Influenza in Humans, Pandemic

Influenza is a highly infectious viral disease that affects the respiratory system, primarily the nose, throat, and lungs. It can cause mild to severe illness and can lead to complications that can be fatal, especially in vulnerable populations like the elderly, young children, and people with underlying health conditions. Influenza viruses can be transmitted from person to person through respiratory droplets when an infected person coughs, sneezes or talks. In this article, we will discuss influenza in humans, pandemics, including what it is, when it occurred, how it spreads, symptoms, the first case, treatment, precautions, and conclusion.

What is Influenza?

Influenza is a highly contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. There are three types of influenza viruses, A, B, and C, with influenza A viruses being the most severe and causing pandemics. Influenza A viruses are classified into subtypes based on two surface proteins, hemagglutinin (H) and neuraminidase (N), with 18 H subtypes and 11 N subtypes identified so far. Influenza viruses can mutate rapidly, and new strains can emerge, leading to annual epidemics and occasional pandemics.

When did the Pandemic occur?

Influenza pandemics are outbreaks of a new strain of influenza virus that spreads globally and affect a large proportion of the population. The most severe influenza pandemic in history was the Spanish flu pandemic of 1918-1919, which infected an estimated 500 million people worldwide and caused at least 50 million deaths. Other pandemics include the Asian flu pandemic of 1957-1958, the Hong Kong flu pandemic of 1968-1969, the H1N1 pandemic of 2009-2010, and the ongoing COVID-19 pandemic, which is caused by a novel coronavirus.

How does Influenza Spread?

Influenza viruses are primarily spread through respiratory droplets when an infected person talks, coughs, or sneezes. The virus can also be spread by touching a surface contaminated with the virus and then touching one's mouth, nose, or eyes. Influenza viruses can survive on surfaces for up to 48 hours, and people infected with the virus can be contagious from one day before symptoms develop to up to seven days after becoming ill.

Symptoms of Influenza

The symptoms of influenza can vary from mild to severe and can include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills, and fatigue. Some people may also experience vomiting and diarrhea, although these symptoms are more common in children than adults. Influenza can lead to complications such as pneumonia, bronchitis, sinus and ear infections, and can be fatal, especially in vulnerable populations like the elderly, young children, and people with underlying health conditions.

The First Case of Influenza

The first recorded outbreak of influenza was in 1580, but the exact origin of the virus is unknown. Influenza viruses are believed to have originated in aquatic birds and have adapted to infect humans and other animals. The first recorded pandemic was the Russian flu pandemic of 1889-1890, which is believed to have been caused by an H3N8 influenza virus. The Spanish flu pandemic of 1918-1919 was caused by an H1N1 influenza virus that is believed to have originated in birds.

Treatment for Influenza

There is no cure for influenza, but antiviral medications like oseltamivir (Tamiflu) and zanamivir (Relenza) can be used to treat the illness and reduce the severity of symptoms if taken within the first 48 hours of onset. These medications work by blocking the action of the neuraminidase protein on the surface of the influenza virus, preventing it from spreading to other cells in the body. Other treatments for influenza include over-the-counter medications to relieve symptoms like fever and cough, rest, hydration, and avoiding close contact with others to prevent the spread of the virus.

Precautions to Prevent Influenza

The best way to prevent influenza is to get vaccinated annually with the seasonal influenza vaccine, which is updated each year to include the strains of influenza virus that are expected to circulate during the upcoming season. Other precautions to prevent influenza include practicing good hand hygiene by washing hands frequently with soap and water for at least 20 seconds, covering the mouth and nose when coughing or sneezing, avoiding close contact with sick people, and staying home when sick to avoid spreading the virus to others.

Conclusion

Influenza is a highly infectious viral disease that affects the respiratory system, causing mild to severe illness and can lead to complications that can be fatal, especially in vulnerable populations. Pandemics of influenza have occurred throughout history, with the most severe being the Spanish flu pandemic of 1918-1919, which infected an estimated 500 million people worldwide and caused at least 50 million deaths. Influenza viruses can be transmitted from person to person through respiratory droplets, and new strains can emerge, leading to annual epidemics and occasional pandemics. The best way to prevent influenza is to get vaccinated annually with the seasonal influenza vaccine, practice good hand hygiene, and avoid close contact with sick people. While there is no cure for influenza, antiviral medications can be used to treat the illness and reduce the severity of symptoms if taken within the first 48 hours of onset.