Low Frequency of Adenovirus, Rotavirus, and Norovirus in Pediatric Diarrheal Samples from Central Iran

Background: Acute viral gastroenteritis is a disorder that affects children globally but mostly in developing countries. Adenoviruses, rotaviruses, and noroviruses are the leading viral causes of childhood gastroenteritis. Objectives: This study is the first to investigate the frequency of these viruses in diarrheal samples from pediatric patients living in central Iran. Methods: A total of 173 samples of pediatric diarrhea, from May 2015 to May 2016, were included in this descriptive cross-sectional study. The samples were analyzed using in-house developed PCR and reverse transcription (RT)-PCR methods to investigate the frequency of adenoviruses, rotaviruses, and noroviruses. Results: Out of 173 samples of pediatric diarrhea, eight were shown to contain enteric viruses (4.6%): (1) four with adenoviruses (2.3%); (2) three with rotaviruses (1.7%); and (3) one with a genogroup II norovirus (0.6%). Most of the positive samples were obtained from children under the age of seven. The most common additional clinical symptoms in pediatric patients with viral agents were fever, vomiting, and abdominal pain. Conclusions: In central Iran, adenoviruses and rotaviruses were rarely found as agents responsible for gastroenteritis. Although viral gastroenteritis in this area had less frequency than bacterial gastroenteritis, we need to monitor all enteropathogenic agents for longer periods to understand better real endemicity and the possibility of unexpected viral enteritis outbreaks.

Norovirus outbreaks in long-term care facilities in Catalonia from 2017 to 2018

Norovirus is the leading cause of outbreaks of acute viral gastroenteritis. We carried out this study to investigate outbreaks in long-term care facilities reported in 2017 and 2018 in Catalonia (Spain). The characteristics of the centers, exposed persons and the genogroups responsible were analyzed. Viral loads were estimated. The attack rate (AR) of the outbreaks studied, and the rate ratio (RR) and the odds ratio (OR) and their 95% confidence intervals as measures of association were calculated. The mean cycle thresholds were compared using the t-test for independent means. We included 30 outbreaks (4631 exposed people). The global AR was 25.93%. The RR of residents vs. staff was 2.28 (95% CI 2.0–2.6). The RR between AR in residents with total or severe dependence vs. residents with moderate, low or no-dependence was 1.23 (95% CI 1.05–1.45). The AR were higher in smaller centers than in larger ones (38.47% vs. 19.25% and RR 2; 95% CI 1.82–2.2). GII was responsible for 70% of outbreaks. No association was found between the genogroup and presenting symptoms (OR 0.96; 95% CI 0.41–2.26). Viral loads were higher in symptomatic than in asymptomatic patients (p = 0.001).

Dasabuvir inhibits human norovirus infection in human intestinal enteroids

Human noroviruses (HuNoVs) are acute viral gastroenteritis pathogens that affect all age groups, yet no approved vaccines and drugs to treat HuNoV infection are available. In this study, with a human intestinal enteroid (HIE) culture system where HuNoVs are able to replicate reproducibly, we screened an antiviral compound library to identify compound(s) showing anti-HuNoV activity. Dasabuvir, which has been developed as an anti-hepatitis C virus agent, was found to inhibit HuNoV infection in HIEs at micromolar concentrations. Dasabuvir also inhibited severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and human A rotavirus (RVA) infection in HIEs. To our knowledge, this is the first study to screen an antiviral compound library for HuNoV using HIEs and we successfully identified dasabuvir as a novel anti-HuNoV inhibitor that warrants further investigation.

Clinical Implications of Multiplex Pathogen Panels for the Diagnosis of Acute Viral Gastroenteritis

Acute gastroenteritis remains a significant cause of morbidity and mortality both in high and low-resource settings. The development of nucleic acid based testing has demonstrated that viruses are a common, yet often undetected, cause of acute gastroenteritis. The development of multiplex pathogen PCR panels makes it possible to detect these viral pathogens with greater sensitivity and rapidity than with previous methods. At present, there is insufficient evidence to recommend the routine use of these panels for the average patient with acute gastroenteritis. However, there are specific scenarios and patient populations such as epidemiology/outbreak surveillance, antimicrobial stewardship, and the care of immunocompromised patients where these tests could be clinically useful today. Further research on the effect of these syndromic panels on provider antibiotic prescribing behavior and patient length of stay will be necessary in order to know their ultimate role in clinical practice.

