Influenza a virus

Courtesy, NIAID Contagiousness One difference between COVID-19 and influenza is that the former appears to be more contagious than seasonal influenza. A person infected with influenza spreads the disease to Severity of illness and death rate COVID-19 also appears to Along those same lines, COVID-19 is deadlier than influenza. The mortality rate of influenza Seasonal nature Seasonal influenza, as its name suggests, tends to come and go as the weather changes. Influenza viruses circulate year-round, but the number of new influenza casesgenerally increases in the cooler months and tapers off in the warmer months of the year. This does not mean that cold weather causes the flu; rather, cool weather, by bringing people indoors, It is possible that COVID-19 could turn out to be a seasonal illness, similar to influenza. However, Causative agent A more obvious difference between influenza and COVID-19 is in their causative agents. Influenza viruses belong to a virusfamily known as More specifically, influenza viruses express two surface

Cold, flu and other related viruses may stay infectious for several hours to days, depending on where their droplets fall. Viruses generally stay active longer on stainless steel, plastic and similar hard surfaces than on fabric and other soft surfaces. The amount of virus that lands on a surface, as well as the temperature and humidity of the environment, also determines how long cold, flu and other viruses stay active outside the body. It's possible to catch the flu or a cold virus after touching an object that a person with one of these viruses sneezed or coughed on a few moments before. But close contact with a person who has one of these viruses — such as a handshake or breathing in droplets from a cough or sneeze — is the most common way these viruses spread. The COVID-19 virus also spreads in these ways. To reduce the risk of catching or spreading viruses that cause colds, the flu or COVID-19: • Wash your hands frequently with soap and water for at least 20 seconds. Or use an alcohol-based sanitizer. • Get a flu vaccine every year. And get a COVID-19 vaccine, too. • Clean and disinfect high-touch surfaces, such as light switches and doorknobs, often. • Avoid touching your nose, mouth and eyes. • Avoid close contact with people who are ill. • Cover your mouth and nose with your elbow or a tissue when you cough or sneeze. Throw the tissue away and wash your hands right away. • Wear a face mask in indoor public spaces and outdoors where there is a high risk of COVID-19...

Before the H1N1 pandemic in 2009, the influenza A(H1N1) virus had never been identified as a cause of infections in people.Genetic analyses of this virus have shown that it originated from animal influenza viruses and is unrelated to the human seasonal H1N1 viruses that have been in general circulation among people since 1977. After early reports of influenza outbreaks in North America in April 2009, the new influenza virus spread rapidly around the world. By the time WHO declared a pandemic in June 2009, a total of 74 countries and territories had reported laboratory confirmed infections. Unlike typical seasonal flu patterns, the new virus caused high levels of summer infections in the northern hemisphere, and then even higher levels of activity during cooler months. The new virus also led to patterns of death and illness not normally seen in influenza infections. The H1N1 (2009) virus continues to circulate as a seasonal virus and is included in the vaccines against seasonal influenza.

Influenza A virus is the only Alphainfluenzavirus of the virus family [ citation needed] H = N = The hemagglutinin is central to the virus's recognizing and binding to target cells, and also to its then infecting the cell with its [ citation needed] Different influenza viruses encode for different hemagglutinin and neuraminidase proteins. For example, the Some variants are identified and named according to the isolate they resemble, thus are presumed to share lineage (example [ citation needed] Variants are sometimes named according to the species (host) in which the strain is endemic or to which it is adapted. The main variants named using this convention are: [ citation needed] • • • • • • Variants have also sometimes been named according to their deadliness in poultry, especially chickens: [ citation needed] • Low pathogenic avian influenza (LPAI) • Highly pathogenic avian influenza (HPAI), also called deadly flu or death flu Most known strains are extinct strains. For example, the annual flu subtype H3N2 no longer contains the strain that caused the [ citation needed] Annual flu [ ] Main article: The annual flu (also called "seasonal flu" or "human flu") in the US "results in approximately 36,000 deaths and more than 200,000 hospitalizations each year. In addition to this human toll, influenza is annually responsible for a total cost of over $10 billion in the U.S." The annually updated, trivalent Measured resistance to the standard antiviral drugs [ citation needed] "...

