Thousands of postal workers in New York and at all 36 Washington, D.C., post offices are being offered the antibiotic Cipro because of positive anthrax tests at postal facilities. It has been confirmed that two postal workers in Washington, D.C., died of inhalational anthrax. Two others are currently known to have the disease and a third case is suspected in a postal worker from Trenton, N.J.  On Tuesday, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease said that the treatment of even thousands of people who are at clear risk for developing anthrax is not a problem and that he is not concerned about antibiotic resistance in the postal worker population.  Yet, the more people who take antibiotics, the greater the odds that other bacteria  such as those that cause pneumonia, food poisoning, and blood infections  will have a chance to develop antibiotic resistance. These resistant organisms are very difficult and sometimes impossible to treat.  While the chance of contracting anthrax remains very small for the average person, recent events have placed postal workers in select cities in a much higher risk category.  "That risk may now justify the use of prophylaxis for the entire exposed group because no one can any longer be sure who in the postal worker group is at highest risk," says Dr. Dale Gerding, professor and associate chairman of medicine at Northwestern University Medical School.  The benefit of treating such a large group of people, perhaps soon reaching into the tens of thousands, may outweigh the risks of antibiotic resistance and side effects.  "I think that resistance is going to be an issue," says Dr. Stephen Jay, chair of the department of public health at Indiana University School of Medicine. "But you have to weigh the potential risk of drug-resistant organisms on the one hand and failure to treat anthrax on the other. We're between a rock and a hard place."  The decision to increase the treatment range to include those who are at high risk of exposure but have not yet been tested is not an easy one to make. Considering the government's current approach, it seems likely that if another large exposure event occurs, the treatment response will be similar.  Consider a hypothetical situation with an office building that has 20,000 employees and anthrax spores are detected. Will all 20,000 employees receive antibiotics?  "It depends on the chance that they are in contact with anthrax spores," says Dr. Stuart Levy, director of the Center for Adaptation Genetics and Drug Resistance at Tufts University. "Is everyone really at risk?"  Because anthrax is not transmissible between people, physical exposure to the spores is required. That goes a long way in determining who should be treated and limiting the inevitable development of drug resistance that goes hand in hand with widespread antibiotic use.  "We should only do what we need," says Levy.  ABCNEWS' Lynne Adrine contributed to this report
Prescribing antibiotics to large numbers of high risk people may increase the development of antibiotic resistant bacteria, but it is a risk many are willing to take.