Disease Symptoms

Inspite the fact that anthrax has been usually observed in well defined areas or as an occupational hazard , nowdays it is very important due to its potential use as a biological weapon. Anthrax it is mainly a zoonosis; it mainly affects herbivores (horses, cattle, sheep), who come in contact with Bacillus antracis spores that contamine their pastures. The people are infected usually by direct contact with animals or their contaminated biological
The disease has three forms, with different symptoms and progression: cutaneous, pulmonary and gastrointestinal. In all three forms of the disease meningitis and sepsis may occur due to the lymphematogenous dissemination of bacteria from a primary lesion.

Cutaneous anthrax is the most frequent form of the disease (95% of cases). The bacteria or the spores are being inocculated into the skin through a cut, scratch, or insect bite. After two to five days (in some cases the incubation period lasts up to 3 weeks), at the infection site it appears an initial lesion, an erythematous papule which may be mistaken as an insect bite. In 2-4 days the papule enlarges and it is surrounded by a ring of small vesicles. The area surrounding this lesion is eritematous and edematous. The lesions' diameter is 1-3 cm, it is not painful and pus is absent. When the vesicular ring ruptures (day 7-12) the clear fluid from the vesicles is being discharged and the lesion progresses into an eschar - a specific black necrotic lesion which heals slowly (up to 60 days).Other symptoms are: regional lymphadenopathy, fever, malaise and headaches

In cutaneous anthrax, if the patient receives adequate treatment, mortality is rare; nevertheless in severe cases, less commonly the disease may progress with toxemia, bacteremia, massive local edema and painful adenomegaly, shock and fatal outcome.

Gastrointestinal anthrax is determined by the ingestion of spores in contaminated water or food. After the incubation period wich lasts up to one week, the disease may have two clinical forms: intestinal or oropharyngeal.

Initially the symptoms of intestinal anthrax are non-specific: fever, malaise, vomiting, nausea and anorexia. Later on, the disease progresses and severe abdominal pain, massive ascites, hematemesis (vomiting blood) and bloody diarrhea appear. Toxemia develops, then shock, leading to death (25% to 60% of cases).

In oropharyngeal anthrax the lesion is more frequently localized on the tongue, the buccal mucous membrane, the posterior pharyngeal wall or the tonsils. The main symptoms in this form of the disease are: sore throat, high fever, dysphagia, local lymphadenopathy. The infection may lead to bacteremia and toxemia thus leading to shock and death, in spite of the treatment (50% mortality).

The inhalation of spores leads to pulmonary anthrax. Its initial symptoms are insidious and are similar to a cold. After a short incubation (up to 1 week) the disease begins with unproductive cough, fever, malaise, dyspnea. In a few days the illness worsens and progresses to its next stage characterized by high fever, cianosis, dyspnea, respiratory distress. The bacteria spreads massively to CNS ad bloodstream and toxemia occurs.Once bacteremia has developed the progression to shock and death is very rapid. In spite treatment, pulmonary anthrax is, in most cases, fatal.