antiviral

The flu, also called influenza, is a respiratory infection caused by viruses. Each year, millions of Americans get sick with the flu. Sometimes it causes mild illness. But it can also be serious or even deadly, especially for people over 65, newborn babies, and people with certain chronic illnesses.

The flu is caused by flu viruses that spread from person to person. When someone with the flu coughs, sneezes, or talks, they spray tiny droplets. These droplets can land in the mouths or noses of people who are nearby. Less often, a person may get flu by touching a surface or object that has flu virus on it and then touching their own mouth, nose, or possibly their eyes.

Symptoms of the flu come on suddenly and may include:

• Fever or feeling feverish/chills
• Cough
• Sore throat
• Runny or stuffy nose
• Muscle or body aches
• Headaches
• Fatigue (tiredness)

Some people may also have vomiting and diarrhea. This is more common in children.

Sometimes people have trouble figuring out whether they have a cold or the flu. There are differences between them:

Sometimes people say that they have a "flu" when they really have something else. For example, "stomach flu" isn't the flu; it's gastroenteritis.

Some people who get the flu will develop complications. Some of these complications can be serious or even life-threatening. They include:

• Bronchitis
• Ear infection
• Sinus infection
• Pneumonia
• Inflammation of the heart (myocarditis), brain (encephalitis), or muscle tissues (myositis, rhabdomyolysis)

The flu also can make chronic health problems worse. For example, people with asthma may have asthma attacks while they have flu.

Certain people are more likely to have complications from the flu, including:

• Adults 65 and older
• Pregnant women
• Children younger than 5
• People with certain chronic health conditions, such as asthma, diabetes, and heart disease

To diagnose the flu, health care providers will first do a medical history and ask about your symptoms. There are several tests for the flu. For the tests, your provider will swipe the inside of your nose or the back of your throat with a swab. Then the swab will be tested for the flu virus.

Some tests are quick and give results in 15-20 minutes. But these tests are not as accurate as other flu tests. These other tests can give you the results in one hour or several hours.

Most people with the flu recover on their own without medical care. People with mild cases of the flu should stay home and avoid contact with others, except to get medical care.

But if you have symptoms of flu and are in a high risk group or are very sick or worried about your illness, contact your health care provider. You might need antiviral medicines to treat your flu. Antiviral medicines can make the illness milder and shorten the time you are sick. They also can prevent serious flu complications. They usually work best when you start taking them within 2 days of getting sick.

The best way to prevent the flu is to get a flu vaccine every year. But it's also important to have good health habits like covering your cough and washing your hands often. This can help stop the spread of germs and prevent the flu.

Centers for Disease Control and Prevention

Birds, just like people, can get the flu. Another name for bird flu is avian influenza. The viruses that cause bird flu normally only infect birds, including chickens, other poultry, and wild birds such as ducks. But sometimes the viruses can infect other animals and, in rare cases, people.

A few types of these viruses have caused most of the infections in people. They are the H5N1, H7N9, and H5N6 viruses. These infections in people have mainly been in Asia, Africa, Europe, the Pacific, and the Near East. Although it's very rare, there have also been some infections in people in the United States.

The most common ways you can get bird flu are from:

• Touching your eyes, nose, or mouth after handling infected live or dead birds
• Touching surfaces or handling items contaminated by bird flu viruses and then touching your eyes, nose, or mouth
• Breathing in droplets or dust contaminated with the virus

It's also possible (but very rare) to get bird flu from:

• Another type of animal who has bird flu. Bird flu can also infect many other animals, including some dogs, cats, certain wild and zoo animals, and livestock such as cattle. These animals can then spread the flu to people.
• Another person.
• Eating poultry, eggs, and beef that were not properly handled and cooked.
• Drinking raw milk.

Certain people may be more likely to get bird flu, including:

• Poultry workers
• Animal handlers
• Wildlife biologists
• Disease control workers
• Research laboratory workers
• Veterinarians
• People who travel to countries where bird flu is present

Sometimes bird flu doesn't cause any symptoms. But if you do feel sick, your symptoms can range from mild to severe. Often, the symptoms are similar to the (seasonal) flu, such as:

• Fever (but not everyone has a fever)
• Cough
• Sore throat
• Runny or stuffy nose
• Muscle or body aches
• Fatigue
• Headaches
• Eye redness (conjunctivitis)
• Trouble breathing
• Diarrhea

People with severe illness from bird flu may have pneumonia and might need to be hospitalized.

