PREVENTION OF MYCOBACTERIUM TUBERCULOSIS IN HEALTHCARE SETTINGS

Dr. Moustapha A.Ramadan

Introduction

The mycobacteria are acid-fast rod-shaped bacteria. They are usually slow-growing.

There are many different kinds, the most common one causes tuberculosis and leprosy.

Still others cause infections that are called atypical mycobacterial infections, because they don't cause tuberculosis and can still harm people with low immunity status.

Introduction

The mycobacteria includes:

Mycobacterium tuberculosis -- which causes tuberculosis

Mycobacterium leprae -- which causes leprosy

Mycobacterium ulcerans -- which causes Buruli ulcer

Introduction

The mycobacteria includes:

Mycobacterium avium -- which causes tuberculosis -like illness in birds and immunodeficient people;

Mycobacterium marinum – which causes swimming pool granuloma;

Mycobacterium abscessus – which causes cystic fibrosis and skin lesions

Facts

In 2013, 9 million people fell ill with TB and 1.5 million died from the disease

Globally in 2013, an estimated 480 000 people developed multidrug resistant TB (MDR-TB).

In 2013, an estimated 550 000 children became ill with TB and 80 000 HIV-negative children died of TB.

Facts

About one-third of the world's population has latent TB.

TB is a leading killer of HIV-positive people causing one fourth of all HIV-related deaths.

The TB death rate dropped 45% between 1990 and 2013

Facts

TB is spread from person to person through the air. When people with lung TB cough, sneeze or spit, they propel the TB germs into the air.

The symptoms may be mild for many months.

People ill with TB can infect up to 10-15 other people through close contact over the course of a year

Symptoms

a bad cough that lasts 3 weeks or longer coughing up blood or sputum pain in the chest weakness or fatigue weight loss, loss of appetite chills, fever sweating at night

Multidrug-resistant tuberculosis (MDR-TB) is a form of TB caused by bacteria that do not respond to, at least, isoniazid and rifampicin, the two most powerful anti-TB drugs.

The primary cause of MDR-TB is inappropriate treatment, inappropriate or incorrect use of anti-TB drugs, or use of poor quality medicines.

PREVENTION & CONTROL

Preventing transmission of M.tuberculosis

I. Administrative MeasuresII. Environmental ControlIII. Respiratory Protection

Administrative Measures

The first and most important level of TB controls is the use of administrative measures to reduce the risk for exposure to persons who might have TB disease.

Setting Assessment

Conduct periodic reassessments (annually, if possible) to ensure:

proper implementation of the TB infection control plan

prompt detection and evaluation of suspected TB cases

prompt initiation of airborne precautions of suspected infectious TB cases

Setting Assessment

Conduct periodic reassessments (annually, if possible) to ensure:

recommended medical management of patients with suspected or confirmed TB disease

functional environmental controls

implementations of the respiratory protection program

ongoing HCW training and education regarding TB.

Processing and Reporting of lab results

It is essential that sputum collection and delivery to the laboratory be done in a timely manner, and results should be available within 24 hours of specimen collection.

Processing and Reporting of lab results

The laboratory performing acid fast bacilli (AFB) smears should be proficient at:

Methods of sputum specimen processing

The administrative aspects of specimen processing (e.g., record keeping, notification)

Maintaining quality control of diagnostic procedures (e.g., AFB sputum smears)

Ensuring adequate supplies for processing sputum samples.

Managing patients with suspected or confirmed TB disease

A high index of suspicion for TB disease and rapid implementation of precautions are essential to prevent and interrupt transmission.

Managing patients with suspected or confirmed TB disease

I. Prompt triage/ Proper history taking:

1) a history of TB exposure, infection, or disease;

2) symptoms or signs of TB disease;

3) medical conditions that increase their risk for TB disease.

Managing patients with suspected or confirmed TB disease

II. TB airborne precautions

1. should be initiated for any patient who has symptoms or signs of TB disease.

2. has documented infectious TB disease and has not completed anti-tuberculosis treatment.

3. patients who have confirmed TB disease or who are considered highly probable to have TB disease, promptly start anti-tuberculosis treatment

Managing patients with suspected or confirmed TB disease

II. TB airborne precautions discontinuation (suspected)

another diagnosis is made that explains the clinical syndrome

the patient has three consecutive, negative AFB sputum smear results

Managing patients with suspected or confirmed TB disease

II. TB airborne precautions discontinuation (confirmed)

have received appropriate anti-tuberculosis chemotherapy directly observed for a minimum of two weeks

and have shown clinical improvement

Managing patients with suspected or confirmed TB disease

II. TB airborne precautions discontinuation (confirmed)

In setting known to have high prevalence of MDR-TB sputum smear negative should be added to the previous criteria

Cleaning, disinfection, sterilization of patient care equipment and rooms

The same cleaning procedures used in other rooms in the health-care setting should be used to clean AII rooms.

