Typhus is a sudden severe illness caused by infection with Rickettsia bacteria.
Outbreaks of typhus tend to occur in developing countries and areas where there is poverty, homelessness, close human contact and poor sanitation.
The Rickettsia bacteria that cause typhus are carried by body lice, ticks, mites and fleas.
This page covers the main types:
epidemic typhus (the most serious form) – this type occurs in Africa, South America and Asia, and is transmitted by body lice
endemic typhus (the milder form of the disease) – it occurs throughout the world and is transmitted by ticks, mites and fleas
scrub typhus (also called Tsutsugamushi fever) – this type is caught from mites infected with Orientia tsutsugamushi bacteria, which live in heavy scrub vegetation in parts of rural southeast Asia, Oceania and northern Australia
Typhus is generally not a problem in the UK. But you may become infected abroad if you catch Rickettsia-infected lice from infested people or bedding (in budget accommodation or on a sleeper train, for example), or if you are bitten by a Rickettsia-infected tick, mite or flea.
How do you catch epidemic typhus?
Epidemic typhus is passed from human to human by body lice. These are not the same as head lice or pubic lice, which are a nuisance, but don't transmit disease.
The body lice become infected with Rickettsia prowazekii bacteria when they feed on the blood of an infected person.
If you catch these infected body lice (for example, by using a louse-infested blanket), their infected faeces will be deposited on your skin as they feed on your blood.
You only need to scratch a bite to rub the contaminated lice faeces into the tiny wound on your skin to become infected.
Less commonly, you can catch epidemic typhus by breathing infected dried body louse faeces in airborne dust.
How do you catch endemic typhus?
Endemic typhus is transmitted by ticks, mites and fleas infected with Rickettsia bacteria.
These animal carriers of typhus may live in thick scrub vegetation or on small mammals or rodents, such as rats.
What are the symptoms?
The symptoms of epidemic, endemic and scrub typhus are similar.
Typically, someone with typhus will start to feel unwell 10 to 14 days after becoming infected.
A sudden, severe headache is often the first symptom.
Other symptoms may include:
a fever – where body temperature rises above 38.9C/102F for up to two weeks
a pink or red rash that starts on the chest and spreads to the arms, hands, legs and feet – but not the face, palms and soles
nausea and vomiting
abdominal pain and diarrhoea
joint and muscle pain – backache is common
In addition, the person with typhus is often mentally dazed or delirious – the word "typhus" comes from the Greek word meaning "a cloud". They may become deaf or have ringing in the ears (tinnitus).
These symptoms usually last around two weeks.
How is typhus diagnosed and treated?
Anyone who is unwell shortly after visiting a high-risk country should see their GP, who will listen to your symptoms and take note of the countries you have recently visited.
You will also be physically examined and have a number of tests – for example, a blood test to rule out other diseases such as malaria.
If there is a rash, the GP may take a skin biopsy (a small sample of skin from the rash) and send this to a laboratory for testing.
A diagnosis of typhus is confirmed if the Rickettsia bacteria are identified in a blood or skin sample.
But the patient may be started on antibiotics even before the results come back if typhus is suspected.
If treated promptly with either doxycycline or tetracycline, most patients improve dramatically within 48 hours of treatment and make a full recovery.
If the patient has epidemic typhus (the more serious type), they may need to take antibiotics through a drip in their arm (intravenously) while they are in hospital.
What are the possible complications?
If typhus is not diagnosed and treated promptly, there is a risk of developing complications, including:
long-term hearing loss or tinnitus
low blood pressure
organ damage and kidney failure
secondary bacterial infection, such as pneumonia
The patient may need to have hospital follow-up for some months after recovering from an attack of typhus to receive treatment for these long-term problems.
Some people who previously had epidemic typhus will develop a milder form of the disease years later called Brill-Zinsser disease.
This tends to happen when the bacteria were not properly killed off the first time and lie dormant (inactive) in the body. The bacteria then reactivate at a later date when the person's immune system is weak.
Brill-Zinsser disease will need treating again with antibiotics.
Can typhus be prevented?
There's currently no licensed vaccine for typhus.
The best way to avoid becoming infected with typhus is to avoid areas or crowds where louse-borne typhus is a problem, and take care to avoid contact with ticks, mites and fleas.
Wash and change your clothes regularly, and don't use any bedding or clothing that could be infested with body lice.
If you're about to travel abroad to an area where typhus is a problem, talk to your doctor about taking weekly doses of doxycycline to prevent infection. This is especially effective against scrub typhus.
Orientia tsutsugamushi bacteria (which cause scrub typhus) inside the the abdominal cavity of an infected mouse