RESUMO
BACKGROUND: Bacillus anthracis, the causative agent of anthrax, is well known in human history as a major cause of disease in domestic and wild animals and as a rare condition in humans. For the last seventy years, anthrax was developed and occasionally stored as an agent of biological weapon arsenal in numerous countries. The incubation period in humans is 1-6 days and the disease may be present as three distinct clinical syndromes: cutaneous, inhalational, and gastrointestinal disease. The major concern in regard of biological warfare is the inhalational form of anthrax, which starts as a febrile flu-like disease. The development of malaise, fatigue, cough and mild chest discomfort is followed by severe respiratory distress with dyspnea, diaphoresis, stridor, and cyanosis. Shock and death occur within 24-36 hours after onset of severe symptoms. Physical findings are non-specific, but a widened mediastinum is usually seen on chest x-ray. A positive blood culture, immunohistochemical methods and the use of the polymerase chain reaction method confirm the diagnosis. Although effectiveness may be limited after severe symptoms are present, a high dose of antibiotic treatment should be administered and aggressive supportive therapy may be necessary. In the situation of an anthrax attack, as was recently seen in the United States, penicillin is no longer recommended as an acceptable first line therapy. In this case, ciprofloxacin or doxycycline is the recommended drug of choice since penicillin-resistant strains may be used, as well as the possibility of the emergence of an inducible beta-lactamase positive bacterium. Since a high infecting dose may exacerbate the clinical course of the disease, a combination antibiotic regimen should be considered. The disease is not contagious and standard precautions are sufficient. Pre-exposure prophylaxis is based on a vaccine administration, while post-exposure prophylaxis is feasible by the initial use of oral ciprofloxacin or doxycycline. In this article we reviewed the literature with emphasis on the recent medical reports from the United States analyzing the eleven cases of inhalational anthrax as well as the new guidelines for diagnosis and treatment that resulted from the bioterrorism attack in October 2001. Although physical findings were non-specific, abnormal findings on chest x-rays were present in all the eleven cases. A positive blood culture, immunohistochemical methods and the use of the polymerase chain reaction method were highly valuable in revealing and confirming the diagnosis of anthrax. In the case of an attack with anthrax spores, the likelihood of exposure to a large infective dose of high quality spores, may require a prolonged period of treatment as well as prolonged post-exposure therapy.
