exogenous pyrogen

例句：

1. 1. The bacteria that causes food poisoning are often exogenous pyrogens.
   引起食物中毒的细菌通常是外源性致热原。
2. 2.The study found that the exogenous pyrogen levels in the blood were significantly higher than those in healthy individuals.
   研究发现，血液中的外源性致热原水平显著高于健康个体。
3. 3. The researcher believes that the exogenous pyrogen is responsible for the fever symptoms experienced by patients with certain diseases.
   研究人员认为，某些疾病患者出现的发烧症状是由外源性致热原引起的。