Astrovirus infection in children in lagos, Nigeria

Molecular characterization of human astrovirus infection in children under 5 years of age with acute gastroenteritis in Tehran, Iran, 2021-2022: co-infection with rotavirus

Human astroviruses (HAstVs) are considered important causative pathogens of acute gastroenteritis (AGE) in children under 5 years of age worldwide, along with group A rotavirus (RVA), norovirus (NoV), and enteric adenovirus (EAdV). The present study was aimed to both detect HAstV and its co-infections and investigate genetic analysis of circulating HAstV and co-infected virus in hospitalized children under 5 years of age with AGE in Iran. Accordingly, a sum of 200 stool specimens were screened by PCR for HAstV during 2021-2022. The HAstV was found in 0.5% of 200 specimens (n = 1) while was co-infected with RVA. The genetic and phylogenetic analysis indicated HAstV1 genotype, which clustered with viruses from lineage 1b, which has not been previously reported in Iran. The detected RVA strain belonged to G1 lineage II/P[8]-lineage III, which has been reported previously in Iran as the most common strain. The further genetic analysis of RVA VP6 and NSP4 demonstrated an atypical genotype pattern G1P[8]-I1-E2, as a mono-reassortant of a Wa-like genogroup, which appeared to be reassorted with the NSP4 gene of E2 genotype of the G2P[4] DS-1 genogroup. Although the clinical outcomes of the AGE-causing viruses co-infection is not yet entirely clear, it seems that future studies will be helpful to merge clinical and epidemiological data of co-infecting viruses for a more accurate medical and clinical relevance in symptomatic children.

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.

Molecular study of human astrovirus in Egyptian children with acute gastroenteritis

Introduction

Human astrovirus (HAstV) has been increasingly identified as an important cause of acute gastroenteritis in young children. Limited information is available about the prevalence and genotype distribution of classic HAstV causing acute gastroenteritis in Egyptian children.

Methods

Stool samples were collected from 100 infants and children attending the gastroenterology outpatient clinic in Mansoura University Children Hospital and suffering from acute gastroenteritis during the period extending from January 2018 to January 2019. Samples were tested for HAstV using reverse transcription PCR. Genotyping was performed using type-specific reverse transcription nested PCR.

Results

Among 100 children included in this study, the detection rate of HAstV was 11% (11 patients). There was a significant difference regarding age between cases positive and negative for HAstV (p=0.005). There was a higher prevalence of HAstV in children aged one year or younger. Significant association was detected between HAstV positive cases and rural residence (p=0.002), summer season (p=0.025) and fever (p=0.017). The HAstV genotypes detected were HAstV-8 (8/11, 72.7%), HAstV-3 (2/11, 18.2%) and HAstV-2 (1/11, 9.1%).

Conclusions

This study suggests that HAstV is a common pathogen causing gastroenteritis in Egyptian children especially in rural areas. The most frequent HAstV genotype in our study was HAstV-8.

Molecular epidemiology of astrovirus in children with gastroenteritis in southwestern Nigeria

Human astrovirus (HAstV) is recognized as one of the major causative agents of acute gastroenteritis in children worldwide. Data on the genetic diversity of HAstV in Nigeria are limited. The aim of this study was to determine the prevalence and molecular epidemiology of classical HAstV in children under 5 years of age with acute gastroenteritis in Ogun State, Nigeria. Fecal samples (331) as well as socio-demographic and clinical data were collected across the three senatorial districts of the state from February 2015 to April 2017. One hundred seventy-five samples were randomly selected and analyzed for the presence of HAstV using RT-PCR. PCR amplicons from positive samples were sequenced, and phylogenetic analysis was done to determine genotypes and lineages. The overall prevalence rate was 19.4% (34), with the highest occurrence observed in 2015 (41.4%). Viral coinfections were detected in 13 cases (38.2%). HAstV infection occurred throughout the year and in all age groups, mainly in the age group of 0-12 months. There was significant association between prevalence rate and collection year; however, no association was observed with gender, age, symptoms or risk factors. HAstV-5 was the predominant genotype (76.5%) circulating throughout the study period, followed by HAstV-1 (23.5%), which circulated only in the first 2 years of the study. Phylogenetic analysis showed that all HAstV-5 strains detected belonged to the 5a lineage, while HAstV-1 strains were grouped into lineage 1b. This study, to the best of our knowledge, is the first comprehensive report on molecular characterization of classical HAstV among children with gastroenteritis in the country, and this will serve as baseline information for implementing appropriate infection control practices.

Prevalence of astrovirus, adenovirus, and sapovirus infections among Iranian children with acute gastroenteritis

AIM

This study aimed to determine the prevalence of Human Astroviruses (HAstVs), enteric Adenoviruses (HAdVs), and Sapoviruses (SaVs) in acute diarrhea patients, as well as their relation to age, sex, and season.

BACKGROUND

Acute gastroenteritis is one of the most common diseases affecting children <5 years old and viral agents with approximately >75% are the major causative agent of acute infectious diarrhea. After Rotavirus and Norovirus, the greater viral agents of acute gastroenteritis include HAstVs, HAdVs, and SaVs. To the best of our knowledge, there are sparse studies in Iran detecting at least three enteric viruses as causative agents of diarrhea simultaneously.

METHODS

The sample was collected from children referring to pediatric medical centers in Tehran, Iran; they were tested for Astrovirus, enteric Adenovirus, and Sapovirus by conventional PCR method. The association of incidence of viral enteric agents was evaluated with age, sex and seasonal pattern in children <5 years old.

RESULTS

The positive case number among acute gastroenteritis patients was 17/120 (14.1%). Patients ranged in age within 1-60 months, but 52.9% were aged ≤ 12 months. Males comprised the majority (70.6), and the male: female ratio was 2.4. HAstV was the most frequently detected virus (6.7%), while SaVs were detected only in 2.5% of cases. Mixed infections were not detected in these samples. The highest rate of HAstV was identified in winter (66.7%), HAdV in fall (66.7%), and SaV in winter (33.3%).

CONCLUSION

These findings underscore the importance of monitoring the epidemiology of HAstV, HAdV, and SaV as causative agents of viral diarrhea infections.