An airborne disorder is any disease that is caused by a microorganism that is transmitted through the air. There are many airborne diseases that are of clinical importance and include bacteria, viruses, and fungi. These organisms may be spread through sneezing, coughing spraying of liquids, the spread of dust or any activity that results in the generation of aerosolized particles. It is important to be aware that airborne diseases, in general, do not include disorders caused by air pollution such as poisons, smog, and dust.
The microorganisms transmitted airborne may be spread via fine mist, dust, aerosols, or liquids. The aerosolized particles may be generated from a source of infection such as body secretions of an infected patient or even an animal. In addition, aerosols may also be generated from biological waste products that accumulate in garbage, caves and dry arid containers. During aerosolization, the microorganisms that are less than 5 microns in size float in the air. Sometimes, the microorganisms may be contained in dust particles that are present in the air. Once the droplets containing the microorganisms have been formed, they are then dispersed via air currents to varying distances and can be inhaled by susceptible hosts.
The infected aerosolized particles often remain suspended in the air currents and may travel considerable distances, although many particles will drop off within the vicinity. As the distance traveled of the aerosol particle increases, the risk of infection starts to drop. Airborne precautions necessitate the prevention of infections and use of available interventions in healthcare facilities to prevent the transmission of airborne particles. The airborne particles often remain suspended in the facility air environment and with air currents move along to different parts of the institution where there is a potential of them being inhaled by other patients. The airborne particles may remain localized to the room or move depending on the airflow. In some cases where there is inadequate ventilation, the airborne particle may remain in the hospital room and be inhaled by a newly admitted patient.
The control and prevention of airborne transmission of infections are not simple as it requires the control of airflow with the use of specially designed ventilator systems, the practice of antiseptic techniques, wearing personalized protection equipment (PPE) and performing basic infection prevention measures like hand washing.
In almost all cases, airborne pathogens cause an inflammatory reaction of the upper airways including the nose, sinuses, throat, and lungs. The involvement of these structures may result in nasal and sinus congestion, and sore throat. Any coughing or sneezing activity may then generate aerosolized particles. Some of the common infections that can spread via airborne transmission include the following:
Airborne disease is not exclusive to humans but can also affect non-humans. For example, many types of poultry are often affected by an avian disorder (Newcastle disease), that is also transmitted via an airborne route. However, it is important to understand that exposure to an animal or a patient with an airborne disease does not automatically ensure disease transmission. The infection also depends on the host immunity, how much exposure the individual has suffered and the duration of exposure to the infected patient.
Besides patients, there are also several medical and surgical procedures that can generate aerosolized particles. In most cases, these airborne particles are generated during manipulation of the large airways. Examples include:
Factors that influence airborne transmission
Airborne transmission of microorganisms depends on several physical variables endemic to the infectious particle. Factors that influence the spread of airborne infections to include the following:
When patients are seen in the emergency room or admitted to the hospital, it is impossible to know immediately if there have an airborne infection.  Hence, healthcare workers need to maintain a high degree of suspicion in patients who present with signs and symptoms compatible with an airborne infection. The earlier the airborne prevention methods are implemented, the lower the risk to other patients and staff.
Airborne Isolation Room
This is a single patient room that is equipped with special air handling (negative pressure) and ventilation capacity. The negative pressure room is also known as an Airborne Isolation Room. This negative pressure room is usually a single-occupancy patient-care room and frequently used to isolated individuals with confirmed or suspected airborne infection.
Elements of an Airborne Isolation Room
What is an Anteroom?
This is relatively clean and is a frequently used area to transition patients/healthcare workers in and out of the airborne isolation room when it is under negative pressure. An anteroom is frequently used as a transitional space between the airborne isolation room and the hallway. It is in this transition area where healthcare workers store their PPE and put on their PPE before entering the airborne isolation room.
Personal Protective Equipment (PPE)
All healthcare workers who enter the negative pressure room should wear an appropriately fit-tested N95 respirator. The N95 Respirators is individually fitted and can filter particles one micron in size. Studies show that the mask has a 95% filter efficiency and provides a tight facial seal with less than a 10% leak.
To use the respirator appropriately, one should do the following:
In hospitals, patients admitted to the negative room often have to be transported to other departments like radiology, physical therapy, the pulmonary laboratory or even another hospital. Before sending a patient with an airborne infection, one must always communicate with the relevant department first. This communication should include the following:
Patient and Family Education
Duration of Precautions
In general, airborne precautions can be discontinued once the patient shows no signs or symptoms of an infection. However, one also has to be aware of the period of incubation and if unsure, always consult with an infectious disease expert
What if there are many infected patients?
Managing Deceased Patients
When a patient is deceased, airborne precautions are necessary when handling and preparing the body during transfer to the morgue and an autopsy.
Managing specimens and rooms of patients and with airborne infections
Ways to prevent airborne diseases include the following: