DHS: Secretary Napolitano Announces Implementation of National Terrorism Advisory System

DHS: Secretary Napolitano Announces Implementation of National Terrorism Advisory System.

Brucellosis

Photo source CDC.gov

OVERVIEW: 

The Brucellae are a group of gram-negative cocco-baccillary organisms, of which four species are pathogenic in humans.  Abattoir and laboratory workers infections suggest that Brucella spp. are highly infectious via the aerosol route.  It is estimated that inhalation of only 10 to 100 bacteria is sufficient to cause disease in man.  The relatively long and variable incubation period (5-60 days) and the fact that many infections are asymptomatic under natural conditions has made it a less desirable agent for weaponization, although large aerosol doses may shorten the incubation period and increase the clinical attack rate.  Brucellosis infection has a low mortality rate (5% of untreated cases) with most deaths caused by endocarditis or meningitis.  It is an incapacitating and disabling disease in its natural form.

HISTORY AND SIGNIFICANCE:  Marston described disease caused by B. melitensis among British soldiers on Malta during the Crimean War as “Mediterranean gastric remittent fever”.  Work by the Mediterranean Fever Commission identified goats as the source of human brucella infection on Malta, and restriction of the ingestion of unpasteurized goats milk and cheese soon decreased the number of cases of brucellosis among military personnel.

In 1997, most cases were associated with ingestion of unpasteurized dairy products and abattoir and veterinary work.  In the United States most cases are reported from Florida, California, Virginia, and Texas.  It is a rare disease in the United States with an incidence of 0.5 per 100,000 population.

In 1954,Brucella suis became the first agent weaponized by the U.S. in the days of its offensive BW program at the newly constructed Pine Bluff Arsenal.  Despite this, B melitensis actually produces more severe human disease.

CLINICAL FEATURES:  Brucellosis may present as a nonspecific febrile illness which resembles influenza.  Fever, headache, myalgia, arthralgia, back pain, sweats, chills, and generalized weakness and malaise are common complaints.  Cough and pleuritic chest pain may occur in up to twenty percent of cases, but these are usually not associated with acute pneumonitis.  Pulmonary symptoms may not correlate with radiographic findings.  The chest x-ray may be normal, or show lung abscesses, single or miliary nodules, bronchopneumonia, enlarged hilar lymph nodes, and pleural effusions.  Gastrointestinal symptoms occur in up to 70 percent of adult cases, and less frequently in children.  These include anorexia, nausea, vomiting, diarrhea and constipation, ileitis, colitis and granulomatous or a mononuclear infiltrative hepatitis may occur.  Lumbar pain and tenderness can occur in up to 60% of cases is due to various osteoarticular infections of the axial skeletal system.  Paravertebral abscesses may occur and can be imaged by CT scan or MRI.  CT scans often show vertebral sclerosis.  Vertebral and disc space destruction may occur in chronic cases.  One or, less frequently, both sacroiliac joints may be infected causing low back, and buttock pain that is intensified by stressing the sacroiliac joints on physical exam.  Hepatomegaly and splenomegaly can occur in up to 45-63 percent of cases.  Peripheral joint involvement may vary from pain on range of motion testing to joint immobility and effusion.  Peripheral joint effusions usually show a mononuclear cell predominance and organisms can be isolated in up to 50% of cases.  The hip joints are the most commonly involved peripheral joints, but ankle, knee, and sternoclavicular joint infection may occur.  Plain radiographs of involved sacroiliac joints usually show blurring of articular margins and widening of the joint space.  Technetium or Gallium-67 bone scans are 90% sensitive for detecting sacroileitis and will also detect other sites of bone and joint involvement; they are also useful for differentiating sacroiliac from hip joint involvement.

Meningitis occurs in less than 5% of cases and may be an acute presenting illness of a chronic syndrome occurring late in the course of a persistent infection.  The cerebrospinal fluid contains an increased number of lymphocytes and a low to normal glucose.  Culture of the CSF has sensitivity of 50%, and specific brucella antibodies can be detected in the fluid in a higher percentage of cases.  Encephalitis, peripheral neuropathy, radiculoneuropathy and meningovascular syndromes have also been observed in rare cases.  Behavioral disturbances in children and psychoses may occur as the most frequent genitourinary form of burcellosis.  Rases occur in less than 5% if cases and include macules, papules, ulcers, purpura, petechiae, and erythema nodosum.

