Anthrax: What Every Clinician Should Know, Part 2
(November 1, 2001)
(View the webcast on the University of North Carolina School of Public Health site.)
When we look at the diagnostic and laboratory findings associated with this, which we’ll see on the next slide, the white blood cell count doesn’t necessarily have to be elevated. In one of the patients that we saw who died within 72 hours, on his initial assessment by his primary care provider, he had a normal white blood cell count, with the assumption I assume that they felt that this was more of a viral syndrome. But you can see increased neutrophils and bands and an elevated leukocytosis of a more later in regard to this infection. So remember, pleural effusions can be present, which were seen in 5 out of 8. You don’t necessarily see pulmonary infiltrates, which is associated with bronchial pneumonia, but they can be present and, in most instances, blood cultures were positive in almost everybody who had not received antibiotics. You and I know a lot of patients have antibiotics sometimes at home. They don’t always want to tell you, “Doctor, I opened up my cabinet and I found some of those ampicillin antibiotics up there and I thought, ‘Boy, I’m starting to feel bad,’ and I started to take a few antibiotics,” and they don’t always want to admit that they have taken those antibiotics. So that is one key theme, you have to explain the importance of telling you whether they have taken some antibiotics unbeknowingly in order for you to really understand the value of your laboratory test because you may have a false-negative test. Next panel.
Just want to say that if you have someone that is evaluating powder that they think there is a high likelihood that they have anthrax spores present, and you have a suspiciousness of this illness, go ahead and treat for this anthrax. Don’t wait. You know, if there is a suspicious occupation of a worker that has been associated with this, if there has been significant exposure, or the recipient is a likely target, or there is a suspicious letter or package, strongly consider starting these patients on prophylactic antibiotics. I think we do have to be cautionary that you know we are giving out a lot of antibiotics can generate resistance, but at the other side of the coin, let’s not miss somebody who, if we could just look at the clues from the epidemiological standpoint, it is really critical to treat them. But we don’t want to forget about the young healthcare worker who died in New York, who, from the epidemiological background, we don’t have any diagnostic clues. So that if we have someone in your office and something doesn’t seem right, but they don’t seem to fit into all these categories that we have realized in the past, pay attention and consider this. Next slide.If for some reason this happens in your environment, we want to tell people there has been exposure and it happens that someone opened up an envelope with powder. One of the key things that we ask you to do is try to secure the area. We don’t want to have a lot of people moving in that area. If you have a ventilation system, it needs to be shut down, and we have to assess the potential for shared air zones in these cases that are occurring, whether it’s in a business setting or a hospital setting or whatever setting. One of the things we have to look at is try and identify those persons with direct contact with shared air and to the site to initiate antimicrobial prophylaxis whether it is doxycycline or ciprofloxacin. Next slide.
Postexposure prophylaxis prevents inhalation anthrax. Treatment now is ciprofloxacin or doxycycline. Doxycycline is very inexpensive, very tolerable, and so it’s a great drug to use besides ciprofloxacin. But if you have young children and pregnant women, they can be switched to amoxicillin because, as I will show you in a later slide, in most of the screens that we have tested, susceptibility studies (if you know that strain) show that they have been susceptible. Pediatric amoxicillin dose is 80 mg/kg/day in 3 divided doses. But one thing I want to say is, and I have to re-emphasize again, that although penicillinase activity has been known to occur in the past, it is probably not an issue, and I have to re-emphasize again for your patients to be clear, because they can lie dormant inside the pulmonary lungs; late reactivation can occur as long as 60 days later. It is very critical to do the 60 days’ worth of antibiotics. Next slide.
One key thing I do want to emphasize—it is a question that comes up quite frequently—and that is, when should we do nasal swabs and is it diagnostic? Nasal swabs have never been recommended as a diagnostic tool. It is only to be used in epidemiologic settings where we are trying to look to see for exposure. It is a not a great diagnostic tool. The sensitivity is not all that great and so we don’t want to give people a false sense of utility in regard to that, but we do do surface swabs in the environments when we think we are at high risk, and we can initially start somebody on a short course of antibiotics, 7-10 days, depending on how rapidly you can get your results, in the likelihood there is some high suspicion, and then when those results are confirmed, you can stop the treatment. But if there is likely exposure treat for 60 days. Next slide.
