adenoviruses

Viruses are very tiny germs. They are made of genetic material (either DNA or RNA) inside of a protein coating. There are a huge number of viruses on earth. Only a small number of them can infect humans. Those viruses can infect our cells, which may cause disease. Some of the diseases that viruses can cause include the common cold, the flu, COVID-19, and HIV.

Viruses can be spread in different ways:

• Through droplets and particles that are breathed out by someone who has the infection. You might breathe in the droplets or particles, or they could land on your mouth, nose, or eyes.
• By touching surfaces or objects that have the virus on them and then touching your mouth, nose, or eyes.
• From the pregnant parent to the baby during pregnancy.
• Through contaminated food or water.
• By being bitten by an infected insect or animal.
• Through sexual contact (usually vaginal, anal and oral sex) with someone who has the infection.

Viruses are like hijackers. They invade living, normal cells. They then use those cells to multiply (make copies of themselves). This process is also called replication. The process can kill, damage, or change the infected cells. Sometimes this can make you sick. The symptoms can range from mild to very severe. Other times, your immune system may be able to fight it off and you may not have any symptoms.

Each different virus usually only infects one type of cell in your body. For example, hepatitis viruses affect the cells in the liver. HIV infects a certain type of immune system cell.

For most viral infections, treatments can only help with symptoms while you wait for your immune system to fight off the virus. There are antiviral medicines to treat some viral infections. Antibiotics do not work for viral infections.

Vaccines can help prevent you from getting many viral diseases. You may be able to prevent some viral infections by:

• Proper hand washing.
• Paying attention to food safety.
• Cleaning surfaces that may be infected with germs.
• Avoiding contact with wild animals.
• Preventing insect bites by using insect repellent when you go outdoors. If you travel to an area that has a high risk of diseases from insect bites, also wear long pants, shirts, and socks.
• Practicing safe sex (using a condom every time you have anal, vaginal, or oral sex).
• Avoiding close contact with people who are sick.

Acute flaccid myelitis (AFM) is a neurologic disease. It is rare, but serious. It affects an area of the spinal cord called gray matter. This can cause the muscles and reflexes in the body to become weak.

Because of these symptoms, some people call AFM a "polio-like" illness. But it is different from polio. AFM is not caused by polioviruses.

AFM can be caused by several different viruses. Researchers think that enteroviruses have been causing the recent increases in the number of children with AFM. AFM can also be caused by other viruses, including flaviviruses, herpesviruses, and adenoviruses.

Most people with AFM had a mild respiratory illness or fever (like you would get from a viral infection) before they got AFM.

Anyone can get AFM, but most cases (more than 90%) have been in young children.

Most people with AFM will suddenly have:

• Arm or leg weakness
• A loss of muscle tone and reflexes

Some people also have other symptoms, including:

• Facial drooping/weakness
• Trouble moving the eyes
• Drooping eyelids
• Trouble swallowing
• Slurred speech
• Pain in the arms, legs, back, or neck

Sometimes AFM can weaken the muscles that you need for breathing. This can lead to respiratory failure, which is very serious. If you get respiratory failure, you may need to use a ventilator (breathing machine) to help you breathe.

If you or your child develops any of these symptoms, get medical care right away.

AFM causes many of the same symptoms as other neurologic diseases, such as transverse myelitis and Guillain-Barre syndrome. This can make it difficult to diagnose. To find out if you have AFM, your doctor may use:

• A neurologic exam, including looking at where there is weakness, poor muscle tone, and decreased reflexes
• An MRI to look at the spinal cord and brain
• Lab tests on the cerebrospinal fluid (the fluid around the brain and spinal cord)
• Nerve conduction and electromyography (EMG) studies. These tests check nerve speed and the response of muscles to the messages from the nerves.

It is important that the tests are done as soon as possible after the symptoms start.

There is no specific treatment for AFM. A doctor who specializes in treating brain and spinal cord illnesses (neurologist) may recommend treatments for specific symptoms. For example, physical and/or occupational therapy may help with arm or leg weakness. Researchers do not know the long-term outcomes of people who get AFM.