Personnel should follow airborne precautions while cleaning these rooms when they are still in use.

Cleaning, disinfection, sterilization of patient care equipment and rooms

Critical Medical Instruments should be sterile at the time of use.

Semi-critical Medical Instruments is preferred to be sterile however, high-level disinfection that destroy vegetative microorganisms is accepted

Non-critical Medical Instruments or devices cleaning and disinfection

Training and Education of HCWs

HCW training and education can increase adherence to TB infection-control measures.

Training and education should emphasize the increased risks posed by an undiagnosed person with TB disease in health-care setting and the specific measures to reduce this risk.

Training and Education of HCWs

Follow-up TB Training and Education is based

on the number of untrained and new HCWs,

changes in the organization and services of the setting,

availability of new TB infection control information.

HCW surveillance

Baseline testing for M. tuberculosis infection is recommended for all newly hired HCWs, regardless of the risk classification of the setting

Any HCW with a newly recognized positive test result for M. tuberculosis infection, test conversion, or symptoms or signs of TB disease should be promptly evaluated.

HCW surveillance

Such HCWs should be excluded from the workplace and should be allowed to return to work when the following criteria have been met:

Three consecutive sputum samples collected in 8–24-hour intervals that are negative, with at least one sample from an early morning specimen;

The person has responded to antituberculosis treatment that will probably be effective

HCW surveillance

Such HCWs should be excluded from the workplace and should be allowed to return to work when the following criteria have been met:

The person is determined to be noninfectious by a physician experienced in managing TB disease.

HCWs with extra pulmonary TB disease usually do not need to be excluded from the workplace as long as no involvement of the respiratory tract has occurred.

Patient Education

Patients should be educated about M.tuberculosis transmission and the importance of cough etiquette. Posters emphasizing cough etiquette should be placed in the waiting areas.

Environmental Controls

The second level of the hierarchy is the use of environmental controls to prevent the spread and reduce the concentration of infectious droplet nuclei in ambient air.

By law, the local health department must be notified when TB disease is suspected or confirmed in a patient or HCW so that follow up can be arranged and a community contact investigation can be conducted.

Environmental Controls

Primary environmental controls consist of controlling the source of infection by using local exhaust ventilation (e.g., hoods, tents, or booths) and diluting and removing contami nated air by using general ventilation.

Secondary environmental controls consist of controlling the airflow to prevent contamination of air in areas adjacent to the source (AII rooms) and cleaning the air by using high efficiency particulate air (HEPA) filtration

AII Room Practices

AII rooms should be single bed and has a private bathroom.

Keep doors to AII rooms closed except when patients, HCWs, or others must enter or exit the room.

Monitor and record direction of airflow (i.e., negative pressure) in the room on a daily basis, while the room is being used for TB airborne precautions.

AII Room Practices

Perform diagnostic and treatment procedures (e.g., sputum collection and inhalation therapy) in an AII room.

Ensure that patients with suspected or confirmed infectious TB disease who must be transported to another area bypass the waiting area and wear a surgical mask

AII Room Practices

Schedule procedures on patients with TB disease when a minimum number of HCWs and other patients are present and as the last procedure of the day to maximize the time available for removal of airborne contamination.

Maintenance of environmental control measures

Ensure the optimal selection, installation, operation, and maintenance of environmental controls.

Personnel should schedule routine preventive maintenance for all components of the ventilation systems (e.g., fans, filters, ducts, supply diffusers, and exhaust grills) and air-cleaning devices.

Respiratory Protection

The third level of the hierarchy is the use of respiratory protective equipment in situations that pose a high risk for exposure .

training HCWs on respiratory protection, and training patients on respiratory hygiene and cough etiquette procedures

Respiratory Protection

All persons, including HCWs and visitors, entering rooms in which patients with suspected or confirmed infectious TB disease are being isolated;

Persons present during cough-inducing or aerosol generating procedures performed on patients with suspected or confirmed infectious TB disease;

Laboratorians conducting aerosol-producing procedures might require respiratory protection.

Respiratory Protection

Persons who transport patients with suspected or confirmed infectious TB disease in vehicles (e.g., EMS vehicles or, ideally, ambulances) and persons who provide urgent surgical or dental care to patients with suspected or confirmed infectious TB disease.

Respiratory Protection

Disposable respirators (e.g., N-95s) are commonly used in TB isolation rooms, in transport of TB cases, or in other areas of the health care facility.

Full face piece negative-pressure respirators, powered air-purifying respirators (PAPRs) is required when high-risk procedures such as bronchoscopy or autopsy are conducted.