Download Nosocomial Infection

Nosocomial Infection
----Prevention and control
Wang kefang（王克芳）
[email protected]
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.
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?
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.
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
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.

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。
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
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
。。。。。。
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
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。
SARS

During the SARS pandemic, the proportion of
infected health-care workers ranged from
approximately 20% to 60% of cases worldwide.
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
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.
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.
Chain of Infection
Source of
Infection
Susceptible
Host
Chain of Infection
Mode of
Transmission
Sources of Infection

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

patients,
healthcare personnel,
family members
and other visitors
Environment, equipment and apparatus
Chain of Infection
Modes of Transmission

Contact: the most common



Airborne




Direct contact
Indirect contact
Droplet ??
Droplet nuclei
Dust
Other
Chain of infection
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
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
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
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
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
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
Chain of Infection
Source of
Infection
Susceptible
Host
Chain of Infection
Mode of
Transmission
Risks for Nosocomial Infection

Immune defense decline




Numerous invasive procedures


Invasive devices are more important than underlying
diseases in determining susceptibility to nosocomial
infection
Antibiotics abuse


Physiologic factors
Pathologic factors
Psychological factors
can cause resistant microorganisms to colonize in clients
Ineffective management

Health care workers who use poor aseptic or hand washing
techniques
Chain of Infection
隔离
消毒灭菌
增强抵
抗力
WHO: Measures
Aseptic
technique
Isolation
Cleaning
Disinfection
Sterilization
Infection
control
Correct use of
antibiotics
Surveillance of
disinfection and
sterilization
efficacy
1
Basic Knowledge

Concepts

Classification

Risk factors

Chain of infection

Measures for infection control
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？
Concepts
Cleaning

Cleaning is to remove 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.

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

A process that destroys all forms of microorganisms,
including bacterial spores

For surgery and aseptic technique.
Decontamination Steps
Methods of Disinfection and Sterilization
Dry heat ： burning、toasting
Boiling
Heat

Moist heat:
Physical Methods
Microwave
Ionizing radiation
Sunshine
Radiation
Steam Disinfection
Low Temperature
Steam Disinfection
High-Pressure Steam
Sterilization
Ultraviolet light
ozone
Mechanical removing microorganisms

Chemical Methods:
Immersion; Rubbing; Nebulization; Fumigation
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
Physical Methods
High-Pressure Steam Sterilization
Sterilization parameters
Sterilizers
Pressure
Temperature
Time
下排气式灭菌器
103kPa
121ºC
20-30 min
预真空灭菌器
205kPa
132ºC
5-10 min
Sterilization
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
Monitoring the Effectiveness
Mechanical indicators
Chemical indicators
Biological indicators
Indicatiors
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
Chemical Indicators

Each pack must have external chemical indicators.

Indicator strips will change color when temperature,
time, and pressure has been achieved.
Indicators
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
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
Notes:

Clean and dry all items to be sterilized.

Package size：10cm×10cm×20cm.

Organic items：temperature no more than
170℃
Sterilization
Other Physical Methods

Disinfection by Boiling

Ultraviolet Light Radiation

Microwave Disinfection
High Level Disinfection
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 515 minute. From this point on do not add or remove
any water or items.
High Level Disinfection
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
Ultraviolet (UV) Light Radiation
The best anti-bacterial effect: 250-270nm.

Air disinfection




Object surface disinfection



A 30W UV light for every 10 m2
The effective distance：≤ 2 meters
The radiation time： 30-60 min.
The effective distance: 25-60 cm
The radiation time： 20-30min.
Fluid disinfection

The fluid depth : ≤ 2 cm
High Level Disinfection
Notes:


Keep UV light clean: alcohol cotton twice a week.
Effective condition:




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



Temperature: 20-40 ºC
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
Microwave disinfection
Uses: food, tableware, medication and some heattolerant 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
Methods of Disinfection and Sterilization
Dry heat ：burning、toasting
Boiling
Heat

Moist heat:
Physical Methods
Microwave
Ionizing radiation
Sunshine
Irradiation
Steam Disinfection
Low Temperature
Steam Disinfection
High-Pressure Steam
Sterilization
Ultraviolet light
ozone
Mechanical removing microorganisms

