In 1992, a Soviet defector revealed to Western intelligence that he had overseen an extensive, illegal program to develop smallpox into a highly effective biological weapon.
Since 911, Governments around the world have been warned to prepare against a terrorist smallpox attack, which could kill millions. The World Health Organization has told them to ensure they can produce enough vaccine to protect their population against the disease, and is preparing to order mass precautionary vaccination of all citizens.
The numbers of people killed by smallpox in previous centuries are so large that they are numbing. Some authors credit smallpox with the collapse of both the Aztec and Incan empires, civilizations that had prospered for centuries in South America, Mexico, and nearly halfway into the North American continent.
Smallpox is a viral disease unique to humans and has been rated among the most dangerous of all potential biological weapons. Animals and insects cannot be infected by smallpox, or carry the virus in any form. Most infections are caused by contact with a person who had already developed the characteristic skin lesions (pox) of the disease, although a person who had a less severe infection could unwittingly spreading the virus.
Smallpox has two forms:
Variola major -- a serious illness with a mortality rate according to the CDC of 30% or more, in unvaccinated people.
Variola minor -- a milder infection with a mortality rate of less than 1%.
The value of any biological weapon is that it serves both a tactical and strategic function:
Tactical because it can quickly destroy enemy troops, and disrupts production and distribution of equipment. Friendly troops and citizens can be protected through inoculation.
Strategic because it can act as a major psychological factor, even if it抯 tactical success is limited. Further, unlike nuclear weapons, there is no destruction of property. An attacker only has to clean up the bodies when they move into an unoccupied city.
Where might the virus come from? At one time, it was believed that the smallpox virus could be found only in one or two high-security laboratories, one at the Centers for Disease Control and Prevention in Atlanta, Georgia, and one at the Russian State Center for Research on Virology and Biotechnology, Koltsovo, Novosibirsk Region. By resolution of the 1996 WHA (World Health Assembly), those stocks were supposed to be destroyed at the end of June 1999. On May 22, 1999, the WHA, however, passed a resolution postponing destruction until 2002, by which time any promise of the variola virus stocks for public health research could be determined. Destruction of the virus would be at least one step to limit the risk for the reemergence of smallpox. Despite widespread acceptance of the 1972 Bio-weapons Convention Treaty, which called for all countries to destroy their stocks of bio-weapons and to cease all research on offensive weapons, other laboratories in Russia and perhaps in other countries maintain the virus.
Iraq and the Soviet Union were signatories to the convention, as was the United States. Recently, it was reported by the former deputy director of the Russian Bio-weapons Program, officials of the former Soviet Union took notice of the world's decision in 1980 to cease smallpox vaccination, and in the atmosphere of the cold war, they began to produce smallpox virus in large quantities for potential use it as a weapon. At least two other laboratories in the former Soviet Union have now be reported to have maintained the smallpox virus, and one may have the capacity to produce the virus in tons at least monthly. Also, it is likely that Russian biologists, like their physicists and chemists, may have left Russia to sell their services to other governments.
The following is a list of some of the countries commonly cited by experts as having probable or known involvement in chemical and/or biological weapons. However, many other countries are suspected of having such programs. Russia, North Korea, South Korea, China, United States, Libya, Syria, Israel, Iraq, Iran, and Taiwan. The United States can protect its citizen抯 through mass inoculation and contain the spread of the disease, but third-world countries will not be able too. A large smallpox outbreak could spread and engulf the attacker's community with a much higher casualty rate. It is possible that terrorists whose objective is to spread fear without a national strategic purpose would find a even a few deaths gratifying, and would be willing to risk it spreading to other less prepared countries.
Bio-terrorism is the intentional use of infectious biological agents, or germs, to cause illness. An act of bio-terrorism will present itself in 1 of 3 ways: a credible threat, a site or a package, or a clandestine release. Smallpox could be released by aerosol, and it would spread easily because the virus remains very stable in aerosol form. It would take no more than 50-100 cases to cause legitimate concern on an international level. Emergency measures would need to be taken immediately. It is also important to remember that during the smallpox epidemics in the 1960s and 1970s in Europe, there was considerable public alarm whenever outbreaks occurred and, often, a demand for mass vaccination throughout a very widespread area, even when the vaccination coverage of the population was high.
