Lung Cavitation as a Long-Term Imaging Pattern of COVID-19

Viral Diseases 101

Viral diseases are caused by viruses. They can impact many parts of your body, including your respiratory system, digestive tract, and skin.

Viral disease definition

Viruses are very small infectious agents. They're made up of a piece of genetic material, such as DNA or RNA, that's enclosed in a coat of protein.

Viruses invade cells in your body and use components of those cells to help them multiply. This process often damages or destroys infected cells.

A viral disease is any illness or health condition caused by a virus. Read on to learn more about some of the main types of viral diseases:

Not all viral diseases are contagious. This means they aren't always spread from person to person. But many of them are. Common examples of contagious viral diseases include the flu, the common cold, HIV, and herpes.

Other types of viral diseases spread through other means, such as the bite of an infected insect.

Respiratory viral diseases are contagious and commonly affect the upper or lower parts of your respiratory tract.

Common symptoms of a respiratory viral disease include:

runny or stuffy nose

coughing or sneezing

fever

body aches

Examples

Examples of respiratory diseases include:

Transmission

Respiratory viruses are spread by droplets generated through coughing or sneezing. If someone with a viral illness coughs or sneezes nearby and you inhale these droplets, you may develop the disease.

These viruses can also be spread through contaminated objects, such as doorknobs, tabletops, and personal items. If you touch one of these objects and then touch your nose or eyes, you could develop a disease.

Treatment

Respiratory viral diseases usually heal on their own. But over-the-counter (OTC) medications, including nasal decongestants, cough suppressants, and pain relievers, can help to reduce symptoms.

In addition, Tamiflu, an antiviral drug, is sometimes prescribed if someone is in the very early stages of developing the flu.

Prevention

The best way to avoid respiratory viral diseases is to practice good personal hygiene. Wash your hands often, cover your mouth when you cough or sneeze, and limit your interactions with people who show symptoms of a respiratory condition.

There's also a vaccine that can help to reduce your risk of getting the seasonal flu.

Gastrointestinal viral diseases affect your digestive tract. The viruses that cause them are contagious and usually lead to a condition called gastroenteritis, also called the stomach flu.

Common symptoms of gastrointestinal viral diseases include:

abdominal cramps

diarrhea

vomiting

Examples

Examples of gastrointestinal viral diseases include:

Transmission

Gastrointestinal viruses are shed in the stool during bowel movements. Food or water that's been contaminated by feces can spread the virus to others. You can also get the virus from sharing utensils or personal objects with someone who has a virus.

Treatment

There aren't any treatments for gastrointestinal viral diseases. In many cases, they resolve on their own within a day or two. In the meantime, drink plenty of fluids to replace those lost from diarrhea or vomiting.

Prevention

You can prevent gastrointestinal viral diseases by washing your hands often, especially after using the bathroom. Wiping down contaminated surfaces and not sharing personal items or eating utensils can also help.

There's also a vaccine for rotavirus that's recommended as part of a child's vaccination schedule.

Exanthematous viruses cause skin rashes. Many of them cause additional symptoms as well.

Many of the viruses in this category, such as the measles virus, are highly contagious.

Examples

Examples of exanthematous viral diseases include:

Transmission

Many exanthematous viruses are spread through respiratory droplets from the cough or sneeze of someone with the virus.

Other exanthematous viral diseases, such as chickenpox and smallpox, can be transmitted by coming into contact with fluid in broken skin lesions.

Shingles only occurs in people who've had chickenpox at some point. It's a reactivation of the varicella-zoster virus that's been lying dormant in your cells.

Chikungunya virus is spread through a mosquito bite and cannot be transmitted from person to person.

Treatment

Treating exanthematous viral diseases focuses on managing symptoms. Fever-reducing medications, such as acetaminophen, can help with some of the more bothersome symptoms.

Antiviral drugs, such as acyclovir, may be given for chickenpox or shingles.

