19%), and astrovirus (12%). Interestingly, the single infection with HPeV was 5%. Among the 19 HPeV positive samples, the co-infection of HPeV with other enteric viruses was detected in 9(43.9%) for rotavirus, 7(36.8%) for norovirus, 2(10.5%) for astrovirus, in 3(15.8%) for rotavirus and norovirus and 1(5.3%) for norovirus and astrovirus. Regarding the clinical presentation, there was no significant difference between children infected with HPeV alone and those infected with viruses other than HPeV alone; fever (p = 0.3), vomiting (p = 0.12), abdominal pain (p = 0.12), and grades of severity (P = 0.82). HPeV alone infected children were of mild severity (60%), and their main presenting symptom was fever (60%).

CONCLUSIONS

Detection of HPeV as a single viral pathogen in the stool of some children with AGE showed that this virus could be a causative agent of AGE in Egyptian children. Therefore, HPeV could be included as one of the viruses screened for AGE diagnosis in children in Egypt.

Polymerase Chain Reaction Study of Human Bocavirus in Children with Acute Gastroenteritis

Aim:

The present study aimed to detect Human bocavirus (HBoV) in stool samples from young children below 5 years complaining of acute gastroenteritis (GE) in addition to detection of rotavirus, norovirus, and astrovirus.

Methods:

The study included 90 children below 5 years with acute GE with excluded bacterial pathogens. The determination of the presence of HBoV was performed by nested polymerase chain reaction (PCR) beside determination of astrovirus and norovirus by multiplex PCR and rotavirus antigen by enzyme-linked immunosorbent assay (ELISA).

Results:

The most prevalent virus among the studied viruses was rotavirus (33.3%) detected by ELISA for antigen in the stool. The other three viruses detected by molecular methods were bocavirus (14.4%), astrovirus (13.3%), and norovirus (10%). Mixed viral infection with two or more viruses was detected in 16 children (17.8%). The most common was bocavirus and rotavirus in 6 patients (37.5%). In the study of demographic and clinical presentations of the children with HBoV, the affected children were mainly females, i.e., 10 (76.9%), from rural residence i.e., 11 (84.6%) with the mild classification of GE in 7 children (53.8%) and moderate GE in 6 children (46.2%) and none of them had severe GE. Fever was the most common presenting sign in those children (53.8%) followed by vomiting (46.2%).

Conclusion:

The study highlights the existence of HBoV in children with acute GE under the age of five. The infection associated with this virus was either mild or moderate in severity. The combined viral infection was common especially associated with rotavirus. There is a need for further additional study to identify the type of the circulated strain of bocavirus and the confections with other pathogens.

Investigation of Children with Acute Gastroenteritis by Multiplex PCR Method in Central Part of Turkey

Objective Gastroenteritis is a disease that affects all age groups, especially children, and causes high mortality and morbidity in all countries. The most common agents of acute gastroenteritis are viral agents. As a result, millions of diarrhea attacks and hospital admissions occur worldwide every year due to viral gastroenteritis. This study uses the multiplex polymerase chain reaction (PCR) method to investigate the viruses that are the causative agents of viral gastroenteritis in the pediatric patient group in Konya, Turkey.

Methods Stool samples of 94 patients aged 0 to 18 years sent from Emergency clinics and Pediatric outpatient clinics, Meram Medical Faculty Hospital Pediatric clinics, Konya Necmettin Erbakan University to Medical Microbiology Laboratory with a diagnosis of gastroenteritis between February and December 2018 were included in the study. Stool samples were stored at –80°C until the time of the analysis. Deoxyribonucleic acid/ribonucleic acid isolation from stool samples was performed with EZ1 Virus Mini Kit v2.0 (Qiagen, Hilden, Germany) using an automatic extraction system (BioRobot EZ1 system, Qiagen). The presence of astrovirus, rotavirus, adenovirus, norovirus (GI, GII), and sapovirus agents was investigated by the multiplex PCR method (Fast Track Diagnostics, Luxembourg) viral gastroenteritis kit.

Results Viral gastroenteritis agents were detected in 56.3% of the patients. One viral agent was detected in 47 (50%) of these patients and at least two viral agents in 6 (6.3%) of them. Norovirus GII was detected in 20 (21.2%) of the children included in the study, adenovirus in 13 (13.8%), rotavirus in 11 (12.8%), astrovirus in 11 (11.7%), sapovirus in 4 (4.2%), and norovirus GI in 1 (1.06%). When the distribution of viral agents was examined by months, the most number of agents were observed (21; 35%) in May, followed by April and June (12; 20%). Considering the distribution of the prevalence of the agents by age, it was seen to be mainly between 0 and 12 months (42%).

Conclusion Considering that the most common viral agent in our region is norovirus GII, it will be useful to investigate the norovirus that is not routinely examined in children who are admitted to clinics with the complaint of gastroenteritis. It will be appropriate to examine routinely adenovirus, rotavirus, and norovirus in the laboratory, especially in children with diarrhea and vomiting in the winter and spring months.

High divergence of human astrovirus genotypes circulating in pediatric patients hospitalized with acute gastroenteritis in Chiang Mai, Thailand, 2017-2020

Human astrovirus (HAstV) is one of the common causes of acute gastroenteritis in children. The investigation of molecular epidemiology of HAstV is essential for monitoring the emergence and/or re-emergence of new HAstV genotypes, as well as understanding the evolution of HAstV circulating in children suffering from acute gastroenteritis. The present study aimed to investigate the prevalence and distribution of HAstVs strains circulating in children hospitalized with acute gastroenteritis in Chiang Mai, Thailand during 2017-2020. A total of 1500 fecal specimens collected from children with acute gastroenteritis were screened for HAstV by RT-PCR that targeted the partial RdRp in ORF1b and strains were characterized by sequencing and phylogenetic analysis. Of the 1500 fecal samples, 39 (2.6%) were positive for HAstV. Of these, both classic and novel HAstV genotypes, including classic HAstV1-HAstV5, novel HAstV-MLB1, MLB2, and HAstV-VA2, were detected. The data in this study revealed a high divergence of HAstV genotypes circulating in pediatric patients admitted to the hospitals with acute gastroenteritis in Chiang Mai, Thailand during 2017-2020.