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Nosocomial infections (pronounced /nɒsəˈkoʊmiəl/ nos-ə-koh-mee-əl), are infections that are a result of treatment in a hospital
or a healthcare service unit. Infections are considered nosocomial if
they first appear 48 hours or more after hospital admission or within 30
days after discharge.[citation needed] Nosocomial comes from the Greek word nosokomeio (νοσοκομείον) meaning hospital (nosos = disease, komeo = to take care of). This type of infection is also known as a hospital-acquired infection (or, in generic terms, healthcare-associated infection).
In the United States, the Centers for Disease Control and Prevention estimate that roughly 1.7 million hospital-associated infections, from all types of microorganisms, including bacteria, combined, cause or contribute to 99,000 deaths each year.[1] In Europe, where hospital surveys have been conducted, the category of Gram-negative infections are estimated to account for two-thirds of the 25,000 deaths each year. Nosocomial infections can cause severe pneumonia and infections of the urinary tract, bloodstream and other parts of the body. Many types are difficult to attack with antibiotics, and antibiotic resistance is spreading to Gram-negative bacteria that can infect people outside the hospital.[1]
[edit] Known nosocomial infections
[edit] Epidemiology
Nosocomial infections are commonly transmitted when hospital
officials become complacent and personnel do not practice correct
hygiene regularly. Also, increased use of outpatient treatment means
that people who are hospitalized are more ill and have more weakened
immune systems than may have been true in the past. Moreover, some medical procedures
bypass the body's natural protective barriers. Since medical staff move
from patient to patient, the staff themselves serve as a means for
spreading pathogens. Essentially, the staff act as vectors.
[edit] Categories and treatment
Among the categories of bacteria most known to infect patients are the category MRSA, Gram-positive bacteria and Helicobacter, which is Gram-negative.
While there are antibiotic drugs that can treat diseases caused by
Gram-positive MRSA, there are currently few effective drugs for Acinetobacter. However, Acinetobacter
germs are evolving and becoming immune to existing antibiotics. "In
many respects it’s far worse than MRSA," said a specialist at Case Western Reserve University.[1]
Another growing disease, especially prevalent in New York City hospitals, is the drug-resistant Gram-negative germ, Klebsiella pneumoniae. An estimated more than 20 percent of the Klebsiella infections in Brooklyn hospitals "are now resistant to virtually all modern antibiotics. And those supergerms are now spreading worldwide."[1]
The bacteria, classified as Gram-negative because of their reaction to the Gram stain test, can cause severe pneumonia and infections of the urinary tract,
bloodstream, and other parts of the body. Their cell structures make
them more difficult to attack with antibiotics than Gram-positive
organisms like MRSA. In some cases, antibiotic resistance is spreading
to Gram-negative bacteria that can infect people outside the hospital.
"For Gram-positives we need better drugs; for Gram-negatives we need any
drugs," said Dr. Brad Spellberg, an infectious-disease specialist at Harbor-UCLA Medical Center, and the author of Rising Plague, a book about drug-resistant pathogens.[1]
One-third of nosocomial infections are considered preventable. The
CDC estimates 2 million people in the United States are infected
annually by hospital-acquired infections, resulting in 20,000 deaths.[2] The most common nosocomial infections are of the urinary tract, surgical site and various pneumonias.[3]
[edit] Country estimates
The methods used differ from country to country (definitions used,
type of nosocomial infections covered, health units surveyed, inclusion
or exclusion of imported infections, etc.), so that international
comparisons of nosocomial infection rates should be made with the utmost
care.
United States: The Centers for Disease Control and Prevention
(CDC) estimates that roughly 1.7 million hospital-associated
infections, from all types of bacteria combined, cause or contribute to
99,000 deaths each year.[1]
Other estimates indicate that 10%, or 2 million, patients a year become
infected, with the annual cost ranging from $4.5 billion to $11
billion.
France: estimates ranged from 6.7% in 1990 to 7.4% (patients may have several infections).[4] At national level, prevalence among patients in health care facilities was 6.7% in 1996,[5] 5.9% in 2001[6] and 5.0% in 2006.[7] The rates for nosocomial infections were 7.6% in 1996, 6.4% in 2001 and 5.4% in 2006.