DIAGNOSIS:  The leukocyte count is usually normal but may be low.  Anemia and thrombocytopenia may occur.  Blood and bone marrow culture during the acute febrile phase of the illness will yield a positivity rate of 15-70% and 92% respectively.  A biphasic culture method for blood (Castaneda bottle) may increase the number of isolates.  The serum agglutination test (SAT) will detect both IgM and IgG antibioties.  A titer of 1:160 or greater is indicative of active disease.  The IgM titer can be measured by adding a reduced agent such as 2-mercaptoethanol to the serum.  This will destroy the agglutinability of IgM allowing the IgM titer to be measured by subtracting the now lower titer from the total serum agglutinin titer.  A dot-ELISA using an autoclaved extract of B. abortus has been found to be a sensitive and specific screening test for detection of Brucella antibodies under field conditions.  ELISA tests for antibody detection require standardization using a specific antigen before they will be widely available.  Antigen detection on DNA extracted from blood mononuclear cells has been accomplished using PCR analysis of a target sequence on the 31-kilodalton B. abortus protein BCSP 31.  This test has been proven to be rapid and specific and may replace blood culture in the future, since the latter may require incubation for up to 6 weeks.  PCR for Brucella species is not available at this time except in research laboratories, but shows promise for future use.

MEDICAL MANAGEMENT:  Isolation is not required other than contact isolation for draining lesions.  Person to person transmission is possible via contact with such lesions.  Biosafety level 3 practices should be used for suspected brucella cultures in the laboratory because of the danger of inhalation infection.  Antibiotic therapy is recommended as the sole therapy unless there are surgical indications for the treatment of localized diseases (e.g., valve replacement for endocarditis).

The treatment recommended by the World Health Organization for acute brucellosis is adults is doxycycline 200 mg/day p.o. plus rifampin 600-900 mg/day for a minimum of six weeks.  The previously established regimen of intramuscular streptomycin along with an oral tetracycline may give fewer relapses but is no longer the primary recommendation.   Ofloxacin 400 mg/day and rifampin 600mg/day p.o. is also an effective combination.  Combination therapy with rifampin, a tetracycline, and an aminoglycoside is indicated for infections with complications such as meningoencephalitis or endocarditis.  Doxycycline clearance is increased in the presence of rifampin and plasma levels are lower than when streptomycin is used instead of rifampin.

PROPHYLAXIS:  Live animal vaccines are used widely.  Consumption of unpasteurized milk and cheese should be avoided.  No approved human brucella vaccine is available.  An experimental human burcellosis vaccine has been tested on 271 subjects with a 25% rate of unpleasant acute side effects, but no long term adverse side effects.

Reference: Biological Warfare and Terrorism, The Military and Public Health Response, Satellite Broadcast, Sept. 1999.

History of Biological Warfare and Current Threat

The use of biological warpons and efforts to make them more useful as a means of waging war have been recorded numerous times in history.  Two of the earliest reported uses occurred in the 6th century BC, with the Assyrians poisoning enemy wells with rye ergot, and Solon’s used of the purgative herb hellebore during the siege of Krissa.  In 1346, plague broke out in the Tartar army during its siege of Kaffa (at present day Feodosia in Crimea).  The attackers hurled the corpses of those who died over the city walls; the plague epidemic that followed forced the defenders to surrender, and some infected people who left Kaffa may have started the Black Death pandemic which spread throughout Europe.  Russian troops may have used the same plague-infected corpse tactic against Sweden in 1710.

On several occasions, smallpox was used as a biological weapon.  Pizarro is said to have presented South American natives with variola-contaminated clothing in the 15th century, and the English did the same when Sire Jeffery Amherst provided Indians loyal to the French with smallpox-laden blankets during the French and Indian War of 1754 to 1767.  Native Americans defending Fort Carillon sustained epidemic casualties which directly contributed to the loss of the fort to the English.

