Molecular Diagnosis of Streptococcus equi subsp equi along with Carrier Potential in Clinically Affected Horses

Streptococcus equi subsp. equi is highly contagious equine-specific disease characterized by abscessation of the neck and head lymph nodes. The prevalence and carrier potential of S. equi was investigated using 194 nasal swabs and 56 pus samples collected from clinically infected horses and examined by PCR. S. equi was detected in 122 (48.8%) horses. Of these, 20 (10 <2 year and 10 between 2 and 5 years old) remained positive after one week of recovery, and wee monitored for 12 weeks to study their carrier status using PCR. It is concluded that PCR is rapid and sensitive diagnostic method for the identification of S. equi and the recovered horses should be quarantined at least for 9 weeks because they remained carriers and potential source of infection for susceptible equines.