In 2006, the most common infection sites were urinary tract infections (30,3 %), pneumopathy (14,7 %), infections of surgery site (14,2 %). infections of the skin and mucous membrane (10,2 %), other respiratory infections (6,8%) and bacterial infections / blood poisoning (6,4 %).[8] The rates among adult patients in intensive care were 13,5% in 2004, 14,6% in 2005, 14,1% in 2006 and 14.4% in 2007.[9]
It has also been estimated that nosocomial infections make patients
stay in the hospital 4-5 additional days. Around 2004-2005, about 9,000
people died each year with a nosocomial infection, of which about 4,200
would have survived without this infection.[10]
Italy: since 2000, estimates show that about 6.7 % infection
rate, i.e. between 450,000 and 700,000 patients, which caused between
4,500 and 7,000 deaths.[11] A survey in Lombardy gave a rate of 4.9% of patients in 2000.[12]
United Kingdom: estimates of 10% infection rate,[13] with 8.2% estimated in 2006.[14]
Switzerland: estimates range between 2 and 14%.[15] A national survey gave a rate of 7.2% in 2004.[16]
Finland: estimated at 8.5% of patients in 2005[17]
[edit] Transmission
The drug-resistant Gram-negative germs for the most part threaten
only hospitalized patients whose immune systems are weak. The germs can
survive for a long time on surfaces in the hospital and enter the body
through wounds, catheters, and ventilators.[1]
Main routes of transmission
Contact transmission is divided into two subgroups: direct-contact transmission and indirect-contact transmission.
Routes of contact transmission
[edit] Risk factors
Factors predisposing a patient to infection can broadly be divided into three areas:
[edit] Prevention
Hospitals have sanitation protocols regarding uniforms, equipment sterilization, washing, and other preventative measures. Thorough hand washing and/or use of alcohol rubs
by all medical personnel before and after each patient contact is one
of the most effective ways to combat nosocomial infections.[19] More careful use of antimicrobial agents, such as antibiotics, is also considered vital.[20]
Despite sanitation protocol, patients cannot be entirely isolated
from infectious agents. Furthermore, patients are often prescribed antibiotics and other antimicrobial drugs to help treat illness; this may increase the selection pressure for the emergence of resistant strains.
[edit] Isolation
Isolation precautions are designed to prevent transmission of
microorganisms by common routes in hospitals. Because agent and host
factors are more difficult to control, interruption of transfer of
microorganisms is directed primarily at transmission.
[edit] Handwashing and gloving
Handwashing frequently is called the single most important measure to reduce the risks of transmitting skin microorganisms
from one person to another or from one site to another on the same
patient. Washing hands as promptly and thoroughly as possible between
patient contacts and after contact with blood, body fluids, secretions, excretions, and equipment or articles contaminated by them is an important component of infection control and isolation precautions.
Although handwashing may seem like a simple process, it is often
performed incorrectly. Healthcare settings must continuously remind
practitioners and visitors on the proper procedure in washing their
hands to comply with responsible handwashing. Simple programs such as Henry the Hand, and the use of handwashing signals can assist healthcare facilities in the prevention of nosocomial infections.
All visitors must follow the same procedures as hospital staff to
adequately control the spread of infections. Visitors and healthcare
personnel are equally to blame in transmitting infections.[citation needed] Moreover, multidrug-resistant infections can leave the hospital and become part of the community flora if steps are not taken to stop this transmission.
In addition to handwashing, gloves
play an important role in reducing the risks of transmission of
microorganisms. Gloves are worn for three important reasons in
hospitals. First, gloves are worn to provide a protective barrier and to
prevent gross contamination of the hands when touching blood, body
fluids, secretions, excretions, mucous membranes, and nonintact skin. In
the USA, the Occupational Safety and Health Administration has mandated wearing gloves to reduce the risk of bloodborne pathogen infection.[21]
Second, gloves are worn to reduce the likelihood that microorganisms
present on the hands of personnel will be transmitted to patients during
invasive or other patient-care procedures that involve touching a
patient's mucous membranes and nonintact skin. Third, gloves are worn to
reduce the likelihood that hands of personnel contaminated with
microorganisms from a patient or a fomite
can transmit these microorganisms to another patient. In this
situation, gloves must be changed between patient contacts, and hands
should be washed after gloves are removed.
