Auerbach S B, Schwartz B, Williams D, Fiorilli M G, Adimora A A, Breiman R F, Jarvis W R
Epidemiology Branch, Centers for Disease Control, Atlanta, GA.
Arch Intern Med. 1992 May;152(5):1017-22.
Nine outbreaks of group A streptococcal (GAS) infections in nursing homes were reported to the Centers for Disease Control (Atlanta, Ga) during the past two winters. We conducted an intensive epidemiologic and laboratory investigation of one of these outbreaks to determine clinical characteristics, risk factors for transmission and infection, and methods of control and prevention.
Cases were detected using cultures and serologic tests. Matched case-control and retrospective cohort studies were performed to determine risk factors for infection.
Between December 13, 1989, and January 31, 1990, 16 (20%) of 80 residents, and three (7%) of 45 staff, were infected with GAS. Eleven of the residents had invasive disease and four died. Isolates were available from four persons; all were serotype M-1, T-1. There was strong spatial clustering of cases within the nursing home; having a roommate with prior infection was the most important risk factor. Residents with preexisting decubiti had a reduced risk of infection, perhaps because of stricter infection control practices in their care. No evidence was found for common-source transmission of infection. No further cases occurred after improvement of infection control practices and administration of prophylactic antimicrobials to all residents and staff.
Invasive GAS disease is increasing nationwide, and is a potentially serious problem in the growing and high-risk setting of nursing homes. These data suggest that, in this outbreak, a virulent GAS strain was introduced, with subsequent person-to-person transmission. Adherence to infection control practices can prevent or control GAS outbreaks. Prophylactic antimicrobials may be an effective adjunct to control severe or ongoing outbreaks.
在过去两个冬季，有9起养老院A组链球菌（GAS）感染暴发事件报告给了疾病控制中心（佐治亚州亚特兰大）。我们对其中一起暴发事件进行了深入的流行病学和实验室调查，以确定临床特征、传播和感染的危险因素以及控制和预防方法。
通过培养和血清学检测来发现病例。进行了匹配病例对照研究和回顾性队列研究，以确定感染的危险因素。
在1989年12月13日至1990年1月31日期间，80名居民中有16人（20%）、45名工作人员中有3人（7%）感染了GAS。11名居民患有侵袭性疾病，4人死亡。从4人身上分离出了菌株；所有菌株均为M-1型、T-1型血清型。养老院内部病例存在强烈的空间聚集性；有先前感染的室友是最重要的危险因素。已有褥疮的居民感染风险降低，可能是因为对他们的护理采取了更严格的感染控制措施。未发现感染的共同来源传播证据。在改进感染控制措施并对所有居民和工作人员给予预防性抗菌药物后，未再出现病例。
侵袭性GAS疾病在全国范围内呈上升趋势，在养老院这种不断扩大且高危的环境中是一个潜在的严重问题。这些数据表明，在此次暴发中，引入了一种毒性较强的GAS菌株，随后发生了人际传播。遵守感染控制措施可预防或控制GAS暴发。预防性抗菌药物可能是控制严重或持续暴发的有效辅助手段。
