Influenza: Treatment, symptoms, advice and help
Influenza, commonly referred to as the flu, is an infectious disease caused by viruses that affect mainly the nose, throat, respiratory tract and occasionally, the lungs.
Influenza: Incidence, age & sex
Influenza spreads around the world in seasonal epidemics resulting in deaths between 250000 & 500000 people per year; up to millions in some pandemic years. Both sexes are affected. Persons in extremes of age and those suffering from chronic diseases and immune suppression are at high risk.
Signs and symptoms of influenza: Diagnosis
Symptoms of influenza can start quite suddenly in about 1-2 days after exposure. Symptoms include fever, chills, cough, nasal congestion, body aches, fatigue, headache, watering of the eyes & reddened eyes and skin (especially of the face). In children, gastrointestinal symptoms such as diarrhoea and abdominal pain may be seen.
According to United Nations Centre for Disease Control and Prevention, rapid diagnostic tests have a sensitivity of 70 – 75% & specificity of 90 – 95% when compared with viral culture.
Cause and prevention of influenza
Influenza is caused by RNA viruses of the family Orthomyxoviridae. The 3 genera are Influenza virus A, B & C. The type A virus is the most virulent and causes the most severe disease. Type A virus can be subdivided into different serotypes based on the antibody responses to these viruses. H1N1 serotype had caused Swine Flu in 2009. The virus is transmitted by an air-borne route (i.e. by droplet or aerosol) & by physical contact. Vaccines against such viruses are available and are recommended for high risk populations. Due to the high mutation rate of virus, a particular influenza vaccine can usually ensure protection for only a few years.
Reasonable effective measures to reduce transmission include good personal hygiene, frequent hand washing, covering the nose and mouth while coughing and sneezing and by avoiding close contact with sick people. Quaternary ammonium compounds and bleach is generally used to disinfect the rooms of patients.
Most people recover completely in about 1–2 weeks but some may develop complications like pneumonia, bronchitis, sinusitis, ear infections and Guillain-Barré syndrome. Influenza can be potentially fatal in malnourished individuals, new born babies, elderly and chronically ill or immune compromised individuals.
Patients with flu are advised to take adequate rest, drink plenty of fluids and, if necessary, take acetaminophen for relief of fever and muscle aches. Aspirin should be avoided in children as it may lead to another health concern known as Reye’s Syndrome. Antibiotics can be prescribed for secondary infections such as bacterial pneumonia. Antiviral drugs like Oseltamivir (Tamiflu) & Zanamivir (Relenza) are neuraminidase inhibitors that are designed to halt the spread of virus in the body. Other medications include Amantadine and Rimantadine which block viral ion channel and prevent the virus from infecting the cells. Supportive care along with antiviral medications usually results in complete recovery of the affected individual.