Anthrax: our newest enemy
Anthrax, one of the microbes known to have the greatest amount of research into using it as a bioweapon. It is heard all over the news these days as people are receiving contaminated letters in the mail since the sept 11 attacks. Interesting enough, some of these letters were sent prior to sept 11 and some were sent after. We do not know as of yet if they are related to Osama bin Laden's terrorist network Al Qaeda but we do know that anthrax in the mail definitely is Bioterrorism, and any news agent saying otherwise is simply ignorant! It is not a cause of concern for us if we are prepared to handle contaminated letters, but we should also be prepared for large scale attacks JUST IN CASE. After all, education is free, the internet is free, and word of mouth is free, so read, learn, and go inform your family and friends.
First anthrax scare in Florida
Here's a pic of some CDC personnel wearing positive pressure suits aimed at preventing any contact with microbes. If the suit is torn the air inside will be blown out and away, hopefully giving the person enough time to get to safety.
ROUTES OF INFECTION
Infection can occur in 3 forms: 1- pulmonary, from inhaling spores, 2- cutaneous, from entering through the skin, and 3- gastrointestinal, from ingesting infected meat for example. They are ALL CAUSED BY THE SAME BACTERIA, only depending on route of infection. Of these, pulmonary is the only one associated with bioterrorism on a mass scale, where spores would be released from a crop duster or from high buildings but wind conditions would have to be optimal for effective dispersal. However, cutaneous infection is possible if the spores are able to penetrate the skin barrier, such as is the case with Tom Brokaw's assistant and the 7 month old son of the freelance producer from ABC news.
Initial Symptoms
There is an incubation period usually 1-6 days. This is followed by a few days of flu like symptoms such as fever, malaise, fatigue, coughing, and mild chest discomfort. After a 2-3 day improvement there is sudden onset of dyspnea (shortness of breath), stridor (high pitched noisy respiration, like blowing of the wind) and cyanosis (dark bluish coloration of the skin, brought on by lack of available hemoglobin resulting in oxygen deficiency)
Bacillus AnthracisB.Anthracis is a spore forming, gram-positive bacillus. Person to person transmission DOES NOT OCCUR. |
 Cutaneous Anthrax Infection-must have direct contact with sporescommonly seen on the head,forearms or hands-localized itching, followed by papular lesion that turns vesicular, and within 2-6 days develops into a depressed black scab -usually NOT FATAL, easily treated with antibiotics |
PULMONARY INFECTION
PULMONARY: non-specific prodrome of flu-like symptoms, could last up to six days before a brief 2-3 day improvement. This is followed by a sudden onset of respiratory failure due to the spores having germinated and infected the lymph nodes around the lung area. It is treatable in the early days with antibiotics such as penicillin and tetracycline, or Cipro if the strain has been genetically modified for resistance to these common antibiotics.
Widened mediastinum on chest radiograph |
Aerial Dispersal
Anthrax is highly infective but difficult to disperse. And since our skies are generally thought to be protected from mysterious crop dusters flying over cities instead of farms we can feel safe that this won't happen. ONE REQUIRES THE INHALATION OF APPROXIMATELY 1,000-25,000 SPORES TO BE INFECTED. That would require massive amounts released by a plane.
Lab Detection
I received via email some info regarding the CDC's methods of detection although
this has not been "confirmed" from news reports or from the CDC website directly,
yet. My colleague, a professor from the biology dept at Palm Beach Community
College in Florida writes:
"From my understanding the nasal swabs are being streaked on blood agar, then
the colonies are Gram stained. If Gram positive rods show up, they then use
a fluorescent antibody stain...I'm not sure of the specificity and sensitivity
of the fluorescent
stain...most of them are fairly high.
The blood samples are being tested for antibodies using ELISA tests with
acute (immediate) and convalascent samples. These are often 2-3 weeks apart
but they've decreased that time to one week. Again, I'm not familiar with
the specific sensitivity, etc. on the ELISA for anthrax." He then describes
how the media in his area is misusing terminology, which can be seen everywhere.
It's too bad some popular news stations can still be heard with their highly
payed hosts calling anthrax a virus, which can certainly stoke the fire in
the publics panic.
These are great lessons for class!
 There is no protection from initial infection, only education to understand how to manage and limit the spread of the bacteria. |