Nosocomial Blood-Borne Pathogens
In the health care setting, blood-borne pathogens pose a threat to patients and HCWs. HBV, HCV, and HIV represent the three most commonly transmitted blood-borne viruses in health care settings (19). Percutaneous injuries commonly occur via needle sticks or contact with sharp objects such as a scalpel. Surgeons are at the greatest risk of percutaneous injuries. During surgery, most (73%) injuries are related to suturing operations lasting longer than 1 h, and procedures with more than 250 ml of blood loss (244, 327). Blood-borne pathogens are generally transmitted from patient to provider, with fewer infections being transmitted from patient to patient and even fewer being transmitted from provider to patient. However, increased awareness and the implementation of preventative measures suggest that HCWs are less frequently exposed to blood-borne pathogens than they were 10 to 15 years ago (68). Still, a risk exists for blood-borne infection, and the likelihood of infection after exposure to a blood-borne pathogen is multifactorial and differs for each virus.
医院血源性病原体
在医疗保健环境中，血源性病原体不仅对病人也对医务人员（health care workers，HCM）造成威胁。HBV，HCV和HIV是医疗保健环境中最常见的三种血源性传播病毒。皮肤损伤往往由于针刺或与锐器（如手术刀片）接触而致。外科医生发生皮肤损伤的危险性最大。手术中，大部分损伤（73%）与手术持续时间超过1小时、出血量大于250ml的缝合操作相关。血源性病原体通常由病人传播给医务人员，病人之间的传播较前者少，而由医务人员传播给病人就更为少见。由于对血源性病原体的防护意识增强并采取了防护措施，目前医务人员暴露于血源性病原体的机会较10-15年前有所减少。尽管如此，血源性感染的危险性仍然存在，暴露于血源性病原体后导致感染发生的因素多种多样，而且不同病毒各不相同。
Patients are also at risk of acquisition of blood-borne pathogens once they come into contact with the health care system. This risk has fallen significantly in developed countries since 1985, when widespread HIV, HBV, and HCV testing became available; however, the nosocomial spread of blood-borne pathogens remains a problem in developing countries. In this setting, transmission to patients occurs following transfusion of infected blood or blood products, the use of infected transplanted organs, or invasive procedures performed without sterile needles or syringes and rarely occurs through transmission from an infected HCW (105).
病人一旦进入医疗保健体系，他们也有发生血源性病原体感染的危险。自1985年以来，由于HIV、HBV和HCV检测措施的普及，发生这些疾病的危险性在发达国家已显著下降。但在发展中国家，血源性病原体在医院内的传播仍然是一个问题。在发展中国家，血源性病原体主要通过输入感染的血液或血液制品、感染器官的移植、使用未灭菌的针头或注射器进行侵入性操作而传播，偶尔也有感染的医务人员传播给病人的报导。
It is estimated that approximately 5% of worldwide AIDS cases are acquired through the transfusion of contaminated blood products (105). The screening of blood donors for HIV has not been universally adopted around the world despite the demonstration that this practice reduces transfusion-related transmission. In fact, it is estimated that 40% of donated blood in Kenya is not screened for blood-borne pathogens, and in 2007, the transmission of HIV to 103 children through unscreened blood products was reported in Kazakhstan (1, 105).
据估计，全球约有5%的AIDS病例是由于输入污染的血液制品获得的。尽管研究表明对供血者进行HIV筛选可降低输血相关HIV传播，但在世界范围内还没有普遍采取筛选措施。据估计，肯亚有40%的供血未进行血源性病原体的筛选。2007年，卡萨克斯坦有103名儿童因输入未经过筛选的血液制品而感染HIV。
The reuse of needles and syringes is a practice still reported in resource-limited settings, many of which have a high prevalence of HIV and hepatitis viruses. The transmission of HIV and HCV has been linked to the contamination and reuse of multidose medication vials (52, 166). The transmission of all three primary blood-borne pathogens to patients with chronic renal failure through the reuse of hemodialysis filters, reused needles, and a lack of infection control practices has been documented.
在资源有限地区，针头和注射器仍在重复使用，这些重复使用的针头或注射器上检出很高的HIV和乙肝病毒感染率。HIV和HCV的传播也与多（大）剂量药瓶的污染和重复使用相关。由于重复使用的血透过滤器、重复使用针头、缺乏感染控制措施而导致的慢性肾衰病人感染这三种主要血源性病原体的报道时有发生。
Lastly, HCWs rarely transmit HIV or hepatitis viruses to patients (19, 46). Mathematical modeling suggests that 2 to 24 patients per million procedures will be infected if the procedure is performed by an HIV-positive surgeon (105). The most famous account of HIV transmission from an HCW to a patient occurred in 1995, when an HIV-positive dentist reportedly infected six patients (66). Several outbreaks of HCV and HBV have been associated with infected surgeons, although the precise mode of transmission is disputed (46, 93). In general, these transmissions involve health care providers performing invasive and “exposure-prone” procedures where blind suturing and other practices occur. Furthermore, these transmissions occurred prior to the widespread use of standard precautions and other barrier precautions such as single or double gloving.
