Nosocomial Infection ----Prevention and control

1. Nosocomial Infection----Prevention and control Wang kefang（王克芳） kefangwang@126.com

2. Questions:1. What kind of signs and symptoms indicated that there’re something wrong with Helen?2 . How do you explain Mrs. Helen’s pain in her hip and fever? ScenarioⅠMrs. Helen is a 63-year-old woman with diabetes who underwent a total hip replacement. She did well after surgery, and her blood glucose levels are well controlled with medication and diet. On the afternoon of her seventh postoperative day, she complains to her nurse Kathy that she is having increased pain in her hip. Mrs. Helen also has a low-grade fever with a temperature of 37.7℃. Kathy observes the incision and notes that it is red, swollen, and warm. Kathy and a registered dietitian do a nutritional assessment on Mrs. Helen and find that she had a poor nutritional intake 1 month before her surgery because of hip pain and an inability to stand to prepare meals.

3. ScenarioⅠ Mrs. Helen is a 63-year-old woman with diabetes who underwent a total hip replacement. She did well after surgery, and her blood glucose levels are well controlled with medication and diet. On the afternoon of her seventh postoperative day, she complains to her nurse Kathy that she is having increased pain in her hip. Mrs. Helen also has a low-grade fever with a temperature of 37.7℃. Kathy observes the incision and notes that it is red, swollen, and warm. Kathy and a registered dietitian do a nutritional assessment on Mrs. Helen and find that she had a poor nutritional intake 1 month before her surgery because of hip pain and an inability to stand to prepare meals.

4. Nosocomial Infection ----Hospital Acquired Infection • Broad concept • Any infection or disease that any individual suffers from the invasion of pathogens in hospital. • Narrow concept • Any infection that patient suffers during their hospital care which was not present or incubating at the time of admission. • This includes infections acquired in hospital but appearing after discharge, and also occupational infections among heath-care workers. Concepts

5. Classification • Endogenous infection (autogenous infection) • can occur when part of the client’s flora becomes altered and an overgrowth results. • Exogenous infection (cross infection) • The causative microorganisms from the source other than the clients’ themselves, such as：hospital personnel, other clients, and hospital environment.

6. 宿州眼球事件 2005年12月11日，宿州市立医院眼科为10名患者做白内障手术，至17日9名患者因感染实施单眼眼球摘除手术。 西安交大医院8名新生儿死亡 自2008年９月３日起新生儿科９名新生儿相继出现发热、心率加快、肝脾肿大等临床症状，至9月15日8名新生儿发生弥漫性血管内凝血相继死亡。 肌注部位分支杆菌感染暴发 1998年8月～11月某诊所59例病人发生肌注部位感染 山西煤炭中心医院血液透析感染事件 2008年12月至2009年１月，47名患者在太原公交公司职工医院进行血液透析，20名患者丙肝抗体阳性。

7. 宿州眼球事件 • 医院手术室布局、流程、环境、设施等不符合开展无菌手术的基本要求 • 手术器械的消毒和灭菌工作没有达到基本标准 • 术中微创手术器械不能做到一人一用一灭菌

8. 西安交大医院8名新生儿死亡 • 新生儿科建筑布局和工作流程不合理，人流与物流相互交叉 • 对部分新生儿使用的物品和器具采用了错误的消毒方法 • 医务人员没有规范地进行手卫生 • 用于新生儿的肝素封管液无使用时间标识 • 。。。。。。

9. 肌注部位分支杆菌感染暴发 玻璃注射器15支 煮沸消毒，时间凭经验 病人多时使用同种药物者换针头不换注射器

10. 山西煤炭中心医院血液透析感染事件 • 重复使用一次性血液透析 • 对丙肝抗体阳性患者不能实施专机血液透析和专区处理血液透析器 • 使用工业用过氧乙酸对血液透析器进行消毒。

11. SARS • During the SARS pandemic, the proportion of infected health-care workers ranged from approximately 20% to 60% of cases worldwide.

12. Impact of nosocomial infection • more serious illness • prolong of stay in a health-care facility • long-term disability • excess deaths • high personal costs on patients and their families • high additional financial burden

13. Scenario Ⅱ • Mrs. Helen was diagnosed as surgical site infection. It is hospital acquired infection (HAI). Her doctor orders a wound culture for Etiological diagnosis and treatment. In addition, Mrs. Helen is receiving wound care, antibiotic therapy, and supportive care, including nutrition and progressive exercise.

14. Questions: • The presence of a pathogen does not mean that an infection will begin. The process resulting in an infection is referred to as the chain of infection. Please list the components of the chain, and explain in detail. • The number of microorganisms needed to cause an HAI depends on the virulence of the organism, the host’s susceptibility, and the body site affected. Please list the common factors affect host’s susceptibility to infection. • What are the possible risk factors for Mrs. Helen’s fever? • Do you have any suggestion for the hospital to prevent patient like Mrs. Helen from infection? Please describe in details.

