EPIDEMIOLOGICAL STUDIES ON JAPANESE ENCEPHALITIS IN KYOTO CITY AREA, JAPAN IV. NATURAL INFECTION IN SENTINEL PIGS

Abstract
Natural infection with Japanese encephalitis virus in 3 sentinel pigs held in separate experimental huts was examined daily by virus recovery from blood samples of the pigs and from mosquitoes after incubation for about 7 days from their blood feeding and by HI [hemagglutination inhibition] antibody titration of the blood samples. After a period of low infection rates, below 6%, for about 2 wk in engorged Culex tritaeniorhynchus summorosus, high mosquito infections of over 30% from each viremic pig occurred for 2-3 days. The pigs were probably bitten by many infected but not infective mosquitoes in a period of about 10 days before infection.