Chow A W, Taylor P R, Yoshikawa T T, Guze L B
J Infect Dis. 1979 Jun;139(6):621-7. doi: 10.1093/infdis/139.6.621.
An outbreak of nosocomial infections involving an unusual strain of multiply resistant Proteus mirabilis (phage type 8888) occurred in 15 patients, 14 of whom were in the surgical intensive care unit at that time. No common source of infection was identified, and person-to-person transmission was the most likely mode of spread. Case-control analysis indicated a significantly increased risk infection related to length of hospital stay (P less than 0.005), number of operations (P less than 0.005), proximity to another case (P less than 0.01), number of antibiotics received (P less than 0.02), and use of a respirator (P less than 0.01). Only the number of operations (P less than 0.01) and proximity to another case (P less than 0.05) remained significant risk factors when related parameters were controlled by multivariate analysis. Thirteen of 14 patients prospectively cultured were colonized by the epidemic organism in the intestinal tract, while rectal carriage preceded infection by the same strain in at least four patients. These data suggest that intestinal colonization may have been an important reservoir for this outbreak, and the findings may explain the unduly prolonged course of intrahospital spread as well as the difficulty encountered in the eradication and control of the outbreak.
一起医院感染暴发涉及15例患者，感染源为一株罕见的多重耐药奇异变形杆菌（噬菌体分型8888），其中14例患者当时在外科重症监护病房。未确定共同感染源，最可能的传播方式为人传人。病例对照分析表明，与住院时间（P<0.005）、手术次数（P<0.005）、与另一病例的接近程度（P<0.01）、接受抗生素的数量（P<0.02）以及使用呼吸机（P<0.01）相关的感染风险显著增加。当通过多变量分析控制相关参数时，只有手术次数（P<0.01）和与另一病例的接近程度（P<0.05）仍然是显著的风险因素。前瞻性培养的14例患者中有13例肠道被该流行菌株定植，而至少4例患者在感染同一菌株之前直肠已携带该菌株。这些数据表明，肠道定植可能是此次暴发的一个重要储存库，这些发现可能解释了医院内传播过程过度延长以及根除和控制此次暴发所遇到的困难。