There is no specific way to prevent AFM. But you can take steps to prevent getting sick from a virus by:

• Washing your hands often with soap and water
• Avoiding touching your face with unwashed hands
• Avoiding close contact with people who are sick
• Cleaning and disinfecting surfaces that you frequently touch, including toys
• Covering coughs and sneezes with a tissue or upper shirt sleeve, not hands
• Staying home when sick

Centers for Disease Control and Prevention

The common cold is a mild infection of your upper respiratory tract (which includes your nose and throat). Colds are probably the most common illness. Adults have an average of 2-3 colds per year, and children have even more. Colds are more common in the winter and spring, but you can get them at any time.

More than 200 different viruses can cause a cold, but rhinoviruses are the most common type. The viruses that cause colds are very contagious. They can spread from person to person through the air and close personal contact. You can also get infected when you touch something that has the virus on it and then touch your eyes, mouth, or nose. For example, you could get a cold after you shake hands with someone who has a cold or touch a doorknob that has the germs on it, and then touch your face.

The symptoms of a common cold usually include:

• Sneezing
• Stuffy nose (congestion)
• Runny nose
• Sore throat
• Coughing
• Headache

The symptoms usually start a few days after you become infected with the virus. Some symptoms can last for 10-14 days.

There is no cure for the common cold. But there are treatments that can make you feel better while you wait for the cold to go away on its own:

• Getting lots of rest.
• Drinking plenty of fluids.
• Using a clean humidifier or cool mist vaporizer.
• Gargling with warm salt water.
• Using saline nose drops or sprays.
• Taking over-the-counter pain or cold and cough medicines. But you need to be careful with certain medicines:
  • Children and teens should not take aspirin.
  • Some cold and cough medicines contain ingredients that are not recommended for children. Talk with your child's health care provider before giving your child any cold and cough medicines.
  • Some cold and cough medicines contain pain relievers. If you also take a separate pain reliever with these medicines, you could be getting a dangerous amount of the pain reliever. Read the labels on the medicines and follow the instructions carefully. If you have questions, ask your provider or a pharmacist.

Antibiotics will not help with a cold. Antibiotics help with bacterial infections, not with viral infections such as colds.

Most people who have a cold will feel better after a week or two. However, some people who get a cold may develop other illnesses, such as bronchitis or pneumonia. This is more common in people with weakened immune systems, asthma, or other respiratory conditions. Contact your provider if you or your child have symptoms that concern you, such as:

• Trouble breathing or fast breathing
• Dehydration
• Fever that lasts longer than 4 days
• Symptoms that last more than 10 days without improvement
• Symptoms, such as fever or cough, that improve but then return or worsen
• Worsening of chronic medical conditions

There is no vaccine to protect against the common cold. But you may be able to reduce your risk of getting or spreading a cold by:

• Washing your hands often with soap and water for at least 20 seconds.
• Avoiding touching your face, nose, or mouth with unwashed hands.
• Avoiding close contact, such as kissing, shaking hands, and sharing cups and eating utensils, with others if you are sick or they are sick.
• Cleaning and disinfecting surfaces that you frequently touch.
• Covering coughs and sneezes with a tissue. Then throw away the tissue and wash your hands.
• Staying home when sick.

Centers for Disease Control and Prevention

Gastroenteritis is an inflammation of the lining of the stomach and intestines. The main symptoms include vomiting and diarrhea. It is usually not serious in healthy people, but it can sometimes lead to dehydration or cause severe symptoms.

There can be many different causes of gastroenteritis:

• Viruses
• Bacteria
• Parasites
• Chemicals
• Reactions to certain medicines and food

Viral gastroenteritis is the most common type. It can be caused by many different viruses, including noroviruses and rotaviruses. Some people call viral gastroenteritis the "stomach flu." But this name is not medically correct. It is not caused by flu viruses. The flu is a respiratory infection that affects your nose, throat and lungs.

When gastroenteritis is caused by consuming foods or drinks contaminated with viruses, bacteria, parasites, or chemicals, this is called food poisoning.

