HOSPITAL ACQUIRED INFECTIONS DEFINITION

Hospital Acquired Infections definition are infections acquired in a hospital by patient who was admitted for a reason other than that infection. An infection occuring in a patient in a hospital or other health care facility in whom the infection was not present or incubating at the time of admission. This includes infections acquired in the hospital but appearing after discharge, and also occupational infections among staff of the facility.

NOSOCOMIAL INFECTIONS ON PUBLIC HEALTH

Nosomical 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.

CROWDING A MAJOR FACTOR

Increasing numbers and crowding of people. More frquirent impaired immunity (age, illness, treatments)
Increasing bacterial resistance to antibiotics contributed as emerging problem.

WHEN THE NOSOCOMIAL INFECTIONS MANIFEST?

Majority of such infections become evident during their stay in the Hospital or some times only after their discharge from the patient.

HOW AND WHEN HOSPITAL ACQUIRED INFECTIONS OCCUR?

Nosomical infections are infections which are a result of treatment in a hospital or a healthcare service unit, but secondary to the patient’s original condition. Infections are considered Nosomical if they first appear 48 hourrs or more after hospital admission or within 30 days after discharge.

COMMONLY OCCURING MICROORGANISMS IN HOSPITAL INFECTIONS

MICROORGANISMS AND NOSOCOMIAL INFECTIONS

The patient is exposed to a variety of microorganisms during hospitalization. Contact between the patient and a microorganisms does not by itself necessarily result in the development of clinical disease – other factors influence the nature.

URINARY TRACT INFECTIONS

Escherichia coli
Klebsiella, Serratia, Proteus spp
Pseudomonas aeruginosa
Enterococcus spp
Candida alibcans

RESPIRATORY INFECTIONS

Hemophilus influenzae
Streptococcus pneumonia
Staphylococcus aureus
Enterobacteriaceae
Respiratory viruses
Fungi, Candida spp
Aspergillus’s spp

SKIN SEPSIS AND WOUNDS

Staph aureus
Streptococcus pyogenes
E. Coli
Peoteus spp
Anaerobic bacteria
Enterococcus spp
Coagulase negative Staphylococcus

GASTRO INTESTINAL INFECTIONS

Salmonella serotypes
Clostridium difficile
Norwalk like viruses

DRUG RESISTANCE – NOSOCOMIAL INFECTION

The likelihood of exposure leading to infection depends partly on the characteristics of the microorganisms, including resistance to antimicrobial agents, intrinsic virulence, and amount (inoculum) of infective meterial.

PATHOPHYSIOLOGY

Within hours of admission, colonies of hospital strains of bacteria develop in the patient’s skin, respiratory tract, and genitourinary tract. Risks factors for the invasion of colonizing pathogens can be categorized into 3 areas: iatrogenic, organizational, and patient-related

PATHOPHYSIOLOGY

IATROGENIC RISK

Iatrogenic risk factors include pathogens on the hands of medical personnel, invasive procedures (eg. incubation and extended ventilation, indwelling vascular lines, urine catherization) and antibiotic use and prophylaxis

ORGANIZATIONAL

Organizational risk factors include contaminated air-conditioning systems, contaminated water systems, and staffing and physical layout of the facility (eg, nurse-to-patient radio, open beds close together).

PATIENT ASSOCIATED

Patient risk factors include the severity of illness, underlying immunocompromised state, and length of stay.
Prolonged stay in the hospital is a Major contributing factor.

ROUTES OF TRANSMISSION OF INFECTION

A susceptible host and appropriate inoculum of infecting microorganism with an appropriate route of transmission contributed in majority of cases.

AIR-BORNE ROUTE

From respiratory tract via talking, coughing, sneezing
From the skin by natural shedding of the skin scales during would dressing or bed making.
From aerosols from equipment, respiratory apparatus, air conditioning plants.

CONTACT SPREAD

In direct contact spread from person to person
By indirect contact spread via contaminated hands or equipment.
Clothing of staff.
Urinary catheters, contaminated with hands of the operator may introduce organisms or patients own flora from urethra may contribute to infection.

FOOD BORNE SPREAD

From hospital kitchen, or in special diets, infant feeds, kitchen, or commercial supplies.
Mechnical vectors flies, cockroaches or insects, or rodents act as a carriers of infection.

BLOOD BORNE SPREAD

The accidental transmission of infections as HIV, HBV, and HCV by needle stick injuries is documented.
Syphilis and malaria a concern in high prevalence areas.

SELF INFECTIONS AND CROSS INFECTIONS

Lower bowel surgery
Self infection may occur due to flora from nose, Staphylococcus may be introduced into wounds.
Cross infection between patients occur due to spread of Staphylococcus or coli forms.

OTHER CONTRIBUTING FACTORS

Surgeons punctured surgical gloves, or moistened gown, imperfectly sterilized surgical instruments, or by airborne theatre dust. Faulty wound dressings may cause infections.

