Australian racing officials ordered an inspection of more than 100 racetracks Friday after a Hendra virus health scare at Sydney\'s Randwick Racecourse. Racing New South Wales chief Peter V\'Landys said parts of the prestigious course had already been sealed off due to their proximity to large fruit bat colonies and similar measures could be taken at the state\'s other tracks. \"What we\'re doing is a risk assessment to see if there are bats at race courses and training facilities,\" said V\'Landys. \"If there are, we\'ll put in place biosecurity measures to make sure there\'s no exposure ... we\'re doing a complete audit to make sure.\" No weekend races would be cancelled, he stressed. The audit follows a Hendra scare at the Randwick stables, where an ill thoroughbred was thought to have contracted the deadly virus. Tests cleared it of Hendra infection, but V\'Landys said the incident underscored the need for vigilance. Highly fatal to humans, Hendra is carried by fruit bats (flying foxes) and spread to horses through half-chewed fruit or water and food contaminated by their urine and droppings. Nine horses have died since early June in the biggest ever outbreak of Hendra since it was discovered in 1994, including one case just 500 kilometres (300 miles) from Sydney, the furthest south the virus has been seen. At least 48 people have been exposed but no human cases have been recorded in this outbreak. Four of the seven people to ever contract Hendra have died. \"Considerable\" numbers of fruit bats visited Randwick Racecourse daily to feed on its fig trees and V\'Landys said horses trained and stabled there could be at risk. Any other racecourse in populous New South Wales state found to be vulnerable to Hendra would be ordered to take similar precautions to those in place at Randwick, including covering food and water and roping off fruit trees so horses can\'t feed beneath them.