医务人员将HIV或肝炎病毒传播给病人的例子较为罕见。数学模型结果提示，如果一项操作由HIV阳性的外科医生进行的话，那么每百万操作将会有2-24病人被感染。最著名的医务人员传播给病人HIV的例子发生于1995年，据报道，一位HIV阳性的牙科医生引起了6名患者感染HIV。此外，还有数例HCV和HBV的感染暴发与感染的外科医生相关，尽管对于这些暴发的确切的传播途径仍有争议。总体来说，这些传播均与医务人员进行侵入性及“暴露性”操作相关。此外，这些传播均发生于标准预防措施以及其它屏障性预防措施（如戴单层或双层手套）的广泛采用之前。
Reducing nosocomial blood-borne pathogen transmission requires education, infrastructure, and resources. In 1991, the CDC published guidelines for the prevention of transmission of HIV and HBV to patients (51). Since that time, recommendations have expanded. In all settings, the public and HCWs need to be educated about the risk of transmission of HIV and hepatitis viruses from unsanitary and unsafe health care practices. This will encourage transparency in hospitals. Surveillance for blood-borne pathogen exposures among HCWs is not mandatory in many countries. All countries should screen blood and organ donors for blood-borne pathogens. Other necessary prevention strategies include (i) standard precautions, (ii) adequate and low-cost disinfectants, (iii) proper sterilization of equipment, and (iv) policies limiting the reuse of
certain supplies and equipment. Single-use safety injection devices have revolutionized modern medicine and should be made available at a low cost in resource-limited settings.
降低医源性血源性病原体的传播需要对人员的培训、基础设施的完善和足够的资源。1991年，CDC发表了预防HIV和HBV向病人传播的指南。自此以来，又有各种建议出台。在任何情况下，均需教育公众和医务工作者，使他们明白不卫生和不安全的医疗保健行为有导致HIV和肝炎病毒传播的危险性。这也可以增强医院的透明度。在许多国家，没有强制性地在医务工作者中监测血源性病原体的暴露状况。所有国家均应该对供血者和器官捐献者进行血源性病原体的筛查。其它必须的预防性措施包括：(i)标准预防， (ii) 充足且价格低廉的消毒剂；(iii)对设备的适当灭菌； (iv)限制某些产品以及设备重复使用的政策。一次性安全注射装置使现代医学发生了革命性的改变因此应该使其能够低价提供给资源有限的国家或地区。
HIV. Although it is the most commonly feared blood-borne virus, the nosocomial transmission of HIV is less commonly reported than HBV and HCV. This is likely due to the lower global burden of HIV than HBV or HCV and lower blood titers of HIV (105). Based on prospective studies of HCWs, the average risk of transmission of HIV after occupational percutaneous exposure is 0.3%, with the risk of transmission after mucosal exposure being much lower, at 0.09% (19). No transmission of HIV through the contact of blood with nonintact skin occurred in these studies. Therefore, the risk of HIV transmission appears to be low (113). Similarly, the risk of HIV transmission after exposure to other potentially infectious body fluids or tissues has not been well studied. In one study, 559 HCWs reported cutaneous exposure to different potentially infectious body fluids from patients presumed to have HIV, and no HCW became infected (95).
HIV 尽管HIV是人们最为恐惧的血源性传播病毒，但报导的HIV的医源性传播较HBV和HCV例子要少，这可能是由于HIV的全球的总体病例较HBV和HCV少、且HIV的血液滴定度要低。对医务工作者进行的回顾性研究结果表明，皮肤损伤职业暴露所致HIV感染的危险性平均为0.3%，黏膜暴露的危险性为0.09%。在这些研究中没有发现因非完整皮肤接触血液而导致HIV感染的病例。因此，HIV感染的危险性似乎并不高。同样，对于暴露于其他潜在感染性体液和组织后HIV感染的危险性也未做充分研究。有一项涉及559位医务人员的研究表明，其皮肤暴露于HIV感染病人的各种潜在感染体液，但无一例医务人员感染HIV。 |
发表于 2011-6-11 16:40
