Hello and welcome to the Zero to Finals podcast. My name is Tom and in this episode I'm going to be

talking to you about influenza and you can find written notes on this topic at zero to finals.com

slash influenza or in the infectious diseases section of the second edition of the Zero to Finals Medicine book.

So let's get straight into it.

The influenza virus is an RNA virus.

Three types of influenza, A, B and C, affect humans. There is a D type that affects cattle but not humans.

Type A and type B are the most common. Type A has different H and N subtypes.

Examples of A strains of influenza are H1N1, which caused the Spanish flu pandemic of

1918 and the swine flu pandemic of 2009, and H5N1, which causes bird flu.

Outbreaks of influenza typically occur during winter months.

Let's talk about vaccination.

Every year the influenza vaccine or flu vaccine is altered to target different strains that

are circulating that year.

Yearly vaccines are required to stay protected.

The flu vaccine is free on the NHS to people that are at higher risk of developing flu

or flu-related complications.

For example, people aged 65 and over, young children, pregnant women, people with chronic health conditions

such as asthma, COPD, heart failure and diabetes, as well as healthcare workers and carers.

Let's talk about the presentation. The delay between exposure and symptoms is usually around two days.

Typical presenting features include a fever, lethargy and fatigue, anorexia or a loss of appetite,

muscle and joint aches, headache, dry cough, sore throat and carisal symptoms.

The thumb tip for you, there's a lot of overlap between the common cold and flu,

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