Nosocomial infections or Hospital acquired infections

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• Any clinical infection that was neither present nor was in its incubation period when the patient is admitted in a hospital.

• The term "nosocomial" comes from two Greek words: "nosus" meaning "disease" + "komeion" meaning "to take care of." It is now synonymous with hospital-acquired.

• Nosocomial infections may also make their appearance after discharge from the hospital, if the patient was in the incubation period at the time of discharge.

• If someone in a hospital slips and breaks their hip, could that be a nosocomial fracture of the femur? No way. The only things that are nosocomial these days are infections.

• One of the earliest records of hospital infections are found the famous writings of physician Charaka and surgeon Sushuruta

(400 B.C.) who have emphasized the need for prevention of infection in clinical practice.

WHY ARE NOSOCOMIAL INFECTIONS COMMON?• Patients with infections or carriers of pathogenic

microorganisms are admitted• Hospitals house large numbers of people whose

immune systems are often in a weakened state.• Medical staff move from patient to patient,

providing a way for pathogens to spread.• Many medical procedures bypass the body's natural

protective barriers.• Increased incidence of antibiotic resistance.• Decreased bed spacing

Epidemiology & Burden

• Nosocomial infections occur in about 5-10 percent of hospital admissions, worldwide. In India, the nosocomial infection rate is alarming and is estimated at about 30-35 percent of all hospital admissions.

• According to WHO average of 8.7% of hospital patients have nosocomial infections.

• At any time, over 1.4 million people worldwide suffer from NCI

NOSOCOMIAL INFECTIONS IN INDIA

• Frequency is 1 in every 4 patients admitted into the Hospital.

• 1/3rd of all such infections are preventable.• Responsible for more mortality than any

other form of accidental death.

NOSOCOMIAL INFECTIONS IN DEVELOPED NATIONS

• In U.S. around 1.7 million HAI’s occur each year and 99,000 people lose their lives.

• In Europe around 25,000 deaths occur each year.• Overall there are about 2 million annual cases of

HAI’s in developed nations.• Frequency of HAI’s in developed nations is 5-10%. • It accounts for annual cost of $4.5 - $11 billions in

U.S.

• Rates vary between countries, within the country, within the districts and sometimes even within the hospital itself, due to

1) complex mix of the patients 2) aggressive treatment 3) local practices

CONSEQUENCES OF NOSOCOMIAL INFECTIONS

1. Prolongation of hospital stay: Varies by site, greatest with pneumonias and wound infections2. Additional morbidity3. Mortality increases - in order - LRI, BSI, UTI4. Long-term physical &neurological consequences5. Direct patient costs increased- Escalation of the cost of care

TYPES BY ORIGIN 1.Patients own flora - Endogenous (50%) Auto-Infection ( Greatest source of potential danger)

2.Environment - Exogenous(50%) (Air-5%; Instruments-10%) Another Patient/Staff - Cross Infection (35%)

Pathological agents – important nosocomial pathogens

• Bacteria (most common nosocomial pathogens):

Commensal bacteria - Staphylococcus epidermidis, Escherichia coli Pathogenic bacteria - Staphylococus aureus, M.R.S.A, Streptococcus, Clostridium, . E. coli, Proteus, Klebsiella, Enterobacter, Pseudomonas , Legionella , VRE

• Viruses: hepatitis B and C viruses ,RSV, rotavirus, and enteroviruses .Other viruses such as C.M.V, HIV, Ebola, influenza viruses, herpes simplex virus, and varicella-zoster virus

• Parasites and Fungi: Many of tham are opportunistic organisms and cause infections during extended antibiotic treatment and severe immunosuppression (Candida albigans, Aspergillus spp., Cryptococcus neoformans, Cryptosporidium, Pneumocystis carini, Toxoplasma pneumoniae). Sarcoptes scabies (scabies) is an ectoparasite – outbreaks In health care facilities.

MECHANISMS OF TRANSMISSION

1) Contact: direct (person-person), indirect (transmission through an intermediate object-- contaminated instruments---Cross transmission

2) Airborne: organisms that have a true airborne phase as pattern of dissemination (TB, Varicella)

3) Common-vehicle: common animate vehicle as agent of transmission (ingested food or water, blood products, IV fluids)

4) Droplet: brief passage through the air when the source and patient are in close proximity

5) Arthropod

ICUs Are Dangerous Places!!!