Wearing gloves does not replace the need for handwashing, because
gloves may have small, non-apparent defects or may be torn during use,
and hands can become contaminated during removal of gloves. Failure to
change gloves between patient contacts is an infection control hazard.
[edit] Surface sanitation
Sanitizing surfaces is an often overlooked, yet crucial component of
breaking the cycle of infection in health care environments. Modern
sanitizing methods such as NAV-CO2 have been effective against gastroenteritis, MRSA, and influenza. Use of hydrogen peroxide
vapor has been clinically proven to reduce infection rates and risk of
acquisition. Hydrogen peroxide is effective against endospore-forming
bacteria, such as Clostridium difficile, where alcohol has been shown to be ineffective.[22]
A Bio-Intervention process is effective for hard surface disinfection,
providing a 6-log kill (99.9999%)for many organisms including MRSA, VRE,
Psudomonas aeruginosa, Staphylococcus aureus, Rhinovirus, Salmonella
enterica, H1N1, HIV-1 and Hepatitis A. The unique kill mechanism is new
to the market and will be an effective method against mutation and
resistance of organizations.
[edit] Aprons
Wearing an apron during patient care reduces the risk of infection.[citation needed] The apron should either be disposable or be used only when caring for a specific patient.
[edit] Mitigation
The most effective technique of controlling nosocomial infection is to strategically implement QA/QC measures to the health care sectors and evidence-based management can be a feasible approach. For those VAP/HAP diseases (ventilator-associated pneumonia, hospital-acquired pneumonia), controlling and monitoring hospital indoor air quality
needs to be on agenda in management, one major method to stop the
spread of nosocomial infection through blood pressure cuffs is to use
disposable cuffs or to use disposable cuff covers like Cuff-Guard from [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط][23] whereas for nosocomial rotavirus infection, a hand hygiene protocol has to be enforced.[24][25][26] Other areas that the management needs to be covered include ambulance transport.[citation needed]
From Wikipedia, the free encyclopedia
Jump to: navigation,
search
| Classification and external resources | |
| [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة] Contaminated surfaces increase cross-transmission | |
| Y95. | |
| [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذه الصورة] | Look up nosocomial in Wiktionary, the free dictionary. |
or a healthcare service unit. Infections are considered nosocomial if
they first appear 48 hours or more after hospital admission or within 30
days after discharge.[citation needed] Nosocomial comes from the Greek word nosokomeio (νοσοκομείον) meaning hospital (nosos = disease, komeo = to take care of). This type of infection is also known as a hospital-acquired infection (or, in generic terms, healthcare-associated infection).
In the United States, the Centers for Disease Control and Prevention estimate that roughly 1.7 million hospital-associated infections, from all types of microorganisms, including bacteria, combined, cause or contribute to 99,000 deaths each year.[1] In Europe, where hospital surveys have been conducted, the category of Gram-negative infections are estimated to account for two-thirds of the 25,000 deaths each year. Nosocomial infections can cause severe pneumonia and infections of the urinary tract, bloodstream and other parts of the body. Many types are difficult to attack with antibiotics, and antibiotic resistance is spreading to Gram-negative bacteria that can infect people outside the hospital.[1]
Contents [hide]
|
- Ventilator associated pneumonia (VAP)
- Staphylococcus aureus
- Methicillin resistant Staphylococcus aureus (MRSA)
- Pseudomonas aeruginosa
- Acinetobacter baumannii
- Stenotrophomonas maltophilia
- Clostridium difficile
- Tuberculosis
- Urinary tract infection
- Hospital-acquired pneumonia (HAP)
- Gastroenteritis
- Vancomycin-resistant Enterococcus (VRE)
- Legionnaires' disease
[edit] Epidemiology
Nosocomial infections are commonly transmitted when hospital
officials become complacent and personnel do not practice correct
hygiene regularly. Also, increased use of outpatient treatment means
that people who are hospitalized are more ill and have more weakened
immune systems than may have been true in the past. Moreover, some medical procedures
bypass the body's natural protective barriers. Since medical staff move
from patient to patient, the staff themselves serve as a means for
spreading pathogens. Essentially, the staff act as vectors.
