Comparison of mice and cell cultures for the isolation of tick-borne viruses.

Three methods of isolating viruses from 10 tick pools were compared; none of the methods produced all 13 of the viruses isolated (7 viruses of the bunyaviridae and 6 orbiviruses). Inoculation of homogenised ticks into various cell lines was the most successful, yielding 11 virus isolations. Only 2 tick homogenates induced overt signs of infection following intra-cerebral inoculation of 2-day-old mice. However, when inoculated mouse brain was passaged in various cell lines, 8 of 12 isolations were made. The rates of success of the 3 methods of virus isolation appeared to vary according to the type and titre of the virus in the tick pool.