Laboratory testing is used to diagnose bird flu. It's usually done with a nasal or throat swab. This testing is more accurate when the swab is collected during the first few days of illness.

For people who are severely ill, health care providers may do testing of a different sample, such as fluid taken during a bronchoalveolar lavage or other procedure.

Bird flu is treated with antiviral medicines. It's important to get them as soon as possible. The medicines may make your illness less severe.

You may also be given antiviral medicines if you were exposed to a person or animal who has the virus. This may help prevent you from getting sick.

There is currently no vaccine available to the public. The government has developed a virus that is similar to some H5N1 viruses. The virus could be used to produce a vaccine for people, if needed.

It's important to take precautions to prevent bird flu:

• If you have a job or pastime that puts you in contact with birds or other animals, make sure to use proper protective equipment.
• Otherwise try to avoid direct contact with wild birds and other animals.
• Wash your hands with soap and water after touching birds or other animals.
• Since it's possible to get bird flu through some foods, make sure to handle and cook your food safely and avoid raw milk.

Centers for Disease Control and Prevention

Mpox, which used to be called monkeypox, is a rare disease caused by infection with the mpox virus. The mpox virus is in the same family of viruses as the smallpox virus. But mpox is less contagious than smallpox. And its disease causes milder symptoms and is usually not fatal.

In the past, most of the people who got mpox lived in certain parts of central and western Africa, had traveled there, or had been exposed to infected animals imported from there. During the recent outbreak, the disease has been found in people who live in other countries, including the United States.

Mpox spreads in different ways:

• Through close, personal, often skin-to-skin contact with someone who has the virus:
  • Through direct contact with their rash, scabs, or body fluids.
  • By breathing in the virus during prolonged, face-to-face contact.
  • During intimate physical contact such as kissing, cuddling, hugging, massage or sex.
• During pregnancy, from the pregnant person to the baby.
• From touching items (such as clothes, bedding, or towels) that were used by someone who has the virus. The risk of getting mpox this way is low.
• From infected animals:
  • By being scratched or bitten by the animal.
  • By preparing or eating meat or using products from the animal.

Someone who has mpox can spread it from the time their symptoms start until their rash has fully healed, all scabs have fallen off, and a fresh layer of skin has formed. This usually takes 2-4 weeks.

Researchers have found that some people can spread mpox to others from 1 to 4 days before their symptoms appear. It is not known how often this happens.

The symptoms of mpox usually start within 3 weeks from the time you were exposed to the virus. The symptoms may include:

• A rash with sores that can look like pimples or blisters. It could be on the face, inside the mouth, and on other parts of the body, like the hands, feet, chest, genitals, or anus. It goes through different stages, including scabs, before healing. This can take 2-4 weeks.
• Fever.
• Chills.
• Swollen lymph nodes ("swollen glands").
• Exhaustion.
• Headache.
• Muscle aches and backache.
• Respiratory symptoms, such as a sore throat, nasal congestion, or cough.

You may have all or only a few symptoms:

• You may get a rash first, followed by other symptoms
• You may have flu-like symptoms and then develop a rash 1-4 days later
• You may only get a rash

To find out if you have mpox, your provider:

• Will ask about your symptoms and medical history.
• Will look at your rash.
• Will take a sample of tissue from one of the sores so it can be tested for mpox virus.
• May do blood tests to check for mpox virus or for antibodies to the virus. Antibodies are proteins that your immune system makes to fight foreign substances, such as viruses and bacteria.

There are no treatments specifically for mpox, but many people get better on their own.

Since mpox and smallpox are similar, antiviral medicines that protect against smallpox may also help treat mpox. Antiviral medicines may be recommended for people who are more likely to get severely ill, such as patients who have weakened immune systems.

There are steps you can take to help prevent mpox:

• Avoid close, skin-to-skin contact with the mpox rash. So, while a person is sick with mpox:
  • Do not touch their rash or scabs.
  • Do not kiss, hug, cuddle, or have sex with them.
  • Do not share eating utensils or cups with them.
• Do not touch the bedding, towels, or clothing of a person who has mpox.
• Wash your hands often with soap and water or use an alcohol-based hand sanitizer, especially after contact with sick people.
• In Central and West Africa, avoid contact with animals that can spread mpox virus, such as rodents and primates. Also, avoid sick or dead animals, as well as any bedding or other materials they have touched.

