Instead, it was more likely to be from an infectious source.

相反，更有可能来自一个传染源。

youdao

Hosts can be diseased from latency condition by the decreasing of host's immunity and stimulation of condition, and so on , then become a carrier and infectious source.

外界刺激、宿主免疫力的降低等因素都可以使宿主由潜伏感染状态发病，成为带毒者和传播源，因此，对潜伏感染建立及维持机理的研究就显得尤为重要。

youdao

The peasants, especially middle-aged and old populations, were key crowd of malaria treatment and prevention. Malaria control measures for treating infectious source were well implemented.

疟疾防治工作重点人群为农民，以青壮年及老年人为主。针对治疗传染源的抗疟措施执行情况较好。

youdao

The first involves sheep. Researchers have found that hair sheep are a good source of blood for use in tests to diagnose infectious diseases in people.

VOA: special.2009.08.03

The 13 cases, many of them linked to one Saudi hospital, suggest that the spread of this coronavirus may have reached a dangerous new stage in which it is spreading from one human to another, rather than infecting humans from another source such as an infected animal, according to infectious-disease experts.

WSJ: Virus's Toll in Saudi Arabia Raises Fears of Faster Spread