Bacillus anthracis is a gram-positive spore-forming aerobic rod

-Spores are the infectious form of the organism

-They cause a zoonotic infectious disease called Anthrax 

-the spores are inoculated through the skin, ingested, or inhaled 

-Anthrax occurs naturally in mammals and human anthrax follows exposure to infected animals or animal products or rarely bioterrorism

Symptoms & Signs 

Clinically, the disease occurs in three forms: Cutaneous, inhalational, and gastrointestinal

Cutaneous anthrax: the most common and the least morbid form of anthrax.

A painless papule progressing through vesicular, pustular, and escharotic phases resulting in painless, umbilicated ulcer (black eschar/malignant pustule); It can be associated with fever, headache, chills, cough, dyspnea, chest pain, vomiting, and fatigue. 

Inhalation anthrax: Fever, cough, dyspnea, respiratory failure, pleural effusion, hemoptysis, mediastinal edema and widening 

Gastrointestinal anthrax: nausea, vomiting, ulcers, bloody diarrhea, abdominal pain, ascites, and shock 

Diagnosis 

Culture of skin lesions, sputum, blood, and CSF

CXR: a widened mediastinum and pleural effusions

Treatment 

-Supportive care 

-Antibiotics: Ciprofloxacin, Doxycycline, Amoxicillin, Penicillin, Rifampin, Clindamycin, Clarithromycin, Erythromycin, Vancomycin, Imipenem 

Q. What is the most sensitive test for inhalational disease? Chest radiograph

Q.What is the most accurate predictor of inhalation anthrax on chest radiograph?     Mediastinal widening