How is influenza transmitted

The body's immune system can make antibodies that can recognize these specific virus proteins antigens and therefore fight that specific influenza virus. Researchers have found 18 kinds of HA proteins and 11 NA proteins in many combinations in bird flu viruses. These combinations are reported as strains of the influenza virus H number N number. It can take 1 to 4 days for symptoms to appear after exposure to the virus. Other common symptoms include sore throat, runny nose, headache, chills, loss of appetite, and fatigue.

Some adults will also experience stomach ache, vomiting and diarrhea, but these symptoms are more common with children. Most people who get the flu recover completely in 7 to 10 days.

However, some people especially the elderly and those with chronic health problems can develop serious complications. These complications include pneumonia and aggravation of pre-existing medical conditions such as congestive heart failure, asthma, or diabetes.

The influenza viruses mainly are spread from person to person through droplets produced while coughing or sneezing. Droplets of an infected person are propelled by coughing, sneezing, and talking into the air and are deposited on the mouth or nose of people nearby.

This droplet transmission of the flu is known as contact transmission. The influenza viruses can also be transmitted by indirect contact by touching a contaminated object or surface and then touching your own mouth, eyes or nose before washing your hands. This action is also called fomite transmission — a fomite is any surface or inanimate thing door knobs, phones, television remotes, towels, money, clothing, dishes, books, toys, etc.

Period of Contagiousness You may be able to pass on flu to someone else before you know you are sick, as well as while you are sick. People with flu are most contagious in the first days after their illness begins. Some otherwise healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Some people, especially young children and people with weakened immune systems, might be able to infect others with flu viruses for an even longer time.

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Some people, especially young children and people with weakened immune systems, might be able to infect others for an even longer time. Onset of Symptoms. Complications of Flu. People at High Risk from Flu.

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Cancel Continue. Nasal secretions, which contain virus particles, are responsible for transmission by direct contact or by contaminated objects. An infected person will frequently touch their nose or conjunctiva, placing virus on the hand.

Intimate or non-intimate contact e. When contaminated hands touch other objects, the virus is transferred to them. Others have shown that infectious influenza virus may be persist on paper currency for several weeks. Influenza transmission can be reduced by covering your nose and mouth when coughing or sneezing, and by washing hands often with soap and water or alcohol-based hand cleaners.

Note that CDC does not recommend the use of face masks for reducing viral spread. It is important to recognize that, in human infections, maximum levels of virus shedding may occur about a day before the peak of symptoms.