Anthrax

Anthrax: definition

In the medical field, the term anthrax refers to a serious acute infection, fortunately rare, sustained by the bacillus anthracis, involving the skin, the gastrointestinal tract and the lungs: the anthrax danger is very high, since many of its variants are lethal . Anthrax develops mainly in herbivorous mammals, both wild and domestic (eg sheep, goats, cattle, pigs, etc.) but, following contact with these infected animals, the bacterium can also infect humans, both with ingestion of infected meat, both with inhalation of spores. The inter-human contagion does not seem to be possible. The areas where the risk of contracting anthrax is real are the poor countries of Asia, Africa and Europe.

Causes

Otherwise called anthrax (not to be confused with staphylococcus carbuncle), anthrax is triggered by a bacterial infection supported by Bacillus antraci ; more precisely, the disease is an expression of Bacillus spores, which are found naturally in the soil of many areas of the world.

The spores of the Bacillus anthracis are extremely resistant, just think that they can remain dormant and unchanged in the soil for decades; only when they find an ideal host, the spores activate and cause damage. Anthrax is mostly transmitted through the ingestion of meat from infected animals, although even the airway is an important and extremely dangerous means of propagating the bacterium.

Curious and particular is the mode of contagion of anthrax in some African peoples: these tribes have the custom of building drums with animal skins; given the poor compliance with hygiene standards in these countries, it is not uncommon for drums to be coated with the skins of infected animals. In this way, anthrax has caused many victims.

Equally curious, as rare, is the contamination of the anthrax bacillus through the post: a decade ago, 22 cases of anthrax were diagnosed following exposure to bacillus spores through the post. Five of the unfortunates died.

Deepening: anthrax and drug addiction

There is no proven correlation between drug addiction and the risk of contracting anthrax; however, a few years ago, in Scotland, the number of drug addicts infected with Bacillus anthracis increased dramatically . This correlation, at first glance unexplained, was soon clarified: it seems that the spores of the anthrax beating have contaminated heroin (or cutting substance), so the toxic ones, by inhaling, smoking or injecting heroin, have been involved in infection.

Classification

There is no single form of anthrax; we see, below, the most frequent:

1. Cutaneous anthrax: occurs at the skin level, following direct contact with the skins or with animals previously infected by the anthrax bacillus. The subjects most at risk are workers in tanneries, especially in contact with skins from abroad or of dubious origin.
2. Anthrax of the respiratory tract (pulmonary variant): inhalation of the spores of the anthrax bacillus can promote infection. It is a typical affection of those who are in contact with animal skins, wool and foreign bones.
3. Intestinal anthrax: probably the rarest form ever, anthrax causes severe intestinal disorders when contracted by ingestion of infected animal meat.

Symptoms

To learn more: Symptoms Anthrax

The characteristic symptoms of anthrax usually begin after 1-7 days from contact with the bacillus (incubation time) as far as the skin variant is concerned, and after 2 days in the case of inhalation of the anthrax bacterium.

The characteristic symptoms for each form of anthrax are described below:

1. Cutaneous anthrax (95% of diagnosed cases): the etiopathological agent comes into contact with the body through small wounds or cuts in the skin, creating considerable damage which, in the most extreme forms, can lead to death. After a few days (incubation time: 2-5 days), the cutaneous anthrax manifests itself with the formation of skin rush, including blisters and boils similar to those of mosquitoes, with a black nucleus, associated with swelling and pain of the lymphatic glands nearby.
2. Pulmonary anthrax: the spores of the bacillus, coming into contact with the mucous membranes of the respiratory tract (before), and with the other districts of the body (after), create an exaggerated damage, whose prognosis is often ominous. Pulmonary anthrax is the most dangerous form of the disease, which begins with flu-like symptoms, such as fever, sore throat, muscle pain, fatigue and chest pain. As the disease progresses, the subject complains of high fever, serious breathing difficulties, shock and haemorrhagic meningitis, until death.
3. Gastrointestinal anthrax: following the ingestion of raw or undercooked meat of animals infected with the anthrax bacillus, humans can manifest typically gastrointestinal symptoms, such as diarrhea (with possible blood loss), nausea, vomiting (also bloody) . In addition to these prodromes, the affected patient complains of swallowing difficulties, chest pain, fever, swelling of the neck, loss of appetite, sore throat and general tiredness.

To learn more: Symptoms Anthrax

Diagnosis

Differential diagnosis is essential to distinguish anthrax from other infectious forms: in fact, the lung form of the disease can be confused, at least in the very early stages, with common flu illnesses, since it begins with very similar symptoms. The differential diagnosis must be made especially with pneumonia and influenza. The most common diagnostic tests are:

1. Blood test: indicated to detect white blood cell counts
2. Liver function test: to detect the possible increase in transaminases
3. Skin analysis: removal of a flap of skin, to ascertain whether or not the diagnosis of cutaneous anthrax. The sample taken will be analyzed in the laboratory.
4. Endoscopy of the throat or intestine: to ascertain intestinal anthrax
5. Serological diagnosis (ELISA test)
6. Chest X-ray or chest CT: often inhalation anthrax is associated with a particular pain in the chest
7. Sputum analysis
8. Stool sampling: for ascertaining intestinal anthrax
9. Spinal specimen collection: for the diagnosis of anthrax hemorrhagic meningitis

Care

See also: Anthrax medications

Given the dangerous nature of the disease, it is strongly recommended to start drug treatment for anthrax within the shortest time after the onset of symptoms. The treatment is based on a 60-day antibiotic cycle: the most commonly used drugs are ciprofloxacin, penicillin and doxycycline, often taken in combination. The drug therapy is quite long (60 days): prolonging the therapy for such a long time is important, since the spores of the Bacillus anthracite germinate for long periods.

The cutaneous form of anthrax can be cured by administering antibiotics (especially ciprofloxacin and doxycycline) for a shorter period, normally varying from 7 to 10 days; sometimes, for prophylactic reasons, treatment for 60 days is also indicated.

Due to the advanced form of inhalation anthrax, not even a combination of antibiotics can reverse the disease.

Prevention

A vaccine for anthrax is available on the market; however it is not obligatory and, in general, it is reserved for patients at risk and to soldiers (classic method of administration: recall of 5 doses in a period of 18 months).

For subjects exposed to the anthrax bacillus but who have no symptoms, post-exposure prevention is recommended, to be carried out by administering specific antibiotics. It is not necessary to undertake any antibiotic treatment following skin contact with a patient infected with Bacillusantraci, unless both have been exposed to the same source of infection: the interhuman transmission of anthrax has not yet been found.