Lepine L A, Jernigan D B, Butler J C, Pruckler J M, Benson R F, Kim G, Hadler J L, Cartter M L, Fields B S
Epidemic Intelligence Service, Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Infect Control Hosp Epidemiol. 1998 Dec;19(12):905-10.
In 1994, a hospital reported an increase in nosocomial legionnaires' disease after implementing use of a rapid urinary antigen test for Legionella pneumophila serogroup 1 (Lp-1). This hospital was the site of a previous nosocomial legionnaires' disease outbreak during 1980 to 1982.
Infection control records were reviewed to compare rates of nosocomial pneumonia and the proportion of cases attributable to legionnaires' disease during the 1994 outbreak period with those during the same period in 1993. Water samples were collected for Legionella culture from the hospital's potable water system and cooling towers, and isolates were subtyped by monoclonal antibody (MAb) testing and arbitrarily primed polymerase chain reaction (AP-PCR).
Nosocomial pneumonia rates were similar from April through October 1993 and April through October 1994: 5.9 and 6.6 per 1,000 admissions, respectively (rate ratio [RR], 1.1; P=.56); however, 3.2% of nosocomial pneumonias were diagnosed as legionnaires' disease in 1993, compared with 23.9% in 1994 (RR, 9.4; P<.001). In 1994, most legionnaires' disease cases were detected by the urinary antigen testing alone. MAb testing and AP-PCR demonstrated identical patterns among Lp-1 isolates recovered from a patient's respiratory secretions, the hospital potable water system, and stored potable water isolates from the 1980 to 1982 outbreak.
There may have been persistent transmission of nosocomial legionnaires' disease at this hospital that went undiscovered for many years because there was no active surveillance for legionnaires' disease. Introduction of a rapid urinary antigen test improved case ascertainment. Legionella species can be established in colonized plumbing systems and may pose a risk for infection over prolonged periods.
1994年，一家医院报告称，在实施针对嗜肺军团菌血清1型（Lp-1）的快速尿抗原检测后，医院内军团病的发病率有所上升。该医院曾在1980年至1982年期间发生过一次医院内军团病暴发。
查阅感染控制记录，比较1994年暴发期间与1993年同期医院内肺炎的发病率以及军团病所致病例的比例。从医院的饮用水系统和冷却塔采集水样进行军团菌培养，分离株通过单克隆抗体（MAb）检测和任意引物聚合酶链反应（AP-PCR）进行亚型分型。
1993年4月至10月和1994年4月至10月的医院内肺炎发病率相似，分别为每1000例入院患者5.9例和6.6例（发病率比[RR]，1.1；P = 0.56）；然而，1993年3.2%的医院内肺炎被诊断为军团病，而1994年这一比例为23.9%（RR，9.4；P < 0.001）。1994年，大多数军团病病例仅通过尿抗原检测发现。MAb检测和AP-PCR显示，从患者呼吸道分泌物、医院饮用水系统以及1980年至1982年暴发期间储存的饮用水分离株中回收的Lp-1分离株具有相同的模式。
该医院可能多年来一直存在医院内军团病的持续传播但未被发现，因为对军团病没有进行主动监测。快速尿抗原检测的引入改善了病例的确诊。军团菌可在定植的管道系统中存活，并可能在较长时间内构成感染风险。