In this century, there is evidence that during World War 1, German agents inoculated horses and cattle with glanders in the U.S. before the animals were shipped to France.  In 1937, Japan started an ambitious biological warfare program, located 40 miles south of Harbin, Manchuria, in a laboratory complex code named “Unit 731″.  Studies directed by Japanese General Ishii continued there until 1945, when the complex was leveled by burning it.  A post World War II investigation revealed that numerous organisms had received Japanese research attention, and that experiments had been conducted on prisoners of war.  Slightly less than 1,000 human autopsies apparently were carried out at Unit 731, most on victims exposed to aerosolized anthrax.  Many more prisoners and Chinese nationals may have died in this facility some have estimated up to 3,000 huan dealths.  In 1940, a plague epidemic in China and Manchuria followed reported overflights by Japanese planes dropping plague-infected fleas.  By 1945, the Japanese program had stockpiled 400 kilograms of anthrax to be used in a specially designed fragmentation bomb.

In 1943, the United States began research into the offensive use of biological agents.  This work was stated, interestingly enough, in response to a preceived German biological warfare (BW) threat as opposed to a Japanese one.  The United States conducted this research at Camp Detrick (now Fort Detrick), which was a small National Guard airfield prior to that time, and produced agents at other sites until 1969, when President Nixon stopped all offensive biological and toxin weapon research and production by executive order.  Between May 1971 and May 1972, all stockpiles of biological agents and munitions from the now defunct U.S. program were destroyed in the presence of monitors representing the United States Department of Agriculture, the Department of Health, Education, and Welfar, and the states of Arkansas, Colorado, and Maryland.  Included among the destroyed agents were Bacillus anthracis, botulinum toxin, Francisella tularensis, Coxiella Burnetii, Venezuelan equine encephalitis virus, Brucella suis, and Staphylococcal enterotoxin B.  The United States also had a medical defensive program, begun in 1953, that continues today at USAMRIID.

In 1972, the United States and many other countries signed the Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destrution, commonly called the Biological Weapons Convention.  This treaty prohibits the stockpiling of biological agents for offensive miltary purposes, and also forbids research into such offensive employment of biological agents.  The former Soviet Union and the government of Iraq were both signatories to this accord.  However, despite this historic agreement among nations, biological warfare research continued to flourish in many countries hostile to the United States.  There were also several cases of suspected or actual use of biological weapons.  Among the most notorius of these were the “yellow rain” incidents in Southeast Asia, the accidental release of anthrax at Sverdlovsk, and the use of ricin as an assassination weapon in London in 1978.

Testimony from the late 1970′s indicated that the countries of Laos and Kampuchea were attacked by planes and helicopters delivering aerosols of several colors.  After being exposed, people and animals became disoriented and ill, and a small percentage of those stricken died.  Some of these clouds were thought to be comprised of trichothecene toxins (in particular, T2 mycotoxin).  These attacks are lumped under the label “Yellow Rain”.  There has been a great deal of controversy about whether these clouds were truly biological warfare agents: some have argued that the clouds were nothing more than bee feces produced by swarms of bees.

In late April of 1979, an incident occurred in Sverdlovsk (now Yekaterinburg) in the former Soviet Union which appeared to be an accidental release of anthax in aerosol form from the Soviet Military Compound 19, a microbiology facility.  Residents living downwind from tis compound developed high fever and difficulty breathing, and a large number died.  The death toll was estimated at the time to be between 200 and 1,000.  The Soviet Ministry of Health blamed the deaths on the consumption of contaminated meat, and for years controversy raged in the press over the actual cause of the otubreak.  All evidence available to the United States government indicated a massive release of aerosolized anthrax.  In the summer of 1992, U.S. intellegence officials were proven correct when new Russian President Boris yeltsin acknowledged that the Sverdlovsk incident was in fact a large scale accident involving the escape of an aerosol of anthrax spores from the military research facility.  In 1994, Meselson and colleagues published an in-depth analysis of the Sverdlovsk incident (Science 266:1202-1208).  They documented tht all of the 1979 cases occurred within a narrow zone extending downwind in a southerly direction from Compound 19.  A total of 77 patients were identified by Meselson’s team, including 66 fatalities and 11 survivors.

Before the Sverdiovsk incident, in 1978, a Bulgarian exile named Georgi Markov was attacked in London with a device disguised as an umbrella which injected a tiny pellet filled with ricin toxin into the subcutaneous tissue of his leg while he was waiting for a bus.  He died several days later.  On autopsy, the timy pellet was found and determined to contain the toxin.  This assassination, it was later revealed, was carried out by the communist Bulgarian government, and the technology to commit the crime was supplied to the Bulgarians by the former Soviet Union.

