A minor prevalent strain in a severe outbreak of foal diarrhea associated with serotype 3 rotavirus.

The researchers investigated an outbreak of foal diarrhea due to a particular strain of rotavirus and discovered a unique isolate strain that had markedly different characteristics from the majority of isolates found in the sample group.

Introduction to Foal Diarrhea Outbreak Due to Serotype 3 Rotavirus

• The study examined an episode of severe foal diarrhea which was caused by serotype 3 rotavirus (RV).
• This outbreak was observed in 53% of the 168 recorded cases within the period between March and July 1987. The outbreak was classified as an epizootic, referring to a disease that appears as new cases in a given animal population, during a given period, with a frequency substantially exceeding what is “expected” based on an established baseline.

Isolation and Examination of RV Strains

• The researchers identified and isolated a total of 51 strains of RV from the 62 diarrheal feces samples that were examined during the study.
• One particular isolate, named CH-3, stood out due to its unique electropherotype of viral RNA that was distinct from the other prevalent strains on the farm.

Testing of the CH-3 Strain

• The unique CH-3 strain was tested against antisera from serotypes 1 to 12 of human and animal RV in neutralization tests. However, no positive reactions were observed, indicating this isolate could be a new or rare variant.
• The double-stranded RNAs (dsRNAs) of the CH-3 virus were, however, hybridized – that is, they interacted to form a hybrid – with a probe, which was prepared from a strain of equine serotype 3 RV. This implies that there may be a genetic similarity or relationship between this unique CH-3 isolate and other serotype 3 RVs found in horses.