• The sickest patients are placed in proximity• AB are given empirically in large doses• Devices are everywhere (often pts have 3, 4 or more)• Frequent use of invasive devices• Staff busy caring for very ill pts• Staff move from one pt to other without washing

hands• Longer ICU stay prolonging the risk of exposure• Space limitations

RISK FACTORS• Extremes of age • Sex (females with UTI) • Malnutrition• Use of antibiotics• Diabetes, and causes of immunosuppression • Altered mental status • Surgery • ICU setting, endotracheal intubation with

mechanical ventilation

Sites of NCI with their incidence

• Average Incidence - 5% to 10%, but maybe up to 28% in ICU

1) Urinary Tract Infection - usually catheter related -28%

2) Surgical Site Infection or wound infection -19%

3) Pneumonia -17% 4) Blood Stream infection - 7% to 16% 5) Others – GIT, CNS- 10 to 20%

AGE RANKS OF NCIs

Ranks in infants

1) SKIN2) LRI3) BSI4) UTI5) SWI

Ranks in children

1) SKIN 2) LRI3) BSI4) UTI5) SWI

Ranks in adults

1) UTI2) LRI3) SWI4) BSI

Nosocomial Urinary Tract Infections

URINARY TRACT INFECTIONS

• Most common site of NI• Affects (5%) of admissions• 80% related to urinary catheters• Associated with 2/3 of cases of

nosocomial gram negative bacteremias.

PATHOGENESIS

• Major risk factors: • 1) pathogenic bacteria in

periurethral area • 2) indwelling urinary catheter

– Duration catheterization• Bacterial factors:

– properties which favor attachment to uroepithelium, catheters

• Bladder trauma decreases local host defenses

Urinary (Foley) Catheter

TREATMENT

• Is this a UTI vs asymptomatic bacteruria?– Use clinical judgement

- urine WBC- pyuria - bacterial colony counts > 103

- clinical signs/symptoms• No antibiotic treatment for bacteruria - resolves with catheter removal• Empiric therapy typically initiated pending microbiologic

results

Surgical Site Infections

SURGICAL SITE INFECTIONS

• (2nd most common)• Incisional infections

– Infection at surgical site– Within 30 days of surgery– Involves skin, subcutaneous tissue, or muscle above

fascia– Accompanied by:

• Purulent drainage• Dehiscence of wound• Organism isolated from drainage• Fever, erythema and tenderness at the surgical site

SSI: Superficial

SURGICAL SITE INFECTIONS

• Deep surgical wound infection– Occurs beneath incision where operation took place– Within 30 days after surgery if no implant, 1 year if

implant– Infection appears to be related to surgery– Occurs at or beneath fascia with:

• Purulent drainage• Wound dehiscence• Abscess or evidence of infection by direct exam• Clinical diagnosis

SSI: Deep

SURGICAL SITE INFECTIONS

• Risk of infection dependent upon:–Contamination level of wound–Length of time tissues are

exposed–Host resistance

PATHOGENS ASSOCIATED WITH SWI

Pathogen % of IsolatesS. aureus 17Enterococci 13Coag - Staph 12E. coli 10P. aeruginosa 8Enterobacter 8P. mirabilis 4K. pneumoniae 3Streptococci 3

Treatment• Surgical-site infections (SSIs) should be managed

with a combination of surgical care and antibiotic therapy. Antibiotic coverage should be modified once culture results are available.

• Severe infections such as streptococcal gangrene and extensive tissue necrosis need aggressive surgical intervention. For these kinds of infections, antibiotics alone may not work.

Nosocomial Pneumonia

NOSOCOMIAL PNEUMONIA

• Lower respiratory tract infection • Develops during hospitalization• Not present or incubating at time of

admission• Does not become manifest in the

first 48-72 hours of admission

EPIDEMIOLOGY

• 13-18% of nosocomial infections• 6-10 episodes/1000 hospitalizations• Leading cause of death from NI• Economic consequences

–prolongation of hospital stay 8-9 days

Nosocomial Pneumonia

• Cumulative incidence = 1-3% per day of intubation

• Early onset (first 3-4 days of mechanical ventilation)– Antibiotic sensitive, community organisms

(S. pneumoniae, H. influenzae, S. aureus)

• Late onset– Antibiotic resistant, nosocomial organisms (MRSA, Ps.

aeruginosa, Acinetobacter spp, Enterobacter spp)

Multiresistant bacteria are a problem in VAP

7.7S. pneumoniae

% of all isolatesOrganism

3.1MSSA

8.4H. influenzae

11.8A. baumannii

11.8MRSA

31.7 P. aeruginosa

Rello J. Am J Respir Crit Care Med 1999; 160:608-613.

