NOSOCOMIAL INFECTIONS

Katie McIntyre

Kevin Jaggi

Maya D’Alessio

WHAT ARE NOSOCOMIAL INFECTIONS?“An infection acquired in a hospital by a

patient who was admitted for a reason other than that infection”

Infections acquired during a hospital stay If you didn’t walk in with it – it’s

nosocomial Also known as hospital acquired

infections (HAI) A major factor in terms of cost and time

for the current health care system

SOME SCARY FACTS Roughly 1.7 MILLION HAIs a year in the

USA leading to 99,000 deaths Roughly one third of nosocomial

infections are estimated to be preventable

Costs the USA between $4 billion and $11 billion per year

RISK FACTORS Immune suppression Major surgery/invasive procedures Prolonged use of invasive devices

(ventilators) Long hospital stays Major wounds Elderly/infants Antimicrobial therapies Chemotherapy

HOW CAN THEY BE SPREAD? Exogenous cross-infection Endemic or epidemic exogenous

environmental infections Endogenous infection

Indirect or direct contact transmission Droplet transmission Airborne transmission Vehicle transmission (contaminated

medication or surgical equipment)

SOURCES OF INFECTIOUS AGENTS Past

Infections were caused by pathogens of external origins

Microorganisms not present in the normal flora

PresentOpportunistic pathogens that are common

in the general population Shift due to use of antibiotic treatments

and hygiene practices

TUBERCULOSIS Pulmonary Infection caused by

Mycobacterium tuberculosis – inhabits the lung

Leading cause of death by bacterial infections in the world

Person can be Tb (+) however may not develop the actual disease~10% of Tb infected patients actually get

the disease HIV patients are at higher risk for TB

TB IN HOSPITALS Patients who have latent TB infections can

enter the hospital If they become immunocompromised they go

into active disease and can spread it TB can spread through droplet contact to

surrounding patients and healthcare workers Recently TDR TB has been detected in India, along with MDR and XDR TB TB treatment is long term and complicated

URINARY TRACT INFECTION (UTI) Most common nosocomial infection Bacterial Infection caused by E. coli

Gram Negative BacteriaNormal flora in body, however, some can

cause infections such as E. coli 0157:H7 known as a shiga producing toxin

Affects bladder, kidneys, urethra

URINARY TRACT INFECTION (UTI) Women are more prone than men Patients who have nerve damage

around the bladder are more prone Patients who have weakened immune

systems are more prone Patients in hospitals or care homes who

use catheters are more prone

SYMPTOMS/TREATMENT

Bladder InfectionsBurning sensation while urination, fatigue,

bloody urine Kidney Infections

High Fever, abdominal pain, chills Antibiotics up to 14 days

Amoxicillin Fluroquinolones

Lots of fluids is recommended

HAP- HOSPITAL ACQUIRED PNEUMONIA 2nd most common nosocomial infection,

however has the highest mortality rate Pneumonia (infection of lungs), which

develops when a patient is hospitalized for an extended period of time

Caused by Psuedomonas aeruginosa, Staphylococcus aeurus, and Entrobacter, Acetinobacter

Patients who are on ventilators for more than 48 hours are most at risk, followed by patients in ICU and patients in post-op care.

MECHANICAL VENTILATORS AND HAP The most common way to get

pneumonia in a hospital or long term care facility (old age home) is through a ventilator VAP (Ventilator associated pneumonia)

~86% of all VAP cases have occurred in ICU wards

Patients who have been hospitalized for more than 5 days and have been on a ventilator for more than 48 hours should be screened

SYMPTOMS/DIAGNOSIS Hard to distinguish However the following are the main

symptoms to look for Fever, sputum, change in the

characteristics (color, etc.) of the discharge over a period of time, rapid or shallow breathing, hypoxia

Blood tests- WBC count Chest X-rays- Infiltrates indicate

pneumonia Bronchoscopy

PREVENTION Reduction of time the patient uses a

ventilator New research on coating the endotracheal

tubes with silver or hexetidine, which prevents bacteria to adhere to it

Using sterile fluid in the suction that is used to clear the catheter

Tilting the hospital bed 30-40° at all time to reduce GI reflux

Changing tubes and machines of the ventilators frequently

METHICILLIN RESISTANT S. AUREUS Includes any S. aureus strain that is

resistant to penicillins and cephalosporins

MRSA strains are not more virulent Infects respiratory tract, open wounds,

the sites of intravenous catheters and the urinary tract

Becoming resistant to vancomycin Human carriers

SCREENING FOR MRSA Upon admittance to the hospital, patient

history is taken If there is a potential that the patient is

carrying MRSA, they are swabbed for further testing

MRSA testing is not immediate Suspected patients are put on contact

precautions until the test results are released

VANCOMYCIN RESISTANT ENTEROCOCCUS Includes bacterial strains of

Enterococcus that are resistant to vancomycin

4% of hospital nosocomial infections in US

Spread through fecal to oral route

Use of cephalosporins is a risk factor for VRE infection

CLOSTRIDIUM DIFFICILE Causes severe diarrhea and intestinal

disease Normally can’t compete with commensal

bacteria In a patient on antibiotics, the commensal

bacteria have been killed The use of fluoroquinolones and

clindamycin are strongly associated with cases of C. difficile

Can lead to pseudomembranous colitis, a severe inflammation of the colon or toxic megacolon which can be fatal

TREATMENT Treatment in mild cases of C. difficile can

be as simple as halting antibiotic treatment

In more serious cases metronidazole is used and vancomycin may be used as well

Relapses of C. difficile have been reported in up to 20% of cases

Antidiarrheal drugs make the damage worse

In Australia they are experimenting with fecal bacteriotherapy

ACINETOBACTER Pleomorphic gram negative bacillus Only rare cases of community acquired

infections Preferentially colonizes aquatic environments

- in hospitalized patients it is commonly found in their:

-sputum/respiratory secretions -urine -wounds

Capable of long-term survival in hospital environments

-contact patients via -inanimate objects-human reservoirs

A.baumannii is the most common species associated with infection causing opportunistic infections

Predominant role as an agent of ventilator-associated pneumoniaCan also cause

Bacteremia UTIs Secondary meningitis Skin and wound infections

Combination therapy is generally required to treat infections due to growing antibiotic resistance

CANDIDA In the 1990s Candida albicans was

responsible for approximately 80% of candidemias

There has been a shift in the type of Candidia infections away from C.albicansC.albicans (48%)C.glabrata (24%)C.tropicalis (19%)C.parapsilosis (7%)

These other species are less susceptible to the commonly used azole antifungal agents!

HOW DO WE STOP IT?…HAND HYGIENE Compliance with proper hand hygiene is

lower than 40% and leads to the transmission of infections between patients

Hand hygiene is simple In Ontario, hospitals must report their

hand hygiene compliance rates 80% of hospital staff who dressed a

MRSA infected wound carried the bacteria on their hands for THREE HOURS

FOUR MOMENTS FOR HAND HYGIENE

CONTAINING SPREAD Private rooms or cohorting Proper cleaning protocols, using bleach

or other heavy duter cleaners Frequent cleaning Replacing any damaged equipment Repainting of walls/surfaces Curtains and surfaces are depositories

for bacterial growth

IMPLEMENTING PRECAUTIONS Depending on the confirmed or

suspected illness patients on put on a specific “precaution” guideline

Contact precautions

Droplet precautions

Airborne precautions

CONCLUSION Many nosocomials are caused by

ubiquitous opportunistic pathogens Avoid hospitals when possible

Hand hygiene

Avoid antibiotics when possible