Facts about Anthrax

VERSION 10/29/2001 5:52:45 PM


What is anthrax?

Anthrax is an infectious disease caused by the bacterium Bacillus anthracis. It is not known to be transmitted from person to person. In nature, anthrax usually affects livestock like sheep and goats, and only rarely infects humans. Anthrax forms spores (small dried up forms) that can exist naturally in soil for a long time. It is commonly present in soil in many rural areas. Normally, human disease occurs only as a result of skin contact with anthrax infected animals or animal products, or consuming large amounts of anthrax infected animal products. However, it is possible to make concentrated amounts of anthrax spores in order to use anthrax as a weapon of war or terrorism. Anthrax can cause disease only if the spores enter the body through the lungs, the skin or by eating them. If identified early, anthrax can be treated rapidly and effectively. Early antibiotic treatment of anthrax is essential–delay lessens chances for survival. Anthrax usually is susceptible to the antibiotics penicillin, doxycycline, and fluoroquinolones (like Cipro). Since there are several antibiotics to treat anthrax, and because production has been increased, there is no need for individuals to purchase and stockpile their own antibiotics. The decision about which antibiotic to take is based on the situation.

 What are the symptoms of anthrax?

Symptoms can occur within 24 hours of exposure and may take as long as weeks to occur. In most cases they occur within 7 days. Some studies indicate that anthrax spores may survive in the body for several weeks. In nature, the most common form of anthrax is cutaneous (skin) anthrax; inhalation (lung) and gastrointestinal forms are much less common and will not be described here.

 Inhalation anthrax: This life threatening disease occurs when anthrax spores are inhaled in numbers sufficient to cause disease and almost never occurs in nature. Initial symptoms of inhalation anthrax infection may resemble flu. Within days, the symptoms may progress to severe breathing problems, shock, and death. A blood test is available but it takes a few days to complete; there are characteristic findings that can be seen on chest X-rays. Treatment of inhalation anthrax is a medical emergency.

Cutaneous anthrax: This is the most common naturally occurring form of the disease and generally is not life threatening. It occurs when there is skin contact with anthrax spores and those spores are able to enter the skin through skin breakage (even breaks that are too small to see with the naked eye.) The anthrax forms a local infection that can cause a skin rash that generally looks like a spider bite or an ulcer. (Photos are available at some of the websites linked below.) Diagnosis is via a blood test, skin culture, or skin biopsy. Cutaneous anthrax responds well to antibiotic therapy and should be treated aggressively.


How do you get anthrax?

Anthrax is almost never transmitted from person to person. You get it from exposure to infected animals, from weapons of war or terrorism, or from careless handling of laboratory materials.


What do I do if I think I may have anthrax?

See a physician immediately. If you are in a high-risk group, it is important that you identify yourself to the physician as a postal worker or otherwise at higher risk. The CDC has stated, “Clinicians and laboratories should be vigilant for symptoms or laboratory findings that indicated possible anthrax infection, particularly among workers involved in mail sorting and distribution.” CDC guidelines clearly spell out recommendations for medical treatment of anthrax. (MMWR, 10/26/2001)

Who needs treatment for anthrax?

Anyone with a medical diagnosis of suspected anthrax disease needs treatment. In persons exposed to anthrax, infection can be prevented with antibiotic treatment. Therefore, people who have been present in a location known to have been contaminated with anthrax (e.g., postal facilities with known cases) are being treated, as a preventive measure. There is no need to treat contacts of persons who are ill with anthrax or workers from facilities that have not been contaminated by anthrax. Medical treatment for anthrax only protects against past exposures so it is important to follow steps to reduce exposures as described below.

Should I be immunized for anthrax?

At present, only laboratory and military personnel at very high risk for anthrax exposure are vaccinated. The vaccine requires six initial injections over 18 months, and annual booster shots. There is no need to immunize contacts of persons ill with anthrax, such as household contacts, friends, coworkers, or the public at this time.

 Why not treat everyone as a precautionary measure?

The first principle of medicine is “First do no harm.” Both antibiotics and vaccines have rare but harmful side effects – and widespread use of antibiotics can contribute to the development of antibiotic resistance in other potentially harmful microorganisms. If doctors treat people who are not at risk, some will be harmed by that. However, this is a rapidly evolving situation. If anthrax is found to be more widely disseminated, then the medical advice would change also.

 Should I receive the flu shot?

Ordinarily the flu shot (influenza vaccine) is only helpful for people the CDC has identified as high risk: “health care workers, people with certain chronic medical conditions and the elderly who are at high risk for developing serious complications from influenza." It provides no direct health benefit for other people. However, the vaccine has been provided for all postal workers to avoid unnecessary anxiety and medical treatment for flu illnesses this year. This year, because there is a particular concern about anthrax, which has flulike symptoms, it is recommended everyone be vaccinated, after the high-risk groups (by December 1 or so). However, it is important to understand that the flu vaccine is not 100% effective and therefore many people who are vaccinated will nonetheless develop the flu. The flu shot will not interfere with any treatment for anthrax.