If you are sick with mpox it is recommended that you stay home while you are sick, if possible. If you have an active rash or other symptoms, it would be best to stay in a separate room from your family members and pets if you can.

The U.S. government has two vaccines in the U.S. to protect against mpox. One was approved for smallpox and mpox (JYNNEOS), and the other was approved for smallpox (ACAM2000):

• JYNNEOS is the preferred vaccine to protect against mpox. It is a two-dose vaccine.
• ACAM2000 may be an alternative to JYNNEOS. ACAM2000 is a single-dose vaccine. But it has the potential for more side effects and adverse events than JYNNEOS. And it is not recommended for people who are pregnant, are under 12 months old, have severely weakened immune systems, or have certain medical conditions.

The U. S. Centers for Disease Control and Prevention (CDC) recommends vaccination for people who have been exposed to mpox or who are more likely to get mpox.

Centers for Disease Control and Prevention

Bell's palsy is the most common cause of facial paralysis. It usually affects just one side of the face. Symptoms appear suddenly and are at their worst about 48 hours after they start. They can range from mild to severe and include:

• Twitching
• Weakness
• Paralysis
• Drooping eyelid or corner of mouth
• Drooling
• Dry eye or mouth
• Excessive tearing in the eye
• Impaired ability to taste

Scientists think that a viral infection makes the facial nerve swell or become inflamed. You are most likely to get Bell's palsy if you are pregnant, diabetic or sick with a cold or flu.

Three out of four patients improve without treatment. With or without treatment, most people begin to get better within 2 weeks and recover completely within 3 to 6 months.

NIH: National Institute of Neurological Disorders and Stroke

Chickenpox is an infection caused by the varicella-zoster virus. Most cases are in children under age 15, but older children and adults can get it. It spreads very easily from one person to another.

The classic symptom of chickenpox is an uncomfortable, itchy rash. The rash turns into fluid-filled blisters and eventually into scabs. It usually shows up on the face, chest, and back and then spreads to the rest of the body. Other symptoms include:

• Fever
• Headache
• Tiredness
• Loss of appetite

Chickenpox is usually mild and lasts 5 to 10 days. Calamine lotions and oatmeal baths can help with itching. Acetaminophen can treat the fever. Do not use aspirin for chickenpox; that combination can cause Reye syndrome.

Chickenpox can sometimes cause serious problems. Adults, babies, teenagers, pregnant women, and those with weak immune systems tend to get sicker from it. They may need to take antiviral medicines.

Once you catch chickenpox, the virus usually stays in your body. You probably will not get chickenpox again, but the virus can cause shingles in adults. A chickenpox vaccine can help prevent most cases of chickenpox, or make it less severe if you do get it.

Centers for Disease Control and Prevention

Cold sores are caused by a contagious virus called herpes simplex virus (HSV). There are two types of HSV. Type 1 usually causes oral herpes, or cold sores. Type 1 herpes virus infects more than half of the U.S. population by the time they reach their 20s. Type 2 usually affects the genital area.

Some people have no symptoms from the infection. But others develop painful and unsightly cold sores. Cold sores usually occur outside the mouth, on or around the lips. When they are inside the mouth, they are usually on the gums or the roof of the mouth. They are not the same as canker sores, which are not contagious.

There is no cure for cold sores. They normally go away on their own in a few weeks. Antiviral medicines can help them heal faster. They can also help to prevent cold sores in people who often get them. Other medicines can help with the pain and discomfort of the sores. These include ointments that numb the blisters, soften the crusts of the sores, or dry them out. Protecting your lips from the sun with sunblock lip balm can also help.

Cytomegalovirus (CMV) is a virus found around the world. It is related to the viruses that cause chickenpox and infectious mononucleosis (mono). Between 50% and 80% of adults in the United States have had a CMV infection by age 40. Once CMV is in a person's body, it stays there for life.

CMV is spread through close contact with body fluids. Most people with CMV don't get sick and don't know that they've been infected. But infection with the virus can be serious in babies and people with weak immune systems. If a woman gets CMV when she is pregnant, she can pass it on to her baby. Usually the babies do not have health problems. But some babies can develop lifelong disabilities.

