Hospital infection control programme & practices

 

Hospital associated infection (HAI) or Nosocomial infection(NI) is defined as:

Localized or systemic condition that,

1. Results from adverse reaction to the presence of an infectious agent(s) or its toxin(s) and

2. Was neither present nor incubating at the time of admission to the hospital.

Healthcare associated infection: Infections associated with healthcare facilities like, hospitals, ambulatory services, home care, laboratories, etc.

Nosocomial infection, the term derived from two Greek words “nosos” (disease) and “komeion” (to take care of). Florence Nightingale who is the pioneer of nosocomial infection theory said,"Hospitals should do the sick no harm”. Lister is credited with the beginnings of sterilization in the Operating Room. Before surgery, he sprayed the operating rooms with carbolic acid, because he thought that the infections were caused by dust particles in the air. Nosocomial infections occur worldwide. The incidence is about 5-8% of hospitalized patients, 1/3^rd of which are preventable. Nosocomial infections can affect the patients as well as community in the following ways:

·        They lead to functional disability and emotional stress to the patient.

·        They lead to disabling conditions that reduce the quality of life.

·        They are one of the leading causes of death.

·        They increase economic costs by: Increased length of hospital stay, extra investigations, extra use of drugs and extra health care by doctors and nurses.

 

Learning objectives:

1. Definition of Hospital associated infection

2. Sources of HAI

3. Mode of transmission of HAI causing organisms

4. Common nosocomial infections observed in present era.

5. Preventive strategies to reduce HAI

               - Infection control precautions including standard universal precautions and specific precautions         to prevent transmission by various routes

               - Identification of source of infection

               - Environmental disinfection

               - Appropriate use of antibiotics

7. Infection control programme in the Hospital

               - Infection control committee

               - Infection control policy

               - Hospital waste management

8. Bio medical waste (BMW) management:

               - Definition

               - Category of BMW

               - Segregation of BMW

               - Safe handling of infectious sharps

               - transport and disposal of BMW

 

NOSOCOMIAL OR HOSPITAL ASSOCIATED INFECTION

Clinically, Nosocomial infections is defined as those occurring within 48 hours of hospital admissionorwithin 3 days of discharge orwithin 30 days of an operation.

 

SOURCES OF NOSOCOMIAL INFECTIONS

·        Endogenous:

Almost 50% of HAI are endogenous in origin &caused by patient’s own flora.These organisms  are not pathogenic under normal conditions, but only when they found opportunity will produce infection.The following conditions may enable these organisms to reproduce, spread and implant themselves at the sites, where they produce infection.

1. Invasive diagnostic or therapeutic proceduresleading breach in epithelial lining of skin or mucus membrane and allow the surface colonizing bacteria to enter within.

2. Catheters, implants or stitches may provide the path for organism from their normal colonizing sites to otherwise sterile sites of the body.

3. Immuno-compromised status of body may allow the development of  infections by these low virulent commensals.

 

·        Exogenous (cross-infection): These are

1. Other patients

2. Health care worker

3. Environment: Several types of micro-organisms survive well in the hospital environment.They form the hospital flora.

The common environmental sources are

·        Water & food.

·        Linen, equipments and other inanimate articles and furniture in Hospital premises.

·        Dust and droplet nuclei present in air.

 

 

MODES OF TRANSMISSION OF NOSOCOMIAL INFECTIONS

A.     Direct contact route:

1.      Via hands or clothing of hospital staff or other patients

2.      Through inanimate objects

3.      Through instruments or disinfecting  solutions

B.     Oral route and faeco oral route

C.     Air borne route

1.      From patients and hospital personnel:  by droplet or droplet nuclei containing organisms.

2.      Environmental sources

i.                 Dust

ii.                Aerosols produced by humidifiers, nebulizers, and air conditioning systems

D.     Parenteral route: by blood transfusion, tissue donation, contaminated blood products, contaminated infusion fluid or from sharp instruments.

 

COMMON NOSOCOMIAL INFECTIONS

 

TYPE OF INFECTION	COMMON RISK FACTORS	COMMON ORGANISMS	USUAL CRITERIA
Urinary tract infection (30-40%)	1.   Indwelling urinary catheter 2.   Instrumentation	·        E.coli ·        Enterococci ·        Pseudomonas ·        Candida ·        Klebsiella ·        Proteus ·        Providencia ·        Staphylococci	Positive urine culture (1 or 2 species) with at least 105c.f.u./ml, with or without clinical symptoms
Respiratory infections(20%)	1.   Intubation, 2.   Mechanical ventilation 3.   Aspiration 4.   Underlying chronic lung diseases.	·        Pseudomonas ·        Staphylococci ·        Candida ·        Klebsiella ·        Acinetobacter ·        Legionella ·        Respiratory viruses	Respiratory symptoms with at least 2 signs: cough, purulent sputum, new infiltrate on chest, appearing during hospitalization
Wound infection(15%)	1.   Wound contamination 2.   Duration of surgery 3.   Associated predisposing conditions	·        Pseudomonas ·        E.coli ·        Proteus ·        Staphylococci ·        Enterococci ·        Acinetobacter	Any purulent discharge, abscess or spreading cellulitis at the site of traumatic or surgical wound.
Bacteremia and septicemia (5-10%)	Intravenous cannulation	·        Pseudomonas ·        E.coli ·        Klebsiella ·        Candida ·        Staphylococci	Inflammation, lymphangitis or purulent discharge at the vascular catheter insertion site. Fever or rigors and at least one positive blood culture; SIRS.