PATIENTS OWN FLORA TOO INFECTIVE

Self infection from patient’s own flora from Bowel can be major contributor of infections in bowel surgery.

OTHER SOURCE OF HOSPITAL INFECTIONS

Hospital environment, includes defective constructions.
People their behavior has great impact. Objects, food, water, Air in the hospital too contribute to infections.

CROSS INFECTION

Many different bacteira, viruses, fungi and parasites may cause Nosocmial infections. Infections may be caused by micro organism acquired from another person in the hospital (cross-infection) or may be caused by patient’s own flora (endogenous infection)

USED/CONTAMINATED SYRINGES A GREAT THREAT IN DEVELOPING WORLD

Some organisms may be acquired from an inanimate object or substances recently contaminated from another human source.

CHANGING TRENDS IN INFECTION ETIOLOGY

With advances in more elaborate surgery and intensive care, with combined use of broad spectrum antibiotics and immunosuppressive drugs, Gram Negative bacteria increased in importance.
Pseudomonas aeruginosa gained importance in causing infection in compromised patients.
They exhibit natural resistance to antibiotics and antiseptics.

EMERGING INFECTIOUS AGENTS

A group of Microbes that played no role in the pas have emerged. Coagulase negative Staphylococci and Acinetobacter baumanii

MICROBES FROM ENVIRONMENT

The dissemination from environment such as cooling towers and hot water system is proving a threat with Legionella pneumophila causing infections of respiratory systems.

VIRUS TOO PLAY A IMPORTANT ROLE

Awareness on risk of Blood born viruses including: Hepatitis B, C and HIV essential.
CMV virus in association with organ and cellular transmission

Human Herpes simplex virus on colorful background. 3D illustration

IATROGENIC SPREAD A CONCERN

The possible risk of iatrogenic spread of Prions causing Creuzfeldt-Jacob disease is a concern.

COMMON SITES ASSOCIATED WITH ETIOLOGICAL AGENTS

Urinary Tract
Surgical wounds
Respiratory tract
Skin (especially burns)
Blood (bacteraemia)
Gastrointestinal tract
Central nervous system

COLLECTION OF DATA IN CROSS INFECTIONS

Always collect information and document information on:

Patient details
Site and extent of infection
Date of admission – operative procedure first recognition of infection
Specimen and laboratory isolates and typing results
Ward and staff details

PREVENTION AND CONTROL

The basic responsibility of any good hospital remain with establishment of good infection control policies, which can always be archieved with an infection control committee and an infection team.

INFECTION CONTROL COMMITTEE

Should meet regularly to formulate and update policies for the whole hospital on all matter which have bearing on infection control and to mange outbreaks of Nosocomial infection.

INFECTION CONTROL TEAM

Which will function under the guidance of infection control Doctor.
a Medically qualified Microbiologist, who will take responsibility of day to day for the policies formulated.

THE FUNCTIONS OF THE COMMITTEE

To do surveillance and infection monitoring of hygiene practices.
Educate the Medical and Paramedical staff on policies relating to prevention of infection, and safe procedures

INFECTION CONTROL NURSE

Is the key member of the team.
Maintain the close working relations between Microbiology Laboratory, different clinical services like laundry, pharmacy and engineering.

ALL ARE CAMPAIGNERS OF SAFE PRACTICES

It is the minimal responsibility of the members to campaign on issues related to safe practices including hand washing.

DECONTAMINATION AND STERILIZATION

Fundamental importance lies with supply of sterile instruments, dressings and fluids.
a availability of single use syringes, needles, catheters and drainage bags to be assured and planned for the regular supplies.

ASEPTIC TECHNIQUES

No touch technique when dealing with sterile equipment coupled with strict personal hygiene.
a strict rules laid when dealing the patients in the operation theatre and other procedures such as wound dressing and insertion of IV and urinary catheters

CLEANING AND DISINFECTION

Basic cleaning, waste disposal, and laundry carry priority.
The use of chemical disinfectants for wall floors, and furniture is warranted in special circumstances, such as spillages, of body fluids from patients with blood born viral infections.

CARE OF MOP HEADS AND OTHER ITEMS

All the Mop heads and cloths used in crucial areas should be heat disinfected and stored in dry places after use.
Bed pans washers and disinfectants and dishwashers should be monitored to ensure reliable performance.

SKIN DISINFECTION AND ANTISEPTICS

Hand washing is a most important procedure which should be practiced by health care worker, gram-ve bacteria on the hands of the staff is an important factor in the spread of hospital infection.

HAND WASHING

Thorough hand washing after any procedure involving nursing care or close contact with the patient is essential.

Alchool based hand antiseptics gaining importance where washing with water and soap are not practicable.

HAND WASHING

WEARING A GLOVE

Gloves may be worn for any dirty contact procedure such as emptying a urinary cans, or bed pans, however it should not be forgotten gloved hand may also become colonized by transient hospital flora.

