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1. Airborne and Droplet Transmitted Communicable Diseases
- 1 Certain infectious diseases are transmitted when susceptible persons are exposed to pathogens contained in droplets or droplet nuclei (e.g., through aerosolized oral and nasal secretions from infectious patients). When an infectious person talks, sneezes, coughs or vomits, microbe- laden droplets are expelled. These droplets can travel a short distance (1 meter) and infect people within this distance. Examples of diseases spread in this manner are influenza, rubella and SARS.
- 2 The spread of airborne infectious diseases via droplet nuclei is another important form of disease transmission. Droplet nuclei are the residuals of droplets where pathogens attached to them remain suspended for a longer time in the air and transported over longer distances. Examples of infectious diseases transmitted this way include tuberculosis, chickenpox and measles.
- 3 There are four important factors causing the spread of airborne / droplet- borne communicable diseases outbreak. They are (1) source (infectious persons), (2) pathogen dose, (3) transmission pathway and (4) host (susceptible persons). We can control the spread of communicable diseases by targeting at these factors.
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Factors of transmission
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Examples of control measures
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Source of infection
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- Early detection, isolation and treatment of patients
- Proper use of face mask
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Pathogen
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Transmission pathway
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- Proper personal hygienic practices (hand washing)
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- Maintenance of good indoor ventilation
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Host
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- Building up personal immunity
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- Proper use of face mask and personal protective equipment
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- 4 This supplement focuses on maintaining good ventilation in an indoor environment. Please note that efficient prevention of communicable diseases requires measures targeted at all the above factors to be implemented together.
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