宿主细胞:是病毒繁殖的活细胞。主要宿主或确定的主机:是寄生虫成熟的宿主,如果适用,则可以重现性行为。辅助主机或中间主机:是一个仅在短期过渡期内携带寄生虫的主机,在此期间(通常)(通常)某些发育阶段已完成。For trypanosomes, strictly, humans are the secondary host, while the tsetse fly is the primary host, given that it has been shown that reproduction occurs in the insect ANAEOBES: Organisms that grow in the absence of free oxygen OBLIGATE OR STRICT ANAEROBES are those that grow only in the absence of oxygen FACULTATIVE ANAEROBES these are able to grow either with or without free oxygen MICRO-AEROPHILES在低量的氧气