Final answer:
The proportion of deaths due to influenza B from the 1976-1977 through 1998-1999 influenza seasons is estimated to be 5% to 10%, according to CDC data. So , correct option is (a).
Step-by-step explanation:
According to the systematic review by the Centers for Disease Control and Prevention (CDC) regarding influenza-related mortality during the 1976-1977 through 1998-1999 influenza seasons, the proportion of deaths believed to be due to influenza type B is estimated to be 5% to 10%. Influenza, or flu, is caused by influenza viruses and is a contagious respiratory illness.
Overall mortality caused by influenza can vary dramatically based on the virulence of the specific strains circulating in any given season. Moreover, the overall impact of influenza on morbidity and mortality is complex and can be influenced by a range of factors including the demographics of the infected population, existing health conditions, secondary infections, and the effectiveness of public health interventions.
There are around a billion cases of seasonal influenza annually, including 3–5 million cases of severe illness.
It causes 290 000 to 650 000 respiratory deaths annually. Ninety-nine percent of deaths in children under 5 years of age with influenza-related lower respiratory tract infections are in developing countries. Symptoms begin 1–4 days after infection and usually last around a week. Seasonal influenza (the flu) is an acute respiratory infection caused by influenza viruses. It is common in all parts of the world. Most people recover without treatment. Influenza spreads easily between people when they cough or sneeze. Vaccination is the best way to prevent the disease. Symptoms of influenza include acute onset of fever, cough, sore throat, body aches and fatigue. Treatment should aim to relieve symptoms. People with the flu should rest and drink plenty of liquids. Most people will recover on their own within a week. Medical care may be needed in severe cases and for people with risk factors.