Anthrax

Question 1

What organism causes anthrax?

Answer 1

Bacillus anthracis; Gram positive rod-shaped anaerobic bacteria

Question 2

What are the forms of B.anthracis infection in humans? (4)

Answer 2

Cutaneous (most common form, 95%)
Inhalation (rare but fatal)
GI (rare but also fatal)
Injection (sx like cutaneous but with more rapid spread)

Question 3

What are the symptoms of cutaneous anthrax?

Answer 3

Localized, inflammatory, black, necrotic skin lesions (eschar)
Most often, sores will appear on the face, neck, arms, or hands
Develops 1-7 days after exposure

Question 4

What are the symptoms of inhalation anthrax?

Answer 4

Flu-like symptoms 
Chest discomfort 
Shortness of breath
Diaphoresis
Body aches
Confusion and dizziness
Hemoptysis
Nausea and vomiting 

Symptoms usually develop one week after exposure but can take up to two months

Without treatment, almost always fatal; with aggressive treatment ~55% survival :(

Question 5

What are the symptoms of gastrointestinal anthrax?

Answer 5

Fever and chills 
Neck swelling 
Painful swallowing 
Hoarseness
Nausea and vomiting, including hematemesis 
Diarrhea 
Flushing 
Red eyes 
Abdominal distension 

Symptoms typically develop within 1-7 days
Fatal in 25% of cases

Question 6

What are the symptoms of injection anthrax?

Answer 6

Fever
Chills
Blistering skin at injection site which transform into a painless sore with a black center 
Swelling around sore 
Abscess formation near injection site

Question 7

Is anthrax a notifiable disease in the UK?

Answer 7

YES

If anthrax infection is suspected, discuss with an infectious disease specialist and arrange urgent consultation. For community level outbreaks, specialist advice should be sought from Public Health England or, in Scotland, Health Protection Scotland

Question 8

What is the treatment of anthrax?

Answer 8

FIRST LINE
Adults and children >12yo EITHER
- ciprofloxacin: 500 mg BD orally or 400 mg 12 hourly to be given over 60 min by IV infusion OR
- doxycycline: 100 mg BD orally using immediate-release medicines
Children 12 or younger: ciprofloxacin

PLUS

One or two other antibacterials eg benzylpenicillin sodium, clindamycin, rifamicin, or vancomycin

OR

SECOND LINE:
Alternatively, a combination of amoxicillin + imipenem + cilastatin OR meropenem + chloramphenicol

**remember: tetracyclines cause tooth enamel discoloration in children and are therefore not recommended for use in patients 12 yo or younger

Question 9

What drugs are used in post-exposure prophylaxis of anthrax?

Answer 9

Oral ciprofloxacin, doxycycline, or amoxicillin (same as treatment dose)

• ciprofloxacin: 500 mg BD orally or 400 mg 12 hourly by IV infusion
• doxycycline: 100 mg BD orally
• amoxicillin: 500 mg TDS orally

May be continued for up to 60 days

Question 10

Is there a vaccine available for anthrax?

Answer 10

YES

Made from antigens of inactivated B.anthracis

Indicated for individuals who handle infected animals or process infected animal products where there is a potential risk of occupational exposure.
Also recommended for occupations where workers are at risk of one-off high level exposure eg following a deliberate or accidental release of spores

Question 11

What are the indications for B.anthracis vaccination?

Answer 11

Anthrax immunisation is indicated for individuals who handle infected animals or process infected animal products where there is a potential risk of occupational exposure to B. anthracis. It is also recommended for occupations where workers are at risk of one-off high level exposures to anthrax (e.g. following a deliberate or accidental release of spores).

• 4-dose regimen for PRIMARY immunisation
• Single dose BOOSTER given at 10-year intervals on up to 3 occasions for workers at continuous LOW-level risk of exposure
• In those with potential intermittent HIGH-level exposure, a single BOOSTER dose should be offered just before entering situations with a specific high exposure risk
• In the event of proven or high probability of EXPOSURE to anthrax spores, a single BOOSTER dose should be given, IN ADDITION to antibacterial prophylaxis, EXCEPT when a dose has been given in the preceding 12 months.

Question 12

What are the vectors for B.anthracis transmission? (2)

Answer 12

1. Animal vector, especially farm animals (majority)

2. Biological warfare

Question 13

What is the mode of transmission of anthrax?

Answer 13

Contact with spores from an infected animal (inhalation, ingestion, contact with open cut/sore), zoonotic infection

• ingestion of or direct contact with contaminated vegetation or soil, contaminated meat, bone meal, blood, or other tissues
• insect vector eg flies that transfer spores onto food etc