 

Other nosocomial infections are:

1.      Skin and soft tissue infection (i.e. infection of bed sore or burns site)

2.      Gastroenteritis, antibiotic associated diarrhea

3.      Sinusitis, infections of eyes and conjunctiva

4.      Endocarditis.

5.      Hepatitis B, Hepatitis C, HIV

6.      Air borne viral haemorrhagic fever

 

PREVENTION OF NOSOCOMIAL INFECTIONS

Prevention of nosocomial infection is the responsibility of all individuals and service providerof healthcare setting.

Infection requires a “chain” of events.

•        There must be sufficient quantities of the pathogen,

•        The pathogen must be virulent enough to cause disease,

•        The pathogen moves through a route of transmission,

•        Reaches a “portal of entry,” such as eyes, nose, mouth, or puncture wound,

•        To enter the susceptible host.

 

The role of the hospital epidemiologist/infection control is to understand this chain and the most efficient means of interrupting transmission.

Disease transmission can be prevented by breaking one or more of the links in this chain of transmission

 

STRATEGIES TO REDUCE NOSOCOMIAL INFECTION

1.    Infection control precautions

Refer chapter 1

 

2.    Identification of source :

The source of infection in the hospital should be identified by

               - Regular surveillance,

               - Outbreak investigation and

               - Epidemiological data analysis.

 

               Surveillance of nosocomial infections include following points

o   Active surveillance: by surveillance personnel (i.e. infection control nurse)  including environmental sampling for bacteria and fungi.

o   Passive surveillance: by medical personnel

o   Laboratory or clinical based surveillance by analyses of clinical and laboratory data.

 

3.    Environmental disinfection:

Environmental services should approach cleaning in an orderly and regularly scheduled methods with appropriate concentration of disinfecting solutions.

Commonly used hospital disinfectants:

- 1 - 5% Na hypochlorite

- 2 % Gluteraldehyde

- Hydrogen peroxide + silver nitrate

- Phenolic compouds

 

4.    Appropriate use of antibiotics :

There is a Causal Association between Antimicrobial Use and the Emergence of Antimicrobial Resistance; This fact is supported by following evidences

        • Changes in antimicrobial usage are paralleled by changes in the prevalence of resistance.

• Resistance is more prevalent in healthcareassociated bacterial infections compared with those from community-acquired infections.

• Patients with healthcare-associated infections caused by resistant strains are more likely than control patients to have received prior antimicrobials.

• Areas within hospitals that have the highest rates of resistance also have the highest rates of use.

• Increasing duration of patient exposure to antimicrobials increases the likelihood of colonization with resistant organisms.

 

Antibiotic stewardship program.

To control the use of antibiotics every hospital should have an antibiotic stewardship program.

Definition: “Coordinated interventions designed to improve and measure the appropriate use of antimicrobial agents by promoting the selection of the optimal antimicrobial drug regimen including dosing, duration of therapy, and route of administration.”

In other words antimicrobial stewardship is the:

–                 Right drug, in the

–                 Right person, at the

–                 Right time, using the

–                 Right dose, and for the

–                 Right duration.

 

The primary goal of antimicrobial stewardship is to:

• Improve patient outcomes

• Optimize selection, dose and duration of treatment

• Reduce adverse drug events including secondary infection (e.g. C. difficileinfection)

• Reduce morbidity and mortality

• Limit emergence of antimicrobial resistance

• Reduce length of stay

• Reduce health care expenditures

 

Interventions for Antibiotic stewardship program:

Discussed in detail refer Chap 14 : Antimicrobial sensitivity

 

 

INFECTION CONTROL PROGRAMME IN THE HOSPITAL

Every hospital must have an effective hospital acquired infection control committee (ICC) which should be with responsibilities for the control of hospital acquired infections (HAI) and monitoring of hygienic practices in the hospital.

 

INFECTION CONTROL COMMITTEE (ICC)

It is a multidisciplinary committee responsible for preparation of infection control policies and monitoring the policy implementation and recommend corrective actions.

Members of Infection control team are general physician, infectious disease specialist, surgeon, clinical microbiologist, infection control nurse and representatives from other relevant departments (Laboratory, housekeeping, pharmacy and central supply).

Functions of ICC:

1. Addressing food handling, laundry handling, cleaning procedures, visitation policies, and direct patient care practices
2. Obtaining and managing critical bacteriological data and information, including surveillance data
3. Developing and recommending policies and procedures pertaining to infection control
4. Recognizing and investigating outbreaks of infections in the hospital and community
5. Intervening directly to prevent infections
6. Educating and training health care workers, patients, and nonmedical caregivers

 

Infection control committee should form policies for prevention and control of HAI;  and make it functional in the hospital.

