Stool Adenovirus Research Articles

Seasonal variation on the presence of adenoviruses in stools from non-diarrheic patients.

Human adenoviruses (HAdV), members of the Adenoviridae family, are excreted through the fecal route and may be present in the feces of humans consuming contaminated food or water. The presence of HAdV from different serotypes in the feces of healthy individuals was already reported using conventional polymerase chain reaction; however, real-time PCR (qPCR) may reveal not only the rates of detection as well as demonstrate the viral loads excreted by healthy persons. Aiming to identify and characterize the presence of adenoviruses in stool samples, 147 fecal samples from patients with no records of diarrhea were analyzed (74 from winter season and 73 from summer) by Real-Time PCR (qPCR) assay and conventional PCR. HAdV genome was present in 43.8% (32/73) of stools samples collected during summer season and 21.6% (16/74) during winter. The rate of detection of genomic copies (gc) ranged from 4.04×102 to 6.72×105gc/g of feces among the 147 samples analyzed, of which the ranged of genomic copies of DNA HAdV was major in summer. All samples were negative when tested for rotaviruses (RV) and noroviruses (NoV) by PCR conventional and qPCR respectively. HAdV is excreted constantly by infected individuals in the absence of clinical signs and the occurrence may vary seasonally.

Detection of small amounts of human adenoviruses in stools: comparison of a new immuno real-time PCR assay with classical tools

The detection of low virus concentrations in biological matrices, especially stool samples, is facing significant limitations as far as common diagnostic methods (enzyme-linked-immunosorbent assay (ELISA) or quantitative real-time PCR (qPCR)) are considered. Here the development of a new immuno real-time PCR (iPCR) is described and its performance in the detection of human adenoviruses (HAdVs) in spiked stools is compared with those of ELISA and qPCR assays. For the iPCR, detection of the sandwich formed by the complexation of capture antibody-antigen-detection antibody was performed by qPCR thanks to the substitution of peroxydase by a chimeric DNA. This modification increased the detection sensitivity 200-fold compared to ELISA. The direct qPCR results revealed that only 0.3–9.5% of the spiked HAdV were detectable, resulting from important losses of DNA occurring at the extraction step. This step was not necessary in the iPCR workflow, avoiding this drawback. The losses of viral particles occurred at the elution step from the stool only. The recovery rate of the iPCR was thus better and ranged between 21 and 54%. As a result, iPCR enabled the detection of lower virus concentrations in stool samples compared to those detected by ELISA and qPCR. The iPCR could be considered as a ‘hyper sensitive ELISA’ for early detection of HAdV infections, especially in the case of immunocompromised patients after haematopoietic stem cell transplant.

First reported outbreak of diarrhea due to adenovirus infection in a hematology unit for adults.

Numerous outbreaks of adenovirus infection from different types of health care settings, except a hematology unit, have been reported. This is the first report describing an outbreak of adenovirus infection causing diarrhea among adult hematopoietic stem cell transplant recipients. Six of 21 patients from the outbreak cohort were affected with diarrhea. Electron microscopy, cell culture, and direct DNA sequencing of amplicons generated from stool and blood samples were used to investigate this outbreak. Electron microscopy and cell culture detected adenovirus in stools from symptomatic patients. DNA sequencing of amplicons generated from stool samples confirmed nosocomial transmission of infection from a single index case. The outbreak strain was also detected in plasma of four of these patients, suggesting systemic infection. The outbreak strain was identified as type 12. Standard infection control measures were effective to control this outbreak.

