Flu is a common infection caused by the influenza virus. It is mainly spread when an infected person coughs or sneezes.
- In colder climates flu is common in the winter months, the 'flu season'.
- In tropical climates, flu can occur all year round.
Symptoms of flu commonly include fever, tiredness, sore throat, headache, joint and muscle aches.
If you are visiting a country during its flu season you will be at a similar risk of infection as the local residents.
Your risk of catching flu will increase if you are in crowded places such as pilgrimages, festivals, cruises; or travelling through airports and other busy transport hubs.
The risk of flu infection is reduced by:
There are effective vaccines against flu.
There are numerous different strains of the influenza virus, and each year different ones appear which may cause infection.
- This is why flu vaccine needs to be given every year – the vaccine is modified every year, so that it will continue to provide protection against the strains that are most likely to be causing infections that year.
You can check if you are eligible for free flu vaccine on the following websites:
Do I need a flu vaccine for travelling?
Flu is a common infection caught during travel. Vaccination against flu just for travel-related reasons depends on:
your age and medical history
- If you are more at risk of severe flu you will be eligible for free vaccination in the UK and you should make sure you have been vaccinated before you travel.
the type of travel and activities you will be undertaking
- Your risk of flu increases in crowded areas such as a festival, religious event, sporting event or on a cruise.
- You may wish to be vaccinated to reduce the risk of your trip being disrupted by catching the flu
the part of the world/country you are visiting
- Northern hemisphere 'flu season' occurs in the same winter months as in the UK.
- you may wish to be vaccinated to reduce the risk of your trip being disrupted by catching the flu, even if you are travelling to the tropics or a country in the southern hemisphere (you may catch the infection at airports during transit)
- Southern hemisphere 'flu season' occurs during the UK's summer months - an example of a country where this is typically the case is Australia.
- you may wish to be vaccinated to reduce the risk of your trip being disrupted by catching the flu, but it might not be possible to obtain a southern hemisphere flu vaccine in the UK before you travel
- in this instance, you should therefore try to arrange to be vaccinated against flu after arriving at your destination
- Tropical regions: flu can occur all year round
- you may wish to be vaccinated to reduce the risk of your trip being disrupted by catching the flu
If you are not eligible for free flu vaccine in the UK, you will have to pay out of your own pocket to be vaccinated in a private travel clinic or community pharmacy.
- Vaccines available for travel-related purposes only will be dependent on the availability of flu vaccines, as vaccine supplies in the UK will be prioritised for national schedules and high risk groups.
Flu virus enters the body through the eyes, nose or mouth.
- When an infected person coughs or sneezes they release millions of tiny droplets containing flu virus that can reach the eyes, nose or mouth of people standing near them.
- Flu is also caught by touching surfaces that infected droplets have landed on: when you touch these surfaces you can transfer the virus to your eyes, nose or mouth and become infected.
Three different virus types of human flu are recognised: A, B and C.
Seasonal outbreaks of flu occur almost every year and are caused primarily by A and B viruses:
- November to April in northern hemisphere
- April to September in southern hemisphere
In tropical areas there is no clear seasonal pattern but peaks tend to occur during the rainy season.
If you have been infected with flu virus, you generally start to feel ill within a few days of being infected. Most people begin to feel better within a week or so, although you may feel tired for much longer.
Occasionally however people can become much sicker with flu, although death is very rare.
Complications of flu mostly affect:
- those aged 65 or over
- those who are pregnant
- those who have a long-term medical condition or weakened immune system.
Complications can include:
- chest infections
- middle ear infection
- worsening of existing medical conditions
- pregnancy complications
Signs and Symptoms
Flu can commonly cause any or all of the following symptoms:
- high temperature (fever), chills
- sore throat
- blocked or runny nose
- dry chesty cough
- aching muscles and joints
- tiredness and weakness
- diarrhoea or abdominal (tummy) pain
- nausea and vomiting
Treatment of flu is mainly supportive. If you are otherwise fit and well, you can usually manage your symptoms at home by:
- drinking plenty of fluids to keep well hydrated
- resting and keeping warm
- taking over the counter medicines such as paracetamol for aches and pains, or for managing a high temperature
- seeking medical advice if your symptoms get worse.
There are antiviral drugs available that can be used to specifically prevent or treat flu, but these are only prescribed under special circumstances. You should discuss this with a GP.