Prevention

Measles, rubella, chickenpox, shingles, and smallpox can all be prevented through vaccination. You can reduce your risk of a chikungunya virus infection by protecting yourself from mosquito bites.

Learn more about viral rashes.

The hepatic viral diseases cause inflammation of the liver, known as viral hepatitis. The most common types of viral hepatitis are hepatitis A, B, and C.

It is worth noting that diseases caused by other viruses, such as cytomegalovirus and the yellow fever virus, can also affect the liver.

Examples

Examples of hepatic viral diseases include:

Hepatitis B and C can be transmitted from person to person through bodily fluids. Sharing items that come in to contact with blood, such as needles or razors, can also spread the virus. Hepatitis B can be spread through sexual contact.

People get hepatitis A and E by consuming food or water that's been contaminated with feces from someone with the virus.

You can only develop hepatitis D if you already have the hepatitis B virus.

Treatment

Treatments for hepatitis B, C, and D focus on managing symptoms. In some cases, a doctor might prescribe medication, such as antiviral drugs.

Treatment of hepatitis A and E involves supportive measures, such as getting plenty of rest, drinking fluids, and avoiding alcohol.

Prevention

There are vaccines for both hepatitis A and hepatitis B. There's also a vaccine for hepatitis E, but it's not available in the U.S.

Other ways to prevent viral hepatitis include not sharing needles or razors, practicing safe sex, and avoiding food or drinks that may be contaminated by feces.

Cutaneous viral diseases cause lesions or papules to form on the skin. In many cases, these lesions can stick around for a long time or come back after disappearing for a while.

Examples

Examples of cutaneous viral diseases include:

These viruses are contagious. They're usually spread through close physical contact with someone who has the virus or touching a contaminated object, such as a towel or faucet handle.

Treatment

Papules that form due to warts or molluscum contagiosum often go away on their own. They can also be removed by simple in-office procedures, such as cryotherapy.

There's no cure for herpes, but antiviral medications, such as acyclovir, can help to shorten or prevent outbreaks.

Prevention

Practicing good hygiene habits, avoiding the sharing of personal items, and avoiding close contact with people who have active lesions can reduce your risk of developing a cutaneous viral disease.

Hemorrhagic viral diseases are severe conditions that involve damage to your circulatory system.

Symptoms of a hemorrhagic viral disease include:

high fever

body aches

weakness

bleeding under the skin

bleeding from the mouth or ears

bleeding in internal organs

Examples

Examples of viral hemorrhagic diseases include:

Transmission

Some hemorrhagic viral diseases, such as dengue fever and yellow fever, are spread through the bite of an infected insect.

Others, such as Ebola, are spread to other people through contact with the blood or other bodily fluid of someone with the virus. Lassa fever is spread through inhaling or consuming the dried feces or urine of a rodent with the virus.

Treatment

There's no specific treatment for hemorrhagic viral diseases.

It's important to stay hydrated if you have a viral hemorrhagic disease. Some people may need intravenous (IV) fluids to maintain electrolyte balance. Supportive care to maintain hydration and electrolyte balance is essential. In some cases, the antiviral drug ribavirin may be given.

Prevention

Researchers are in the process of developing vaccines for several hemorrhagic viruses. A yellow fever vaccine is currently available for people traveling to areas where yellow fever is common.

If you live or work in an area where viral hemorrhagic diseases are common, you can do the following to reduce your risk:

Use proper protection, such as gloves, glasses, or a face shield, when working around people who have a virus.

Avoid being bitten by insects, especially mosquitos and ticks, by wearing protective clothing or using insect repellent.

Protect against rodent infestation by keeping food covered, removing garbage often, and making sure windows and doors are secured properly.

Some viruses can infect the brain and surrounding tissues, causing neurologic viral diseases. This can result in a range of symptoms, including:

fever

confusion

drowsiness

seizures

coordination problems

Examples

Examples of neurologic viral diseases include:

Many neurologic viruses are spread through the bite of an infected animal or bug, such as a mosquito or tick.