Molecular detection and phylogenetic analysis of human parechovirus in children with acute gastroenteritis in Iran

Aim: Human parechovirus (HPeV) is one of the major causes of acute gastroenteritis in children. Materials & methods: Stool specimens (n = 250) were collected from children aged ≤3 years during 2018–2019. HPeV RNA was detected by reverse transcription-PCR and genotyping by VP1 gene, Rotavirus (RV) screened by ELISA. Results: HPeV was detected in 12% of the cases. The children under 6-months old (64.2%) were a sensitive group and HPeV was more prevalent during January–February (73.3%). The co-infection of HPeV with RV was 50%. All of the sequenced samples belong to the HPeV-1 genotype. Conclusion: HPeV-1 is one of the major causes of acute viral gastroenteritis in children and the co-infection of RV can be an additional infection in some cases.

Porcine rotavirus B as primary causative agent of diarrhea outbreaks in newborn piglets

Rotavirus (RV) is considered a major cause of acute viral gastroenteritis in young animals. RV is classified into nine species, five of which have been identified in pigs. Most studies worldwide have highlighted diarrhoea outbreaks caused by RVA, which is considered the most important RV species. In the present study, we described the detection and characterization of porcine RVB as a primary causative agent of diarrhoea outbreaks in pig herds in Brazil. The study showed a high frequency (64/90; 71.1%) of RVB diagnosis in newborn piglets associated with marked histopathological lesions in the small intestines. Phylogenetic analysis of the VP7 gene of wild-type RVB strains revealed a high diversity of G genotypes circulating in one geographic region of Brazil. Our findings suggest that RVB may be considered an important primary enteric pathogen in piglets and should be included in the routine differential diagnosis of enteric diseases in piglets.

Epidemiology of Acute Rotavirus Diarrhea Among Hospitalized Children Under Five Years of Age in Hefei, China, During 2015 - 2018

Background: Rotavirus infection is still the leading cause of acute viral gastroenteritis in children under five years of age worldwide. It is also a serious public health concern in China. Objectives: This study aimed to obtain information about rotavirus diarrhea among hospitalized children in Hefei City, Anhui Province, China, in recent years. Methods: We conducted a retrospective study over four years (2015 - 2018) examining hospital admission records of rotavirus infections at the First Affiliated Hospital of Anhui Medical University in Hefei City of Anhui Province, China. Results: A total of 1,095 cases with acute viral gastroenteritis requiring hospital admission from January 2015 to December 2018 were analyzed. Among them, 276 cases were positive for rotavirus A infection, accounting for 25.21% of the total number of children suffering from acute diarrhea. The detection rate of rotavirus A was the highest in children aged 1 - 2 years. The peak month for rotavirus infection during 2015 - 2018 was December and January. The hospitalized children with rotavirus infection showed dehydration, electrolyte disorder, liver function abnormality, and myocardial enzyme abnormality. Conclusions: Rotavirus is still the first pathogen of acute viral diarrhea in children in Hefei, especially children < 2 years of age, which highlights the need for widespread rotavirus immunization in young children.

2’-Fluoro-2’-deoxycytidine inhibits murine norovirus replication and synergizes MPA, ribavirin and T705

Noroviruses are the main causative agents of acute viral gastroenteritis worldwide. However, no vaccine or specific antiviral treatment is available, imposing a heavy global health burden. The nucleoside analogue 2’-fluoro-2’-deoxycytidine (2’-FdC) has been reported to have broad antiviral activity. Here, we report that 2’-FdC significantly inhibits murine norovirus replication in macrophages. This effect was partially reversed by exogenous supplementation of cytidine triphosphate. The combination of 2’-FdC with mycophenolic acid, ribavirin or favipiravir (T705) exerts synergistic antiviral effects. These results indicate that 2’-FdC is a potential candidate for antiviral drug development against norovirus infection.