Forms of pathogens transmitted by air
Pathogens transmitted by air are quite different from those transmitted by blood or food. While the blood pathogens spread by coming in direct contact with blood, the food-borne pathogens invade the humans when foods or water infected by the microbes are consumed by people. On the contrary, pathogens transmitted by the air invade an individual when he or she inhales the air carrying the microbes. And in such cases, the respiratory system is the first to be affected. Basically, there are three varieties of pathogens that are transmitted by air - bacterial, fungal and viral. When a person who is already infected by any of these pathogens sneezes or coughs, they send out minute drips of moisture into the air and such droplets of moisture contains the pathogens.
The environment plays an important role vis-�-vis the period of time these pathogens can remain air-borne. An arid atmosphere not only enables these contaminants to remain airborne for several hours, but also help them to travel greater distances. On the other hand, if there is too much humidity, the pathogens are unable to remain in the air for longer time or travel longer distances. When any individual inhales an air-borne pathogen, it is said to be transmitted. However, it needs to be mentioned that being exposed to air-borne pathogens does not necessarily mean that the individual will be infected by the microbes. Below is a brief discussion regarding some of the air-borne pathogens that are not only common, but keeps us worried all through the day.
- A particular type of bacteria is responsible for causing the pulmonary disease tuberculosis, called TB in short. Usually, these bacteria assail the lungs, but in specific cases it has the ability to even affect the brain, kidneys and spine. Tuberculosis is a worldwide concern as it affects several million people every year and as many as three million patients succumb to this disease annually. What is worse is that experts forecast that by the year 2050 this disease would be claiming five million lives each year. It has been seen that a number of people who have been infected by tuberculosis may not feel sick as their immune system is continually combating the bacteria, which is not considered to be infectious. However, approximately 10 per cent of the people infected by the tuberculosis bacteria may eventually develop the disease at a later stage and then the bacteria are certain to become contagious. The most common way by which an individual may be infected by the tuberculosis (TB) bacteria is when he or she inhales the contaminated air exhaled by a person who is already infected by the bacteria through sneezing or coughing. The tuberculosis pathogens are able to survive for a maximum period of one to one-and-a-half hours outside the body depending on the size of a room, ventilation of the room as well as several other aspects. In the United States alone, the rate of death among patients hospitalized for treatment of acute tuberculosis is about four per cent.
- People around the world were overtaken by a fresh panic when a new disease called severe acute respiratory syndrome (SARS) broke out in many parts of the globe in 2003. In fact, SARS is basically a contagious disease that is attributed to the SARS coronavirus. This air-borne virus is spread when any person infected by the pathogen sneezes or coughs when they are in close proximity with other normal people. During that year, as many as 8,096 people were infected by the virus and among these around 10 per cent of the patients succumbed to SARS across the world. However, only seven people in the United States are known to have contacted this viral disease at that time. Interestingly enough, all of them were infected by the virus when they were traveling abroad to places where the disease had spread like an epidemic.
- Bird flu
- Bird flu or avian influenza is a contagion attributed to the avian or bird influenza viruses. Such influenza viruses are present naturally in the body of almost all birds. Although the wild birds bear the viruses in their intestines and fly across the globe with them, more often than not they themselves do not fall sick owing to the pathogens. Nevertheless, avian influenza is very infectious and may contaminate several domesticated birds, such as ducks, chickens and turkeys making them severely ill and eventually killing them. Scientists are actually concerned over the fact that some day the avian influenza of H5N1 type may infect humans as all the influenza viruses have the aptitude to transform. They fear that once H5N1 is able to infect the humans, it would easily transmit from one human to another giving rise to an epidemic. It is important to note that as these viruses have not infected the humans so far, the immune system in the humans do not have any mechanism to protect them against avian influenza or bird flu. Hence, there is little doubt that when the avian influenza viruses will succeed in infecting humans, they will cause havoc by spreading an influenza pandemic worldwide. In such a situation, the disease will easily transmit from one person to another affecting millions. And the worst thing is that while the human immune system is not prepared to combat these viruses, there is still no cure for the deadly infectious disease.
- Methicillin-resistant Staphylococcus aureus (MRSA) is basically a spherical bacterium often found living on the skin or in the nose of an individual. This bacterium may cause a variety of ailments ranging from minor conditions, such as skin infections like boils, pimples, abscesses (localized gathering of pusses in any part of the body) and cellulitis (inflammation of cellular tissue) to acute and fatal disease, including meningitis, pneumonia, endocarditis (inflammation of the endocardium), toxic shock syndrome (TSS) and even septicemia (blood poisoning). Basically, the bacterium causes infection in the upper region of the respiratory tract and in medical facilities; it is the most widespread reason for Staph contagions. In fact, Methicillin-resistant Staphylococcus aureus (MRSA) are detached parts of the bacterium that have obtained genes capable of programming resistance of antibiotics to all types of penicillins, inclusive of methicillin and additional contracted range of �-lactamase-resistant penicillin antibiotics. This type of bacterium is presently extensively prevalent in the neighborhood hospital surroundings and hence, MRSA has been commonly nick-named as a 'superbug'. It is surprising to note that this bacterium has been conventionally considered to be an infection that is associated with hospitals. Infection by this superbug is not only difficult to cure, but MRSA is also known to be resistant to most medications. Nevertheless, it has been found that gaseous ozone is highly effectual in reducing the presence of this bacterium.
- Stachybotrys is a fungus responsible for causing a disease called mycotoxicosis in humans as well as animals. This virus is also known as 'black mold' and it produces a venomous substance called mycotoxin, which is the main cause for the disease. During the last 15 years, scientists have collected substantiation across North America that shows that Stachybotrys is an acute predicament in most homes and buildings. In addition, this fungus is also responsible for developing a malady called 'sick building syndrome'. This ailment may often turn out to be deadly. So fact, scientists have been able to identify around 15 diverse species of this fungus that develop and thrive well in relatively damp places when the humidity is usually over 50 per cent.
- Cladosporium, Penicillium, Aspergillus and Alternaria are the most familiar molds (growths of minute fungi forming on vegetable or animal matter) found inside any building. When these molds are restrained, especially Penicillium is helpful in producing different varieties of cheese as well as the antibiotic called penicillin. However, at times these fungi also result in contaminating humans and the disease owing to such fungal infections is called penicilliosis. In fact, scientists and medical practitioners have so far been able to isolate Penicillium from patients suffering from endophtalmitis (inflammation of the ocular cavities), keratitis (inflammation of the cornea), necrotizing esophagitis (black esophagus owing to fungal infection), otomycosis (fungal infection of the external auditory canal), peritonitis (inflammation of the peritoneum), endocarditis (inflammation of the endocardium), pneumonia and even in the infections of the urinary tract. It has been seen that the majority of Penicillium contagions occur in people whose immune systems are stifled. In other words, this type of fungi is usually found in immune-suppressed hosts. It may be mentioned here that young people who are exposed to persistent Penicillium mould infection are known to have developed an immune reaction that is denoted as perils of cardiac failure.