What can I do about stress?

First, it is normal to feel stress at a time when our nation is under attack. Individuals have different coping mechanisms for stress. However, it can be expected that many would feel a heightened sense of vigilance, anxiety, and anger. Some have lost friends and coworkers and may be sad or depressed. It is important to understand who the target of anger should be, the terrorists. All need to make an effort to understand when coworkers exhibit signs of stress, anger, or depression. We need to pull together to respond to this attack as a nation, and to support those who have been the closest to the attacks or who otherwise are more vulnerable. There are many who already had problems in their lives, and for whom the current situation could create a crisis. It is important to recognize problems before they become overwhelming, and to make use of family and community support networks as well as employee assistance programs, if needed.


RESPIRATORY PROTECTION (Caveat: It is still unclear at this time what will be the recommendation and/or agreement on respirators in the context of postal work.)

What is a respirator, and how does it protect me?

A respirator provides a physical (or in some cases chemical) barrier against inhalation of dangerous particles or chemicals. There are two basic kinds of respirators. The first, sometimes called an “air-purifying respirator,” passes air from the outside through a filter before you inhale it, removing hazards that are in the air. The second type supplies clean air to you, either through an air line or hose or through a tank that you carry. All of the respirators that would be used in postal facilities would be the first kind, an air-purifying respirator.

There are several types of air purifying respirators (APRs). For single-use respirators, the entire face piece is made of filter material. An example of this type of respirator is a surgical mask; these are not adequate for protection against anthrax. Another type of APR consists of a rubber face piece (either half-mask covering nose and mouth or full-face covering nose, mouth and eyes) and a replaceable filter cartridge. These are called negative-pressure respirators because air is drawn into the respirator by suction created when the user inhales. Powered Air Purifying Respirators (PAPRs) utilize a small fan to blow air through a filter, providing clean air to the wearer and positive pressure inside the mask. The PAPR is more protective than a negative-pressure APR because the positive pressure minimizes the potential for leakage around the face-piece.


Can anyone wear a respirator?

The U.S. Occupational Safety and Health Administration (OSHA) has issued a regulation on respiratory protection. The purpose of the regulation is to assure that respirators are appropriate for the hazard, and that workers are trained in proper use of respirators.

Most people can wear a respirator safely. There are some people who may have difficulty wearing certain respirators, for a number of reasons. For example, people with chronic lung diseases may have trouble breathing with a respirator and may need to consult with a doctor and an industrial hygienist to decide on an appropriate respirator. Other people may have difficulty for other reasons.

Are the respirators effective in preventing exposure to anthrax?

The anthrax spores are small (1-6 microns) and the respirators that have been selected are able to filter them out and prevent them from going into the lungs. However, no respirators are effective unless they fit properly and are worn correctly.

I have heard that a respirator needs a tight seal. What does that mean?

The seal is the “fit” of the respirator on your face. If the respirator does not fit well, air can leak in at the edge of the respirator when you inhale, rather than being forced through the respirator’s filter. If that happens, it reduces the effectiveness of the respirator. This doesn’t mean the respirator is useless, but it does mean it may not protect you as effectively.

Many things can affect the quality of the fit. It is important to get a respirator that fits your face, rather than one that is too big or to small. Facial hair is another important consideration. If you have hair between your face and the respirator, the seal will not be as tight and air can leak around the edge of the respirator.

What is fit testing? Do I need it?

Fit testing is a procedure to check the “fit” or seal” of the respirator. It can be done using a substances that smells, to see if the smell is detected inside the respirator or it can be done with more complicated equipment that gives a more exact estimate of the respirator’s fit.

I use a paper dust mask now. Is that good enough to protect me from anthrax or other hazards?

The anthrax spores are quite small, approximately 1 to 6 microns. While any mask is probably better than no mask, these particles are so small that single-use paper dust masks do not provide the level of protection needed against anthrax.



What about my children? 

As noted above, household contacts are not known to be at risk and no treatment or vaccinations of children are recommended based on employment in postal services. For most of the nation, the greatest risk to children is the stress and anxiety that can be created by the terrorists. The American Academy of Pediatrics (2001) has developed a set of advice for parents and medical practitioners as referenced below. These apply generally to terrorism and include:

"It's important to communicate to children that they're safe. Given what they may have seen on television, they need to know that the violence is isolated to certain areas and they will not be harmed. Parents should try to assure children that they've done everything they can to keep their children safe.

Adolescents in particular can be hard hit by these kinds of events and parents might want to watch for signs such as: sleep disturbances, fatigue, lack of pleasure in activities enjoyed previously, and initiation of illicit substance abuse.

Overexposure to the media can be traumatizing. It's unwise to let children or adolescents view footage of traumatic events over and over. Children and adolescents should not watch these events alone.

Adults need to help children understand the significance of these events. Discussion is critical. It should be stressed that the terrorist acts are ones of desperation and horror -- that there are "bad" people out there, and bad people do bad things. But not all people in a particular group are bad. Children should know that lashing out at members of a particular religious or ethnic group will only cause more harm."(AAP, 2001)

Can children get anthrax?

Yes, and one seven-month-old child in New York did get skin anthrax from a letter that was mailed to a news agency. That child was present in the newsroom. That child is now well. No cases have occurred of anthrax brought home from the workplace, however, we know very little about the potential for anthrax spores to be carried home on clothing. (Hand washing, of parents and children, would prevent one potential route of spread.) However, children with flu like symptoms or with unusual skin rashes (that may resemble spider bites or skin ulcers) should be seen by a physician so that they can make an evaluation and a decision about treatment.



Anthrax is a spore, and you can get it by physical contact, either through inhaling the spore or by breaks in the skin. For skin protection, the first line of defense is keeping anthrax out of the environment. The second is careful hand washing. Using gloves as a barrier should reduce the possibility of spores contacting the skin, but only if used in combination with careful hand-washing. However, gloves do not prevent the inhalation of anthrax spores.

If I use gloves, should I wash my hands?

Yes. Gloves can help to protect you, but careful and frequent hand washing will further reduce the possibility of spores contacting the skin, or of their being transferred from something you handle to your mouth, nose, or eyes.

Do I need to use special soap, and is there any special way to wash?

In general, hand washing removes the bacteria on top of the skin through mechanical action and anti-microbial soaps and detergents help to reduce some of the organisms that are deeper in the skin. The most important thing is to wash thoroughly with a lot of lather, washing for at least 15 seconds vigorously.

Should I reuse my gloves?

No. Studies in hospitals suggest that washing and reusing gloves may reduce their effectiveness, so in general you should use a new pair of gloves after a day’s use.

What kind of gloves should I use, and how do I wear them?

There are many different kinds of gloves. Most of the vinyl and nitrile gloves will provide some barrier against anthrax. The more durable the glove, the better its barrier will hold up over time. Discard worn gloves. Remember to remove gloves and wash up before eating, drinking or smoking.

Latex gloves are not being used because of the potential for allergies. However, some people may find that it is helpful to wear a cotton glove under the nitrile or vinyl gloves, to reduce sweating and discomfort.

It is important to remove the glove in such a way that you do not come into contact with the outer surface, where contamination could take place. The best way of doing this is as follows. With a gloved hand, remove the first glove by pulling it off, without "snapping" it (which could spread contamination into the air). To remove the second glove, place your index finger under the cuff edge of the glove (the inside, next to your skin) and slide it along your hand towards the fingers, so that the glove turns inside out. This way you can remove it without touching the surface.

You will be shown where to dispose of the gloves. Do not leave them in the general trash containers. Always wash your hands for at least 15 seconds with soap and water after removing the gloves.



There are a number of valuable sources of information for those who would like to learn more. Many of these require that you first have downloaded and installed a free software program called adobe acrobat reader. Here are the links:

1. In 1999, an expert consensus panel reviewed the use of anthrax as a weapon of bioterrorism. That review was published in the prestigious Journal of the American Medical Association and is available on the web at:


2. The CDC has posted health advisories regarding anthrax among postal workers. They can be found at:



3. CDC’s most recent update on the anthrax cases that have been identified in association with mail containing anthrax is available at:


4. The CDC has posted on its website an excellent slide presentation on the clinical presentation of anthrax for physicians and other health care providers, most of whom have never encountered this rare disease. The slides can help recognize the skin lesions and X-ray changes that are characteristic of the two major forms of the disease:


5. The CDC has provided a number of video broadcasts of lectures on anthrax, including valuable information for clinicians and laboratories. These are often large files and make take some time and patience on systems with slower connections.


The CDC advise on handling suspicious mail and packages is available at:



6. The Johns Hopkins University Center for Biodefense Studies contains extensive materials on a number of issues related to biological warfare and terrorism, including anthrax.


7. The American Academy of Pediatrics has developed a set of materials on how to help children cope with terrorism. These are available at:


8. The American Academy of Pediatrics reviewed chemical and biological terrorism and its impact on children:


9. The National Institute for Occupational Safety and Health website contains guidelines for the selection of particulate respirators. This can be viewed at:


10. The U.S. Occupational Safety and Health Administration regulation on respirators and many useful technical documents can be viewed at:





Lynn Goldman (1)

Samar Khoury (1)

Peter Lees (1)

Clifford Mitchell (1)

Glenn Morris (2)

Tara O’Toole (1)

Patrick Breysse (1)

  • The Johns Hopkins Bloomberg School of Public Health, Department of Environmental Health
  • The University of Maryland, Department of Epidemiology

    Please note that this is a rapidly evolving situation and that, while the information contained herein is the authors’ best effort at this time, that it is subject to change as more evidence is generated.

    Our thanks to Corey Thompson, Health and Safety, American Postal Workers Union, and Maria Jeffords and Kelly Moore, Communications, U.S. Postal Service, for their review and comments. All the information in this is the responsibility of the authors, however.