They start with muscle and joint aches, high fever, nausea, perhaps a skin rash. Evidence of bleeding follows, leading to organ failure, shock and often death. This is the terrible course of the hemorrhagic fever viruses (HFVs), such as the dread Ebola and Marburg, and if terrorists mounted a biological attack using them, the consequences could be disastrous. So say a panel of experts in a report published today in the Journal of the American Medical Association.

An outbreak could occur between two and 21 days after the agents were released, report Luciana Borio of the Johns Hopkins Center for Civilian Biodefense Strategies in Baltimore and her colleagues. HFVs' inherent ability to sicken aside, the situation would be made all the worse by clinicians' lack of familiarity with such scourges. The panel thus made a number of recommendations concerning diagnosis, handling and treatment of infected patients, noting that any suspicious clinical specimens would need to be sent to the Centers for Disease Control and Prevention (CDC) or the U.S. Army Medical Research Institute of Infectious Diseases--the only laboratories equipped to rapidly diagnose these viruses.

But exactly what could be done for infected individuals is worryingly unclear. So far, the USDA has yet to approve any antiviral drugs for treatment of HFVs, although the drug ribavirin has apparently shown some promise in combating certain of them. And with the exception of yellow fever, licensed vaccines against these viruses do not exist. Indeed, as the authors conclude, "the diagnostic and therapeutic armamentarium urgently needs to be augmented. There also is an urgent need to develop vaccines and drug therapy."

"An outbreak of Ebola and Marburg would have a significant impact on our society because they carry significant morbidity and mortality, and other than supportive medical care, there are no specific treatments," Borio remarks. "It is not possible to predict whether any of the hemorrhagic fever viruses are likely to be used as a bioweapon. However, we know that it is not impossible to weaponize these viruses, and we in medicine and public health are obliged to prepare."