The viruses, bacteria, and parasites that cause gastroenteritis can also spread from person to person. You could be infected when you touch something that has the germs on it and then touch your eyes, mouth, or nose.

The symptoms of gastroenteritis include:

• Diarrhea
• Pain or cramping in your abdomen (belly)
• Nausea
• Vomiting
• Sometimes fever

Gastroenteritis is usually not serious. But it can sometimes cause lead to dehydration or cause severe symptoms. Certain people are at higher risk for these problems. They include:

• Pregnant women
• Older adults
• People with weakened immune systems or other serious health conditions
• Infants
• Babies who were born prematurely or have other health conditions

If you or a family member are at higher risk and have symptoms of gastroenteritis, contact a health care provider right away. Even if you are not at high risk, it is possible to become dehydrated or have more serious symptoms. There are some warning signs to watch for. It's important to contact a provider right away if you or your child have any of them:

• For adults, they include:
  • Change in mental state, such as irritability or lack of energy
  • Diarrhea lasting more than 2 days
  • High fever
  • Vomiting often
  • Six or more loose stools in a day
  • Severe pain in the abdomen (belly) or rectum
  • Stools that are black and tarry or contain blood or pus
  • Symptoms of dehydration, such as thirst, dry mouth, headache, dark-colored urine, and urinating less than normal
• For infants and children, they include:
  • Change in the child's mental state, such as irritability or lack of energy
  • Diarrhea lasting more than a day
  • Any fever in infants
  • High fever in older children
  • Frequent loose stools
  • Vomiting often
  • Severe pain in the abdomen (belly) or rectum
  • Signs or symptoms of dehydration, such as thirst, dry mouth, urinating less than usual or no wet diapers for 3 hours or more, and no tears when crying
  • Stools that are black and tarry or contain blood or pus

To find out if you have gastroenteritis, your provider:

• Will do a physical exam
• Will ask about your symptoms
• May do tests of your stool

Usually, people with gastroenteritis get better on their own, with rest and plenty of fluids and electrolytes. Your provider may suggest that you take a probiotic. Studies suggest that some probiotics may help shorten a case of diarrhea.

People with more severe symptoms may need medicines to control nausea or vomiting. Providers may also give other medicines for certain types of gastroenteritis, such as antibiotics for some bacterial types and antiparasitic medicines for some parasitic types.

Gastroenteritis cannot always be prevented. But proper hand washing, cleaning surfaces that may be infected with germs, and safe food preparation may help prevent some of the infections that can cause gastroenteritis. There are vaccines for infants to protect against rotavirus infections.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

When you breathe, your lungs take in oxygen from the air and deliver it to the bloodstream. The cells in your body need oxygen to work and grow. During a normal day, you breathe nearly 25,000 times. People with lung disease have difficulty breathing. Millions of people in the U.S. have lung disease. If all types of lung disease are lumped together, it is the number three killer in the United States.

The term lung disease refers to many disorders affecting the lungs, such as asthma, COPD, infections like influenza, pneumonia and tuberculosis, lung cancer, and many other breathing problems. Some lung diseases can lead to respiratory failure.

Dept. of Health and Human Services Office on Women's Health

Pneumonia is an infection in one or both of the lungs. It causes the air sacs of the lungs to fill up with fluid or pus. It can range from mild to severe, depending on the type of germ causing the infection, your age, and your overall health.

Bacterial, viral, and fungal infections can cause pneumonia.

