Health Care : Current Reviews

Influenza Symptoms Range from Mild to Severe after Exposure to the Virus

Michael Thomas^* Department of Health and Kinesiology, Massachusetts Institute of Technology, Cambridge, United States
^*Correspondence: Michael Thomas, Department of Health and Kinesiology, Massachusetts Institute of Technology, Cambridge, United States, Email:

Received: 04-Jan-2022, Manuscript No. HCCR-22-15275; Editor assigned: 06-Jan-2022, Pre QC No. HCCR-22-15275; Reviewed: 20-Jan-2022, QC No. HCCR-22-15275; Revised: 24-Jan-2022, Manuscript No. HCCR-22-15275; Published: 31-Jan-2022, DOI: 10.35248/2375-4273.22.10.275.

Description

Influenza, commonly called as “influenza,” is an infectious disease caused by the influenza virus. Symptoms range from mild to severe and usually include fever, runny nose, sore throat, myalgia, headache, cough, and malaise. These symptoms begin 1 to 4 days (usually 2 days) after exposure to the virus and last about 2 to 8 days. Diarrhoea and vomiting can occur especially in children. Influenza can progress to pneumonia, which can be caused by a viral or subsequent bacterial infection. Other complications of infection include acute respiratory distress syndrome, meningitis, encephalitis, and deterioration of existing health conditions such as asthma and cardiovascular disease.

Symptoms

Symptomatic infections are usually mild and confined to the upper respiratory tract, but progression to pneumonia is relatively common. Pneumonia can be caused by a primary viral or secondary bacterial infection. Primary pneumonia is characterized by a rapid progression of hypoxic levels that cause fever, cough, dyspnoea, and bluish skin. This is especially common in people with underlying cardiovascular disease, such as rheumatic heart disease. Secondary pneumonia usually has a stage of improvement of symptoms for 1 to 3 weeks, followed by fever, sputum production, and fluid accumulation in the lungs but only a few days after the onset of influenza. It may occur later. Symptoms. Approximately one-third of cases of primary pneumonia are followed by secondary pneumonia, most commonly caused by bacteria.

Types of virus

There are four types of influenza virus. Each of the four species is the only member of its own genus, and the four influenza genera make up four of the seven genera of the Orthomyxoviridae family.

• Influenza A virus (IAV), alpha influenza virus genus

• Influenza B virus (IBV), Beta influenza virus genus

• Influenza C virus (ICV), gamma influenza virus genus

• Influenza D virus (IDV), Delta influenza virus genus

IAV is responsible for not only the most serious illnesses, but also seasonal epidemics and occasional pandemics. It infects people of all ages, but tends to cause disproportionately serious illness in the elderly, very young people, and people in chronic health. Birds, especially waterfowl such as ducks, geese, ginger and seagulls are the main reservoirs of IAV, and influenza viruses have a segmented single-strand RNA genome.

Conclusion

The negative meaning of the genome means that it can be used as a template for the synthesis of messenger RNA (mRNA). AV and IBV have eight genomic segments that encode 10 major proteins. ICVs and IDVs have seven genomic segments that encode nine major proteins. The three segments encode three subunits of the RNA-dependent RNA polymerase (RdRp) complex: PB1, transcriptase, 5’cap-recognizing PB2, and PA (for ICV and IDV). P3), endonuclease. Matrix proteins (M1) and membrane proteins (M2) share segments, as do non-structural proteins (NS1) and nuclear transport proteins (NEP). In IAV and IBV, hem agglutinin (HA) and neuraminidase (NA) are each encoded in one segment, and ICV and IDV combine the functions of HA and NA in one segment to form a hem agglutinin esterase fusion protein (HEF). Encode.

The final genomic segment encodes a viral nucleoprotein (NP). The influenza virus also encodes various accessory proteins such as PB1F2 and PAX. They are expressed through an alternative open reading frame and are important for host defense suppression, pathogenicity, and pathogenicity. It circulates among mammals such as pigs, horses and marine mammals. IAV is classified into subtypes based on the viral proteins hem agglutinin (H) and neuraminidase (N). As of 2019, 18 H-subtypes and 11 N-subtypes have been identified. The most possible combinations have been reported.