机会感染的定义尚不统一。一般认为,机体在全身免疫力低下时,由平素致病力很低的微生物(细菌、病毒、原虫等)引起的一组炎性疾病即称为机会感染或机会感染病。引起机会感染的微生物统称为机会病原菌(Opportunistic pathogen)。中枢神经、呼吸、泌尿、肝胆、血液等系统及儿科等各个领域均可发生机会感染。机会病原菌多为抗药性 The definition of opportunistic infections is not uniform. It is generally believed that a group of inflammatory diseases caused by organisms with low pathogenicity (bacteria, viruses, protozoa, etc.) is called an opportunistic or opportunistic infection when the body is in a state of general immunity. Microbes that cause opportunistic infections are collectively referred to as Opportunistic pathogen. Central nervous system, respiratory, urinary, hepatobiliary, blood and other systems and pediatrics and other fields can occur opportunistic infections. Pathogens are mostly drug-resistant