The policies should include the following:

a.      Infection control policy

b.      Sterilization and disinfection policy

c.      Hospital waste management

d.      Antibiotic policy

e.      Surveillance policy

f.       Training of healthcare provider

 

 

BIOMEDICAL WASTE MANAGEMENT

The hospital waste like bodyparts, organs, tissues, blood and body fluids alongwith soiled linen, cotton, bandage and plaster castsfrom infected and contaminated areas are veryessential to be properly collected, segregated,stored, transported, treated and disposed of in safemanner to prevent nosocomial or hospital acquired infection .

Definition of biomedical waste:

According to Biomedical Waste(Management and Handling) Rules, 1998 of Indiadefinition of Biomedical Waste is “Any waste which is generated during thediagnosis, treatment or immunization of human beings or animals or in research activitiespertaining thereto or in the production or testing ofbiological components”.

                   World Health Organization states that 85%of hospital wastes are actually non-hazardous,whereas 10% are infectious and 5% are noninfectious but they are included in hazardouswastes.

 

SEGREGATING BIOMEDICAL WASTES

• Segregation of infectious wastes should be done at the point of origin.
•  Segregation of infectious waste with multiple hazards as necessary for management and treatment.
•  Use of distinctive, clearly marked containers or plastic bags for infectious wastes.
•  Use of the universal biological hazard symbol on infectious waste containers as appropriate.
• Whenever possible, do not combine medical waste with hazardous chemicals or radioactive waste.
•  Separate sharps waste from other medical wastes. Sharps should be stored in puncture-proof containers.
•  Separate pathology wastes from other medical wastes.
•  Separate chemotherapy wastes from other medical wastes.

 

Colour coding and type of container for segregation & disposal of biomedical waste

 

It is essential to segregate the waste at source in different colour coded bags.
Colour codes and type of containers used for disposal of biomedical waste are as follows:

 

Colour coding	Type of Container	Waste Category	Treatment options
Yellow	Plastic Bags	Human and animal wastes, Microbial and Biological wastes and soiled wastes (Cat 1,2,3 and 6)	Incineration/ Deep Burial
Red	Disinfected container/ Plastic bags	Microbiological and Biological wastes, Soiled wastes, Solid wastes (Cat 3,6,7)	Autoclave/ Microwave/ Chemical Treatment)
Blue/ White/ Transparent	Plastic bag, Puncture proof container	Waste sharps and solid waste ( Cat 4 &7)	Autoclave/ Microwave/ Chemical Treatment Destruction and Shredding
Black	Plastic bag	Discarded medicines, Cytotoxic drugs, Incineration ash and chemical waste (Cat 5,9 & 10)	Disposal in secured land fills
Green	Plastic Container	General waste such as office waste, food waste & garden waste	Disposed in secured landfills

 

 

Labels for biomedical waste containers and bags

 

PACKAGING INFECTIOUS WASTE

·        Selection of packaging materials which are appropriate for the type of waste handled:

o   Plastic bags for many types of solid or semisolid infectious waste.

o   Bottles, flasks, or tanks for liquids.

·         Use of packaging that maintains its integrity during storage and transport,

·         Closing the top of each bag by folding or tying as appropriate for the treatment or transport

·         Place liquid wastes in capped/ tightly stoppered bottles.

·         Do not compact infectious wastes before treatment.

 

HANDLING SHARPS

To protect against needlestick injuries, take the following precautions:

·        Avoid the use of needles where safe and effective alternatives are available.

·        Help your employer select and evaluate devices with safety features that reduce the risk of needlestick injury.

·        Avoid recapping needles.

·        Plan for safe handling and disposal of needles before using them.

·        Promptly dispose of used needles in appropriate sharps disposal containers.

·        Report all needlestick and sharps-related injuries promptly to ensure that you receive appropriate followup care.

·        Participate in training related to infection prevention.

·        Get a hepatitis B vaccination.

·        Containers for disposal of used needle are rigid puncture-resistant containers that, when sealed, are leak resistant and cannot be reopened without great difficulty.

TRANSPORTATION OF BIOMEDICAL WASTE

A separate trolley reserved for transport of above bags from each source to the central waste collection room. The trolley should be disinfected thoroughly with Na hypochloride or 2% Gluteraldehyde daily. The waste generated from wards should timely being transported to central waste collection room. From the central collection room, the waste should be picked up by the waste management contractor daily. The waste cannot be stored at hospital premises for beyond 48 hours.

 

TREATMENT AND DISPOSAL

1. Incineration Technology: This is a high temperature thermalprocess employing combustion of the wasteunder controlled condition for converting theminto inert material and gases. Incinerators can beoil fired or electrically powered or a combinationthereof.

2. Non-Incineration Technology: The main purpose of the treatmenttechnology is to decontaminate waste by destroyingpathogens.

a. Autoclaving: Steam sterilization is most effective with low-density material such as plastics, metal pans, bottles, and flasks. High-density polyethylene and polypropylene plastic should not be used in this process because they do not facilitate steam penetration to the waste load.

b. Microwave Irradiation

c. Chemical Methods

d. Plasma Pyrolysis