The first occurred in Meschede, Germany, in 1970. A man came back from Pakistan with a fever, diarrhea, and an atypical rash and cough, which disseminated a fine particle aerosol that stayed suspended in the air. He was taken to a smallpox hospital and the workers were vaccinated, yet the virus spread through the whole building. This outbreak showed that smallpox virus in an aerosol form can spread widely and infect at very low doses.
Another outbreak occurred in Yugoslavia in February 1972. A man returned from Iraq with a rash. This rash was directly transferred to people from various places, and over 10,000 had eventually been in contact. Nearby countries closed their borders and the government vaccinated 19 million people in 10 days. Only 175 cases of smallpox actually occurred, but it was a devastatingly huge outcome economically. If such a case occurred here we would not have enough of the vaccine to cover every susceptible person who had been in contact with the virus. Despite routine vaccination in Yugoslavia, the first case in the 1972 outbreak resulted in 11 others; those 11, on average, each infected 13 more.
Other outbreaks in Europe from 1958 on showed that such explosive spread was not unusual during the seasonal period of high transmission, (December through April). No one can predict how rapidly the smallpox virus might spread in a population where no one younger than 25 years of age has ever been vaccinated and older persons have little or no remaining residual immunity.
In the United States, where few people now have protective levels of immunity (childhood vaccination ceased in 1972), such levels of concern need to be anticipated. However, the US vaccine supply is limited at present; thus, vaccine would have to be carefully conserved and used in conjunction with measures to implement rapid isolation of smallpox patients.
Smallpox is a highly contagious virus that is usually spread through the air and infects 30% of the people who are exposed to it. Once infected, there is no cure. None of our current antiviral medications is effective. Smallpox can also be spread from person to person and through infected blankets, linens, and clothing. Symptoms don't start until about 12 days after exposure to the virus. At first, it's like the flu, causing an under-the-weather feeling of fever, nausea, vomiting, headache, and backache. Then, severe abdominal pain and disorientation can set in, as small round sores breakout all over the skin. About 30% of people who become infected will die, and the survivors can be left with permanent scars and are often blind (blindness from scarring in conjunctivus).
Death is caused by infection of the lungs, heart, or brain. Blindness and male infertility are possible side effects of smallpox among survivors. A person with smallpox is infectious from about the third day through the erupting phase. Survivors usually experience long-term immunity to the disease.
If a person is exposed to smallpox, giving that person the smallpox vaccine within four days can lessen the severity of the illness and may even prevent it. Otherwise, there is no treatment to date, but researchers from the government and the pharmaceutical industry are working to find possible therapies. Depending on the strain, 1% - 30% mortality is likely. Most deaths are due to infections, so a good portion of life saving is from keeping the wounds clean.
A clandestine aerosol release of smallpox, even if it infected only 50 to 100 persons to produce the first generation of cases, would rapidly spread expanding by a factor of 10 to 20 times or more with each generation of cases. Between the time of an aerosol release of smallpox virus and diagnosis of the first cases, an interval as long as 2 weeks or more can occur because of the average incubation period of 12 to 14 days and the lapse of several additional days before a rash would be sufficiently distinct to suggest the diagnosis of smallpox. By that time, there would be no risk of further exposure from the original airborne aerosol release because the virus would have been fully inactivated within 2 days. As smallpox is so highly contagious, anyone exposed to it is considered at risk. For this reason, VIG (variola immune globulin) and smallpox vaccine will probably be given to anyone known to come into contact with a smallpox patient.
Smallpox (Vaccinia virus), if released as an aerosol and not exposed to UV light, may persist for as long as 24 hours or somewhat longer under favorable conditions. By the time patients had become ill and it had been determined that an aerosol release of smallpox virus had occurred; there would be no viable smallpox virus in the environment. Vaccinia virus, if released as an aerosol, is almost completely destroyed within 6 hours in an atmosphere of high temperature (31癈-33癈) and humidity (80%). In cooler temperatures (10癈-11癈) and lower humidity (20%), nearly two thirds of a vaccinia aerosol survives for as long as 24 hours.
