The UK Health Security Agency's (UKHSA) list includes 15 of the most frightening infectious diseases.
These are known as high consequence infectious diseases (HCID).
For a pathogen to be given this category, it typically has a high fatality rate and requires an official organised response to ensure it is managed effectively, because symptoms are often difficult to recognise.
The data was created to allow health professionals to assess the infection risk to each country.
Crimean-Congo haemorrhagic fever (CCHF)
Crimean-Congo haemorrhagic fever (CCHF) is a tick-borne viral disease.
It triggers symptoms including high fever, muscle pain, dizziness, abnormal sensitivity to light, abdominal pain and vomiting.
Later on, sharp mood swings may occur, and the patient may become confused and aggressive.
There is no vaccine or specific antiviral drug that works against CCHF. But a broad-spectrum antiviral called ribavirin can be given to patients to prevent severe illness.
CCHF has been found among ticks in Africa, Asia, the Middle East and Eastern Europe and South Western Europe.
It kills up to 40 per cent of everyone who gets infected, according to the World Health Organization (WHO).
It might be infamous for killing millions in Europe during the Middle Ages.
But the plague is still a threat in parts of the world, including areas of Africa, Asia, South America and even the US.
People are usually infected after being bitten by fleas lurking on rodents.
However, the disease can also spread through inhaling respiratory droplets from people infected with one type of plague called pneumonic.
Bubonic plague, responsible for the Black Death, causes the tell-tale signs of swollen nodes. These can then turn into open, pus-filled sores.
Other symptoms include shortness of breath, chest pain and coughs.
Between 30 and 100 per cent of people with confirmed infections die if they don't get treatment.
Antibiotics are effective against the plague if patients are diagnosed early.
The WHO recommends that only people at high-risk of exposure to the plague, such as lab and hospital workers, get a vaccine against it.
Marburg virus belongs to the filovirus family, making it a cousin of Ebola.
It was initially detected in 1967 after an outbreak in Marburg, Germany, among workers exposed to African green monkeys.
Fruit bats are thought to be the natural hosts of the disease, which causes sporadic outbreaks in Africa.
It spreads among humans through direct contact with the bodily fluids of infected people, surfaces and materials.
Symptoms appear abruptly and include severe headaches, fever, diarrhoea, stomach pain and vomiting. They become increasingly severe.
Infected patients can become 'ghost-like', often developing deep-set eyes and expressionless faces.
This is usually accompanied by bleeding from multiple orifices — including the nose, gums, eyes and vagina.
Marburg virus has a mortality rate of up to 88 per cent, data suggests.
There are no proven treatments or vaccines for Marburg.
The virus is found in the central areas of the Pampas, vast plains stretching from Argentina's Atlantic coast to the Andes.
Data suggest the haemorrhagic fever kills up to 30 per cent of patients who don't get treated.
Symptoms include chills, headaches and pain.
Rodents are natural hosts of the virus. Human-to-human transmission is rare, experts say.
The Andes virus — found in rodents in South America — is a hantavirus.
Although it is usually spread through coming into contact with infected rodents or their droppings, it can be passed through close human contact.
Early symptoms include headaches, a fever and muscle aches, meaning it can closely resemble the flu.
The mortality rate is close to 50 per cent, according to the UKHSA.
Many scientists think bird flu will be the trigger of the next pandemic.
Four strains of bird flu have sparked concerns for humans: H5N1, H7N9, H5N6, and H5N8.
Although rare, avian influenza can spread to humans through touching infected birds, touching droppings or bedding, killing or preparing infected poultry for cooking.
H5N1 — the avian influenza strain behind the current outbreak sweeping the world, considered the biggest ever — does not transmit easily between humans.
But mutations to the virus that makes mammal-to-mammal transmission easier could change that, some experts fear.
Globally, fewer than 900 human cases of H5N1, which kills close to 50 per cent of those it strikes, have ever been recorded.
Symptoms of bird flu in humans may involve a very high temperature or feeling hot or shivery, aching muscles, a headache and a cough or shortness of breath.
Nipah is a type of henipavirus, which are naturally held in fruit bats.
The virus is usually spread to humans through direct contact with infected animals, usually pigs and bats.
But human-to-human transmission can occur.