During the COVID-19 pandemic, you may have heard that coronavirus disease 2019 (COVID-19) is similar to the flu (influenza). COVID-19 and the flu are both contagious respiratory diseases. They are both caused by viruses. They have some common symptoms. But COVID-19 and flu infections can affect people differently. Also, since the flu has been around much longer, health care providers know more about how to treat it, while they continue to learn more about COVID-19. How COVID-19 and flu spread The viruses that cause COVID-19 and the flu spread in similar ways. They both can spread between people who are in close contact. They can spread farther when people are in a poorly ventilated indoor space. The viruses spread through respiratory droplets or aerosols released through talking, sneezing or coughing. These droplets can land in the mouth or nose of someone nearby or be inhaled. These viruses also can spread if a person touches a surface with one of the viruses on it and then touches the mouth, nose or eyes. COVID-19 and flu symptoms COVID-19 and the flu have many symptoms in common, including: • Fever • Cough • Shortness of breath or difficulty breathing • Tiredness • Sore throat • Runny or stuffy nose • Muscle aches • Headache • Nausea or vomiting, but this is more common in children than in adults The signs and symptoms of both diseases can range from no symptoms to mild or severe symptoms. Because COVID-19 and the flu have similar symptoms, it can be hard to diagnose wh...

Diagnosis Flu vaccines at Mayo Clinic Mayo Clinic offers flu shots in Arizona, Florida and Minnesota. Learn more about how to get your flu shot at Mayo Clinic Your health care provider will conduct a physical exam, look for signs and symptoms of flu, and possibly order a test that detects influenza viruses. During times when flu is widespread, you may not need to be tested for it. Your health care provider may diagnose you based on your symptoms. In some cases, your health care provider may suggest that you be tested for influenza. Your provider may use many tests to diagnose flu. Polymerase chain reaction (PCR) testing is becoming more common in many hospitals and labs. This test may be done while you're in your health care provider's office or in the hospital. PCR testing is more sensitive than other tests and may be able to identify the influenza strain. It's possible to have a test to diagnose both flu and COVID-19. You may have both COVID-19 and influenza at the same time. Treatment Usually, you'll need nothing more than rest and plenty of fluids to treat the flu. But if you have a severe infection or are at higher risk of complications, your health care provider may prescribe an antiviral medication to treat the flu. These drugs can include oseltamivir (Tamiflu), zanamivir (Relenza), peramivir (Rapivab) or baloxavir (Xofluza). These medications may shorten your illness by a day or so and help prevent serious complications. Oseltamivir is a medicine taken by mouth. Za...

×Top Health Categories • Coronavirus Disease COVID-19 • Gastrointestinal Health • Artificial Intelligence • Heart Disease • Mpox • High Blood Pressure • Allergies • Lung Cancer • Alzheimer's & Dementia • Mental Health • Arthritis & Rheumatology • Pregnancy • Breast Cancer • Type 1 Diabetes • Cold, Flu & Cough • Type 2 Diabetes • Diet & Nutrition • Sexual Health • Eating Disorders • Sleep • Eye Health • By Dr. Catherine Shaffer, Ph.D. Reviewed by Influenza virus is a common cause of human respiratory infection with a high rate of morbidity and mortality, particularly in the elderly and in infants. Credit: Katryna Kon/Shutterstock.com Influenza A belongs to the Orthomyxoviridae family. It has a negative sense RNA genome encoding 11 viral genes, contained within a viral envelope. The viral genes are as follows: • hemagglutinin (HA) • neuraminidase (NP) • matrix 1 (M1) • matrix 2 (M2) • nucleoprotein (NP) • non-structural protein (NSP1) • non-structural protein 2/nuclear export protein (NS2/NEP) • polymerase acidic protein (PA) • polymerase basic protein 1 (PB1) • polymerase basic protein 2 (PB2) • polymerase basic protein 1-F2 (PB1-F2) Outer virus particle The influenza particle, or virion, is typically spherical, but sometimes filamentous. It has an outer lipid membrane layer called an envelope derived from the host cell that it replicated in. The envelope is covered with glycoproteins HA and NA which form structures like spikes. The ratio of HA to NA molecules is about four...

Type A influenza is a common infection that can cause widespread flu outbreaks. It can cause fever, body aches, chills, fatigue, and other symptoms. Common symptoms of type A infection can be confused with other conditions. While in some milder cases the flu can resolve on its own without significant symptoms, severe cases of type A influenza can be life-threatening. Types A and B influenza are the more common forms of this infection, routinely causing seasonal outbreaks. Type C influenza usually only causes mild respiratory infections. Type B influenza can be just as severe as type A influenza but is less common throughout the flu season compared to type A. Humans are the natural host for type B infection. Type B viruses mutate much slower than type A infections and are categorized by strains, but not subtypes. The B virus strains take longer for their genetic makeup to change than influenza A. This drastically reduces the risk of a widespread pandemic due to type B influenza. Type A influenza can be dangerous and is known to cause outbreaks and increase your risk of disease. Unlike a type B infection, type A viruses are categorized by subtypes and strains. Influenza A mutates faster than influenza B, but both viruses are always changing, creating new strains from one flu season to the next. Past flu vaccinations will not prevent infection from a new strain. Wild birds are the natural hosts for a type A virus, also called avian flu and bird flu. This infection can also sp...