DISINFECTION POLICIES

All the hospitals should create disinfection policies which suit circumstances and economic resources.
The procedures and products should have a limited range of options, and chemicals to be used only in desired circumstances.
The policies should take into consideration surgical instruments, heat disinfection, Laundry, crockery and cleaning of floors and furniture.

IMPORTANCE OF STAFF

Staff should have well undrestood responsibilities.
Effective implementation of policy requires, motivated staff, with training.
Regular updating as new methods become available.

PROPHYLACTIC ANTIBIOTICS

Wide spread and haphazard use of antibiotics hasten emergence of antibiotic resistant bacteria.
Rational antibiotic prophylaxis plays an important role in infection control.
Antibiotic policy limits the use of broad spectrum agents, and is important in both prophylaxis and treatment.

PROTECTIVE CLOTHING

Different activities within the hospital require different degrees of protection to staff and patients.

In operation theatre the wearing of sterile gowns, gloves, head gear and face mask minimizes the shedding of microorganisms.

BARRIER NURSING

Barrier nursing is highly essential when soiling of clothing is anticipated, and dealing with communicable diseases, eg in EBOLA and MARBURG infections.

OTHER MEASURES

Gloves, face mask, and goggles are indicated in specific procedures.
The use of the above should confirm to international standards and the staff should be trained in their proper use and disposal.

ISOLATION IN INFECTIOUS DISEASES

Practiced as a source isolation and to protect the susceptible or immunocompromised.

It needs a highly disciplined approach by all staff to ensure that none of the barriers to transmission are breached.

CUBICLE ISOLATION

In which patient nursed alone in a room separated by door and corridor from other patients confers a substantial measures of protection.
Desirable to supply clean, filtered air is supplied to room with facilities for own toilet and washing facilities.

CRITICAL SITUATIONS

In some critical situations such as bone marrow transplant units where air borne contamination with environmental fungal spores is a problem the efficiency of an air filtration may be increased and laminar airflow maintained as barrier around the patient.

TREXLER ISOLATOR

Stringent isolation such as a plastic tent or Trexler isolator, is required only for patients with highly contagious infections.

HOSPITAL BUILDING AND DESIGN

Routine maintenance of the Hospital building is important, ensuring that surfaces wherever possible are smooth, impervious and easy to clean.
All contructions around the existing Hospitals generate fungal spores and bacterial spores with have impact on specialized units serving immunocompromised patients.

LEGGIONNAIRES’S DISEASE PREVENTION

The risk of Legionnaires disease is reduced by regular flushing all outlets and installing water supplies that ciculate below 20°C for the cold and above 60°C for the hot circuit.

EQUIPMENT

All the equipment in contact with patients need decontamination and sterilization.
Heat is a preferred method.
However heat sensitive to the sterilized with chemical and other newer emerging methods.

PERSONNEL CARE OF HEALTH CARE WORKERS

All health care workers should screened for possible communicable diseases before employment, and offered immunization against Hepatitis B Viral infection.

NEEDLE STICK INJURIES

Who sustain needle stick injuries from potentially contaminated sources should have access to advise and post exposure prophylaxis with antiviral agents or immunization.

MONITORING OF THE ENVIRONMENT?

Routine Microbiological monitoring of the environment is of little benefit, but monitoring of the air conditioning plants, and machinery used for disinfection and sterilization is essential.

SCREENING OF STAFF OR PATIENTS

Microbiological screening of staff and patients not undertaken routinely, but it may be needed for specific purpose to detect carriers or MRSA and Hepatitis viruses in those performing some types of surgery or where transmission to patients has occurred.

SURVEILLANCE AND ROLE OF MICROBIOLOGY LABORATORIES

The detection and identification of hospital infection incidents or outbreaks rely on the laboratory data that alert the infection control team to unusual cluster of infection called as allert organism system.

SURVEILLANCE

Identification of MRSA & ESBL and timely information to clinicians will help the ongoing events in the Hosptial warrant to track the events on source of outbreaks and action to control the similar situations in future.

PRACTICAL TEACHING TO STAFF

Regular visits to wards are also important to record data on infected patients from whom no speciments have been received and to respond to problems as they occur.

Such visits will bring in grater human interaction with paramedical staff and deliver the practical teaching.

EFFICACY OF INFECTION CONTROL

The following measures will certainly control the infections:

Sterilization
Hand washing
Closed drainage systems for urinary catheters
Intravenous catheter care
Peri operative antibiotic prophylaxis for contaminated wounds, and care of equipment used in respiratory therapy.

WHAT IS MOST IMPORTANT

Effective surveillance and action by the infection control team have shown to reduce infection rates.
One important role of the team is to monitor compliance and practices known to be effective.

SAVING THE COSTS IN PREVENTION INFECTIONS

With raising economic costs in running safe hospitals eliminate the many rituals or less effective practices that they may even increase the incidence or cost of cross infection.

Also we recommend check Hospital-acquired infection WIKI