In August of 1991, the first United Nations inspection of Iraq’s bilogical warfare capabilities was carried out in the aftermath of the Gulf War.  On August 2, 1991, representatives of the Iraqui government announced to leaders of United Nations Special Commission Team 7 that they had conducted research into the offensive use of Bacillus anthracis, botulinum toxins, and Clostridium perfringens(presumably one of its toxins).  This was the first open admission of biological weapons research by any country in recent memory, and it verified many of the concerns of the U.S. intelligence community publicly.  Iraq had extensive and redundant research facilities at Salman Pak and other sites, many of which were destroyed during the war.

In 1995, further information on Iraq’s offensive program was made available to United Nations inspectors.  Iraq conducted research and development work on anthrax, botulinum toxins, Clostridium perfringens, aflatoxins, wheat cover smut, and ricin.  Field trials were conducted with Bacillus subtilis(a simulant for anthrax), botulinum toxin, and aflatoxin.  Biological agents were tested in various delivery systems, including rockets, aerial bombs, and spray tanks.  In December 1990, the Iraqis filled 100 R400 bombs with botulinum toxin, 50 with anthrax, and 16 with aflatoxin.  In addition, 13 Al Hussein (SCUS) warheads were filled with botulinum toxin, 10 with anthrax, and 2 with aflatoxin.  These weapons were deployed in January 1991 to four locations.  All in all, Iraq produced 19,000 liters of concentrated botulinum toxin (nearly 10,000 liters filled into munitions), 8,500 liters of concentrated anthrax (6,500 liters filled into munitions) and 2,200 liters of aflatoxin (1,580 liters filled into munitions).

The threat of biological warfare has increased in the last two decades, with a number of countries working on offensive use of these agents.  The extensive program of the former Soviet Union is now controlled largely by Russia.  Russian president Boris Yeltsin has stated that he will put an end to further offensive biological research; however, the degree to which the program has been scaled back, if any, is not known.  Recent revelations from a senior BW proram manager who defected from the FSU in  1992 outlined a remarkable robust biological warfare program including active research into genetic engineering, binary biologicals and chimeras.  There is also growing concern that the smallpox virus, elminated from the face of the earth in the late 1970′s and now stored in only two laboratories at the CDC in Atlanta and the Institute for Viral Precautions in Moscow, Russia, may have been “bargained” away by desperate Russian scientists seeking money.

There is intense concern in the West about the possibility of proliferation or enhancement of offensive programs in countries hostile to the western democracies, due to the potential hiring of esxpatriate Russian scientists.  It was reported in January 1998 that Iraq had sent about a dozen scientists involved in BW research to Libya to help that country develop a biological warfare complex disguised as a medical facility in the Tripoli area.  In a report issued in November 1997, Secretary of Defense William Cohen singled out Libya, Iraq, Iran, and Syria as countries “aggressively seeking” nuclear, biological, and chemical weapons.

There is also an increasing amount of concern over the possibility of terrorist use of biological agents to threaten either military or civilian populations.  There have been cases of persons loyal to extremist groups trying to obtain microorganisms which could be used as biological weapons.  The Department of Defense is leading a federal effort to train the first responders in 120 American cities to be prepared to act in case of a domestic terrorist incident involving WMD.

Certainly the threat of biological weapons being used against U.S. military forces is broader and more likely in various geographic scenarios than at any point in our history.  Therefore, awareness of this potential threat and education of our leaders and medical care providers on how to combat it are crucial.

Reference: Biological Warfare and Terrorism, The Military and Public Health Response, Satellite Broadcast, September 21-23, 1999.

Bioterrorism

Bioterrorism

Bioterrorism is terrorism by intentional release or dissemination of biological agents (bacteria, viruses or toxins); these may be in a naturally-occurring or in a human-modified form.

Definition

According to the U.S. Centers for Disease Control and Prevention (CDC):

A bioterrorism attack is the deliberate release of viruses, bacteria, or other germs (agents) used to cause illness or death in people, animals, or plants. These agents are typically found in nature, but it is possible that they could be changed to increase their ability to cause disease, make them resistant to current medicines, or to increase their ability to be spread into the environment. Biological agents can be spread through the air, through water, or in food. Terrorists may use biological agents because they can be extremely difficult to detect and do not cause illness for several hours to several days. Some bioterrorism agents, like the smallpox virus, can be spread from person to person and some, like anthrax, can not.