Outbreaks occur almost annually in parts of Asia, primarily Bangladesh and India, the US CDC says.
Symptoms, such as a fever, headache and drowsiness, may appear between five and 14 days after becoming infected, and can last up to two weeks.
Eventually, patients can progress into a coma or suffer breathing problems.
The virus is thought to be fatal in up to 75 per cent of cases.
No vaccine or cure exists, but patients may receive supportive treatment to relieve symptoms.
According to the World Health Organization, 80 per cent of people who get infected won't develop any symptoms.
But the virus has a case-fatality rate of around 1 per cent.
Lassa fever is endemic in Nigeria and several other countries on the west coast of Africa, including Liberia and Guinea, according to the WHO.
Symptoms begin with headaches, sore throats and vomiting, but it can trigger bleeding from the mouth, nose or vagina.
However, they gradually progress to shock, seizures, tremors, disorientation and comas without prompt treatment.
A quarter of patients will also experience temporary deafness that will eventually return, medical literature states.
Pregnant women who contract the disease late in pregnancy face an 80 per cent chance of losing their child or dying themselves.
It can either be spread by rats or from person-to-person by exposure to bodily fluids of someone who is infected.
Ebola is an often-fatal viral haemorrhagic fever named after a river in Democratic Republic of Congo (DRC), where it was discovered in 1976.
The virus is mainly transmitted through exposure to bodily fluids, with the main symptoms being fever, vomiting, bleeding and diarrhoea.
It naturally resides in fruit bats, monkeys and porcupines living in the rainforest, and can also be transmitted through eating uncooked 'bushmeat'.
Ebola outbreaks are difficult to contain, especially in urban environments.
People who are infected do not become contagious until symptoms appear, which is after an incubation period of between two and 21 days.
Ebola has a mortality rate of around 50 per cent, the WHO says.
Monkeypox is a rare viral infection which people usually pick up in the tropical areas of west and central Africa.
It is usually spread through direct contact with animals such as squirrels, which are known to harbour the virus.
However, it can also be transmitted through very close contact with an infected person.
Monkeypox was first discovered when an outbreak of a pox-like disease occurred in monkeys kept for research in 1958.
Monkeypox is usually mild, with most patients recovering within a few weeks without treatment. Yet, the disease can prove fatal.
Common symptoms are a skin rash or mucosal lesions, accompanied by a fever, headache, muscle aches, back pain and fatigue.
Severe Acute Respiratory Syndrome (SARS)
SARS is the cousin of Covid, causing similar flu-like symptoms.
It infected 8,000 people and killed nearly 800 in an outbreak in Asia in 2003.
SARS is, however, deadlier than Covid.
Data suggests it kills around one in 10 people, compared to fewer than one in 100 from Covid.
The airborne virus can spread through small droplets of saliva, in a similar way to colds and influenza.
Middle East respiratory syndrome coronavirus (MERS-CoV)
Middle East respiratory syndrome coronavirus (MERS), also known as camel flu, is a rare but severe respiratory illness.
People can catch MERS from infected animals — though doctors say camels in the Middle East are the main source of the virus. The virus was first detected region in 2012.
It can also be transmitted through an infected person's cough droplets — but this is rare.
Its symptoms include a fever, cough, breathing difficulties, diarrhoea and vomiting.
There is no specific treatment for the illness, so doctors work to ease a patient's symptoms.
Around 35 per cent of those who get MERS die as a result.
Severe fever with thrombocytopaenia syndrome (SFTS)
The syndrome is caused by a tick-borne virus.
Human-to-human transmission of SFTSV can occur, however.
Human cases have been identified in China, as well as Japan, South Korea and Taiwan.
The virus starts with flu-like symptoms, but it can quickly progress.
Patients suffer thrombocytopaenia — a reduction in the number of platelets in their blood, reducing its ability to clot.
Data suggests SFTSV has a mortality rate of around 5 per cent.
Lujo virus has a death rate of around 80 per cent, it is estimated.
Humans can get infected by handling rodents carrying the disease.
Human-to-human transmission has been observed, however.
Symptoms include a rash of the face and body, face and neck swelling, a sore throat and diarrhoea.
In fatal cases, patients may improve slightly before suddenly deteriorating.