There have only been four reports of anthrax in the UK since 1990, and in the US, the most recent case of respiratory anthrax is the first of this most severe respiratory form since 1978.

What causes anthrax?

Anthrax is caused by the organism Bacillus anthracis.

In some parts of the world, this can be found in cattle or other hoofed mammals.

It is infrequent in western Europe and the US, and is more likely to be found in animals in south and central America, south and east Europe, Asia and Africa.

This bacteria can form spores which can either be eaten in contaminated meat, breathed in, or simply infect the skin directly through human to animal contact.

Those at highest risk in the UK are those who directly handle dead animals, such as abattoir workers and tanners.

An infected patient cannot pass on the disease to other people.

What are the symptoms?

What makes anthrax dangerous is that the symptoms are often difficult to distinguish from other, less serious infections.

There are three types of anthrax, depending on where the infectious spore has arrived on the patient.

The first, cutaneous anthrax, is the least serious of the three, and produces a skin lesion, which is rarely painful.

However, if left untreated, the infection can spread and cause blood poisoning, which is fatal in one in 20 cases.

The second type is intestinal anthrax, caused by the consumption of contaminated meat.

This produces severe food-poisoning type symptoms, leading to fever and blood poisoning. It is frequently fatal.

The third is respiratory anthrax, which happens when spores are breathed in by the patient and lodge in the lung.

Symptoms of this disease start out as similar to simple flu, but respiratory symptoms rapidly worsen and the patient usually goes into some kind of shock between two and six days later.

Again, this is frequently fatal.

Symptoms of anthrax normally develop within two days of exposure.

Can anthrax be treated?

Giving antibiotics to anthrax patients can cure the disease, particularly the cutaneous variety.

However, unless they are given swiftly after intestinal or respiratory infection, the chances of cure are greatly reduced.

There is a vaccine against anthrax, but this is not recommended except for those at high risk, such as meat industry workers and laboratory scientists handling the disease.