Treatment of inhalational, gastrointestinal, oropharyngeal or complicated cutaneous anthrax—we recommend that you use multiple-antibiotic therapy. Monotherapy alone is not sufficient. This is a really deadly disease and, even though you may have the cutaneous form of anthrax, always realize that those individuals are also at risk for inhaled anthrax, as well as the cutaneous form. And so we recommend using ciprofloxacin or doxycycline and there are 1 or 2 other drugs that can be used, and I’ll show the susceptibility studies that will show you like imipenem and clindamycin, vancomycin, or some other drugs that can sometimes be used in combination and some people actually use 3 drugs, adding rifampin also, to give them additional activity. But if you have seen this involvement, avoid doxycycline for CNS disease. And once they are clinically improved and the susceptibility studies have been assured, you can switch to oral therapy when appropriate. Next slide.
In my final statement, these are the 11 isolates of anthrax that were identified from Florida, New York, and D.C., and as you can see, penicillin and amoxicillin were very susceptible. Erythromycin and azithromycin were intermediate. So we are telling you that cephalosporins are not an indication in the treatment of anthrax. Do not use cephalosporins in these cases as you see the ceftriaxone is resistant. I’ll stop and introduce you now—we have the honor to have Dr. Ivan Walks, who is the Chief Medical Officer with the District of Columbia Department of Health, to share the lessons learned by the local health department.
Dr. Ivan Walks:
Good afternoon. There are several lessons learned in looking at this sort of a bioterrorism attack. I think the first lesson learned is that you need to be prepared for something that you can’t possibly prepare for. What we’ve learned most is that you need to have some sort of a Day 1 plan in place. There should be some series of events, some series of steps, that you will initiate as the local health officer that will help you do a couple of things. One is do something productive in response to the event, but two, and most importantly, bring in the folks to help you. Here in Washington, D.C., we have tremendous resources, but they are all based on relationships and the relationships allowed us to do a couple of things. When we had that first confirmed case of inhalation anthrax, that call came to me from the CDC at 7 a.m. on Sunday morning. By noon on Sunday we had fully mobilized and we were ready to begin administering antibiotics. We had a lot of folks come in and plan with us and we were able to do a couple of things. One is, provide treatment, keep people safe, get them safe now, right away, real time. When you are doing a lot of investigating about something new, the focus has to be on safety, public safety, protecting public health first, while you investigate. That is why the medication is distributed early, up front. Cipro, big gun, make sure we are being effective. As we find the characterization, we go to doxycycline.
We had another problem locally. Here is another lesson learned. Multiple jurisdictions here in the district, Capitol Hill, Hart Building, letter there, attending physician different from the local health officer, and we had people wondering why the attending physician’s folks were given one medication, the regular folks were getting another medication. Many of you are going to be faced with those kinds of questions in your community—is the governor, the mayor, the rich person getting a different kind of treatment from everybody else? Public health is critical when you are talking about public confidence, and consistency is going to be important. We were able to make people aware that the switch from medication one to medication two was something that was scientifically based. We had the CDC in there working with us and it’s that kind of focus that I think is going to be critical for the local public health folks. Make sure that you aren’t in there by yourself trying to answer these very real concerns about racial differences and class differences, but have the scientists there to back you up so that you can maintain public confidence as you deal with a very scary thing. And I’ll turn it back over to our moderator.
Okay. Thank you, Dr. Walks, for that enlightening information that you provided to us.
I want to remind individuals that if you want further information, you can contact the Web site here at Howard University School of Medicine, and that is www.whut.org. Also remember Centers for Disease Control and Prevention have a wonderful Web site. Check out the Morbidity and Mortality Weekly Reports and also the Web site for the National Medical Association.
- Page last updated November 20, 2002
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