[edit] Categories and treatment
Among the categories of bacteria most known to infect patients are the category MRSA, Gram-positive bacteria and Helicobacter, which is Gram-negative.
While there are antibiotic drugs that can treat diseases caused by
Gram-positive MRSA, there are currently few effective drugs for Acinetobacter. However, Acinetobacter
germs are evolving and becoming immune to existing antibiotics. "In
many respects it’s far worse than MRSA," said a specialist at Case Western Reserve University.[1]
Another growing disease, especially prevalent in New York City hospitals, is the drug-resistant Gram-negative germ, Klebsiella pneumoniae. An estimated more than 20 percent of the Klebsiella infections in Brooklyn hospitals "are now resistant to virtually all modern antibiotics. And those supergerms are now spreading worldwide."[1]
The bacteria, classified as Gram-negative because of their reaction to the Gram stain test, can cause severe pneumonia and infections of the urinary tract,
bloodstream, and other parts of the body. Their cell structures make
them more difficult to attack with antibiotics than Gram-positive
organisms like MRSA. In some cases, antibiotic resistance is spreading
to Gram-negative bacteria that can infect people outside the hospital.
"For Gram-positives we need better drugs; for Gram-negatives we need any
drugs," said Dr. Brad Spellberg, an infectious-disease specialist at Harbor-UCLA Medical Center, and the author of Rising Plague, a book about drug-resistant pathogens.[1]
One-third of nosocomial infections are considered preventable. The
CDC estimates 2 million people in the United States are infected
annually by hospital-acquired infections, resulting in 20,000 deaths.[2] The most common nosocomial infections are of the urinary tract, surgical site and various pneumonias.[3]
[edit] Country estimates
The methods used differ from country to country (definitions used,
type of nosocomial infections covered, health units surveyed, inclusion
or exclusion of imported infections, etc.), so that international
comparisons of nosocomial infection rates should be made with the utmost
care.
United States: The Centers for Disease Control and Prevention
(CDC) estimates that roughly 1.7 million hospital-associated
infections, from all types of bacteria combined, cause or contribute to
99,000 deaths each year.[1]
Other estimates indicate that 10%, or 2 million, patients a year become
infected, with the annual cost ranging from $4.5 billion to $11
billion.
France: estimates ranged from 6.7% in 1990 to 7.4% (patients may have several infections).[4] At national level, prevalence among patients in health care facilities was 6.7% in 1996,[5] 5.9% in 2001[6] and 5.0% in 2006.[7] The rates for nosocomial infections were 7.6% in 1996, 6.4% in 2001 and 5.4% in 2006.