History

Biological terrorism dates as far back as ancient Roman civilization, where dead and rotting animals were thrown into wells to poison water supplies. (Bock,2001) This early version of biological terrorism was used to destroy enemy forces covertly. It continued on into the 14th century where the bubonic plague was used to infiltrate enemy cities by both instilling the fear of infection in residences, in hopes that they would evacuate, and also to destroy defending forces that would not yield to the attack. The use of disease as a weapon in this stage of history exhibited a lack of control aggressors had over their own biological weapon. Primitive medical technology provided limited means of protection for the aggressor and a battles surrounding geographical regions. After the battle was won, the inability to contain enemies who escaped death lead to wide spread epidemics affecting not only the enemy forces, but also surrounding regions inhabitants. Due to the use of these biological weapons, and the apparent lack of medical advancement necessary to defend surrounding regions from them, wide spread epidemics such as the bubonic plague quickly moved across all of Western Europe, destroying a large portion of its population. The victims of biological terrorism in fact became weapons themselves. This was noted in the Middle Ages, but medical advancements had not progressed far enough to prevent the consequences of a weapons use. (Eitzen and Takafuji, 1997)

In the 15th century, smallpox was used on contaminated clothing to defeat South American and Native American forces. (Bock, 2001) Again, the use of biological weapons for which limited protection and containment was available, lead to casualties on both sides of battles. Bioterrorism continued to be an effective method of weakening an adversary but it was also difficult to contain. In the Revolutionary War, colonists were vaccinated from the small-pox virus and then used the virus to intentionally infect enemies. This demonstrates a major advancement in the evolution of bioterrorism. Once the ability to defend from biological warfare became possible through medical advancement, the weapons became far more valuable.

As time continued the use of biological warfare became more and more sophisticated. Countries were developing weapons that delivered much higher effectiveness and less chance of infecting the wrong party. One significant enhancement in biological weapon development was the first use of Anthrax. Anthrax effectiveness was initially limited to victims of large dosages. This became a weapon of choice because it is easily transferred, has a high mortality rate, and can be easily obtained. Also, variants of the Anthrax bacterium can be found all around the world making it the biological weapon of choice in the early 19th century. Another property of Anthrax that helped fuel its use as a biological weapon is its poor ability to spread far beyond the targeted population.

By the time World War I began, attempts to use anthrax were directed at animal populations. This was ineffective. Instead, the use of poisonous mustard gas became the biological weapon of choice. The sheer horror of its affects lead to a treaty called the Geneva Protocol of 1925. The treaty was created to prevent the use of asphyxiating gas as a method of biological warfare. (Brooks, 2001) While this was a significant advancement toward the prevention of biological weapon use, the treaty said nothing about weapon development. Secretly, biological weapon development programs existed in many nations. While no documented instances of biological weapon use exist it is believed that this was primarily due to the programs immaturity and not the unwillingness to use them.

American biological weapon development began in 1942. President Franklin D. Roosevelt placed George W. Merck in charge of the effort to create a development program. You may recognize the name Merck, Mr. Merck is also the founder of Merck Pharmaceuticals. These programs continued until 1969, when by executive order President Richard Nixon shut down all programs related to American offensive use of biological weapons. (http://fas.org/nuke/guide/usa/cbw/bw.html)

Accusations of the use of biological weapons against North Korea were spread during Viet Nam, however it is believed that those accusations were propaganda developed by the North Korean regime to villainize American Armed Forces. As the 70’s passed, global efforts to prevent the development of biological weapons and their use were widespread. In 1972 the prohibition of development, production and stockpiling biological weapons was developed.

In the 1980’s Iraq made substantial efforts to develop and stockpile large amounts of biological weapons. By the end of the 80’s Iraq had several sites dedicated to the research and development of biological warfare. They began to test their findings in the late 80’s. These actions lead to the first Gulf war in which Iraq’s biological weapons were dismantled and destroyed.

Since that time, efforts to use biological warfare has been more apparent in small radical organizations attempting to create fear in the eyes of large groups. Some efforts have been partially effective in creating fear, due to the lack of visibility associated with modern biological weapon use by small organizations. In 1995 a small terrorist group launched a terrorist attack aboard a Tokyo subway. The attack killed twelve and affected more than 5000. The response of Japanese emergency services successfully prevented an outcome with much higher mortality rates.