Other viruses, such poliovirus and other enteroviruses, are quite contagious and spread through close contact with someone with the virus. Contaminated objects can also contribute to the spread of these viruses.

Treatment

There's no specific treatment for people with mild viral meningitis or encephalitis. Getting plenty of rest, staying hydrated, and taking OTC anti-inflammatories to ease pain or headaches can all help. In some cases, antiviral medication may be prescribed.

Polio or severe cases of meningitis or encephalitis may require additional treatment, such as breathing assistance or IV fluids.

If an animal that's suspected to have the rabies virus bites you, you'll be given a series of shots to help prevent the rabies virus from infecting you.

Prevention

There's a vaccine for both poliovirus and the mumps virus, which can cause meningitis and encephalitis.

Practicing good hygiene, avoiding close contact with those who have the virus, and protecting against insect bites can all help to reduce the spread of encephalitis and meningitis.

To reduce the risk of spreading rabies, keep your pets vaccinated and avoid approaching wild animals.

There are many viral diseases. Some, such as the common cold or the stomach flu, are minor and go away on their own within a few days. Others, however, are more serious.

Unlike bacterial infections, viral diseases don't respond to antibiotics. Instead, treatment usually focuses on managing symptoms and supporting the immune system with plenty of rest and hydration.

Is Pneumonia Contagious?

Some types of pneumonia can spread from person to person, meaning in some cases, pneumonia can be contagious. A person with an infection can transmit pneumonia by coughing, sneezing, or talking.

Pneumonia is an infection of the lung tissue that can make it difficult to breathe due to inflammation, fluid, and pus. Viruses or bacteria, which are contagious, cause most forms of pneumonia.

Not all cases of pneumonia are contagious, however, and the period during which it can spread from one person to another depends on the cause of the infection.

Pneumonia refers to an infection in the lungs caused by certain germs, such as bacteria or viruses. When one person spreads germs that can cause pneumonia to someone else, the recipient can develop a range of respiratory infections, from mild cold symptoms to pneumonia.

A range of factors determine whether pneumonia is contagious:

Type of pneumonia

Most cases of pneumonia are due to the spread of bacteria and viruses. Bacteria are living organisms that respond to antibiotics. Viruses are tiny strands of protein and genetic material that cannot be treated with antibiotics. Both viruses and bacteria are contagious.

Pneumonia often develops after a person has had a different infection, such as a head cold. This makes a person more vulnerable to other types of infections. An infection that develops in the lungs is called pneumonia.

Some organisms are more likely to cause pneumonia than others. One common example is pneumococcal disease, a bacterial infection that can cause ear infections, sinus infections, infections of the brain and blood, and pneumonia.

Another type of bacteria called Mycoplasma pneumoniae can cause other forms of pneumonia. Mycoplasma bacteria are also contagious.

The influenza virus or the flu is a common cause of viral pneumonia. The virus spreads easily from person to person, causing a range of symptoms and conditions.

Less common causes of pneumonia include:

inhaling food particles or contents from the intestinal tract

some fungi

These forms of pneumonia are not contagious.

Length of infection

In most cases, infections are contagious for a few days before symptoms appear and for a few days after. The exact length of time a person is contagious depends on the type of microorganism causing the infection.

Some forms of pneumonia, such as pneumonia caused by mycoplasma, remain contagious for several weeks. If a person has pneumonia, they should speak to a doctor about how long the infection will be contagious.

Pneumonia treatment

People with bacterial pneumonia will usually be prescribed antibiotics that stop the infection from progressing. Pneumonia will usually stop being contagious a day or two after treatment begins.

A person is also considered contagious during a fever, so it is best to stay home from work or school until the fever is gone.

People who have been vaccinated against infections that can cause pneumonia, such as pneumococcal bacteria, are usually immune to those specific germs. Getting the vaccination can help prevent this type of infection from developing.

