Description

The influenza a (H1N1), sometimes called swine flu, is a type of influenza virus.

During the 2009-10 flu season, a new a (H1N1) virus began to cause disease in humans. It is often called swine flu, and it was a new combination of the flu viruses that infect pigs, birds and humans.

The World Health Organization (WHO) declared the H1N1 flu to be a pandemic in 2009. That year, the virus caused an estimated 284,400 deaths around the world. In August 2010, the WHO declared the pandemic over. But the strain of the H1N1 flu pandemic became one of the strains that cause the seasonal flu.

Most people with the flu get better on their own.

But the flu and its complications can be deadly, especially for people at high risk. The seasonal flu vaccine can now help to protect against the H1N1 flu and other seasonal flu viruses.

Symptoms

The symptoms of the flu caused by the H1N1 virus, commonly called swine flu are similar to those of other influenza viruses.

The symptoms usually begin quickly and may include:

  • The fever, but not always.
  • Sore muscles.
  • Chills and sweats.
  • For cough.
  • The sore throat.
  • Runny or stuffy nose.
  • Tearing, redness of the eyes.
  • Pain in the eyes.
  • Pain in the body.
  • The pain of a headache.
  • The feeling of tiredness and weakness.
  • The diarrhea.
  • Discomfort in the stomach, the vomiting, but this is more common in children than in adults.

Flu-like symptoms develop about 1 to 4 days after being exposed to the virus.

When to see a doctor

If you are healthy and of developing the symptoms of the flu, most people do not need to see a health care provider. But some people are at higher risk of complications from the flu.

Call your doctor if you have flu symptoms and you are pregnant or have a chronic illness. Some examples are asthma, emphysema, diabetes, or heart disease.

If you have emergency symptoms of the flu, get immediate medical attention. For adults, the emergency symptoms may include:

  • Difficulty breathing or shortness of breath.
  • Pain in the chest.
  • Signs of dehydration, such as urinating.
  • Course of dizziness.
  • Seizures.
  • The worsening of existing medical conditions.
  • Severe weakness or muscle pain.

Emergency symptoms in children may include:

  • Difficulty breathing.
  • Pale, gray or blue colored skin, lips or nails depending on the color of the skin.
  • Pain in the chest.
  • The dehydration.
  • Severe muscle pain.
  • Seizures.
  • The worsening of existing medical conditions.

Causes

Influenza viruses such as the H1N1 virus to infect the cells lining the nose, throat and lungs. The virus is spread through the air in droplets that are released when someone with the virus coughs, sneezes, breathes and speaks. The virus enters the body when you breathe in contaminated droplets. You can also enter your body if you touch a contaminated surface and then touches their eyes, nose or mouth.

You can't catch swine flu from eating pork.

The people with the virus are likely to be able to transmit the virus from one day before symptoms appear until four days after the onset. Children and people with weakened immune systems may be able to transmit the virus for a little more time.

Risk factors

Factors that may increase your risk of developing H1N1 or other influenza virus or its complications include:

  • Age. The flu tends to have worse outcomes in children under 2 years and adults older than 65 years of age.
  • Life or the conditions of work. People who live or work in facilities with many other residents are more likely to get the flu. Some examples are nursing homes or military barracks. The people who stays in the hospital are also at higher risk.
  • Weakened immune system. Treatments for cancer, the anti-rejection drugs, the long-term use of steroids, organ transplant, blood cancer, or HIV/AIDS can weaken the immune system. This can make it more easy to catch the flu and can increase the risk of developing complications.
  • The chronic diseases. Chronic conditions can increase the risk of complications from the flu. Examples include asthma and other lung diseases, diabetes, heart disease and diseases of the nervous system. Other examples are metabolic disorders, problems with the respiratory tract and the kidneys, liver or blood.
  • Of the race. American Indian or Alaska Native persons may have a greater risk of complications from the flu.
  • The use of aspirin under the age of 19 years. People on long-term aspirin therapy and who are under 19 years of age are at risk of Reye's syndrome if infected with the flu virus.
  • Pregnancy. Pregnant people are more likely to develop complications from the flu, especially in the second and third quarter. This risk continues for up to two weeks after the baby is born.
  • Obesity. People with a body mass index (BMI) of 40 or more have a higher risk of complications from the flu.

Complications

Complications of the flu include:

  • The worsening of chronic diseases, such as heart disease and asthma.
  • Pneumonia.
  • Neurological symptoms, ranging from confusion to seizures.
  • The respiratory failure.
  • Bronchitis.
  • Muscle pain.
  • Bacterial infections.

Prevention

The Centers for Disease Control and Prevention (CDC) recommends annual influenza vaccination for all persons aged 6 months or older. The H1N1 virus is included in the seasonal flu vaccine.

The flu vaccine can reduce your risk of getting the flu. You can also lower the risk of having severe illness from the flu and the need to stay in the hospital.

Each year the seasonal flu vaccine protects against the three or four influenza virus. These are viruses that are expected to be the most common during that year's flu season.

