Journal of Clinical Trials
Open Access

Estimated Mortality Associated with Seasonal Influenzas

Adrienne Ohler^{* *}Correspondence: Adrienne Ohler, Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, USA, Email:

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Description

Influenza is an infection of the nose, throat, and lungs, which are part of the respiratory system. Influenza, commonly called the flu, is different from the stomach flu virus, which causes diarrhea and vomiting.

Most people who get the flu get better on their own. But sometimes the flu and its complications can be fatal. People at increased risk of developing flu complications include:

• Young children under age 2

• Adults older than age 65

• Residents of nursing homes and other long-term care facilities

• People who are pregnant or plan to be pregnant during flu season

• People with weakened immune systems

• American Indians or Alaska Natives

• People who have chronic illnesses, such as asthma, heart disease, kidney disease, liver disease and diabetes

• People with a Body Mass Index (BMI) of 40 or higher

The annual flu vaccine is not 100% effective, but it does reduce the chance of serious complications from infection.

There are four types of influenza viruses, A, B, C, and D. Waterfowl are the primary source of Influenza A Virus (IAV), which has spread to a wide variety of mammals, including humans and pigs. Influenza B Virus (IBV) and Influenza C Virus (ICV) primarily infect humans, while Influenza D Virus (IDV) infects cattle and pigs. IAV and IBV circulate in humans and cause seasonal epidemics, while ICV causes mild infections mainly in children. IDV can infect humans but is not known to cause disease. In humans, the influenza virus is transmitted primarily through droplets from coughs and sneezes. Transmission also occurs via virus-contaminated aerosols, intermediate objects and surfaces.

We should wash our hands frequently and cover our mouth and nose when we cough or sneeze to reduce transmission. Annual vaccination helps prevent influenza. Influenza viruses, especially his IAVs, evolve rapidly, so flu vaccines are regularly updated to match the circulating influenza strains. Currently used vaccines provide protection against IAV subtypes H1N1 and H3N2 and one or two of his IBV subtypes. Influenza infections are diagnosed by identifying the viral nucleic acid using tests such as antibody or antigen tests and Polymerase Chain Reaction (PCR). The disease can be managed with supportive care and, in severe cases, with antiviral drugs such as oseltamivir. In healthy individuals, influenza is usually self-limiting and rarely fatal, but can be fatal in high-risk groups.

The flu may initially look like a cold with a runny nose, sneezing, and sore throat. Colds usually progress slowly. But flu usually comes suddenly. A cold can be miserable, but the flu usually makes you feel even worse.

Common symptoms of the flu include:

• Fever

• Aching muscles

• Chills and sweats

• Headache

• Dry, persistent cough

• Shortness of breath

• Tiredness and weakness

• Runny or stuffy nose

• Sore throat

• Eye pain

• Vomiting and diarrhea, but this is more common in children than adults

Seasonal influenza is characterized by:

• A sudden onset of fever, cough (usually dry), headache, muscle and joint pain, severe malaise (feeling unwell), sore throat and a runny nose.

• The cough can be severe and can last 2 or more weeks.

Most people recover from fever and other symptoms within a week without needing medical attention. However, influenza can cause serious illness and death, especially in people at high risk.

• Illnesses range from mild to severe and even death.

• Hospitalization and death occur mainly among high risk groups.

• These annual epidemics are estimated to cause approximately 3 to 5 million serious illnesses and approximately 290,000 to 650,000 respiratory deaths worldwide.

• In developed countries, most influenza-related deaths occur in people over the age of 65.

• Epidemics of infectious diseases can lead to high absenteeism among workers and schools, reducing productivity. Clinics and hospitals can be overwhelmed during peak hours.

• The impact of seasonal influenza epidemics in developing countries is not fully understood, but studies show that 99% of deaths in children under the age of five from influenzaassociated lower respiratory tract infections are found in developing countries.