Influenza

Flu is a highly contagious respiratory infection.  Influenza, commonly known as the “flu”, is an acute infection of the respiratory tract caused by influenza viruses.  There are three types of seasonal influenza viruses - A, B and C.

Although the National Institute for Communicable Diseases (NICD) detects influenza viruses year-round, the virus is most common during the influenza season (usually between May and September).

Uncomplicated influenza: Influenza-like illness that may present with fever, chills, muscle aches and pain, headache, discomfort, nonproductive cough, sore throat, rhinitis and sometimes gastrointestinal symptoms, but without any features of complicated influenza.

Complicated/severe influenza can cause serious illness and, in some cases, even death.  Severely ill patients with influenza are admitted to the hospital.  The commonest complication of influenza is pneumonia.

Other possible serious complications triggered by flu can include inflammation of the heart (myocarditis), brain (encephalitis) or muscle tissues (myositis), and multi-organ failure (for example, respiratory and kidney failure).  Flu virus infection of the respiratory tract can trigger an extreme inflammatory response in the body that can lead to sepsis, the body’s life-threatening response to infection.  Flu also can make chronic medical problems worse.  For example, people with asthma may experience asthma attacks, and people with chronic heart disease may experience a worsening of this condition.

Flu-like symptoms in Spring or Summer

Some possible conditions that may give you flu-like symptoms in the summer include:

• The common cold is respiratory infection caused by a variety of viruses.
• Gastroenteritis often referred to as the stomach flu. However, it’s not related to influenza.  It is caused by a number of viruses, such as noroviruses or rotaviruses.
• Pneumonia is an infection of the lungs. While it can be a complication of the flu, there are also other causes.  These include other viruses, bacteria, fungi, and certain chemical or environmental agents.
• Bronchitis is an inflammation of the bronchial tubes in the lungs. Like pneumonia, bronchitis can sometimes be caused by the flu virus.  However, it can also be caused by other viruses or environmental factors such as cigarette smoke.
• Covid-19 caused by the SARS-CoV-2 virus.
• Malaria, a disease caused by the plasmodium parasite. The parasite is spread to humans through the bites of infected mosquitoes.
• Adenoviruses can infect the membranes (tissue linings) of the respiratory tract, eyes, intestines, urinary tract and nervous system

It is easy to screen or test for malaria, Covid-19, influenza viruses, noroviruses, adenovirus or rotaviruses to determine the underlying cause of the flu-like symptoms to improve the outcome of treatment.