(n = 321 isolates from 290 episodes)

DIAGNOSIS AND TREATMENT

• Clinical diagnosis - fever, change in O2, change in sputum, CXR• Microbiologic Confirmation

– Suctioned Sputum sample– Bronchoscopy with brochoalveolar lavage

• Empiric antibiotic- Rx based on previous cultures, usual hospital flora and susceptibilities

Nosocomial Bloodstream Infections

NOSOCOMIAL BACTEREMIA

• 4th most frequent site of NI• Attributable mortality 20%• Primary * IV access devices * gram positives (S. aureus, CNS)• Secondary * dissemination from a distant site * gram negatives

The CVC- is one of the most commonly used catheters in medicine

The CVC is typically placed through a central vein such as the IJ, Subclavian or femoral

The major risk factor is the Central Venous Catheter (CVC)

These serve as direct line for microbial bloodstream invasion

PATHOGENESIS

• Direct innoculation * during catheter insertion• Retrograde migration * skin→subcutaneous tunnel→fibrin sheath

at vein• Contamination * hub-catheter junction * infusate

Nosocomial Bloodstream Infections

Rank Pathogen Percent

1 Coagulase-negative Staph 31.3%2 S. aureus 20.2%

3 Enterococci 9.4%4 Candida spp 9.0%5 E. coli 5.6%6 Klebsiella spp 4.8%7 Pseudomonas aeruginosa 4.3%8 Enterobacter spp 3.9%9 Serratia spp 1.7%

10 Acinetobacter spp 1.3%

Treatment• Antibiotics with coverage against gram-positive and gram-

negative organisms, including Pseudomonas, should be empirically started and then tailored according to susceptibility pattern of isolated organisms.

• Antifungal therapy (eg, fluconazole, caspofungin, voriconazole, amphotericin B)

• Antiviral therapy (eg, ganciclovir, acyclovir) can be used in the treatment of suspected disseminated viral infections.

• For most bacterial organisms, the duration of therapy is 10-14 days after blood cultures become negative.

Prevention

Hand hygiene is thesingle most important

measure for controlof nosocomial

infections

Why it is the single most important measure??

Healthcare workers can get 100s to 1000s of bacteria on their hands by doing simple tasks like: • pulling patients up in bed• taking a blood pressure or pulse• touching a patient’s hand• rolling patients over in bed• touching the patient’s gown or bed sheets• touching equipment like bedside rails, overbed

tables, IV pumps

Hand Hygiene Techniques

1. Alcohol hand rub

2. Routine hand wash 10-15 seconds

3. Aseptic procedures 1 minute

4. Surgical wash 3-5 minutes

Preventive measures:

• Proper means of disinfection and sterilisation (physical, chemical and biological tests)

• Disposable instruments (cost/effectiveness!),

• Separation or/and exclusion of suspect sources (patients, visitors),

• Strict rules in handling the bedclothes, meals and hospital wastes,

• Proper means of disinfection of patient equipment

• Judicious use of Antimicrobial agents to prevent MDR

• Place patients with a confirmed MDRO or history of an MDRO in single-patient rooms.

• Gown and gloves worn upon entering room• Use eye/face protection if risk of splatter/splash

is anticipated (e.g., patient is coughing or sneezing or has trach)

• Avoid catheter when possible & discontinue ASAP• PROPHYLACTIC PREOPERATIVE ANTIBIOTICS

For pneumonia - Pulmonary toilet• Change position q 2 hours• Elevate head to 30-45 degrees• Deep breathing, incentive spirometry• Frequent suctioning• Bronchoscopy to remove mucous pluggingFor BSI• Line removal should be considered if the line

is no longer needed

Environmental Measures

• Clean and disinfect high-touch surfaces :(e.g. bedrails, faucet handles) and equipment used in the patient’s environment that may be contaminated with pathogens

• Adequate ventilation systems• Proper disposable of wastes

Hospital management measures• Hospital management should establish a

multidisciplinary Infection Control Committee• Identifying appropriate resources for a programme

to monitor infections and apply the most appropriate methods for preventing infection

• Ensuring education and training of all staff through support of programmes on the prevention of infection in disinfection and sterilization techniques

• Bed spacing in general wards - 2.7m• Bed spacing in ICU - 3.6 m

• The director of food services ensuring appropriate handling and disposal of wastes

• The housekeeping service should maintain high level of hygiene in the hospital

• Limiting the risk of endogenous infections by minimizing invasive procedures.

• Periodically reviewing the status of nosocomial infections and effectiveness of interventions to contain them

• Making sure that all medical personnel are immunised with hepatitis B vaccine.

Hospital-Acquired Infection Control Committee(HAICC)

• Committee responsible for investigation hospital acquired infection.

• Committee should be chaired by medical superintendent, microbiologist as a control officer, and heads of all department, blood bank, microbiologist, medical record officer, chief of nursing services and infection control board as its members.

• Chief of all supporting services should be included as invited members.

I may not have gone where I intended to go, but I think I have ended up where I needed to be

Douglas Adams

The ultimate goal: patient safety