15. Chain of Infection Source of Infection Susceptible Host Mode of Transmission Chain of Infection

16. Sources of Infection patients, healthcare personnel, family members and other visitors • Human • may have active infections • Carrier • may be in the asymptomatic and/or incubation period of an infectious disease, • Endogenous patients’ normal flora • Animal and Insect • Health care setting • Environment, equipment and apparatus Chain of Infection

17. Modes of Transmission • Contact: the most common • Direct contact • Indirect contact • Airborne • Droplet ?? • Droplet nuclei • Dust • Other Chain of infection

18. Contact • Direct contact • transferred from one infected person to another person directly. • Indirect contact • the transfer of an infectious agent through a contaminated intermediate object or person. • Extensive evidence suggests that the contaminated hands of healthcare personnel are important contributors to indirect contact transmission Chain of Infection

19. Droplet • A form of contact transmission • Respiratory droplets: • an infected person coughs, sneezes, or talks • during procedures such as suctioning, endotracheal intubation, and cardiopulmonary resuscitation • Short distance • a distance of <3 feet （1feet=30.48cm）around the patient Chain of Infection

20. Airborne • occurs by dissemination of airborne droplet nuclei containing infectious agents that remain infective over time and distance • Mycobacterium tuberculosis • over long distance • not had face-to-face contact with (or been in the same room with) the infectious individual. Chain of Infection

21. Other • Common environmental sources • contaminated food, water, blood • medications (e.g. intravenous fluids) • Vectorborne transmission of infectious agents • mosquitoes, flies, rats, and others Chain of Infection

22. Susceptible hosts • Factors affecting susceptibility include • age, gender, race and heredity • normal immune defenses • underlying disease and medical therapy • nutritional status • social life • mental health • stress Chain of Infection

23. Susceptible hosts • younger children and older adults; • severely impaired immune defenses; • malnutrition; • receiving various immune suppressed treatment; • long-term use of antibiotics; • receiving numerous invasive procedures; • long operation time; • extended length of hospitalization; • not in good spirits, lack of active cooperation. Chain of Infection

24. Chain of Infection Source of Infection Susceptible Host Mode of Transmission Chain of Infection

25. Risks for Nosocomial Infection • Immune defense decline • Physiologic factors • Pathologic factors • Psychological factors • Numerous invasive procedures • Invasive devices are more important than underlying diseases in determining susceptibility to nosocomial infection • Antibiotics abuse • can cause resistant microorganisms to colonize in clients • Ineffective management • Health care workers who use poor aseptic or hand washing techniques

26. Chain of Infection 增强抵抗力 隔离 消毒灭菌

27. WHO: Measures Aseptic techniqueIsolation Correct use of antibiotics Cleaning Disinfection Sterilization Infection control Surveillance of disinfection and sterilization efficacy

28. 1 Basic Knowledge • Concepts • Classification • Risk factors • Chain of infection • Measures for infection control

29. 2 Cleaning, Disinfection and Sterilization 下列物品或情形该怎样处理？ • 体温计需要消毒吗？该怎样处理？ • 你发现手上扎了一根小刺，同学找来缝衣针要给你挑出来，这根缝衣针可以直接用吗？ • 你从商店里买来一件T恤衫，你穿之前处理吗？ • 有个亲戚在你家吃住2天，他走后你想消毒一下餐具和被褥，如何做？

30. Concepts Cleaning • Cleaning is toremove the dirt from item surface by the use of water, detergents and mechanical actions. • Will remove most organisms from a surface. Remove and reduce; not kill • Hospital floors, walls, furniture and other items • Should always precede disinfection and sterilization procedures.

31. Disinfection • A process that eliminates almost all pathogens on objects, except of bacterial spores, to decrease the number of them to a harmless level. • Used in: Items (such as thermometers), skin, and environmental disinfection Sterilization • Aprocess that destroys all forms of microorganisms, including bacterial spores • For surgery and aseptic technique.

32. Decontamination Steps

33. Methods of Disinfection and Sterilization Heat Microwave Ionizing radiation Radiation Mechanical removing microorganisms burning、toasting Dry heat： Moist heat: Boiling Steam Disinfection Low Temperature Steam Disinfection High-Pressure Steam Sterilization • Physical Methods • Chemical Methods: Sunshine Ultraviolet light ozone Immersion; Rubbing; Nebulization; Fumigation

34. Physical Methods High-Pressure Steam Sterilization • the most common and effective method • Advantages: • Highly effective; • Rapid heating and rapid penetration of items; • Nontoxic; • Inexpensive; • 用途: • 常用于: 耐高温、耐高压、耐潮湿物品的灭菌 • ----金属、玻璃、橡胶、搪瓷、敷料等 • 不能用于凡士林等油剂、滑石粉等粉剂的灭菌 Sterilization