GASTROINTESTINAL (GI) ADENOVIRUS TREATED WITH ORAL RIBAVIRIN IN SEVERE COMBINED IMMUNODEFICIENCY (SCID). 53

JH presented at 5 months of age with FTT, and respiratory distress due to parainfluenza virus type III (PFIII). Our evaluation led to a diagnosis of SCID. Respiratory symptoms improved with long-term nebulized Ribavirin and supportive care, but GI tract adenovirus (AV) resulted in continuing management problems (cramps, diarrhea, FTT). For definitive therapy JH received a maternal-donor, T-cell-depleted bone marrow stem cell transplant(no pre-conditioning chemotherapy). T lymphocyte function reconstituted during the subsequent 3-4 months, with elimination of the PFIII. GVHD affecting the bone marrow developed, with ensuing life-threatening pancytopenia. Worsening GI symptoms and increase in stool AV were noted with anti-GVHD therapy(corticosteroids and cyclosporin A). We hypothesized that exacerbation of the AV infection was in part due to the immunosupressive treatment and, additionally, that the immune response generated against the AV was resulting in simultaneous activation of maternal T lymphocytes capable of causing and/or worsening the GVHD. Cognizance that systemic AV infections can be catastrophic in immunocompromised patients prompted us to escalate therapy. Recent studies indicating successful and less toxic usage of oral Ribavirin for the treatment of various viruses led us to consider this over parenteral therapy. Low dose therapy, 20 mg/kg/day was initiated, with equivocal results. One week later, dosing of 200 mg/kg/day resulted in immediate clinical improvement (reduction in vomiting, loose stools, abdominal cramping, and improved feeding). Stool AV was quantified by enumerating viral particles via electron microscopy. Post-treatment viral load was decreased to 20% of that of immediate pre-treatment levels. To our knowledge, this is the first report of oral Ribavirin therapy for GI tract AV infection. While long-term effects of Ribavirin remain unknown, clinical improvement in JH demonstrated that oral Ribavirin can be of benefit as anti-viral therapy in immunodeficient patients.

Detection of adenoviruses in stools from healthy persons and patients with diarrhea by two-step polymerase chain reaction.

The use of the polymerase chain reaction (PCR) for detection of human adenoviruses in diluted stool samples was investigated. Two sets of nested primers, including primers specific for the hexon-coding region and for the E1B region of enteric adenoviruses (EAd), were assessed by two-step amplification. The primers constitute two different PCR systems designed for the detection of adenoviruses belonging to all six subgenera (A-F), and the two EAds Ad40 and Ad41, respectively. In a two-step PCR mediated amplification a single virus particle was detected when the two sets of general hexon primers or EAd specific primers were used. Earlier results from PCR detection of adenoviruses in stool from children suffering from diarrhea gave indications that adenovirus particles are commonly shed in stools without being identified as the cause of illness [Allard et al.: Journal of Clinical Microbiology 28:2659-2667, 1990]. Therefore, the general and the EAd specific PCR assays were assessed on 150 stool specimens from three groups including 50 healthy children, 50 healthy adults, and 50 adults suffering from diarrhea. When the two sets of general hexon primers were used, 25 of the 50 specimens from the healthy children (mean age 21 months) were found positive by two-step PCR amplification. Nine of the 50 specimens from the healthy adults (mean age 32 years) were found positive whereas 12 of the 50 specimens from sick adults (mean age 31 years) gave amplification products, using the two sets of general hexon primers in a nested fashion. None of the 150 specimens were found to be positive by two-step PCR amplification using the two sets of EAd-specific primers.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigen Detection with Monoclonal Antibodies for the Diagnosis of Adenovirus Gastroenteritis

A monoclonal antibody-based enzyme immunoassay (EIA) was developed for direct detection of enteric adenoviruses in stool specimens from individuals with gastroenteritis. Tests specific for each of the enteric adenoviruses, adenovirus type 40 (Ad 40) and type 41 (Ad 41), were designed. The sensitivity of the assay was determined by comparing the results of the EIA with isolation of virus in Graham 293 cells from stools that contained particles having adenovirus morphology. The standard for specificity was analysis of adenovirus genome profiles after digestion with SmaI endonuclease. The sensitivity was 95.8% (23 of 24) for Ad 40 and 97.1% (34 of 35) for Ad 41. The specificity was 95.7% (45 of 47) and 97.2% (35 of 36), respectively. The two type-specific monoclonal antibodies could be mixed in an EIA for identification of enteric adenoviruses in stools without loss of reactivity in either type. The EIA permits rapid diagnosis and type-specific identification of enteric adenoviruses in gastroenteritis.

Direct detection and differentiation of fastidious and nonfastidious adenoviruses in stools by using a specific nonradioactive probe.

