FAQ by Health Professionals

A. Anthrax Disease Facts

1. What is anthrax?
Anthrax is a bacterial infection caused by the organism Bacillus anthracis. This bacterium is carried by wild and domestic animals in Asia, Africa, South America and parts of Europe; humans are rarely infected. The bacterium can exist in a form known as a spore, which allows it to survive in the environment (for example, in the soil) for many years.

2. What are the symptoms?
There are different types of Anthrax. The most common type is the skin (cutaneous) type. Very rarely it can cause gut (intestinal), lung (inhalational) disease. Clinical pictures are available here. Since 2009 a new form of anthrax, injection anthrax, has been recognised . Early identification of anthrax can be difficult as the initial symptoms are similar to other illnesses.

In cutaneous anthrax, itching occurs first. This is followed by appearance of a lesion commonly on the head, neck, forearms or hands. At first, the lesion is a small bump. It then ulcerates and becomes weepy, and although surrounded by marked swelling, it is rarely painful. This painless swelling is the cardinal feature of the disease and differentiates it from cellulitis. The ulcer develops a depressed, black centre in 2-6 days; focal lymph nodes may be enlarged. If untreated the infection can spread and cause blood poisoning. Untreated, it used to be fatal in 5-20% of cases but with effective antibiotic therapy very few deaths occur.

Initial symptoms of inhalational anthrax are non-specific and include fever, chills, tiredness, mild cough or chest pain. Symptoms more often associated with inhalation anthrax than other flu-like illness include nausea, vomiting, pallor or cyanosis, sweating, altered mental status and raised red blood cell count. Early antibiotic treatment is vital to reduce mortality. Two to four days after initial symptoms, there is abrupt onset of respiratory failure and on chest X-ray a widen mediastinum is often present, suggestive of mediastinal lymphadenopathy and haemorrhagic mediastinitis. This presentation in a previously healthy patient is highly suggestive of anthrax. At this stage, the disease often has a fatal outcome.

Intestinal Anthrax is a very rare form of food poisoning and results in severe gut disease, fever and blood poisoning. It is very difficult to recognise and consequently is often fatal.

Injection anthrax cases in the UK have had varied presentation including severe soft tissue infection with marked oedema, severe sepsis, meningitis or gastrointestinal symptoms.

3. How is anthrax caught?
Anthrax is primarily a disease of animals not humans. It is an occupational hazard of workers who process hides, hair, bone and bone products, vets and agricultural workers and people in specialist laboratories who work with the bacteria. The reservoir is in infected herbivores. When their blood is spilt, the bacteria come into contact with the air, and then convert to a tough coated spore that can survive in the soil for years.

In over 95% of cases the infection is cutaneous and caught by direct contact with the skins or tissues of infected animals. Cutaneous anthrax may rarely be transmitted from person-to-person through direct contact with skin lesions.

Inhalation anthrax is very rare and classically results from inhalation of spores in industrial processes e.g. processing animal hides. Inhalation anthrax is not transmissible from person-to-person.

Intestinal anthrax is even rarer; it occurs from swallowing spores in contaminated meat.

Injection anthrax has usually (though not exclusively) been acquired through injection of heroin contaminated with anthrax spores.

4. How long can you have the infection before developing symptoms?
The incubation period is dependent on dose and exposure route and may vary. However symptoms usually develop within 48 hours with inhalation anthrax and 1-7 days with cutaneous anthrax.

5. How can anthrax be prevented?
There is a vaccine against anthrax, but this is recommended only for those in highest risk (for example laboratory staff who may be handling the organism or those people working in tanneries). Vaccination is not recommended for the general public.

Correct treatment of hides and wool (washing or disinfecting them) as well as adequate ventilation of work areas in hazardous industries are also recommended.

6. How do you treat Anthrax?
Anthrax can be treated effectively with a variety of antibiotics, but early recognition of the disease is essential if the treatment to be successful.

In case of cutaneous anthrax, antibiotic therapy sterilises a skin lesion within 24 hours but the ulcer goes on through its natural cycle. The antibiotics of choice for cutaneous anthrax are ciprofloxacin or doxycycline, given for 7 days. Amoxicillin may also be used if the organism is known to be susceptible.

Ciprofloxacin is the drug of choice for inhalational anthrax. Treatment is intravenous initially in combination with one or two additional antibiotics (agents with in vitro activity include, rifampicin, gentamicin, vancomycin, chloramphenicol, penicillin, amoxicillin, imipenem, meropenem and clindamycin). Once the patients condition improves and the susceptibility of the organism is available therapy can be switched to a single oral antibiotic (ciprofloxacin or doxycycline) and is continued for 60 days.

If exposure to aerosolised anthrax is credible or confirmed, person(s) at risk should begin post exposure prophylaxis with oral ciprofloxacin, doxycycline or amoxicillin (if the strain is susceptible) for 60 days and may also be given vaccine. Immunisation is recommended because of the uncertainty of when or if the inhaled spores may germinate.

7. Do patients need to be quarantined?
No, there is no need for quarantine.

 

B. Anthrax Threats

1. One of my patients is very concerned about anthrax and believes that he/she should be vaccinated. Where can I get the vaccine?
Anthrax vaccination is not recommended for the general public. It is recommended for a very few people at high risk from their work, for example, those working with animal hides (especially imported hides), in abattoirs or in laboratories. Details are in the recommendations of the UK Joint Committee for Vaccination and Immunisation (JCVI) in the current Green Book (Immunisation Against Infectious Disease). The vaccine is not produced commercially and cannot be purchased.

2. My patient works in a tannery/abattoir - should they be vaccinated against anthrax?
They may be in the group that is at higher risk. You should contact the Immunisation Department at HPA Colindale (020 8200 6868) to discuss vaccination.

3. One of my patients is going to work abroad where I hear anthrax is common. Should they be vaccinated?
No, anthrax vaccine is only recommended for people in the high risk groups.

4. Can I buy anthrax vaccine privately for my patients?
No. The vaccine is produced by the government and is not for sale to private individuals or companies. It is not produced commercially in the UK.

5. My patient has received a suspicious package and is anxious that it could contain anthrax. What shall I advise?
They should not handle or open it. They should call the local police immediately, who will come and assess the package. Click here for further advice on dealing with suspect packages and materials.

6. I am concerned that my patient has inhalation anthrax - what should I do?
Click here for a link to an algortihm for the clinical evaluation and management of people with possible inhalation anthrax

7. I am concerned that my patient has cutaneous anthrax - what should I do?
Click here for a link to an algorithm for the clincal evaluation and management of people with possible cutaneous anthrax.

8. I am concerned that my patient has injection anthrax - what should I do?
Click here for links to algorithms for the clinical evaluation and management of drug users with possible anthrax.

Last reviewed: 30 December 2010