Share on PinterestOlder people and very young children may have weaker immune systems, which means they may be more likely to get pneumonia.

Although anyone can get pneumonia, some people are at greater risk. Pneumonia occurs when an infection develops within the lungs. It can cause complications with breathing and spread to other parts of the body such as the bloodstream.

People who are more likely to get pneumonia include:

very young children and babies whose immune systems are not fully developed

older people with weakened immune systems

pregnant women

people taking medications that suppress the immune system

people with diseases that weaken the immune system, such as cancer, HIV, and AIDS

people with autoimmune diseases, such as rheumatoid arthritis

people with lung and respiratory conditions, such as chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), and asthma

People at risk of pneumonia need to be especially cautious around people who have recently had pneumonia or another respiratory infection.

Pneumonia is transmitted when germs from the body of someone with pneumonia spread to another person. This can happen in a variety of ways, including:

Inhaling the infection. This can occur when a person with pneumonia coughs or sneezes and another person inhales the infected particles. This is more likely between people in close contact with each other, such as parents and children, or in poorly ventilated spaces, such as airplanes.

Through the mouth or eyes. This can happen when a person touches a surface that an infected person has coughed or sneezed on. When a person with an infection coughs into their hand and then shakes another person's hand, the second person can become infected if they touch their mouth or eyes without washing their hands.

Food particles and irritants from the intestinal tract can also cause pneumonia. This is called aspiration pneumonia and can occur when a person accidentally inhales these substances.

Aspiration pneumonia usually happens in people who have trouble swallowing, such as someone having a diagnosis of a stroke or other central nervous system conditions, such as Parkinson's disease.

Fungal pneumonia typically develops when people inhale microscopic particles of fungus from the environment. People with weakened immune systems are more likely to develop this type of pneumonia.

A number of strategies can prevent the spread of pneumonia. The single most effective way to prevent the spread of viruses and bacteria is with frequent hand-washing, especially during the colder months.

People should wash their hands before eating, after using the bathroom, after touching someone else, before visiting people vulnerable to pneumonia, and upon returning home after going out in public.

Other strategies to prevent pneumonia include:

staying up-to-date on all vaccinations, as well as getting a flu shot annually

quitting smoking, since smoking makes the lungs more vulnerable to infection and affects the body's immune system

managing any chronic medical conditions, especially those that affect the immune system or lungs

staying home from school or work when ill or with a fever

Most people recover from pneumonia without any lasting effects. In vulnerable people, pneumonia can be fatal. Worldwide, pneumonia accounts for 16 percent of deaths in children under 5. Older people and those with a weakened immune system are also more likely to experience serious complications.

Older people, people with serious illnesses, parents of newborns, and caregivers to sick people should make sure all visitors wash their hands. It is best that people with symptoms of a respiratory illness or fever do not visit a vulnerable person until their symptoms are gone.

Other strategies that can reduce the risk include:

washing hands before eating, after touching people, and after going out in public

disinfecting all surfaces in the home, particularly if someone has recently been sick

keeping up-to-date on all vaccinations, especially any household members around infants who are too young to be vaccinated

avoiding locations with inadequate air filtration during cold and flu season

Pneumonia killed more than 50,000 people in the United States in 2014. Despite this, around two-thirds of older adults do not get the recommended pneumococcal pneumonia vaccination to prevent pneumonia.

Pneumonia can be prevented, particularly in people who do not have chronic lung diseases. By avoiding sick people, staying home when ill, washing hands, and adopting basic health measures, such as getting vaccinated, it is possible to prevent this potentially fatal illness.

Is Tonsillitis Contagious?

Tonsillitis refers to the inflammation of the tonsils. It typically occurs as an inflammatory response to an infection. As such, tonsillitis itself is not contagious, but the pathogen responsible for the inflammation is.