Restriction fragments of fastidious human adenovirus type 41 (Ad41) were cloned in vector plasmid pBR322. A rapid and sensitive nonradioactive molecular-hybridization technique (M. Renz and C. Kurz, Nucleic Acids Res. 12:3435-3444, 1984) showed that one clone specifically detected fastidious Ad40 and Ad41 (subgenus F) without cross-hybridization with nonfastidious adenoviruses. This clone was mapped in a region of the Ad41 genome corresponding to early transcription unit E1B of Ad2. A number of DNAs from fastidious and nonfastidious adenoviruses were extracted, without cultivation, from stools of children with gastroenteritis and were hybridized with an Ad2 probe and with the cloned probe, allowing the differentiation of the two groups of viruses. This method could detect DNA quantities as low as 10 pg and should be particularly suitable for stool samples containing adenoviral DNA in amounts too low to be detected by staining with ethidium bromide.

Direct identification of enteric adenovirus, a candidate new serotype, associated with infantile gastroenteritis.

Two enzyme-linked immunosorbent assay techniques for detection of adenovirus in stools were developed. The first, which is group-specific, detects the 35 established adenovirus types and, in addition, enteric adenoviruses associated with infantile gastroenteritis. The second technique, which is type-specific, selectively detects enteric adenovirus. The efficiency of these techniques was assayed on nine coded stool specimens from Glasgow children. Eight of nine was classified as adenovirus by the group-speicific enzyme-linked immunosorbent assay. The six enteric adenovirus specimens were antigenically distinct from each of the 35 established adenovirus types but not from each other. They are suggested to represent a new adenovirus serotype which appear to be associated with gastroenteritis without clear-cut respiratory symptoms.

A small-scale feeding trial of an attenuated type 3 poliovirus USOL-D bac vaccine (author's transl)

A small-scale trial of an attenuated type 3 poliovirus vaccine prepared with the USOL-D bac strain was carried out as a part of the collaborative study under the WHO's auspices.In two closed institutions 26 children 5 to 13 months of age who had no history of anti-polio vaccination were administered with the vaccine, and 10 children of similar ages were left unvaccinated as room contacts. Of all the children, 21 vaccinees and 5 contacts had no circulating antibody against polioviruses. Most of the children in one institution (Infant Home H) excreted type 2 adenovirus in stools before or during the trial. No viral agent was isolated from pre-trial stools collected in the other institution (Infant Home B).Inoculated with a single dose of the vaccine containing105.8 TCD50 of the virus, the vaccinees in both institutions excreted considerably large amounts of type 3 poliovirus for long periods. One child in Infant Home B showed only transient excrection of the minimal detectable amount of virus on day 8. In Infant Home H the longest duration of virus excretion was 41 days with an average excretion period of 33.6 days, while in Infant Home B the longest duration of excretion was not less than 85 days with an average of 61.4 days. There was, however, no such great difference in the average of the maximal virus content per gram of stool of individual children between the two infant homes. This average was 107.4 TCD50 in the H institution and 107.1 TCD50 in the B. Stools of the contact children were examined only in Infant Homes H, where only one contact child excreted a small amount of virus on day 6.Circulating antibody response was good in all the vaccinees, except the one mentioned above in Infant Home B. This child and three contacts of Infant Home H, including the one mentioned above, showed no rise of circulating antibody. The contacts of Infant Home B were fed Sabin types 1 and 2 divalent vaccine one week after the commencement of the trial, but they showed only type 3 antibody response. This may indicate that efficient contact infection with the vaccine virus took place during the first week of the trial.Reversion of rct/40 character of virus progeny was observed rather early, and 45per cent of the isolates investigated was positive for rct/40 character, while only 14per cent was negative. The incidence of reversion appeared irregularly in individual children. Some children excreted rct/40± of ract/40+ virus early and again excreated rct/40- virus later.The results obtained indicated that the USOL-D bac virus multiplied well in the gut of children, who showed a good antibody response, although it was genetically unstable. Efficient contact infection was observed in one institution where children were in close contact with one another in a play-room. Contact infection was almost completely prevented in the other institution where children were kept in bed.The USOL-D bac virus was discussed for suitability as a candidate for a more acceptable type 3 poliovirus vaccine strain, in comparison with the Sabin type 3 Leon 12a1b virus.