A blood test can tell whether a person has ever been infected with CMV. Most people with CMV don't need treatment. If you have a weakened immune system, your doctor may prescribe antiviral medicine. Good hygiene, including proper hand washing, may help prevent infections.

Centers for Disease Control and Prevention

Swine flu is an infection caused by a virus. It's named for a virus that pigs can get. People do not normally get swine flu, but human infections can and do happen. In 2009 a strain of swine flu called H1N1 infected many people around the world.

The virus is contagious and can spread from human to human. Symptoms of swine flu in people are similar to the symptoms of regular human flu and include fever, cough, sore throat, body aches, headache, chills and fatigue.

There are antiviral medicines you can take to prevent or treat swine flu. There is a vaccine available to protect against swine flu. You can help prevent the spread of germs that cause respiratory illnesses like influenza by:

• Covering your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
• Washing your hands often with soap and water, especially after you cough or sneeze. You can also use alcohol-based hand cleaners.
• Avoiding touching your eyes, nose or mouth. Germs spread this way.
• Trying to avoid close contact with sick people.
• Staying home from work or school if you are sick.

Centers for Disease Control and Prevention

Hepatitis is inflammation of the liver. Inflammation is swelling that happens when tissues of the body are injured or infected. It can damage your liver. This swelling and damage can affect how well your liver functions.

Hepatitis B is a type of viral hepatitis. It can cause an acute (short-term) or chronic (long-term) infection. People with an acute infection usually get better on their own without treatment. Some people with chronic hepatitis B will need treatment.

Thanks to a vaccine, hepatitis B is not very common in the United States. It is more common in certain parts of the world, such as sub-Saharan Africa and parts of Asia.

Hepatitis B is caused by the hepatitis B virus. The virus spreads through contact with blood, semen, or other body fluids from a person who has the virus.

Anyone can get hepatitis B, but the risk is higher in:

• Infants born to mothers who have hepatitis B
• People who inject drugs or share needles, syringes, and other types of drug equipment
• Sex partners of people with hepatitis B, especially if they are not using latex or polyurethane condoms during sex
• Men who have sex with men
• People who live with someone who has hepatitis B, especially if they use the same razor, toothbrush, or nail clippers
• Health care and public-safety workers who are exposed to blood on the job
• Hemodialysis patients
• People who have lived in or traveled often to parts of the world where hepatitis B is common
• Have diabetes, hepatitis C, or HIV

Often, people with hepatitis B don't have symptoms. Adults and children over 5 are more likely to have symptoms than younger children.

Some people with acute hepatitis B have symptoms 2 to 5 months after infection. These symptoms can include:

• Dark yellow urine
• Diarrhea
• Fatigue
• Fever
• Gray- or clay-colored stools
• Joint pain
• Loss of appetite
• Nausea and/or vomiting
• Abdominal pain
• Yellowish eyes and skin, called jaundice

If you have chronic hepatitis B, you may not have symptoms until complications develop. This could be decades after you were infected. For this reason, hepatitis B screening is important, even if you have no symptoms. Screening means that you are tested for a disease even though you don't have symptoms. If you are at high risk, your health care provider may suggest screening.

In rare cases, acute hepatitis B can cause liver failure.

Chronic hepatitis B can develop into a serious disease that causes long-term health problems such as cirrhosis (scarring of the liver), liver cancer, and liver failure.

If you have ever had hepatitis B, the virus may become active again, or reactivated, later in life. This could start to damage the liver and cause symptoms.

To diagnose hepatitis B, your health care provider may use many tools to make a diagnosis:

• A medical history, which includes asking about your symptoms
• A physical exam
• Blood tests, including tests for viral hepatitis

If you have acute hepatitis B, you probably don't need treatment. Some people with chronic hepatitis B don't need treatment. But if you have a chronic infection and blood tests show that hepatitis B could be damaging your liver, you may need to take antiviral medicines.

The best way to prevent hepatitis B is to get the hepatitis B vaccine.

You can also reduce your chance of hepatitis B infection by:

• Not sharing drug needles or other drug materials
• Wearing gloves if you have to touch another person's blood or open sores
• Making sure your tattoo artist or body piercer uses sterile tools
• Not sharing personal items, such as toothbrushes, razors, or nail clippers
• Using a latex condom during sex. If your or your partner is allergic to latex, you can use polyurethane condoms.