In the United States a more recent biological terrorism attack occurred in 2001 when letters laced with infectious anthrax were delivered to news media offices and the U.S Congress. (Johnston,2005) The letters killed 5. While many believed this attack to be in relation to Iraq’s development of biological weapons, tests on the anthrax strand used in the attack pointed to a domestic source.

Types of biological agents

The CDC has defined and categorized bioterrorism agents according to priority 2 as follows:

Category A agents

These are biological agents with both a high potential for adverse public health impact and that also have a serious potential for large-scale dissemination. The Category A agents are anthrax, smallpox, plague, botulism, tularemia, and viral hemorrhagic fevers.

Anthrax
Anthrax is a non-contagious disease. An anthrax vaccine does exist but requires many injections and has side effects that render it unsuitable for general use.

Smallpox
Smallpox is a highly contagious virus. It transmits easily through the atmosphere and has a high mortality rate (20-40%). Smallpox was eliminated in the world in the 1970s, thanks to a worldwide vaccination program. However, some virus samples are still available in Russian and American laboratories. Some believe that after the collapse of the Soviet Union, cultures of smallpox have become available in other countries. Although people born pre-1970 will have been vaccinated for smallpox under the WHO program, the effectiveness of vaccination is limited since the vaccine provides high level of immunity for only 3 to 5 years. As a biological weapon smallpox is dangerous because of the highly contagious nature of both the infected and their pox. Smallpox occurs only in humans, and has no external hosts or vectors.

Botulinum toxin
Botulinum toxin is one of the deadliest toxins known, and is produced by the bacterium Clostridium botulinum. Botulism causes death by respiratory failure and paralysis. It is also easy to obtain since it is found in the cosmetic products Botox and Dysport.

Ebola
Ebola is a viral hemorrhagic fever, with fatality rates ranging from 50-90%. No cure currently exists, although vaccines are in development. The United States and the erstwhile Soviet Union both investigated the use of ebola for biological warfare, and the Aum Shinrikyo group possessed cultures of the virus. Ebola kills its victims through multiple organ failure and hypovolemic shock.

Plague
Plague is a disease caused by the Yersinia pestis bacterium. Rodents are the normal host of plague, and the disease is transmitted to humans by flea bites and occasionally by aerosol in the form of pneumonic plague. The disease has a history of use in biological warfare dating back many centuries, and is considered a threat due to its ease of culture and ability to remain in circulation among local rodents for a long period of time.

Marburg
Marburg is a viral hemorrhagic fever virus first discovered in Marburg, Germany. Fatality rates range from 25-100%, and although a vaccine is in development, no treatments currently exist aside from supportive care. As with ebola, basic barrier nursing significantly reduces the virulence of the virus.

Tularemia
Tularemia, or rabbit fever, is a generally non-lethal and severely incapacitating disease caused by the Francisella tularensis bacterium. It has been widely produced for biological warfare due to its highly infective nature, and ease of aerosolization.

Category B agents

Category B agents are moderately easy to disseminate and have low mortality rates.

Brucellosis (Brucella species) Brucellosis is an infectious disease caused by the bacteria of the genus Brucella. These bacteria are primarily passed among animals, and they cause disease in many different vertebrates. Various Brucella species affect sheep, goats, cattle, deer, elk, pigs, dogs, and several other animals. Humans become infected by coming in contact with animals or animal products that are contaminated with these bacteria. In humans brucellosis can cause a range of symptoms that are similar to the flu and may include fever, sweats, headaches, back pains, and physical weakness. Severe infections of the central nervous systems or lining of the heart may occur. Brucellosis can also cause long-lasting or chronic symptoms that include recurrent fevers, joint pain, and fatigue

• Epsilon toxin of Clostridium perfringens
• Food safety threats (e.g., Salmonella species, E coli O157:H7, Shigella, Stash)
• Glanders (Burkholderia mallei)
• Melioidosis (Burkholderia pseudomallei)
• Psittacosis (Chlamydia psittaci)
• Q fever (Coxiella burnetii)
• Ricin toxin from Ricinus communis (castor beans)
• Staphylococcal enterotoxin B
• Typhus (Rickettsia prowazekii)
• Viral encephalitis (alphaviruses, e.g.: Venezuelan equine encephalitis, eastern equine encephalitis, western equine encephalitis)
• Water supply threats (e.g., Vibrio cholerae, Cryptosporidium parvum, Cholera )

Category C agents

Category C agents are pathogens that might be engineered for mass dissemination because they are easy to produce and have potential for high morbidity or mortality (examples: nipah virus, hantavirus and multi-drug resistant Tuberculosis (MTB).