The flu vaccine is especially important due to the flu and the virus of the disease 2019 (COVID-19) can cause similar symptoms.

Both COVID-19 and the flu can be broadcast at the same time. Vaccination is the best way to protect yourself against both. Vaccination against the flu could decrease the symptoms that can be confused with those caused by COVID-19 .

Vaccination also helps to reduce the number of people with severe flu and its complications. And that can decrease the number of people who need to stay in the hospital.

The flu vaccine is available as an injection and as a nasal spray.

The nasal spray is approved for people between 2 and 49 years of age. It is not recommended for some groups, such as:

  • Children under 2 years of age.
  • Adults 50 years of age and older.
  • Pregnant people.
  • Children between 2 and 17 years of age who are taking aspirin or salicylate-containing medications.
  • People with weakened immune systems.
  • Close contacts or caregivers of people with very weakened immune system. Examples are the people who are receiving chemotherapy, or the last of the bone marrow or solid organ transplantation.
  • Children 2 to 4 years of age who have ever had asthma or wheezing in the last 12 months.

If you have an egg allergy you can still get a flu vaccine.

These measures also help prevent the flu and limit its spread:

  • Wash your hands often. If available, use soap and water, wash for at least 20 seconds. Or use an alcohol-based hand sanitizer that has at least 60% alcohol.
  • Cover your cough or sneeze. Cough or sneeze into a tissue or with your elbow. Then wash your hands.
  • Avoid touching your face. Avoid touching your eyes, nose, and mouth.
  • Clean and disinfect surfaces. Regularly clean frequently touched surfaces to prevent the spread of the infection from a surface with the virus from your body.
  • Avoid contact with the virus. Try to avoid people who are sick or have flu-like symptoms. And if you have symptoms, stay at home if you can. When the flu is spread, consider the possibility of keeping distance between himself and others, while on the inside, especially in areas with poor air flow. If you are at high risk for complications from the flu, consider the possibility of avoiding swine barns at seasonal fairs and other places.

Diagnosis

Your health care provider may do a physical exam to look for the symptoms of the flu, including the H1N1 flu, often called swine flu. Or the doctor may review your symptoms with you by phone.

The doctor may order a test that finds the virus of influenza, such as H1N1.

There are many diagnostic tests for influenza. But not everyone who has the flu needs to be tested. In most cases, to know that someone has the flu, does not change the treatment plan.

Care providers are more likely to use a test to diagnose the flu if:

  • You're already in the hospital.
  • You are at high risk of complications from the flu.
  • You live with someone who is at higher risk for complications from the flu.

Your doctor may use a test to find out if an influenza virus is the cause of your symptoms. Or that the tests can be used to obtain more information to see if another condition is the cause of your symptoms, such as:

  • Heart problems, such as heart failure or an infection of the heart muscle.
  • Lung and breathing problems, like asthma or pneumonia.
  • Brain and nervous system problems, such as encephalopathy or encephalitis.
  • Septic Shock or organ failure.

A test called polymerase chain reaction (PCR) can be used to see if you have the flu. It is more sensitive than the other types of tests and may be able to find the strain of the flu.

It is possible to have the flu and other viruses such as COVID-19, at the same time.

Treatment

Most people with the flu, including the H1N1 flu, you only need the relief of symptoms. Supportive care such as fluid intake, take pain relievers to relieve the fever and the headache, and in rest, it can be useful.

If you have a chronic respiratory disease, your doctor may prescribe medications to help relieve your symptoms.

Health care providers may prescribe antiviral medications in the first day or two of the symptoms. You can reduce the severity of symptoms and can reduce the risk of complications.

The Food and Drug Administration has approved the use of these four antiviral drugs to treat the flu:

  • Oseltamivir (Tamiflu).
  • Zanamivir (Relenza).
  • Peramivir (Rapivab).
  • Baloxavir (Xofluza).

But the flu virus can develop resistance to these drugs. For providers of health care stockpile of antiviral drugs for certain groups. This includes people at high risk of complications and those who are in close contact with people who have a high risk of complications.

The use of antiviral carefully makes the development of resistance to the least likely and maintains the supply of these drugs to those who need them most.

Lifestyle and home remedies

If you develop any type of flu, stay home. Keep sick children at home until the fever has been gone for 24 hours.

These measures may help to relieve the symptoms:

  • Drink plenty of fluids. Choose water, juice and warm soups to prevent dehydration.
  • Rest. Get more sleep to help your immune system fight infections.
  • Consider the possibility of pain relievers. The use of a nonprescription pain reliever, such as acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin IB, others). Use caution when giving aspirin to children or teenagers. Children and adolescents recovering from flu-like symptoms should never take aspirin. This is due to the risk of Reye's syndrome, a rare but potentially life-threatening.

Avoid being around other people until you feel better, unless you are receiving medical care. If you need to leave your home and get medical care, wear a face mask. Wash your hands often.

Symptoms and treatment of H1N1 influenza (swine flu)