The tonsils are two small lymph nodes located either side of the back of the throat. As with other lymph nodes, they form part of the immune system. Their job is to keep viruses and bacteria from making their way into the body through the nose and mouth.

Sometimes, however, viruses and bacteria manage to infect the tonsils. An infection causes the tonsils to become irritated and inflamed. Doctors call inflammation of the tonsils tonsillitis.

Tonsillitis generally affects children over the age of 2 years, and rarely affects adults. According to the U.S. National Library of Medicine, tonsillitis is such a common childhood illness, that every child experiences it at least once.

This article describes how the bacteria and viruses that cause tonsillitis can spread. We also outline the symptoms of tonsillitis, its treatment, and the prevention steps people can take.

Tonsillitis is the body's inflammatory response to an infection of the tonsils. Tonsillitis itself is, therefore, not contagious.

The viruses and bacteria that cause tonsillitis, however, are contagious.

Consequently, the most effective way to stop the spread of tonsillitis is by halting the spread of the pathogens that cause it.

Tonsillitis can occur as a result of either a bacterial or viral infection.

Bacterial tonsillitis

One of the main bacterial causes of tonsillitis is group A beta-hemolytic streptococcal (GABHS) infection, which doctors often shoten to group A (GA) strep.

GA strep is the bacteria responsible for strep throat. According to a 2016 review, GA strep is responsible for 15–30% of sore throats in children, and 5–15% of sore throats in adults.

GA strep spreads when a person has direct contact with the saliva or mucus of someone who already has the infection. This includes breathing in bacteria-filled droplets from the air.

Bacteria spread more quickly in places where people, especially children, are in close proximity. Examples include schools and daycare centers.

GA strep usually begins causing symptoms between 2–5 days after the bacteria has infected someone.

Viral tonsillitis

The viruses that cause the common cold and influenza can also cause tonsillitis. These viruses can live on surfaces, such as computer keyboards and doorknobs, for hours. This resilience helps them to spread.

Most of the time, tonsillitis develops very quickly. The most common signs and symptoms of tonsillitis are:

Some children may develop chronic, or recurrent, tonsillitis where they experience at least five episodes of tonsillitis in a year.

In children under 5 years of age, the cause of tonsillitis is usually viral. In children between the ages of 5 and 15 years, the cause is usually bacterial.

Up to 70% of acute cases of tonsillitis are caused by one of the following viruses:

Determining whether a person's tonsillitis is due to a virus or bacteria is an essential step in providing effective treatment.

Tonsillitis symptoms usually go away within 1-2 weeks. During this time, a person may benefit from the following home treatments:

rest

drinking plenty of fluids

managing pain with throat lozenges and over-the-counter (OTC) remedies

People who have bacterial tonsillitis will require antibiotic treatment. Antibiotics help speed up recovery and reduce the risk of rheumatic fever and other potential complications of bacterial tonsillitis.

The best way to avoid tonsillitis is to prevent the spread of viruses and bacteria that cause the infection. Healthcare professionals recommend:

washing hands frequently

using hand sanitizer if it is not possible to wash hands

avoiding touching the face with unwashed hands

teaching children to cover their mouths and noses when they cough or sneeze

keeping sick children home from school until their fever has gone or they have received antibiotics for at least 24 hours

making sure that people who are sick do not share food, beverages, or towels with people who are not sick

disinfecting surfaces in shared living spaces

replacing a person's toothbrush after they have recovered from tonsillitis

It is important to maintain good hygiene practices even when nobody appears to be sick. , This is because most people are contagious before they develop symptoms.

Tonsillitis develops when an infection causes inflammation, irritation, and swelling in the tonsils. It is much more common among children than adults. In fact, almost every child in the United States has had tonsillitis at least once.

Tonsillitis itself is not contagious, but the viruses and bacteria that cause it are contagious. There are many precautions people can take to help prevent the spread of pathogens that cause tonsillitis. Examples include practicing good hygiene, containing coughs and sneezes, and avoiding close contact with people who are sick.

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