In 2006, the most common infection sites were urinary tract infections (30,3 %), pneumopathy (14,7 %), infections of surgery site (14,2 %). infections of the skin and mucous membrane (10,2 %), other respiratory infections (6,8%) and bacterial infections / blood poisoning (6,4 %).[8] The rates among adult patients in intensive care were 13,5% in 2004, 14,6% in 2005, 14,1% in 2006 and 14.4% in 2007.[9]
It has also been estimated that nosocomial infections make patients
stay in the hospital 4-5 additional days. Around 2004-2005, about 9,000
people died each year with a nosocomial infection, of which about 4,200
would have survived without this infection.[10]
Italy: since 2000, estimates show that about 6.7 % infection
rate, i.e. between 450,000 and 700,000 patients, which caused between
4,500 and 7,000 deaths.[11] A survey in Lombardy gave a rate of 4.9% of patients in 2000.[12]
United Kingdom: estimates of 10% infection rate,[13] with 8.2% estimated in 2006.[14]
Switzerland: estimates range between 2 and 14%.[15] A national survey gave a rate of 7.2% in 2004.[16]
Finland: estimated at 8.5% of patients in 2005[17]
[edit] Transmission
The drug-resistant Gram-negative germs for the most part threaten
only hospitalized patients whose immune systems are weak. The germs can
survive for a long time on surfaces in the hospital and enter the body
through wounds, catheters, and ventilators.[1]
| Contact transmission | the most important and frequent mode of transmission of nosocomial infections. |
| Droplet transmission | occurs when droplets are generated from the source person mainly during coughing, sneezing, and talking, and during the performance of certain procedures such as bronchoscopy. Transmission occurs when droplets containing germs from the infected person are propelled a short distance through the air and deposited on the host's body. |
| Airborne transmission | occurs by dissemination of either airborne droplet nuclei (small-particle residue {5 µm or smaller in size} of evaporated droplets containing microorganisms that remain suspended in the air for long periods of time) or dust particles containing the infectious agent. Microorganisms carried in this manner can be dispersed widely by air currents and may become inhaled by a susceptible host within the same room or over a longer distance from the source patient, depending on environmental factors; therefore, special air handling and ventilation are required to prevent airborne transmission. Microorganisms transmitted by airborne transmission include Legionella, Mycobacterium tuberculosis and the rubeola and varicella viruses. |
| Common vehicle transmission | applies to microorganisms transmitted to the host by contaminated items such as food, water, medications, devices, and equipment. |
| Vector borne transmission | occurs when vectors such as mosquitoes, flies, rats, and other vermin transmit microorganisms. |
| Direct-contact transmission | involves a direct body surface-to-body surface contact and physical transfer of microorganisms between a susceptible host and an infected or colonized person, such as occurs when a person turns a patient, gives a patient a bath, or performs other patient-care activities that require direct personal contact. Direct-contact transmission also can occur between two patients, with one serving as the source of the infectious microorganisms and the other as a susceptible host. |
| Indirect-contact transmission | involves contact of a susceptible host with a contaminated intermediate object, usually inanimate, such as contaminated instruments, needles, or dressings, contaminated blood pressure cuffs or contaminated gloves that are not changed between patients. In addition, the improper use of saline flush syringes, vials, and bags has been implicated in disease transmission in the US, even when healthcare workers had access to gloves, disposable needles, intravenous devices, and flushes. Contaminated blood pressure cuffs have become one of the major medium for indirect - contact transmission of spread of various diseases hence resulting in hospital acquired infection (nosocomial infection).[18] |
Factors predisposing a patient to infection can broadly be divided into three areas:
- People in hospitals are usually already in a poor state of health, impairing their defense against bacteria – advanced age or premature birth along with immunodeficiency
(due to drugs, illness, or irradiation) present a general risk, while
other diseases can present specific risks - for instance, chronic obstructive pulmonary disease can increase chances of respiratory tract infection. - Invasive devices, for instance intubation tubes, catheters, surgical drains, and tracheostomy tubes all bypass the body’s natural lines of defence against pathogens
and provide an easy route for infection. Patients already colonised on
admission are instantly put at greater risk when they undergo an
invasive procedure. - A patient’s treatment itself can leave them vulnerable to infection – immunosuppression and antacid treatment undermine the body’s defences, while antimicrobial therapy (removing competitive flora and only leaving resistant organisms) and recurrent blood transfusions have also been identified as risk factors.
[edit] Prevention
Hospitals have sanitation protocols regarding uniforms, equipment sterilization, washing, and other preventative measures. Thorough hand washing and/or use of alcohol rubs
by all medical personnel before and after each patient contact is one
of the most effective ways to combat nosocomial infections.[19] More careful use of antimicrobial agents, such as antibiotics, is also considered vital.[20]
Despite sanitation protocol, patients cannot be entirely isolated
from infectious agents. Furthermore, patients are often prescribed antibiotics and other antimicrobial drugs to help treat illness; this may increase the selection pressure for the emergence of resistant strains.
[edit] Isolation
Isolation precautions are designed to prevent transmission of
microorganisms by common routes in hospitals. Because agent and host
factors are more difficult to control, interruption of transfer of
microorganisms is directed primarily at transmission.
[edit] Handwashing and gloving
Handwashing frequently is called the single most important measure to reduce the risks of transmitting skin microorganisms
from one person to another or from one site to another on the same
patient. Washing hands as promptly and thoroughly as possible between
patient contacts and after contact with blood, body fluids, secretions, excretions, and equipment or articles contaminated by them is an important component of infection control and isolation precautions.
Although handwashing may seem like a simple process, it is often
performed incorrectly. Healthcare settings must continuously remind
practitioners and visitors on the proper procedure in washing their
hands to comply with responsible handwashing. Simple programs such as Henry the Hand, and the use of handwashing signals can assist healthcare facilities in the prevention of nosocomial infections.
All visitors must follow the same procedures as hospital staff to
adequately control the spread of infections. Visitors and healthcare
personnel are equally to blame in transmitting infections.[citation needed] Moreover, multidrug-resistant infections can leave the hospital and become part of the community flora if steps are not taken to stop this transmission.
In addition to handwashing, gloves
play an important role in reducing the risks of transmission of
microorganisms. Gloves are worn for three important reasons in
hospitals. First, gloves are worn to provide a protective barrier and to
prevent gross contamination of the hands when touching blood, body
fluids, secretions, excretions, mucous membranes, and nonintact skin. In
the USA, the Occupational Safety and Health Administration has mandated wearing gloves to reduce the risk of bloodborne pathogen infection.[21]
Second, gloves are worn to reduce the likelihood that microorganisms
present on the hands of personnel will be transmitted to patients during
invasive or other patient-care procedures that involve touching a
patient's mucous membranes and nonintact skin. Third, gloves are worn to
reduce the likelihood that hands of personnel contaminated with
microorganisms from a patient or a fomite
can transmit these microorganisms to another patient. In this
situation, gloves must be changed between patient contacts, and hands
should be washed after gloves are removed.
Wearing gloves does not replace the need for handwashing, because
gloves may have small, non-apparent defects or may be torn during use,
and hands can become contaminated during removal of gloves. Failure to
change gloves between patient contacts is an infection control hazard.
[edit] Surface sanitation
Sanitizing surfaces is an often overlooked, yet crucial component of
breaking the cycle of infection in health care environments. Modern
sanitizing methods such as NAV-CO2 have been effective against gastroenteritis, MRSA, and influenza. Use of hydrogen peroxide
vapor has been clinically proven to reduce infection rates and risk of
acquisition. Hydrogen peroxide is effective against endospore-forming
bacteria, such as Clostridium difficile, where alcohol has been shown to be ineffective.[22]
A Bio-Intervention process is effective for hard surface disinfection,
providing a 6-log kill (99.9999%)for many organisms including MRSA, VRE,
Psudomonas aeruginosa, Staphylococcus aureus, Rhinovirus, Salmonella
enterica, H1N1, HIV-1 and Hepatitis A. The unique kill mechanism is new
to the market and will be an effective method against mutation and
resistance of organizations.
[edit] Aprons
Wearing an apron during patient care reduces the risk of infection.[citation needed] The apron should either be disposable or be used only when caring for a specific patient.
[edit] Mitigation
The most effective technique of controlling nosocomial infection is to strategically implement QA/QC measures to the health care sectors and evidence-based management can be a feasible approach. For those VAP/HAP diseases (ventilator-associated pneumonia, hospital-acquired pneumonia), controlling and monitoring hospital indoor air quality
needs to be on agenda in management, one major method to stop the
spread of nosocomial infection through blood pressure cuffs is to use
disposable cuffs or to use disposable cuff covers like Cuff-Guard from [ندعوك للتسجيل في المنتدى أو التعريف بنفسك لمعاينة هذا الرابط][23] whereas for nosocomial rotavirus infection, a hand hygiene protocol has to be enforced.[24][25][26] Other areas that the management needs to be covered include ambulance transport.[citation needed]
