Influenza is a viral infection that attacks your respiratory system — your nose, throat and lungs. Influenza is commonly called the flu, but it’s not the same as stomach “flu” viruses that cause diarrhea and vomiting.
What does the influenza virus do?
Flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and sometimes the lungs. It can cause mild to severe illness, and at times can lead to death. The best way to prevent flu is by getting a flu vaccine each year.
What is the influenza virus made of?
All influenza viruses consist of single-stranded RNA as opposed to dual-stranded DNA. The RNA genes of influenza viruses are made up of chains of nucleotides that are bonded together and coded by the letters A, C, G and U, which stand for adenine, cytosine, guanine, and uracil, respectively.
What is the biology of influenza?
Influenza viruses belong to the family Orthomyxoviridae. The viral particles are about 80-120 nm in diameter and can be spherical or pleomorphic. They have a lipid membrane envelope that contains the two glycoproteins: hemagglutinin (HA) and neuraminidase (NA).
What is Influenza A virus in humans?
Influenza — also known as the flu — is a contagious viral infection that attacks your respiratory system. Influenza viruses that infect humans can be classified into three main groups: A, B, and C. Type A influenza infection can be serious and cause widespread outbreaks and disease.
What is a characteristic of influenza?
Uncomplicated influenza illness is typically characterized by the abrupt onset of constitutional and upper respiratory tract signs and symptoms (e.g., fever, chills, myalgia, headache, malaise, nonproductive cough, sore throat, and rhinitis).
What does influenza do to the lungs?
In severe cases of flu, fluid accumulates in the lungs, making it difficult to breathe and preventing oxygen from reaching the blood stream.
What is influenza A virus in humans?
What is influenza A RNA?
Influenza A viruses are negative-sense, single-stranded, segmented RNA viruses. The several subtypes are labeled according to an H number (for the type of hemagglutinin) and an N number (for the type of neuraminidase). There are 18 different known H antigens (H1 to H18) and 11 different known N antigens (N1 to N11).
Is influenza an RNA virus?
Coronaviruses and influenza viruses are both enveloped, single-stranded RNA viruses, and both are encapsidated by nucleoprotein. However, the genomes of these 2 viruses differ in polarity and segmentation. Influenza virus is comprised of 8 single-stranded, negative-sense, viral RNA segments.
What cells do influenza target?
INFLUENZA PATHOLOGY Influenza virus replicates in the epithelial cells throughout the respiratory tree, with virus being recoverable from both the upper and lower respiratory tract of people naturally or experimentally infected (2).
