A new report from the Working Group on Civilian Biodefense offers medical and public health guidelines for diagnosing, treating and managing future anthrax attacks. The Hopkins Working Group is an expert panel convened by the Center for Civilian Biodefense Strategies at the Bloomberg School of Public Health. The updated consensus statement is based on published research and an analysis of the anthrax attacks of 2001. It appears in the May 1 issue of the Journal of the American Medical Association.
The Hopkins Working Group considers B. anthracis, the bacterium that causes anthrax, one of the most serious biological weapons threats. Concerns were heightened in September 2001 when anthrax spores were deliberately distributed using the United States Postal Service. Of the 22 people diagnosed with anthrax, 11 developed the serious inhalational form, which resulted in five deaths.
"Since the publication of the first Hopkins Working Group consensus statement on anthrax in 1999, a great deal of new information has developed, much of it in the aftermath of the anthrax attacks of 2001," says lead author Thomas Inglesby, deputy director of the Johns Hopkins Center for Civilian Biodefense Strategies and assistant professor of infectious diseases at the School of Medicine. "The 2002 anthrax Working Group consensus statement incorporates this new information and offers revised recommendations for medical and public health responses following an attack. These recommendations reaffirm the critical role of health care professionals in discovering and treating the victims of bioweapons attacks, and they underscore the complexities health officials face in evaluating risk of possible exposure, either from the attack itself or from the environment contaminated by anthrax spores in the aftermath," Inglesby explains.
In the consensus statement, the Hopkins Working Group describes several measures that could help physicians quickly diagnose and treat suspected anthrax infections. It notes that chest X-rays and chest CT scans were abnormal in the great majority of patients with inhalational anthrax. Standard blood cultures provided rapid diagnosis of anthrax in six to 24 hours. The report says that nasal swabs, which were used in the early days of the attack, detected anthrax in a number of persons, but the test's reliability is unknown and should not be used to rule out anthrax exposure. The researchers note that one person died from inhalational anthrax despite having a negative nasal swab.
Because inhalational anthrax symptoms develop quickly, the Hopkins Working Group says early treatment with antibiotics is essential. The group concurred with the Centers for Disease Control and Prevention recommendations in the fall of 2001 to treat persons with inhalational anthrax with two or more effective antibiotics when possible.
While there is only limited data to suggest victims treated with two or more antibiotics may have had better outcomes, the possibility of natural or genetically engineered resistance to antibiotics is a second reason to use more than one class of antibiotics. A 60-day course of antibiotics is recommended to prevent delayed onset of infection following prolonged anthrax spore latency, which the 1999 consensus statement also recommended. The Hopkins Working Group believes that the anthrax vaccine taken in conjunction with antibiotics would provide optimum protection following exposure to anthrax, were anthrax vaccine supplies sufficient and available.
The report suggests new research is needed to develop an anthrax vaccine that is more reliably produced and that requires fewer inoculations. Research efforts should also focus on rapid diagnostic tests and more fundamental scientific study of the bacterium that causes anthrax.