If you think you have been in contact with the hepatitis B virus, see your health care provider right away. Your provider may give you a dose of the hepatitis B vaccine to prevent infection. In some cases, your provider may also give you a medicine called hepatitis B immune globulin (HBIG). You need to get the vaccine and the HBIG (if needed) as soon as possible after coming into contact with the virus. It is best if you can get them within 24 hours.

National Institute of Diabetes and Digestive and Kidney Diseases

Hepatitis is inflammation of the liver. Inflammation is swelling that happens when tissues of the body are injured or infected. Inflammation can damage organs.

There are different types of hepatitis. One type, hepatitis C, is caused by the hepatitis C virus (HCV). Hepatitis C can range from a mild illness lasting a few weeks to a serious, lifelong illness.

Hepatitis C can be acute or chronic:

• Acute hepatitis C is a short-term infection. The symptoms can last up to 6 months. Sometimes your body is able to fight off the infection and the virus goes away. But for most people, an acute infection leads to chronic infection.
• Chronic hepatitis C is a long-lasting infection. If it is not treated, it can last for a lifetime and cause serious health problems, including liver damage, cirrhosis (scarring of the liver), liver cancer, and even death.

Hepatitis C spreads through contact with the blood of someone who has HCV. This contact may be through:

• Sharing drug needles or other drug materials with someone who has HCV. In the United States, this is the most common way that people get hepatitis C.
• Getting an accidental stick with a needle that was used on someone who has HCV. This can happen in health care settings.
• Being tattooed or pierced with tools or inks that were not sterilized after being used on someone who has HCV
• Having contact with the blood or open sores of someone who has HCV
• Sharing personal care items that may have come in contact with another person's blood, such as razors or toothbrushes
• Being born to a mother with HCV
• Having unprotected sex with someone who has HCV

Before 1992, hepatitis C was also commonly spread through blood transfusions and organ transplants. Since then, there has been routine testing of the U.S. blood supply for HCV. It is now very rare for someone to get HCV this way.

You are more likely to get hepatitis C if you:

• Have injected drugs
• Had a blood transfusion or organ transplant before July 1992
• Have hemophilia and received clotting factor before 1987
• Have been on kidney dialysis
• Have been in contact with blood or infected needles at work
• Have had tattoos or body piercings
• Have worked or lived in a prison
• Were born to a mother with hepatitis C
• Have HIV
• Have had more than one sex partner in the last 6 months
• Have had a sexually transmitted disease
• Are a man who has had sex with men (MSM)

If you are at high risk for hepatitis C, your health care provider will likely recommend that you get tested for it.

Most people with hepatitis C have no symptoms. Some people with acute hepatitis C do have symptoms within 1 to 3 months after they are exposed to the virus. These symptoms may include:

• Dark yellow urine
• Fatigue
• Fever
• Gray- or clay-colored stools
• Joint pain
• Loss of appetite
• Nausea and/or vomiting
• Pain in your abdomen (belly)
• Jaundice (yellowish eyes and skin)

If you have chronic hepatitis C, you probably will not have symptoms until it causes complications. This can happen decades after you were infected. For this reason, hepatitis C screening is important, even if you have no symptoms.

Without treatment, hepatitis C may lead to cirrhosis, liver failure, and liver cancer. Early diagnosis and treatment of hepatitis C can prevent these complications.

Providers diagnose hepatitis C based on your medical history, a physical exam, and blood tests.

If you do have hepatitis C, you may need additional tests to check for liver damage. These tests may include other blood tests, an ultrasound of the liver, and a liver biopsy.

Treatment for hepatitis C is with antiviral medicines. They can cure the disease in most cases.

If you have acute hepatitis C, your provider may wait to see if your infection becomes chronic before starting treatment.

If your hepatitis C causes cirrhosis, you should see a doctor who specializes in liver diseases. Treatments for health problems related to cirrhosis include medicines, surgery, and other medical procedures. If your hepatitis C leads to liver failure or liver cancer, you may need a liver transplant.

There is no vaccine for hepatitis C. But you can help protect yourself from hepatitis C infection by:

• Not sharing drug needles or other drug materials.
• Wearing gloves if you have to touch another person's blood or open sores.
• Making sure your tattoo artist or body piercer uses sterile tools and unopened ink.
• Not sharing personal items such toothbrushes, razors, or nail clippers.
• Using a latex condom during sex. If your or your partner is allergic to latex, you can use polyurethane condoms.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases