Transcript Document

Etiology of microorganisms
In hospital, patients may be exposed to, potential
pathogens outside of the healthcare setting before receiving
treatment, or may develop infections caused by those pathogens
when exposed to the conditions associated with delivery of every
healthcare action. Infections of the lungs, wounds, urinary tract
and bloodstream can be contracted in hospital. These are called
hospital-acquired infections (HAI).
Any medical procedure that results in
contact with body fluids and secretions
has associated risks and endoscopic
(colonoscopy, EGD, ERCP)
procedures are no exception.
Nosocomial (Hospital-Acquired) Infections
A nosocomial infection is any infection that is acquired during the
course of stay in a hospital, nursing home, or other health care facility.About
5-15% or all hospitalized patients acquire nosocomial infections.
Three factors contribute to
nosocomial infections:
•Microorganisms in the
hospital
•A compromised host
•The chain of transmission
Nosocomial infections are widespread. They are important
contributors to morbidity and mortality. They will become even more
important as a public health problem with increasing economic and
human impact because of:
• Increasing numbers and crowding of people.
• More frequent impaired immunity (age, illness, treatments).
• New microorganisms.
• Increasing bacterial resistance to antibiotics.
These standards recognize the risks that can be present from contact or
transmission of enteric secretions, which can most notably include C.diff, VRE,
MRSA, and E. coli, in addition to blood borne pathogens, GI borne viruses, and
other pathogens that, when present, are often colonized or have reservoirs in the
GI tract.
HAI Pathogens
The 10 most common infection-causing pathogens,
accounting for 84% of HAIs, are
– negative staphylococci (15%),
– Staphylococcus aureus (15%),
– Enterococcus species (12%),
– Candida species (11%),
– Escherichia coli (10%),
– Pseudomonas aeruginosa (8%),
– Klebsiella pneumoniae (6%),
– Enterobacter species (5%),
– Acinetobacter baumannii (3%) and
– Klebsiella oxytoca (2%).
Factors influencing the development of
nosocomial infections
The microbial agent
Infections may be caused by a
microorganism acquired from another
person in the hospital (cross-infection) or
may be caused by the patient’s own flora
(endogenous infection).
The Compromised Host
Patients with burns, surgical wounds, and
suppressed immune systems are the most
susceptible to nosocomial infections.
The Chain Of
Transmission
Nosocomial infections are
transmitted by direct
contact between staff
members and patients and
between patients.
Fomites such as catheters,
syringes, and respiratory
devices can transmit
nosocomial infections.
Type of HAI Simplified criteria infection
•Surgical site infection
Any purulent discharge, abscess, or spreading
cellulitis at the surgical site during the month
after the operation
•Urinary infection
Positive urine culture (1 or 2 species) with at
least 105 bacteria/ml, with or without clinical
symptoms
•Respiratory infection
Respiratory symptoms with at least two of the
following signs
appearing during hospitalization:
— cough
— purulent sputum
— new infiltrate on chest radiograph consistent
with infection
•Vascular catheter infection
Inflammation, lymphangitis or purulent
discharge at the insertion site of the catheter
•Septicaemia
Fever or rigours and at least one
positive blood culture
Clostridium difficile (C. difficile/C. diff)
• is a spore forming, gram-positive bacillus
that produces exotoxins that are
pathogenic to humans. C. difficileassociated disease (CDAD) can range in
severity from mild diarrhea to fulminant
colitis and death. Risk factors attributed
to acquiring C. difficile associated
disease (CDAD or infection include
gastrointestinal procedures and surgery,
advanced age, and prior exposure to
antibiotics and proton pump inhibitors
(PPI's).
VRE (Vancomycin Resistant
Enterococcus)
• Enterococci are bacteria that are
commonly found in the GI tract of 95% of
the population. As these are generally
normal flora, these bacteria rarely cause
illness in healthy people. Vancomycin in
an antibiotic used to treat very serious
infections. It is often used to treat
enterococci as they are resistant to many
other types of antibiotics. VRE is
associated with increased mortality,
length of hospital stay, admission to the
ICU, surgical procedures and costs.
MRSA (methicillin-resistant
Staphylococcus aureus)
• is a type of staph bacteria that is resistant
to treatment with commonly prescribed
antibiotics such as methicillin, penicillin
and amoxicillin. People infected with
MRSA are more likely to have longer,
more expensive hospital stays or die as a
result of the infection.
Staphylococcus aureus, also known as
“staph,” are bacteria commonly carried on the
skin or in the nose of healthy people.
Sometimes staph bacteria can cause serious
infections.
• MRSA is usually spread from person to person through
direct skin contact or contact with shared items or
surfaces that have touched a person’s infection (e.g.,
towel, equipment surface). This makes some settings
more conducive to the transmission of MRSA, such as
hospitals, recreational facilities, locker rooms, sports
venues, schools and daycare centers.
Risk factors
• At risk populations include:
• People with weak immune systems (people living with HIV/AIDS,
cancer patients, transplant recipients, severe asthmatics, etc.)
• Diabetics
• Intravenous drug users
• Use of quinolone antibiotics
• Young children
• The elderly
• College students living in dormitories
• People staying or working in a health care facility for an extended
period of time
• People who spend time in coastal waters where MRSA is present,
such as some beaches in Florida and the west coast of the United
States
• People who spend time in confined spaces with other people,
including prison inmates, military recruits in basic training, and
individuals who spend considerable time in changerooms or gyms.
How prevent the spread of MRSA?
•
•
•
•
•
The CDC (Centers for Disease Control and Prevention)
recommends practicing good personal hygiene such as
frequent washing of hands with soap and water or an alcoholbased hand rub. Other recommendations include:
Proactive hospital screening of targeted high-risk populations,
which allows for early identification, isolation and treatment of
infected individuals.
Cover cuts and abrasions with clean, dry bandages until
healed.
Avoid sharing personal items such as towels, razors and
ointments.
Cleaning procedures should focus on commonly touched
surfaces.
Use Environmental Protection Agency (EPA) registered
disinfectants.
E. coli (Escherichia coli)
is a type of bacteria commonly found
in the digestive tract, primarily
inhabiting the large intestine. E. coli is
spread through contact with fecal
contamination, and causes 3 primary
types of infection, including urinary
tract infections (UTI's), intestinal
disease (e.g. gastroenteritis), and
neonatal meningitis. E. coli is a
leading cause of both communityacquired and nosocomial urinary tract
infections, accounting for 90% of all
UTI's and up to 50% of nosocomial
infections.
E. coli is also a frequent
cause of other bacterial
infections
including
cholecystitis,
bacteremia,
cholangitis,
travelers
diarrhea, prostatitis, and
pneumonia.
High risk areas in the hospital
These areas in the hospital carry a greater risk:
• Nurseries
• Intensive care unit
• Dialysis unit
• Organ transplant unit
• Burns unit
• Operation theatres
• Delivery rooms
• Post-operative wards
Intensive Care Units (ICU)
• ICU patients may be infected with contagious pathogens,
are often immunocompromised and at very high risk for
spreading or developing HAIs. Disinfect with bleach to
kill pathogens commonly found in ICUs, such as
Staphylococcus aureus, Vancomycin Resistant
Enterococcus faecalis (VRE) and Pseudomonas
aeruginosa, to minimize cross-contamination.
Emergency Room (ER)
• With
many
patients
coming through the door,
ER
surfaces
require
proactive disinfecting to
prevent the spread of
pathogens to the rest of
the facility.
Operating Room
• With frequent surgery turnover and the presence
of blood, tissue and other body fluids, ensuring a
clean and disinfected operating room is of
utmost importance.
Dialysis
• Cross-contamination can pose a
significant risk to patients in
dialysis
centers.
Bacterial
infections are the second leading
cause of death among dialysis
patients. The most prevalent
infections include Staphylococcus
aureus (MRSA), Hepatitis B,
Hepatitis C and HIV, which many
dialysis disinfectants are not EPAregistered to kill. Proper surface
disinfection - with an EPAregistered bleach disinfectant - and
compliance with hand hygiene
protocols are key to preventing
infections in dialysis settings.
Endoscopy/GI Suite
• The tests conducted here
can create a high risk for
organism shedding, such as
Clostridium difficile, and
contamination of surfaces
and medical equipment.
Thorough disinfection of
these areas is critical to
breaking the cycle of
indirect pathogen
transmission.
Isolation Rooms
• Isolating
patients
with
potentially deadly infections is
not enough because HAIcausing pathogens can be
transmitted
through
contaminated surfaces.
Patient Room and Bathroom
With multiple patient, staff and visitor
interactions occurring, these patient areas
are prone to cross-contamination since so
many different hands touch potentially
contaminated surfaces every day. Some
infectious germs can survive on these
patient room surfaces for hours, days,
even months. According to the Healthcare
Infection Control Practices Advisory
Committee (HICPAC) and CDC guidelines,
high-touch surfaces should be more
frequently cleaned and disinfected.
Microbes can spread and pass diseases in a
number of ways:
• 1) By direct contact: physical contact (touching etc) with
an infected person; sexually-transmitted diseases are
passed on this way.
• 2) By indirect contact: touching something which an
infected person has touched eg a towel, door knob, cup
etc.
• 3) By inhalation: breathing in droplets containing
microbes which have been produced by sneezing or
coughing eg flu, TB, pneumonia.
• 4) By contaminated food or drink: eating food or drinking
water which has been infected by microbes eg typhoid,
cholera.
• 5) By animal vectors: animals can pass microbes on to
humans by biting them eg fleas, mosquitoes.
The Transmission Of Disease
Contact Transmission
c) indirect contact
a) direct contact
b) prevention of
contact transmission
d) droplet
Vehicle Transmission
Vectors of Disease
a) water
b) food
c) air