跨物种感染

跨物种感染（Cross-species transmission；host jump）是指病原获得感染新物种宿主能力，进而感染新宿主、在新宿主个体间传播的现象^[1]，关于此现象的研究以病毒为主，但细菌等其他微生物也可能发生^[2]。跨物种感染的第一步为病原与一个新宿主物种个体接触，其后病原可能逐渐适应新的宿主而造成疾病爆发，是新兴传染病（特别是病毒疾病）的起因之一^[3]。多数感染人类的病毒均起源于感染其他动物的病毒，包括SARS-CoV、MERS-CoV、SARS-CoV-2、猪流感病毒、禽流感病毒与埃博拉病毒等^[4]。

跨物种感染的具体机制因病原种类而异，且目前对此了解尚有限，突变率（英语：Mutation rate）较高的病毒可能可较快适应新的宿主物种，抵抗其免疫反应而得以继续传播。经常互相接触的物种间较容易发生跨物种感染，但不常互相接触的物种间也可能透过中间宿主发生，即病原由自然宿主透过中间宿主传给新的宿主^[5][6]，例如SARS-CoV从菊头蝠透过果子狸（果子狸SARS冠状病毒）传给人类^[7]。另外亲缘关系接近的宿主间也较容易发生跨物种感染，可能是其免疫反应机制相近所致，人类病毒即大多源于感染其他哺乳动物的病毒，而植物病毒应无法跨物种感染人类^[3]。若病原在跨物种感染后不再感染原本的宿主，而只在新宿主间传播，则为宿主转换^[8]。

参考文献

• 病毒主题

1. Childs, JE; Mackenzie, JE; Richt, JE, Wildlife and Emerging Zoonotic Diseases: The Biology, Circumstances and Consequences of Cross-Species Transmission, Current Topics in Microbiology and Immunology 315, Springer-Verlag Berlin Heidelberg: Springer Science+Business Media: 129–134, 2007, ISBN 978-3-540-70961-9, doi:10.1007/978-3-540-70962-6
2. Benavides, JA; Cross, PC; Luikart, G; Creel, S, Limitations to estimating bacterial cross-species transmission using genetic and genomic markers: Inferences from simulation modeling, Evolutionary Applications, 2014, 7 (7): 774–787, PMC 4227858 , PMID 25469159, doi:10.1111/eva.12173
3. Parrish, CR; Holmes, EC; Morens, DM; Park, EC; et al, Cross-Species Virus Transmission and the Emergence of New Epidemic Diseases, Microbiol. Mol. Biol. Rev., 2008, 72 (3): 457–470, PMC 2546865 , PMID 18772285, doi:10.1128/MMBR.00004-08
4. Faria, NR; Suchard, MA; Rambaut, A; Streicker, DG; et al, Simultaneously reconstructing viral cross-species transmission history and identifying the underlying constraints, Philos Trans R Soc Lond B Biol Sci, 2013, 368 (1614): 20120196, PMC 3678322 , PMID 23382420, doi:10.1098/rstb.2012.0196
5. Wang LF, Anderson DE. Viruses in bats and potential spillover to animals and humans. Current Opinion in Virology. 2019, 34: 79–89. PMC 7102861 . PMID 30665189. doi:10.1016/j.coviro.2018.12.007.
6. Fagre AC, Kading RC. Can Bats Serve as Reservoirs for Arboviruses?. Viruses. 2019, 11 (3): 215. PMC 6466281 . PMID 30832426. doi:10.3390/v11030215.
7. Xing‐Yi Ge, Ben Hu, and Zheng‐Li Shi. BAT CORONAVIRUSES. Lin-Fa Wang and Christopher Cowled (编). Bats and Viruses: A New Frontier of Emerging Infectious Diseases, First Edition.. John Wiley & Sons. 2015 [2021-06-13]. （原始内容存档于2021-02-01）.
8. Haven, J; Park, AW, Superinfection reconciles host–parasite association and cross-species transmission, Theoretical Population Biology, 2013, 90: 129–134, PMC 7126234 , PMID 24161558, doi:10.1016/j.tpb.2013.09.015