EXPERIMENTAL TRANSMISSION OF LANGAT (TICK-BORNE ENCEPHALITIS-VIRUS COMPLEX) VIRUS BY THE SOFT TICK ORNITHODOROS-SONRAI (ACARI, ARGASIDAE)

Laboratory studies determined that the soft tick Ornithodoros sonrai S autet & Witkowski is a competent vector of Langat (tick-borne encephal itis virus complex) virus. When ticks fed on suckling mice having a me an viremia of 10(7.2) plaque-forming units per ml, 52% (n = 208) becam e infected, and 84% (n = 87) of the infected ticks transmitted virus b y bite when fed individually on suckling mice greater-than-or-equal-to 27 d after the infectious blood meal. Overall, 79 of 184 (43%) of tic ks exposed to the original viremic mice individually transmitted virus by bite when tested up to 351 d after the infectious blood meal. In a ddition, ticks transmitted virus both transstadially and transovariall y. Some ticks that transmitted virus during their first transmission a ttempt were retested. These ticks transmitted virus during 81 (99%) of 82 refeeding attempts, including ticks that transmitted virus 512 d a fter the initial infectious meal. Therefore, Ornithodoros spp. should be considered as potential vectors of Langat and other tick-borne ence phalitis viruses.