Question

a 56-year-old African American man experienced fever, chills, headache, sore throat, and malaise. Symptoms progressed to difficulty in breathing, night sweats, nausea, and vomiting. He went to the hospital on October 19. At admission, he was afebrile, and his heart rate was 100 beats per minute. Physical examination found decreased breath sounds and rhonchi. His complete blood count was unremarkable, and serum and renal functions were normal. Arterial blood gas did not show hypoxia. A chest showed a widened mediastinum, and a computed tomography scan showed edema. Blood cultures were collected, and bacilli presumptively identified as Bacillus anthracis grew within 11 hours. The patient was started on ciprofloxacin, rifampin, and clindamycin. On October 21, the patient developed respiratory distress, and he was treated with diuretics, corticosteroids, and thoracentesis. The patient eventually recovered. Consider the following issues: Why can Bacillus anthracis be classified as both a BSL2 and BSL3 agent? What signs and symptoms are characteristic of respiratory anthrax? What key tests are used for the diagnosis of anthrax? What tests should a sentinel lab perform to rule out Bacillus anthracis?

Answer 1

1.Bacillus anthracis is a gram-positive,rod shaped,aerobic,immobile,capsulated,spore forming bacterium belonging to the family. Bacillacea is the causative agent of the disease.Bacillus anthracis be classified as both a BSL2 and BSL3 agents according to the degree of risk infectivity,pathogenicity,the availability of preventive measures ,effective treatments and potential damage to the environment.

BSL2 AGENTS-Agents that pose moderate hazards to laboratory personnel and the environment

BSL3 AGENTS-Indigenous or exotic agents that may cause serious or potentially lethal disease through inhalation route of exposure.

2 Signs and symptoms of respiratory anthrax

• Shortness of breath
• Mild chest discomfort
• Myalgia lasting for 4 days
• Hypotension
• Sore throat ,mild fever,fatigue and muscle aches
• Painful swallowing
• Coughing up blood
• As the disease progress high fever,breathing difficulty,shock,meningitis.

3.Tests used to diagnose anthrax

1. Chest x ray and CT Scan-They can confirm the mediastinal widening , pleural effusion,peribronchial infiltrates.
2. Blood testes-a small amount of blood is drawn and checked in the lab for anthrax bacteria
3. Stool testing-To diagnose gastrointestinal anthrax
4. Skin testing-To detect cutaneous anthrax
5. Spinal tap-Usually done to confirm anthrax meningitis.

4.

• Routine culture
• Real time PCR tests
• Immunohistochemical staining
• Capsule staining
• Time resolved fluorescence
• Immunochromatography
• Direct flurorescent assay
• Molecular characterization
• Electrophoretic immunotransblot reaction.