Comparison of five enzyme immunoassays, electron microscopy, and latex agglutination for detection of rotavirus in fecal specimens

Recognition of adenovirus types in faecal samples by southern hybridization in South Australia

The distribution of adenovirus types in faecal samples of patients with suspected viral gastroenteritis from South Australia was determined during the 12-month period, July 1991-June 1992. There were 3299 samples tested and 226 (6.9%) were positive for adenovirus by enzyme immunoassay. Of these 226 samples, 154 (68%) were typed directly using virus DNA extracted from the faecal samples according to the Sma I, Hind III and BstE II restriction patterns and Southern hybridization analysis with pooled viral genomic DNA probes. In this group, 86% of the samples were from patients who were < 3 years of age. Enteric adenovirus types 40 and 41 accounted for 20 and 40% respectively, of these samples, and types 1, 2, 3, 5, 6, 7 and 31 comprised the remainder. Type 40 was detected mainly in the winter and spring periods, and type 41 predominated in the autumn period. The majority of the non-enteric types were found during the late winter and spring periods.

Detection of viruses in environmental samples: suitability of commercial rotavirus and adenovirus test kits

Commercially marketed kits are now available for rapid viral assay of clinical specimens. This study was conducted to determine the suitability of these kits for use in environmental testing. Eight rotavirus kits and one enteric adenovirus kit were screened for sensitivity using simian rotavirus SA11, human rotavirus Wa, and adenovirus 41. The most sensitive rotavirus kit and the adenovirus kit were selected for further evaluation using virus-seeded and unseeded sewage samples. The selected rotavirus kit proved capable of detecting virus at the 10(1) PFU/ml level. The enteric adenovirus kit was similarly sensitive, detecting virus at the 10(1) TCID50/ml level. Neither kit was adversely affected by the presence of sewage. Kit assay revealed 3 of 30 unseeded sewage samples to be positive for rotavirus. Adenovirus positive samples were not detected among the 30 samples. These results were confirmed using electron microscopy. It was concluded that sensitive commercial kits could provide a reasonable alternative to cell culture for the presumptive testing of environmental samples.

Survey of rotavirus infection in a dairy herd: comparison between polyacrylamide gel electrophoresis and two commercial tests

A survey of rotavirus infection in a dairy herd with a history of neonatal diarrhoea was carried out. Faecal samples taken from 15 cows before and after calving as well as faeces taken from their calves daily from birth to two weeks of life were tested for rotavirus by polyacrylamide gel electrophoresis (PAGE) and compared with an ELISA and a latex agglutination commercial test. Rotavirus excretion was not detected in faeces from cows around parturition by any of the three tests. However, all of their calves shed rotaviruses during the observation period. The onset of rotavirus excretion determined by PAGE ranged from day 2 to day 8 of life (day 4.8 +/- 1.8 on average) and lasted for 4 to 7 days (5.3 +/- 1.1 days on average). Chi-square test showed a significant association (P = 0.0001) between the presence of rotavirus and the altered consistency of calves faeces. All the three tests showed similar results (overall agreement 92.5%) but discrepancies were detected mainly at the beginning or at the end of the rotavirus excretion period. Results obtained with both commercial kits closely paralleled each other and parameters other than sensitivity, specificity, diagnostic accuracy or predictive values have to be considered as selection criteria.