Smallpox spreads faster during the cool, dry winter months but can be transmitted in any climate and in any part of the world. The only weapons against the disease are vaccination and patient isolation. Vaccination before exposure or within 2 to 3 days after exposure affords almost complete protection against disease. Vaccination as late as 4 to 5 days after exposure, may protect against death. Because smallpox can only be transmitted from the time of the earliest appearance of rash, early detection of cases and prompt vaccination of all contacts is critical.
Smallpox infection among personnel who handled laundry from infected patients has been well documented and it is believed that virus in such material remains viable for extended periods. I do not know for how long. So you will need to take special precautions to ensure that all bedding and clothing of smallpox patients is autoclaved or laundered in hot water to which bleach has been added. Disinfectants that are used for standard hospital infection control, such as hypochlorite and quaternary ammonia, are effective for cleaning surfaces possibly contaminated with virus.
In September 1978 Janet Parker, a medical photographer at the University of Birmingham, was accidentally infected with smallpox and later died. Her illness was initially diagnosed as a drug rash but soon after pustules appeared on her body. Mrs. Parker's mother also developed smallpox, but survived. The ensuing investigation never established exactly how the smallpox virus had escaped from the university's laboratory. This accident was a sharp reminder that humans remained vulnerable to the disease, especially as routine vaccination had ended in many countries in the 1970s.
Routine vaccination is only recommended for laboratory staff that may be exposed to one of the orthopoxviruses. There are two reasons for this. First is the risk for complications. Second, U.S. national vaccine stocks are sufficient to immunize only 6 to 7 million persons. This amount is only marginally sufficient for emergency needs. Plans are now being made to expand this reserve. However, at least 36 months are required before large quantities can be produced. Vaccination has been shown to wear off in most people after 10 years, but may last longer if a person has been successfully vaccinated on multiple occasions.
There are currently approximately 7 million emergency vaccine doses in the U.S. with more stockpiled in other countries. Currently Acambis (formerly OraVax) in Cambridge, Massachusetts has been authorized to make another 40 million doses of the vaccine. These doses were supposed to be ready by 2004, but they are now expected to be available sometime during the summer of 2002.
Scientists have reported that if the United States was attacked with smallpox, doctors may be able to dilute the nation's vaccine stockpile to create as many as 150 million doses, enough to vaccinate more than half the population. The U.S. government has also confirmed that anywhere from 70 million to 90 million doses of smallpox vaccine were found, by Aventis Pasteur of Lyon, France, which has its U.S. operations in Swiftwater, Pa.
Taken together, the two developments mean the country may be in far better shape to counter a smallpox outbreak than it appeared to be right after the Sept. 11 terrorist attacks. Aside from the older stockpiles, the Department of Health and Human Services has reordered smallpox vaccine for the first time in decades and is expected to receive 209 million doses before the year is out.
I have heard that as many as 300 million more doses have been ordered, but I have not been able to verify this. There are complications with the vaccine and such as Bacterial infections at the skin at the sites of the lesions, pitted scars from pustules, arthritis and bone infections, pneumonia, severe bleeding, eye infections, brain inflammation (encephalitis) and even death.
The current CDC plan does not call for mass vaccination of the U.S. population in advance of a smallpox outbreak. According to the plan, rings of personal contacts, such as family members and co-workers, would be identified and then be vaccinated and monitored. This strategy, known as ring vaccination, is credited with helping to wipe out smallpox in the late 1970s and is seen as the most efficient approach today.
It is important to remember that the foremost public health priority during a smallpox outbreak would be control of the epidemic.
The best way for a family to be safe is to be as prepared as possible before any disaster strikes. Consistent with long-standing
guidelines on disaster preparedness, including natural disasters such as hurricanes or blizzards, families should plan to provide
necessities for themselves for at least a 3-4-day period, in the event that they have to remain inside their home for their safety.
All materials at this site not otherwise credited are Copyright ?1996 - 2002 Trip Williams. All rights reserved. May be reproduced for personal use only. Use of any material contained herein is subject to stated terms or written permission.日韩av在线观看一区免费_日韩在线中文字幕有码中文_韩国三级年轻小的胰子