35. Physical Methods High-Pressure Steam Sterilization Sterilization parameters Sterilization

36. Notes: • Clean and dry items • Package size：下排气式30 ×30 × 25cm；预真空式 30 ×30 × 50cm • Arrange all packages in a way that allows the steam to circulate freely. • Timing until the autoclave reaches the required temperature and pressure. • Follow the instruction for operating the autoclave. • Packs should NOT be pick out of the autoclave until dry. • Label accurately with contents, date of processing and expiration and store in storage cabinet. • Monitor the effectiveness of sterilization Sterilization

37. Monitoring the Effectiveness Mechanical indicators Chemical indicators Biological indicators Indicatiors

38. Mechanical Indicators • These indicators, which are part of the autoclave or dry-heat oven itself, record and allow you to observe time, temperature, and/or pressure readings during the sterilization cycle. Indicators

39. Chemical Indicators • Each pack must have external chemical indicators. • Indicator strips will change color when temperature, time, and pressure has been achieved. Indicators

40. Biological Indicators • 非致病性嗜热脂肪肝菌芽孢. • If the bacterial spores have been killed after sterilization, you can assume that all microorganisms have been killed as well. • Advantages: • It directly measures the effectiveness of sterilization. • Disadvantages: • This indicator is not immediate. Bacterial culture results are needed before sterilization effectiveness can be determined. Indicators

41. Physical Methods Toasting Sterilization (Hot Air Oven) • 用途: • 适用于在高温下不变形、不损坏、不蒸发的物品：glass, metal instruments, oil, ointments and powders • 不适用于纤维织物、塑料制品等的灭菌。 • 灭菌参数： • 160 ºC, 2 hours; • 170 ºC, 1 hour; • 180 ºC, 0.5 hour. Sterilization

42. Notes: • Clean and dry all items to be sterilized. • Package size：10cm×10cm×20cm. • Organic items：temperature no more than 170℃ Sterilization

43. Other Physical Methods • Disinfection by Boiling • Ultraviolet Light Radiation • Microwave Disinfection High Level Disinfection

44. Boiling For items which are resistant to moisture and high temperature, such as mental, glass, rubber. • Notes: • Clean • Open all hinged instruments and other items. Catheter should be filled with water. Make sure that all items are completely submerged because water must touch all surfaces. • Once the water is in a rolling boil, start timing for 5-15 minute. From this point on do not add or remove any water or items. High Level Disinfection

45. Notes: • A 1-2% solution of sodium bicarbonate(碳酸氢钠) rises the boiled temperature to 105℃ and helps to prevent corrosion of the instruments. • The boiling point of water is affected by air pressure. Generally, every 300 meters is added, disinfection time should be prolonged for 2 minutes. • Never leave boiled items in water that has stopped boiling; they can become contaminated as the water cools. High Level Disinfection

46. Ultraviolet (UV) Light Radiation The best anti-bacterial effect: 250-270nm. • Air disinfection • A 30W UV light for every 10 m2 • The effective distance：≤ 2 meters • The radiation time： 30-60 min. • Object surface disinfection • The effective distance: 25-60 cm • The radiation time： 20-30min. • Fluid disinfection • The fluid depth : ≤ 2 cm High Level Disinfection

47. Notes: • Keep UV light clean: alcohol cotton twice a week. • Effective condition: • Temperature: 20-40 ºC Humidity: 40-60% • Record radiation time after the UV light has been on for 5-7 minutes. • When turned off, the light should be cooled off for 3-4 minutes before being turned on again • Regularly check the output of the UV light • Intensity≤ 70µW/cm2 , change the light. • Time ≥ 1000 hours, change the light. • Keep people off the room; cover eyes and skin if people couldn’t leave. High Level Disinfection

48. Microwave disinfection Uses: food, tableware, medication and some heat-tolerant non-metal instruments. • Notes: • Microwave is harmful to health, so avoid long term contact in small dose or large dose. • Microwave can not penetrate metal, do not put objects in metal container. • Water is a strong microwave absorbing medium, so wet wrapped item or put a glass of water in the microwave oven can enhance disinfection efficacy. High Level Disinfection

49. Methods of Disinfection and Sterilization Heat Microwave Ionizing radiation Irradiation Mechanical removing microorganisms Dry heat：burning、toasting Moist heat: Boiling Steam Disinfection Low Temperature Steam Disinfection High-Pressure Steam Sterilization • Physical Methods • Chemical Methods:Immersion; Rubbing; Nebulization; Fumigation Sunshine Ultraviolet light ozone

50. Chemical Methods Sterilant • A chemical agent that can destroys all forms of microorganisms to achieve sterilization. Disinfectant • A chemical agent that destroys most pathogens but may not kill bacterial spores. Low-level disinfection (LLD) ,Intermediate-level disinfection (ILD),High-level disinfection (HLD)