Bioterrorism on Wikipedia

For more information about Bioterrorism please visit Bioterrorism on Wikipedia.

Anthrax Infection Control Information

Anthrax Information

Anthrax (Greek Άνθραξ for coal) is an acute disease in humans and animals that is caused by the bacterium Bacillus anthracis and is highly lethal in some forms. Anthrax is one of only a few bacteria that can form long-lived spores. When the bacteria’s life cycle is threatened by factors such as lack of food caused by their host dying or by a change of temperature, the bacteria turn themselves into more or less dormant spores to wait for another host to continue their life cycle.

On breathing, ingesting or getting spores in a cut in the skin, a new host allows these spores to reactivate themselves and multiply in their new host very rapidly. The anthrax spores in soil are very tough and can live many decades and perhaps centuries and are known to occur on all continents except Antarctica. Anthrax most commonly occurs in wild and domestic grass-eating mammals (ruminants) who ingest or breathe in the spores while eating grass. Anthrax can also be caught by humans when they are exposed to dead infected pigs, eat tissue from infected animals, or are exposed to a high density of anthrax spores from an animal’s fur, hide, or wool. Anthrax spores can be grown outside the body and used as a biological weapon. Anthrax cannot spread directly from human to human; but anthrax spores can be transported by human clothing, shoes etc. and if a person dies of anthrax their body can be a very dangerous source of anthrax spores. The word anthrax is the Greek word for coal, the germ’s name is derived from anthrakitis, the Greek word for anthracite, in reference to the black skin lesions victims develop in a cutaneous skin infection.

Anthrax Overview

Anthrax is one of the oldest recorded diseases of grazing animals such as sheep and cattle and is believed to be the Sixth Plague mentioned in the Book of Exodus in the Bible. Anthrax is also mentioned by Greek and Roman authors such as Homer (in The Iliad), Virgil (Georgics), and Hippocrates. Anthrax can also infect humans, usually as the result of coming into contact with infected animal hides, fur, wool (“Woolsorter’s disease”), leather or contaminated soil. Anthrax (“siberian ulcer”) is now fairly rare (a few to no cases per year in the developed world) in humans although it still occasionally occurs in ruminants, such as cattle, sheep, goats, camels, wild buffalo, and antelopes.

Bacillus anthracis bacteria spores are soil-borne and because of their long lifetime they are still present globally and at animal burial sites of anthrax-killed animals for many decades; spores have been known to have reinfected animals over 70 years after burial sites of anthrax-infected animals were disturbed.

Before the last century anthrax infections were a source of many thousands of dead animals and thousands of people dying each year in Europe, Asia and North America. French scientist Louis Pasteur developed the first effective vaccine for anthrax in 1881. Thanks to over a century of animal vaccination programs, sterilization of raw animal waste materials and anthrax eradication programs in North America, Australia, New Zealand, Russia, Europe and parts of Africa and Asia anthrax infection is now rare in domestic animals with normally only a few dozen cases reported every year. Anthrax is even rarer in dogs and cats where there was only one documented case in the USA in the last 15 years. Anthrax outbreaks do occur in a few wild animal populations with some regularity. The disease is more common in developing countries without widespread veterinary or human public health programs.

There are 89 known strains of anthrax, the most widely recognized being the virulent Ames strain used in the 2001 anthrax attacks in the United States. The Ames strain is extremely dangerous, though not quite as virulent as the Vollum strain which was successfully developed as a biological weapon during the Second World War, but never used. The Vollum (also incorrectly referred to as Vellum) strain was isolated in 1935 from a cow in Oxfordshire, UK. This is the same strain that was used during the Gruinard bioweapons trials. A variation of Vollum known as “Vollum 1B” was used during the 1960s in the US and UK bioweapon programs. Vollum 1B was isolated from William A. Boyles, a 46-year-old USAMRIID scientist who died in 1951 after being accidentally infected with the Vollum strain. The Sterne strain, named after a South African researcher, is an attenuated strain used as a vaccine.

Anthrax From Wikipedia

For more detailed Anthrax information see the Anthrax wiki on Wikipedia.