Both of these conditions are the result of respiratory infections - pneumonia infects the lungs while bronchitis is an inflammation of the airways. Whether or not these diseases are contagious depends on what caused them.
Two types of pneumonia that can’t be spread from person to person are fungal pneumonia, which is contracted from the environment, and aspiration pneumonia, which occurs when food or liquid is inhaled into the lungs. Bacterial pneumonia, however, is indeed contagious and is also the most widespread cause of the disease, according to the American Lung Association. Yet, healthcare experts claim it isn’t as infectious as most of us think. The microorganisms that travel from person to person will not automatically lead to pneumonia but might have a much milder effect depending on the individual.
The case for bronchitis is very similar. Acute bronchitis, which is caused by a virus, is contagious, while chronic bronchitis isn’t. The latter is an ongoing condition often caused by long-term smoking or exposure to environmental pollutants.
When we see someone suffering from a skin condition, it is easy to make the mistake of thinking it can be transmitted by touch. While we can’t cover all skin afflictions in one article, we can assure you that one of the most common conditions, psoriasis, is not contagious at all. Psoriasis affects about 2% of the American population and has nothing to do with germs or bacteria that can be passed between people. Rather, it’s an autoimmune condition in which the immune system attacks the skin.
Telltale signs of psoriasis include red, itchy patches of skin with white scales on top, mainly found on the elbows, knees, and scalp. To learn more, check out our previous article A Guide to Understanding Psoriasis.
Ear infections in itself are not contagious, and can’t be ‘caught’. In fact, one of the common causes is water in your ears. The bad news is that oftentimes, ear infections are a complication of the common cold, as the virus leads to fluid buildup in the middle ear. “Due to congestion caused by the cold, the inner ear fills up with fluid and can become secondarily infected by bacteria; these stay in the ear and are therefore not contagious,” explains Matthew Mintz, MD, clinical associate professor of medicine at the George Washington University School of Medicine.
It is important to note that if an ear infection started with a cold and the patient still has cold symptoms, those can still be contagious.
Related: Four Vaccinations You Need After 50
When it comes to Lyme Disease the only ones who are contagious are the infected ticks, according to the CDC. The bacteria-based disease can only be transmitted when a tick attaches to your skin and feasts on your blood. It cannot be transmitted between humans in any way, not through casual contact and not even through kissing.
Pets aren’t infectious either, though they can carry ticks into your home. To learn more about Lyme disease symptoms, treatment and prevention check out the previous article A Guide to Lyme Disease.
Similarly to Lyme disease, mosquitos are the only ones guilty of spreading malaria. Only certain species of mosquitoes of the Anopheles genus - and only the females of those species - can transmit the potentially deadly disease. When they bite you, malaria parasites are released into your bloodstream. Symptoms include fever, headaches, muscle pains, feeling hot and shivering, jaundice, among others.
While malaria cannot be transmitted from person to person, it infects red blood cells, which means you could get it through a blood transfusion, by sharing an infected needle, or during pregnancy or childbirth.
Related: Virus vs Bacteria: Why It’s Key to Know the Difference!
Have you ever been scolded as a child because you were walking barefoot outside? The danger of tetanus likely had something to do with it. Tetanus, also referred to as lockjaw, causes intense muscle spasms which leads to a ‘locking' of the jaw and difficulty in opening the mouth and swallowing. The bacteria responsible for this disease is mainly found in soil, saliva, dust, and manure.
It enters the body through broken skin; the CDC points out that likely ways to get tetanus are via puncture wounds (like from stepping on a nail), wounds that get dirty, and burns. Infected individuals are not contagious. You can get vaccinated against tetanus, and a booster shot is required every 10 years.
Cellulitis is caused by bacteria that live on the outer layer of our skin and are often harmless, most commonly group A strep. It becomes a problem, however, when the bacteria penetrate deep into the skin. “If there is damage — either from a cut, recent surgery, or even athlete’s foot — that damage can allow in bacteria, which can affect the deeper layers of the skin,” explains Dr. Mintz. This can result in a serious infection, characterized by swelling, redness, and fluid-filled blisters. The infected area will typically be warm and painful to touch.
While cellulitis needs to be taken seriously, as it can deteriorate into a life-threatening condition, it isn’t contagious. If there is pus or oozing fluid, however, which is not typical for cellulitis, this material can spread infection.
Legionnaires' disease is a rare form of pneumonia caused by the legionella bacteria. It typically begins with fever, headaches, and muscle aches. By the second or third day, people also develop a cough, chest pain, nausea, vomiting, and confusion or other mental changes. Outbreaks of legionnaires disease are likely, although the disease isn't contagious.
This is because the culprits are contaminated water supplies. According to the National Institutes of Health, exposure can come from faucets, showers, whirlpools, and the ventilation systems of large buildings. Transmission can only occur when a person inhales mist or water droplets that contain the legionella bacteria.
Not everyone who is exposed to the bacteria will contract the disease. Those at higher risk groups are people over 50, especially if they have a weakened immune system due to chronic illness or smoking.
If you found this article interesting, why not share it with family and friends?