Flu (Influenza)
Introduction
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, known as 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.
Recommendations for Travellers
Your risk of catching flu will increase if you are passing through crowded places such as airports and other busy transport hubs, going on a cruise and/or attending events with large crowds of people, such as pilgrimages, festivals, or major sporting events.
You can reduce your risk of becoming infected with and spreading flu by:
- practicing effective respiratory hygiene measures and wash your hands frequently
- keeping your distance from others who are coughing and sneezing
- receiving the seasonal flu vaccine (if available) prior to travel
- avoiding travel if you are unwell with flu-like symptoms
Vaccination
There are effective vaccines against flu.
There are numerous different strains of the influenza virus, and each year different ones appear which can cause people to become sick with flu.
- You need to have a flu vaccine every year because the vaccine is modified every year to provide protection against the flu virus strains that are most likely to cause flu infections that year.
Am I eligible for free flu vaccine in the UK?
You can check if you are eligible for free flu vaccine on the following websites:
- Scotland: NHS inform
- England: NHS.uk
- Northern Ireland: nidirect
- Wales: Public Health Wales
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, major sporting events or on a cruise.
- The Saudi Arabia Ministry of Health recommends seasonal flu vaccine for Hajj and Umrah attendees before arrival, especially for those in the flu risk groups
- please see our Hajj and Umrah page for further information.
- You may wish to be vaccinated to help reduce the risk of becoming sick and 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 still 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 may wish 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 will be dependent on the availability of flu vaccines at the time you are travelling, as UK vaccine supplies in the UK will always be prioritised for national schedules and high risk groups.
Overview of the Disease
Transmission
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.
Attending crowded places and poor hand and respiratory hygiene increase the risk of catching the virus.
Epidemiology
Three different virus types of human flu are recognised: these are known as A, B and C.
Seasonal outbreaks of flu occur almost every year and are caused primarily by A and B viruses:
- in the northern hemisphere, this occurs between November to April
- in the southern hemisphere, this occurs between April to September
In tropical areas there is no clear seasonal pattern, but peaks of infection tend to occur during the rainy season.
The Illness
Clinical Aspects
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.
Risk of Severe Illness
Complications of flu mostly affect:
- those aged 65 or over
- those who are pregnant
- children under 6 months of age
- 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
- headache
- 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
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.