Detection of enteric adenoviruses 40 and 41 in stool specimens by monoclonal antibody-based enzyme immunoassays

Molecular characterization of human adenovirus causing infantile acute gastroenteritis in Venezuela before and after rotavirus vaccine implementation

Human adenoviruses (HAdV) of species F are commonly involved in pediatric acute gastroenteritis (AGE). The real impact on Venezuelan health is unknown. To investigate the prevalence and molecular diversity of HAdV in Venezuela, 630 fecal samples collected from children with AGE in 3 cities, from 2001 to 2013, were tested by PCR. Species F and types F40/41 were identified by REA. HAdV was detected in 123 cases (19.5%), most from outpatient females under 24 months old. A progressive and substantial increase in the detection rate was observed over time, significantly higher in rotavirus vaccinated than unvaccinated children (28.4% vs. 9.5%, P = 0.00019). Phylogenetic analysis of 28 randomly selected genomes showed high similarity among HAdV-F40/41 and those worldwide. HAdV-F of type 41 prevailed (79.8%) and clustered into 2 intratypic major clades. The significant involvement of HAdV-F41 in AGE suggests the importance of actively monitoring viral agents other than rotavirus, especially after vaccine introduction.

Viral gastroenteritis in children hospitalised in Sicily, Italy

The aim of the present study was to describe the epidemiologic and clinical characteristics of acute viral gastroenteritis in hospitalised Italian children. A total of 215 stool specimens were collected from January to December 2003 from patients hospitalised in Palermo for acute diarrhoea. Samples were tested for group A rotavirus, astrovirus, adenovirus, norovirus, enteropathogenic bacteria, and parasites. Rotaviruses, mostly belonging to types G1-G4, were detected in 25.1% of samples, astrovirus in 7%, adenovirus in 6%, norovirus in 18.6%, and bacterial agents in 17.2%. No parasitic infections were diagnosed. Mixed infections represented 9.8% of all cases. The mean and median ages of children with rotavirus gastroenteritis were lower than those of children with other viruses (p = 0.029), with the highest median ages being found in astrovirus-infected patients. Vomiting and dehydration were more frequent among patients with viral infection (p < 0.01), and the severity score was significantly higher for children infected with astrovirus or group A rotavirus (p = 0.008). Rotavirus was the leading cause of prolonged hospitalisation (p = 0.005). In conclusion, viruses were confirmed in Italy as the most common cause of severe enteric illness in childhood, with rotavirus types G1-G4, which correspond to those included in the rotavirus vaccines being developed, playing the main role. Routine testing should be introduced for noroviruses, since they seem to represent an important cause of sporadic paediatric gastroenteritis.

Molecular epidemiology of astrovirus infection in Italian children with gastroenteritis

Abstract A 1-year study involving 157 gastroenteritis samples was conducted to investigate the role of human astrovirus (HAstV) as a cause of gastroenteritis in Italian children aged < 2 years. The overall incidence of HAstV was 3.1%. Most cases occurred between March and May, and four of the five isolates were of the HAstV-1 type, the other being HAstV-3. Analysis of genetic variability showed that the three HAstV-1 isolates collected in 2000 clustered together, but separately from the 1999 isolate. The results indicated that HAstV should be considered as a potential diarrhoeal pathogen in Italian children.

Determination of a universal nucleic acid extraction procedure for PCR detection of gastroenteritis viruses in faecal specimens

Four nucleic acid extraction protocols were examined for their suitability for extraction of the ssRNA, dsRNA and dsDNA genomes of gastroenteritis viruses, for PCR detection. Protocol (A), employed specimen lysis with guanidinium thiocyanate, extraction with phenol-chloroform-isoamyl alcohol and nucleic acid purification by size-fractionated silica particles. Protocol (B), utilised specimen lysis with guanidinium thiocyanate and nucleic acid purification by silica, followed by phenol-chloroform-isoamyl alcohol extraction. Protocol (C), employed specimen lysis with guanidinium thiocyanate and nucleic acid purification by RNAID glass powder. Protocol (D), employed specimen lysis with sodium dodecyl sulphate, proteinase K digestion and extraction with phenol-chloroform-isoamyl alcohol. Of the four protocols, (B) appeared to be a suitable candidate 'universal' nucleic acid extraction procedure for PCR detection of different viral agents of gastroenteritis in a single nucleic acid extract of a faecal specimen, irrespective of genome composition. Omission of the phenol-chloroform extraction step did not affect negatively the ability of protocol (B) to allow PCR detection of gastroenteritis viruses in faecal specimens. PCR detection of NLVs, astroviruses, rotaviruses and adenoviruses, in single nucleic acid extracts of faecal specimens obtained from the field, confirmed the universality of the modified protocol (B). We propose the modified protocol (B) as a 'universal' nucleic acid extraction procedure, for monoplex PCR detection of gastroenteritis viruses in single nucleic acid extracts of faecal specimens and for development of multiplex PCR for their simultaneous detection.

Prevalence of enteric adenoviruses among children with diarrhea in four Brazilian cities

BACKGROUND

Enteric adenoviruses are related to child diarrhea and appear to be spread worldwide.

OBJECTIVES

The aim of the present study was to determine the prevalence of enteric adenovirus infection among children in four Brazilian cities.

STUDY DESIGN

stool specimens were collected from children under 5 years of age with acute diarrhea.

RESULTS AND CONCLUSIONS

Enteric adenoviruses were detected in 1.55% (n=1420) of the samples analyzed indicating the circulation of these viruses among Brazilian children in association to diarrheal disease. These agents were isolated throughout the year demonstrating no specific seasonal distribution. Also, no pattern of serotype distribution between the cities was observed.

Viruses and bivalve shellfish

The epidemiological data clearly demonstrates that filter feeding bivalve shellfish can, and do, act as efficient vehicles for the transmission of enteric viruses transmitted by the faecal-oral route. This identified hazard has been documented as a cause for concern by various international agencies and has a long history. Disease outbreaks can occur on an epidemic scale as graphically illustrated by an outbreak of Hepatitis A in Shanghai, China in 1988 involving about 300,000 cases. Improvement of harvesting area water quality offers the most sustainable route to improvement in the virological quality of bivalve shellfish sold live. However there is growing awareness, and concern, that current regulatory standards based on faecal coliform monitoring do not fully protect the shellfish consumer from viral infection. New viral test methods based on PCR, and the development of alternative more reliable faecal pollution indicators, offer new approaches for the further development of public health controls. However, further work is required to build a scientific consensus and to understand the implications of their introduction into legislation.

Chronic intestinal infection due to subgenus F type 40 adenovirus in a patient with AIDS

A case of chronic intestinal infection due to adenovirus type 40 lasting for 13 months in a patient with AIDS is described. Adenovirus particles were detected by electron microscopy in biopsy samples taken from the duodenum 3 months after the onset of diarrhoea. The virus was identified as adenovirus type 40 in stool samples by ELISA monoclonal antibodies to adenovirus group antigen (MAd-g2) and types 40 and 41 (MA 40-1 and MA 41-1). No other enteropathogens were found. These data support a causal relationship between adenovirus 40 and the gastrointestinal symptoms of the patient. This is the first reported case of intestinal infection caused by adenovirus type 40 in a patient with AIDS.