BACKGROUND:Neonatal calf diarrhea (NCD), also known as
calf scours, is caused by viruses, bacteria, and parasites.
Coronavirus is one of the important causes of NCD syndrome.
Electron microcopy has been used for demonstration of viruses
in fecal samples of diarrheic calves since 1969. OBJECTIVES:
The aim of this study was to determine the prevalence of
coronavirus in fecal samples of neonatal calf diarrhea using
electron microcopy examination of fecal samples. METHODS:
For the purpose of this study, a total of 100 cases (under 2 months
of age) of diarrheic calves from 25 commercial farms in four
districts of East Azerbaijan province of Iran were used. Fresh
Fecal samples using sterile swab were collected from every calf
with clinical diarrhea. All samples were transferred into a sterile
container and then were sent to the laboratory to be kept in -20oC
freezer until examination. Electron microscopic examination
was applied to all fecal samples. Chi-square test was used to
analyze the data. RESULTS:According to the results of this study,
coronavirus was present in 15% of cases and a significant
difference was found between the prevalence rate and the
seasons (p<0.05). The highest prevalence was recorded in winter
(28%) and the least prevalence was seen in summer (4%). There
was not any significant difference in both age groups and
different districts according to the prevalence rate of infection.
CONCLUSIONS: Neonatal calf diarrhea is a multi-etiological
syndrome. Among the viral diarrhea, bovine coronavirus is one
of the major causes of this syndrome. For detection of
coronavirus in feces, electron microscope examination is a gold
standard diagnostic technique. It seems that coronavirus can be
considered as one of the important etiologies of neonatal calf
diarrhea in east Azerbaijan of Iran.