Virus secretion and excretion. Virus shedding was studied
by testing secretions and excretions from weanling voles
inoculated i.m. with 103.5 ID50 of virus. Oropharyngeal
secretions were obtained at weekly intervals from 7 to 42
days postinoculation by using moistened cotton-tipped
swabs. Swab contents from each of three animals were expressed into 1.0 ml
of Eagle minimal essential medium supplemented with 2%
heat-inactivated fetal bovine serum and gentamicin. At weekly intervals from
14 to 63 days postinoculation and at ca. 30- to 60-day
intervals thereafter for 7 months, urine and feces were
collected by placing three or four inoculated animals in
metabolic cages for 3 h. On several occasions, urine
was also collected by direct bladder puncture at the time of
sacrifice. Fecal samples were homogenized in Eagle minimal
essential medium supplemented with 2% heat-inactivated
fetal bovine serum and gentamicin the mixture
was then centrifuged at 900 x g for 10 min to yield 10%