Posted on 12/09/2001 2:56:52 PM PST by TomB
As frightening as the threat of anthrax has been, the nightmare scenario for biological warfare calls for another pathogen—one which, unlike anthrax, can be transmitted from person to person.
Smallpox fits this description well. It is spread through face-to-face contact, by means of infected saliva or respiratory droplets, usually in a closed setting. It can also be spread by infected linens or clothes: It was probably first used as a biological weapon during the French and Indian Wars by British soldiers who deliberately gave blankets that had been used by smallpox patients to American Indians.
Smallpox is fatal in approximately 30% of cases. As a virus, it is not treatable by antibiotics. No American civilian has been vaccinated since 1972, and it is likely that those who were before that have little, if any, immunity left.
Is this cause for panic or resignation, born of a grim reality that there is nothing we can do to protect ourselves? No, not at all. A review of medical and historical realities should give us confidence that if the unthinkable occurs, we could mount an effective campaign against the biological terrorism of smallpox.
First, smallpox no longer exists in nature. The last naturally occurring case was seen in 1977, in Somalia. At present, smallpox, at least officially, is stored in only two repositories: in freezers at the headquarters of the Centers of Disease Control and Prevention in Atlanta, and at a Russian virology installation known as Vector, in Siberia. While there is speculation about rogue nations possessing smallpox as a biological weapon, there is no hard evidence to confirm this.
Second, smallpox is not immediately contagious. A person infected with smallpox does not become contagious until he or she is too sick to be walking around. If you are wondering if the guy next to you on the subway has smallpox and decide to hold your breath between stops just in case, you are worrying needlessly. In the first 12 days or so after infection, the patient feels fine and is not contagious. On or about the 12th day, there is a spike in fever, and then, after a couple of days, the appearance of a rash—the highly visible "pox"—which is the signature of smallpox.
The beginning of the onset of the rash signals communicability. By this time, the patient is bedridden, or in a medical facility, which is why most secondary infections occur at home or in a hospital, not in schools or other public places. For this and other reasons, smallpox transmission throughout the population is generally slower than for such diseases as measles or chickenpox. Of course, should a terrorist attempt to spread the virus by means of an aerosol release, this limitation on venues for infection would not be relevant. But such means of transmission is at this point only theoretical.
Third, it would be difficult to acquire and disseminate the virus—much more so than anthrax. Even if there were an illicit source of smallpox, a terrorist would have to overcome sophisticated scientific and technological obstacles to cultivate it (one would need to grow the virus in eggs or animal cells) and disseminate it (putting it in the form of inhalable particles). Theoretically, it would be possible to have an individual "suicide vector" walk around once contagious, but one might question whether even the most devoted terrorist would be physically capable of effectively spreading the disease given the severity of the illness once it becomes communicable.
Fourth, we have medical means of treating infected persons. While there is no Cipro equivalent to treat smallpox, there is evidence that vaccination within three or four days after infection can prevent or significantly ameliorate subsequent illness. There are some 15 million units of smallpox vaccine available now, and there is an urgent effort underway to try to stretch that supply to cover as many as 150 million people. Hundreds of millions more doses are on order.
The vaccine offers some immunity immediately, and is in full effect after a week. In addition to the use of vaccine after infection, there may be an effective antiviral drug, Cidofovir (made by Gilead Sciences of Foster City, Calif.), sold under the brand name Vistide. This drug won FDA approval in June 1996 for the treatment of cytomegalovirus retinitis, a sight-threatening viral infection in AIDS patients. In March 1998, researchers at the U.S. Army Medical Research Institute of Infectious Disease reported that Cidofovir prevented death and disease associated with a pox disease in primates—monkeypox—similar to smallpox in humans.
Fifth, we have standard protocol in place for dealing with infectious disease. Right now, physicians (nearly all of whom have never seen a case of smallpox) are being educated to be on high alert for the symptoms of smallpox, particularly the high fever and unique rash which appears on the face and extremities. Should a case be diagnosed—and make no mistake, one case would be considered an epidemic and a world-wide catastrophe—the patient would be isolated, all exposed medical personnel would be vaccinated, as would emergency personnel. Case contact tracing to identify recent close contacts of "Patient Zero" would begin, and they would be immunized and/or isolated.
We have something of a model protocol for this emergency activity: In New York City in late March 1947, a man arrived from Mexico, sick with smallpox. He was hospitalized, but the disease was not recognized until two other cases in the hospital were identified. These individuals were isolated, medical personnel inoculated, and a decision made to inoculate all New Yorkers who had not been vaccinated recently. In just over a month, more than 6 million residents were immunized. In the end, that smallpox epidemic resulted in only 12 cases—demonstrating the effectiveness of preparedness and a systematic, scientifically sound response.
The better technology and medical knowledge we have today should offer even more assurance.
Dr. Whelan is president of the American Council on Science and Health.
You had a little "scoop" re this part of the article this past weekend!
"obscuranist"
Ohhhhh, I like that word. Can I use it sometime?
Let not your heart be troubled. :)
Which is what I kept saying on the other thread and you could not understand.
Once again. Wrong. Especially in a population where people are vaccinated against the disease.
Could you please give the post number where I say that is not the case?
The ROUTE of infection was never in dispute. WHEN a person becomes contagious is in dispute.
Free Vulcan posted a very good synopsis. It makes the issue perfectly clear.
Do you agree?
Once again. Wrong. Especially in a population where people are vaccinated against the disease.
From the American Medical Association:
Historically, the rapidity of smallpox transmission throughout the population was generally slower than for such diseases as measles or chickenpox. Patients spread smallpox primarily to household members and friends; large outbreaks in schools, for example, were uncommon. This finding was accounted for in part by the fact that transmission of smallpox virus did not occur until onset of rash. By then, many patients had been confined to bed because of the high fever and malaise of the prodromal illness. Secondary cases were thus usually restricted to those who came into contact with patients, usually in the household or hospital.
and...
In addition, the immune status of those who were vaccinated more than 27 years ago is not clear. The duration of immunity, based on the experience of naturally exposed susceptible persons, has never been satisfactorily measured. Neutralizing antibodies are reported to reflect levels of protection, although this has not been validated in the field. These antibodies have been shown to decline substantially during a 5- to 10-year period.24 Thus, even those who received the recommended single-dose vaccination as children do not have lifelong immunity. However, among a group who had been vaccinated at birth and at ages 8 and 18 years as part of a study, neutralizing antibody levels remained stable during a 30-year period.31 Because comparatively few persons today have been successfully vaccinated on more than 1 occasion, it must be assumed that the population at large is highly susceptible to infection.
It was rather astonishing given that Vulcan had directly contradicted your statements in #293 with his in #295.
In 293 you wrote (accurately):
The other reason smallpox is difficult to diagnose is that the early symptoms mimic the flu or common cold, and the inital infective stages the rash MAY be confined to only the oral cavity. your 293
The above from you is correct and was my point the entire time. I have no idea why it took you until 293 to admit or understand it.
Vulcan, on the other and contradicts you:
2. The first syptoms of smallpox mimic the flu, however the person is still not contagious at this point.
3. Smallpox first becomes contagious when lesions/pox appear, AFTER the flu-like symptoms have existed for a day or two. Vulcun 295
Certainly people are infectious before lesions and pox occur (unless you are calling the rash confined to the oral cavity "lesion/pox", which would not really be accurate within what is commonly understood as lesion/pox.)
Like I said, I was dumbfounded as to your agreeing with him when just two posts prior you had made a statement that his post directly contradicted.
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