Chemical Methods: Immersion; Rubbing; Nebulization; Fumigation
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.
Level
HLD
ILD
LLD
Bacteria
Vegetative
Tubercle
bacilli
﹢
﹢
﹢
﹢
﹢
﹣
Spores
±
﹣
﹣
Fungi
(真菌)
﹢
﹢
±
Viruses
Lipid
﹢
﹢
﹢
Nonlipid
﹢
±
±
Low-level disinfection (LLD) ,Intermediate-level disinfection (ILD),High-level disinfection (HLD)
Disinfectant/Sterilant
消毒灭菌水平、用法及浓度、注意事项





Glutaraldehyde（戊二醛）
Chlorine disinfectant(含氯消毒剂)
Alcohol（乙醇）
Iodophor（碘伏）
Iodine tincture(碘酊)
Textbook p118 表7-3
Principles for Chemical Sterilization/Disinfection






Before deciding to use a chemical method, consider
whether a more appropriate physical method is available.
Select appropriate disinfectant and method according to
the characteristics of items and microorganisms
Pay attention to the effective concentration of disinfectant
and contact time
Make sure the solution is still effective when you use a previously
prepared solution or a new solution.
Put it in a sterile container with a lid and mark the container with the
preparation date and expiration date.
Do not put gauze, cotton in disinfectant.
妇儿医院手术切口分枝杆菌感染暴发
（广东深圳，1998）



表现： 1998年4月1日～5月31日共手术292例，4月22
日～7月14日发生切口感染166例。
调查：20份切口分泌物标本培养出分支杆菌（脓肿亚
型）。使用中和未启用的戊二醛半小时不能杀灭金葡
菌、1小时不能杀灭分支杆菌，测浓度为0.137%。
结论：戊二醛浓度错配导致手术器械分支杆菌污染，
从而引起切口感染
Principles for Chemical Sterilization/Disinfection






Before deciding to use a chemical method, consider
whether a more appropriate physical method is available.
Select appropriate disinfectant and method according to
the characteristics of items and microorganisms
Pay attention to the effective concentration of disinfectant
and contact time
Clean, and dry all items to be sterilized /disinfected.
Maintain enough contact time for items with disinfectant
solution
Rinse thoroughly with sterile/clean saline to remove the
residue that is left on items. This residue is toxic to skin
and to tissues.
Common methods

浸泡法（immersion）

擦拭法(rubbing)

喷雾法(nebulization)

熏蒸法(fumigation)
Immersion

Open all hinged instruments and other items.

Place all items in the solution so that they are
completely submerged.

应用范围

耐湿不耐热的器械物品

如锐利器械（刀剪）、贵重仪器（导管、胃镜等）、
塑料尼龙制品等
Rubbing

应用范围


擦拭被污染物体的表面或皮肤、黏膜
选用：

易溶于水、穿透力强、无显著刺激的消毒剂

如用含氯消毒剂擦拭墙壁、地面
Nebulization

用喷雾器将消毒剂均匀地喷洒于空气或物品表
面进行消毒的方法。

常用于地面、墙壁、空气等的消毒。
Fumigation

将消毒剂加热或加入氧化剂，使其产生气体进行消
毒的方法。如手术室、换药室、病房的空气消毒。
在消毒间或密闭的容器内，也可用熏蒸法对被污染
的物品进行消毒灭菌。

常用的有甲醛气体和环氧乙烷气体。
Daily Cleaning, Disinfection and Sterilization
in Hospital

Levels of disinfection and sterilization

Principles for selecting disinfection and sterilization

Daily Cleaning, Disinfection and Sterilization

Surveillance of the effectiveness
Levels of disinfection and sterilization
Levels
Methods
Sterilization
Heat/Microwave/Ionizing radiation
Glutaraldehyde (戊二醛)/formalin（福尔马林）
/ethylene oxide（环氧乙烷）/peracetic acid（过氧乙
酸）
High-level disinfection
Ultraviolet light/ozone
Chlorine disinfectant （含氯消毒剂）
Intermediate-level
Alcohol（乙醇）/Iodophor（碘伏）/Iodine
tincture(碘酊)
disinfection
Low-level disinfection
Mechanical removing microorganisms
季铵盐类/双胍类消毒剂
Principles for selecting disinfection and
sterilization

Think about items’ risk

High risk(critical) items

Intermediate risk (semi-critical) items

Low risk (noncritical) items
Principles for selecting disinfection and
sterilization

Think about items’ risk

High risk(critical) items

Items that reach the sterile tissues or organs( such as
body cavities and the vascular system).

