31. Gerberding expressed hope that the medical sleuths would be able to trace the source of infection quickly. 32. The search continues for cattle that might have eaten contaminated feed, the most likely source of infection . 33. Bats are presumed to be the culprit only because all other sources of infection were ruled out. 34. "We contact-traced all her movements in Singapore and did not find any sources of infection , " he said. 35. The disease can also be zoonotic, with ruminants and dogs providing the principal source of infection for humans. 36. These stressed trees can then act as a source of infection by other organisms of nearby healthy trees. 37. Clearing an infection does not always create immunity if there is a new or continuing source of infection . 38. In most major outbreaks the source of infection has been water in the air-conditioning systems of large public buildings. 39. That letter had been considered the likely source of infection for all the anthrax cases in and around Washington. 40. Officials acknowledged that the source of infections could be cross-contaminated mail, though epidemiologists are pursuing a multitude of theories.