Bacteria are the most common cause. Bacterial pneumonia can occur on its own. It can also develop after you've had certain viral infections such as a cold or the flu. Several different types of bacteria can cause pneumonia, including:

• Streptococcus pneumoniae
• Legionella pneumophila; this pneumonia is often called Legionnaires' disease
• Mycoplasma pneumoniae
• Chlamydia pneumoniae
• Haemophilus influenzae

Viruses that infect the respiratory tract may cause pneumonia. Viral pneumonia is often mild and goes away on its own within a few weeks. But sometimes it is serious enough that you need to get treatment in a hospital. If you have viral pneumonia, you are at risk of also getting bacterial pneumonia. The different viruses that can cause pneumonia include:

• Respiratory syncytial virus (RSV)
• Some common cold and flu viruses
• SARS-CoV-2, the virus that causes COVID-19

Fungal pneumonia is more common in people who have chronic health problems or weakened immune systems. Some of the types include:

• Pneumocystis pneumonia (PCP)
• Coccidioidomycosis, which causes valley fever
• Histoplasmosis
• Cryptococcus

Anyone can get pneumonia, but certain factors can increase your risk:

• Age; the risk is higher for children who are age 2 and under and adults age 65 and older
• Exposure to certain chemicals, pollutants, or toxic fumes
• Lifestyle habits, such as smoking, heavy alcohol use, and malnourishment
• Being in a hospital, especially if you are in the ICU. Being sedated and/or on a ventilator raises the risk even more.
• Having a lung disease
• Having a weakened immune system
• Have trouble coughing or swallowing, from a stroke or other condition
• Recently being sick with a cold or the flu

The symptoms of pneumonia can range from mild to severe and include:

• Fever
• Chills
• Cough, usually with phlegm (a slimy substance from deep in your lungs)
• Shortness of breath
• Chest pain when you breathe or cough
• Nausea and/or vomiting
• Diarrhea

The symptoms can vary for different groups. Newborns and infants may not show any signs of the infection. Others may vomit and have a fever and cough. They might seem sick, with no energy, or be restless.

Older adults and people who have serious illnesses or weak immune systems may have fewer and milder symptoms. They may even have a lower than normal temperature. Older adults who have pneumonia sometimes have sudden changes in mental awareness.

Sometimes pneumonia can cause serious complications such as:

• Bacteremia, which happens when the bacteria move into the bloodstream. It is serious and can lead to septic shock.
• Lung abscesses, which are collections of pus in cavities of the lungs
• Pleural disorders, which are conditions that affect the pleura. The pleura is the tissue that covers the outside of the lungs and lines the inside of your chest cavity.
• Kidney failure
• Respiratory failure

Sometimes pneumonia can be hard to diagnose. This is because it can cause some of the same symptoms as a cold or the flu. It may take time for you to realize that you have a more serious condition.

Your health care provider may use many tools to make a diagnosis:

• A medical history, which includes asking about your symptoms
• A physical exam, including listening to your lungs with a stethoscope
• Various tests, such as
  • A chest x-ray
  • Blood tests such as a complete blood count (CBC) to see if your immune system is actively fighting an infection
  • A Blood culture to find out whether you have a bacterial infection that has spread to your bloodstream

If you are in the hospital, have serious symptoms, are older, or have other health problems, you may also have more tests, such as:

• Sputum test, which checks for bacteria in a sample of your sputum (spit) or phlegm (slimy substance from deep in your lungs).
• Chest CT scan to see how much of your lungs is affected. It may also show if you have complications such as lung abscesses or pleural effusions.
• Pleural fluid culture, which checks for bacteria in a fluid sample that was taken from the pleural space
• Pulse oximetry or blood oxygen level test, to check how much oxygen is in your blood
• Bronchoscopy, a procedure used to look inside your lungs' airways

Treatment for pneumonia depends on the type of pneumonia, which germ is causing it, and how severe it is:

• Antibiotics treat bacterial pneumonia and some types of fungal pneumonia. They do not work for viral pneumonia.
• In some cases, your provider may prescribe antiviral medicines for viral pneumonia
• Antifungal medicines treat other types of fungal pneumonia

You may need to be treated in a hospital if your symptoms are severe or if you are at risk for complications. While there, you may get additional treatments. For example, if your blood oxygen level is low, you may receive oxygen therapy.

It may take time to recover from pneumonia. Some people feel better within a week. For other people, it can take a month or more.

Vaccines can help prevent pneumonia caused by pneumococcal bacteria or the flu virus. Having good hygiene, not smoking, and having a healthy lifestyle may also help prevent pneumonia.

NIH: National Heart, Lung, and Blood Institute