Items: Surgical instruments, syringes

Items should be sterilized before using
Principles for selecting disinfection and
sterilization

Think about items’ risk

High risk(critical) items

Intermediate risk (semi-critical) items



Items that do not enter sterile areas of the body but
contact with mucous membranes or skin closely.
Items: thermometer, gastrointestinal endoscopy,
ventilator tube
High or Intermediate Level Disinfection. Sterilization
is preferred.
Principles for selecting disinfection and
sterilization

Think about items’ risk

High risk(critical) items

Intermediate risk (semi-critical) items

Low risk (noncritical) items



Items that contact with intact skin, not mucous
membranes
Items: gown, sheet, blood pressure cuff
Low Level Disinfection (in some cases, cleaning is
acceptable)
Principles for selecting disinfection and
sterilization

Think about items’ risk

Consider the type and risk of contaminated
microorganisms
致病性芽胞、真菌孢子—灭菌、高水平消毒
致病性细菌、真菌、亲水病毒、支原体、衣原体—中水平
以上消毒
一般细菌和亲脂病毒—中水平和低水平消毒
Principles for selecting disinfection and
sterilization

Think about items’ risk

Consider the type and risk of contaminated
microorganisms

By the Characteristics of items
耐热、耐湿物品和器材，应首选压力蒸汽灭菌法
耐高温的玻璃器材、油剂类和干粉类可选用干热灭菌
怕热、忌湿和贵重物品，可选择甲醛或环氧乙烷气体
金属器械的浸泡灭菌，应选择腐蚀性小的灭菌剂
在进行物品表面消毒时，应考虑到表面性质
Daily Cleaning, Disinfection and Sterilization

Hospital environment

Preventive disinfection and disinfection of epidemic
focus

Textiles and laundry

Skin and mucous membrane

Equipment, instruments/devices

Waste and sewage
Environmental： Air Disinfection
Category
Including
Methods
I
laminar flow operation room, laminar
flow ward and sterile pharmaceutical
preparation room, et al.
laminar flow
II
operation room, obstetrical ward，
infant room, premature infant room,
protective isolation room, burn ward,
ICU, et al.
air disinfector
III
common ward, examination room,
injection room, emergency room, et al.
II methods
ozone, ultraviolet
light, and
chemical solution
IV
contagious ward
II and III methods
Environmental： Surface Disinfection

Floor:
 If no obvious contamination, Wet cleaning.
 If contaminated by pathogenic microorganisms, use
chemical disinfectants to mop or spay the floor.

Wall:
 Do not need regular disinfection;
 if contaminated, use chemical disinfectants to spay or rub
the wall.

Object surfaces:
 Use clean cloth or cloth with disinfection solution to rub the
surfaces


bed, bedside tables, chair, doorknob, windows, door and urinal.
If contaminated, use chemical disinfectant to spay or rub
them, or use ultraviolet light.
Preventive Disinfection and
Disinfection of Epidemic Focus

Preventive disinfection

Disinfection of epidemic focus


Concurrent disinfection
Terminal disinfection
Textiles and Laundry

The textiles and laundry used by patients are
sterilized by ethylene oxide, then washed and
prepared for use.

If there is no ethylene oxide sterilization room, use
the following methods:




wash and then disinfect patients’ cloth and sheet by high
temperature;
use ultraviolet light to disinfect blankets, pillows, bed
mattress;
wash and disinfect contagious patients’ and other patients’
textiles and laundry separately;
wash and disinfect health care workers’ and patients’
textiles and laundry separately.
Skin and Mucous Membrane

Skin and mucous membrane provide protective
barrier to microorganisms.

choose appropriate antiseptics according to patients’
skin and mucous membrane site, pathogenic
microorganisms.


Use 2% iodine tincture to disinfect skin, after dry deiodinize
it with 75% alcohol.
Use 0.5%-2% iodophor.
Surveillance









Environmental air, object surfaces and HCW’s hands
Equipment, instruments/devices
Disinfection solution
High pressure sterilization and ultraviolet light
Dishware and eating utensils
Sanitary utensils
Drink water
Textiles and laundry, medical waste
Waste
2
清洁、消毒、灭菌
教学内容
教学目标

清洁消毒灭菌概念

解释术语：清洁、消毒、灭菌

消毒灭菌的方法

掌握常用物理消毒灭菌法的方

医院清洁、消毒、
灭菌工作
法和注意事项

掌握常用化学消毒剂的名称、
浓度、使用注意事项
Words:

Nosocomial Infection
Cleaning

Chain of Infection
Disinfection

Source of Infection
Disinfectant

Mode of Transmission
Sterilization

Susceptible Host
Sterilant
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？