The global effect of tuberculosis and prevention in hospitals

WHO Annual report on global preparedness for health emergencies:

The world is at acute risk for devastating regional or global disease epidemics or pandemics that not only cause loss of life but upend economies and create social chaos.

Many financial, human, infrastructure, surveillance and laboratory health resources already exist in countries that can directly support preparedness efforts. However, resources for disease-specific programmes, such as those for HIV, tuberculosis, malaria and polio eradication, often do not include or sustainably support preparedness.

High-impact respiratory pathogens, such as an especially deadly strain of influenza, pose particular global risks in the modern age. The pathogens are spread via respiratory droplets; they can infect a large number of people very quickly and, with today’s transportation infrastructure, move rapidly across multiple geographies. 

Tuberculosis (TB) is one of the top 10 causes of death worldwide.

In 2016, 10.4 million people fell ill with TB, and 1.7 million died from the disease

The HICPAC guidance defines airborne transmission as dissemination of either airborne droplet nuclei or small particles in the respirable size range containing infectious agents that remain infective over time and distance. It states that micro organisms carried in this manner may be dispersed over long distances by air currents and may be inhaled by susceptible individuals who have not had face-to-face contact with (or been in the same room with) the infectious individual.

Furthermore, preventing the spread of pathogens by the airborne route requires the use of special air handling and ventilation systems, such as airborne infection isolation rooms (AIIRs) to contain and then safely remove the infectious agents. Mycobacterium tuberculosis is cited as an example of a pathogen transmitted by the airborne route.

 Guidelines for Preventing the Transmission of M. tuberculosis in Health-Care Settings:

Transmission of M. tuberculosis

Spread by airborne route; droplet nuclei.

Transmission affected by:

• Infectiousness of patient
• Environmental conditions
• Duration of exposure

Persons at High Risk for TB Disease

• Persons coinfected with HIV and M. tuberculosis (highest risk)
• Those with recent M. tuberculosis infection (within 2 years)
• Children under 4 years of age
• Persons with certain clinical conditions or other conditions of compromised immunity
• Those with a history of untreated or poorly treated TB

Environmental Factors That Increase Risk for Transmission

• Exposure in small, enclosed spaces
• Inadequate ventilation
• Recirculating air containing infectious droplets
• Inadequate cleaning and disinfection of equipment
• Improper specimen-handling procedures

Risk for Health-care–Associated Transmission of M. tuberculosis

• Linked to close contact with infectious TB patients during procedures generating aerosols
• Bronchoscopy
• Endotracheal intubation or suctioning
• Open abscess irrigation
• Autopsy
• Sputum induction
• Aerosol treatments

Environmental Controls

• Control source of infection
• Dilute and remove contaminated air
• Control airflow (clean air to less-clean air)
• Relevance to Biologic Terrorism Preparedness
• Multidrug-resistant M. tuberculosis is classified as a category C agent of biologic terrorism

“Airborne infection isolation” (AII)

• AII rooms should be single-patient rooms with a private bathroom

AII Room Policies and Practices

• Keep doors closed as much as possible
• Maintain adequate number of AII rooms
• Check room for negative pressure daily when in use
• Group AII rooms together

Environmental Controls

• Prevent spread, reduce concentration of infectious droplet nuclei
• In AII rooms, these systems control airflow direction to minimize spread of infectious droplet nuclei to adjacent areas
• Technologies for removing or inactivating M. tuberculosis consist of
  
  - Local exhaust ventilation
  - General ventilation
  - Air-cleaning methods

Genano Technology: Destruction of TB (Mycobacterium tuberculosis)

Mycobacterium tuberculosis: Characteristics: the rods are 2-4 µm in length and 0.2-0.5 µm in width. M. tuberculosis is more related to Gram-negative than to Gram-positive bacteria, its double layer structure is more related to Bacillus subtilis.

Risk factors and causes: Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB), spreads in microscopic droplets that are released into the air when someone with the untreated active form of the disease coughs, speaks, laughs, sings, sneezes, talks or spits, etc.

Destruction of TB (Mycobacterium tuberculosis): With reference to LNE microbiological tests where Gram + bacteria (Bacillus subtilis) were exposed to the Genano air decontamination process, experience shows that for similar bacterium such as Mycobacterium tuberculosis, the structure would also undergo the same neutralisation process.  Residues would be in the form of water vapor, carbon, O3 and CO2 gases.

The process:

1) Irreversible electroporation

2) Oxydation by O3 generated by UV and electrostatic capture

3) Capture of molecules by van der Walls forces

4) Conversion of and adsorption of gases by active carbon