Influenza viruses include A, B, and C. Influenza A is a virus that causes epidemics worldwide. This virus periodically mutates and causes epidemics. Sporadic outbreaks every 1 to 3 years are caused by small antigenic mutations, and global pandemics every 10 to 15 years are caused by large antigenic mutations. Is. Since the twentieth century, there have been around 5-6 cases of influenza pandemic worldwide.
Specifically, the global epidemic between 1918 and 1919 during World War I was a major pandemic of around 20 million deaths. In 1957, the incidence rate was reported to exceed 50% of the urban population. It becomes. In the most recent 2009 pandemic, up to 570,000 deaths due to respiratory and cardiovascular disorders were estimated. This global epidemic is only caused by the hepatitis A virus and occurs when genetic structures mutate 50% or more, producing an entirely new antigenic form.
◇ Infection Pathway
Influenza quickly spreads from person to person through small droplets produced when a patient coughs or sneezes. Airborne infections can also be found in densely populated areas such as schools, ships and public transportation. It can last up to 48 hours on the surface of items contaminated with colds or pharyngeal secretions (telephone, computer keyboards, doors, coffee cups, etc.), allowing indirect transmission. The incubation period is 2 to 3 days and the transmission period is 3 to 4 days from the onset of clinical symptoms. Infected people are immune to strains of the virus.
◇ Symptoms and Complications
Influenza often starts suddenly after an incubation period of one to four days (an average of two days). Initially, systemic symptoms, such as fever, chills, headaches, muscle aches, fatigue and loss of appetite, are dominant. Muscle aches and headaches are usually the most painful, and calf muscle pain is significant in children. Joint pain, tears, burning eyes may come, and gastrointestinal symptoms such as abdominal pain, diarrhea and vomiting can be accompanied. Systemic symptoms usually last around three days. Temperatures suddenly rise to 38 to 40 degrees, with persistent fever, but may be a form of intermittent fever. Respiratory symptoms, such as hoarseness and sore throat, appear as systemic symptoms decrease and become more severe, lasting 3 to 4 days after a fever.
Influenza B is similar to influenza A, but experiences lighter travel. Influenza C, on the other hand, is not common and does not cause epidemics. Children experience more severe fevers and cervical lymphadenitis more often than adults. It causes upper respiratory tract infections, laryngeal bronchitis, bronchitis, capillary bronchitis, pneumonia, etc., and is often accompanied by a temporary papular speckle rash. Babies are often associated with sepsis.
Complications can cause pneumonia. Song Young-gu, professor of infectious medicine at Gangnam Severance Hospital, said, "There is a viral pneumonia caused by influenza virus itself, bacterial pneumonia caused by secondary bacterial infection and pneumonia caused by a mixture of viral and bacterial infections. In the elderly, the incidence of lung complications is much higher than other age groups. Other complications include otitis media in children, myositis during influenza B infection, myocarditis and pericarditis, and Reye's syndrome. "
Injections of antiviral drugs can shorten the duration of influenza. However, treatments that are more important than antiviral therapy are getting enough rest and sleep. Drink plenty of fluids and increase your humidity with an air humidifier. Increasing humidity can prevent influenza viruses from multiplying well in a dry environment, making a fever and cough patient feel more comfortable, and if coughing up phlegm occurs This helps. If you do not eat well in children to add calories, sugar or honey water, such as soft drinks or good ions. You can give juice, milk or fruit juice little by little, but children who have a fever often experience vomiting or diarrhea, so eat small portions and drink slowly.
Additional drugs include aspirin and acetaminophen as antipyretic analgesics, which can reduce high fever, headaches and muscle aches, but should be consulted with a doctor when using aspirin in children, which can cause a side effect called lys syndrome. . Professor Song said, "Even if you are under 3 years old or have an adult with a high fever for more than 3 days, the cough lasts longer and becomes severe, accompanied by chest pain, shortness of breath, or phlegm. I succeeded.
◇ Management and Prevention
In high-risk groups, such as the elderly, patients with chronic diseases, and immunosuppressive patients, it is important to prevent colds. As a general precaution, it's better to avoid places where there are lots of people, and make sure to keep your hands, feet, and face clean after exiting. You have to wash your back and brush your teeth. Adequate nutrition and avoid overwork.
Inject vaccination with proactive prevention. All children aged 6 months and older must be vaccinated. If vaccine supplies are limited, the following groups can be given priority. The first is the high-risk group with high complications and mortality when influenza develops. Older people aged 65 or over, patients with chronic diseases (chronic obstructive pulmonary disease, heart disease, diabetes, kidney failure, etc.), immunosuppressive patients (AIDS patients, malignant tumors, organs) and transplant patients, etc.), And the second group is able to transmit the influenza virus to the high risk group. A representative example is a medical person who contacts a patient in a hospital.
Therefore, if there is a high risk group in the family, vaccination is not only effective for the person but also the whole family. In addition, people who treat high-risk patients directly, those whose absence may be a problem due to influenza or upper respiratory infections (eg, being in a critical position at work or very important to the community), work in a very crowded environment. the risk of transmission is very high, people who want to be vaccinated against influenza are eligible for vaccination.
Professor Song said, "If you have a severe hypersensitivity reaction such as anaphylaxis after a previous influenza vaccination or if you have Guillain-Barré syndrome within 6 weeks after a previous vaccination, you should avoid re-inoculation. This is contraindicated in infants and teens who use aspirin ( because of the risk of Reye's syndrome), and pregnant women when taking illness, cardiovascular disease, diabetes, renal insufficiency, chronic diseases with hemoglobinosis, immune deficiency, or immunosuppressive drugs. I do it. "