Airborne Disease Control and Prevention.pdf

What is the prevention of airborne diseases? It is difficult to control and prevent the spread of infections through the air. Maintaining hygiene, washing hands frequently, cleaning common areas and coughing or sneezing into the elbow, using PPE kits are common prevention techniques for airborne diseases.

1. Airborne Infection
Transmission,
Control
and Prevention


Dr. Ravi Kant Bhatia
Assistant Professor
Department of Biotechnology
Himachal Pradesh University Shimla-05

2. Modes of Disease Transmission
•Direct contact
•Indirect contact
•Droplet
•Airborne

3. Direct Contact Transmission
•Microbes directly transferred from an infected
person to another person
•Examples
–Contact with blood or other body fluids
–Ungloved contact with a scabies-infested patient
–Ungloved contact with wounds or mucous
membranes

4. Indirect Contact Transmission
•Microbes transferred through contaminated
intermediate object
•Examples
–Healthcare personnel not performing adequate
hand hygiene between patients
–Sharing medical equipment without cleaning
or disinfection between patients
–Defective medical equipment allowing for
inadequate sterilization

5. Droplet Transmission
•Respiratory droplets carrying
infectious pathogens
–Generated during coughing,
sneezing, talking etc.
–Droplets generally greater than 5 µm
–Typically refers to distances within
3 feet of infected patient

6. Airborne Transmission
•Dissemination of droplet nuclei
containing infectious agents
–Dispersed over long distances
upto 150 feet
–Face-to-face contact not required
–Special ventilation systems are
required to prevent airborne
transmission

7. Difference between Droplet and
Airborne Transmission

8. Examples of Infectious Respiratory
Secretions
•Direct contact: Anthrax, Covid-19,
Enterovirus, Norovirus
•Indirect contact: (Fomite) Rous Sarcoma
Virus (RSV), SARS
•Droplet: Meningococcal meningitis, Rubella,
Pertussis, Common cold, SARS, influenza
•Airborne: Tuberculosis, Measles, Varicella,
Smallpox, SARS, Avian influenza

9. Contact Transmission-Based
Precautions
Personal Protective
Equipment
Gown & Gloves for
all patient
interactions
PPE on entry,
discard before
exiting room. (in
addition to Standard
Precautions)

10. Droplet Transmission-Based
Precautions
Single room preferred, no
special ventilation
Patient must be masked if
transport necessary.
Instruct on respiratory
hygiene/cough etiquette
HCWs wear surgical or
procedure mask within 6 feet
of patient. Eye protection if
splash, spray anticipated

11. Airborne Transmission-Based
Precautions
Airborne Infection Isolation Room (AIIR)
HEPA filter must be fitted at vents
Patient must be masked if transport necessary.
Health care workers (HCWs):
N95 respirator prior to entry into room, discarded
after exit.
Higher level respirators must used if aerosol generating
devices used.
Careful attention to proper putting on & taking off
respirator, including seal check.
Alert others if need to transfer the patient from one place or
room to another

12. Administrative Controls
•Policies, procedures, and programs that
minimize intensity or duration of exposure
WHO, MoHFW, NCDC, NICD, State Health Deptt.
Examples:
•Signs on door of an airborne isolation room
•Mask symptomatic patient
•Provide tissues/ masks/hand sanitizer to
public
•Standard procedures/ behaviors in caring
for patients e.g. hand hygiene, vaccination
of HCW
•Only as good as enforcement

13. Administrative controls?
All policies developed by infection control
team to decrease risk

Procedures for implementing, enforcing,
monitoring, evaluating and revising
infection control plan

14. Administrative controls
•Minimize hospitalization as per current
practice under Direct Observe Treatment
(DOTS)
•Educate patients and attendants on cough
hygiene
•Routine segregation of patients to separate
wards (or separate areas in same ward) so to
reduce risk of transmission, particularly to
immune-compromised
–Where possible, isolate infectious patients
•Maintain spacing, ward decompression

15. Recommended administrative
controls
•Patient screening
•Cough hygiene for patients
•Segregation of respiratory symptomatics
(where possible)
•Fast-tracking of respiratory symptomatics
–Jumping the queue
–Alternate evaluation pathway

16. Sneeze/Cough etiquettes

17. Separate
•Where possible, separate persons
with respiratory symptoms in a
separate well-ventilated waiting area
•The specific criteria for separating
patients will depend on the local
settings and patient population
•Guiding priorities
–Minimize opportunities for
transmission
–Protect immune-compromised patients

18. Environmental controls
•Indoor patient segregation and
bed spacing
•Ensure effective ventilation at all
times and seasons
•Special attention for high-risk
areas and groups

19. Protection
•Optimal arrangement
of patients and staff
should be
implemented in all
outpatient
departments, DOT
centers, microscopy
centers, and
radiology

20. Segregation and Spacing
•Keep infectious patients
away from vulnerable
patients using whatever
approach is feasible:
–Airborne precaution
areas
–Individual rooms
–Designated wards or
ward areas

21. Ventilation
•Health-care facilities should seek to
achieve minimum standards for air
exchange.
•High-risk settings should be
prioritized for immediate
assessment and implementation of
improved ventilation.

22. Personal Protective
Equipment
•Lowest level in hierarchy - requires
employee compliance for efficacy
•Means higher elements of hierarchy
fail to adequately protect employee
•May involve use of gowns, gloves,
eye/splash protection or respirators
•Last line of defense

23. Personal Protective Equipments

24. Prevention
•Actions aimed to minimizing the impact
of disease transmission.
•The concept of prevention is best defined
in the context of levels, traditionally
called Primordial, Primary, Secondary
and Tertiary prevention.

25. Determinants of Prevention
•Successful prevention depends upon:
–a knowledge of cause,
–dynamics of transmission,
–identification of risk factors and risk groups,
–availability of early detection and treatment
measures,
–an organization for applying these measures
to appropriate persons or groups
–continuous evaluation of and development of
procedures applied

26. Levels of prevention
Primordial prevention
Primary prevention
Secondary prevention
Tertiary prevention

27. Primordial prevention
•Primordial prevention
consists of actions and
measures that inhibit
the emergence of risk
factors in the form of
environmental,
economic, social, and
behavioral conditions
and cultural patterns
of living etc.

Health promotion
Health education
Environmental modifications
Nutritional interventions
Life style and behavioral changes

28. Primary prevention
Specific protection
Immunization and seroprophylaxis
Chemoprophylaxis: Medication
Protection against occupational hazards
Safety of drugs and foods
Control of environmental hazards,
e.g. air pollution

29. Secondary prevention
•It is defined as action which halts
the progress of a disease at its
initial stage and prevents
complications.
•Routine screening programs
•Trace and test
•To reduce the impact of disease
•The specific interventions are: Early
diagnosis (e.g. case finding
program and adequate treatment.

30. Tertiary prevention
•It is used when the disease process has
advanced beyond its early stages.
•It is defined as “all the measures
available to reduce or weakening and
chronic disease, and to promote the
patients’ adjustment to prevent severe
conditions.”
•Intervention that should be
accomplished in this stage are ill health
limitation, and rehabilitation.

31. High -risk strategy

•The high -risk strategy aims to
bring preventive care to individuals
at special risk.

•This requires detection of
individuals at high risk by the
optimum use of clinical methods.

32. Strategy for Prevention
Assess
Exposure
Identify
Populations
at High
Disease Risk
(based on demography /
family history,
host factors..)
Conduct
Research on
Mechanisms
(including the study of
genetic susceptibility)

Apply
Population-Based
Intervention
Programs
Evaluate
Intervention
Programs
Modify Existing
Intervention
Programs