References

Argentine Hemorrhagic Fever Virus (Junin Virus)
A species of arenavirus it is an acute febrile viral illness, lasting seven to 15 days. Onset is gradual with malaise headache, retroorbital pain, conjunctival infection, sustained fever and sweats followed by prostration. The disease is characterized by congestion, oedema, generalized lymphadenopathy and haemorrhagic necrosis, leading to death in up to 30 percent of the cases. The United States and the Soviet Union conducted biological warfare-related research with the Argentine Hemorrhagic Fever Virus.

Bolivian Hemorrhagic Fever Virus (Machupo Virus)
Machupo is classified as an Arenavirus. The disease was first noted in Bolivia in 1962, in the village of Magdalena, in Bolivia, but its source was traced to San Joaquin, just above the floodline of the Machupo River, also in Bolivia. The United States and the Soviet Union conducted BW-related research with Bolivian hemorrhagic fever virus.

Crimean-Congo Hemorrhagic Fever
Crimean-Congo hemorrhagic fever (CCHF) is a viral hemorrhagic fever of the family Bunyaviridae in the Nairovirus group. Although primarily a zoonosis, sporadic cases and outbreaks of CCHF affecting humans do occur. The disease is endemic in many countries in Africa, Europe and Asia. During 2001, cases or outbreaks have been recorded in Kosovo, Albania, Iran, Pakistan and South Africa. Symptoms include malaise, prostration, increased vascular permeability and abnormalities of circulatory regulation. The agent is highly infectious via the aerosol route, and is likely stable as a respiratory aerosol.

Eastern Equine Encephalitis Virus
Eastern equine encephalitis (EEE) is a rare disease that is spread to horses and humans by infected mosquitoes. It is among the most serious of a group of mosquito-borne virus diseases that can affect the central nervous system and cause severe complications and even death. EEE is the most severe of the arboviral encephalitides. During outbreaks of EEE, the case fatality rates are estimated to be from 50% to 75%. The illness is characterized by rapid onset of high fever, vomiting, stiff neck and drowsiness. Though natural infections occur following mosquito bites, the virus is also highly infectious via aerosol. Alphaviruses in general replicate readily and are relatively stable, leading to their former use as model systems for studies of viral replication and vector relationships. The intentional release of a small-particle aerosol may be expected to infect a high percentage of individuals within an area of at least 10,000 kilometers. The case is also true for Western Equine Encephalitis and Venezuelan Equine Encephalitis Viruses. The United States conducted research with EEE during its BW program, between 1942 and 1969.

Ebola Virus
Ebola hemorrhagic fever is a severe, often-fatal disease in humans and nonhuman primates (monkeys and chimpanzees) that has appeared sporadically since its initial recognition in 1976. The disease is caused by infection with Ebola virus, named after a river in the Democratic Republic of the Congo (formerly Zaire), where it was first recognized. The virus is one of two members of a family of RNA viruses called the Filoviridae. Three of the four species of Ebola virus identified so far have caused disease in humans: Ebola-Zaire, Ebola-Sudan and Ebola-Ivory Coast. The fourth, Ebola-Reston, has caused disease in nonhuman primates, but not in humans. Ebola is associated with a 53 to 92 percent mortality rate and is highly infectious via aerosol. The Soviet Union investigated the use of Ebola as a biological weapon.

Lassa Fever Virus
Lassa fever is an acute viral illness that occurs in West Africa. The illness was discovered in 1969 when two missionary nurses died in Nigeria, West Africa. The virus, a member of the virus family Arenaviridae, is a single-stranded RNA virus and is zoonotic, or animal-borne. Lassa fever is associated with occasional epidemics, during which the case-fatality rate can reach 50 percent. The United States and the Soviet Union conducted biological warfare-related research with Lassa virus.

Marburg Virus
Marburg hemorrhagic fever is a rare, severe type of hemorrhagic fever, which affects both humans and non-human primates. Caused by a genetically unique zoonotic RNA virus of the filovirus family, its recognition led to the creation of this virus family. The four species of Ebola virus are the only other known members of the filovirus family. Marburg virus was first recognized in 1967, when outbreaks of haemorrhagic fever occurred simultaneously in laboratories in Marburg and Frankfurt, Germany and in Belgrade, Yugoslavia (now Serbia). A total of 37 people became ill; they included laboratory workers as well as several medical personnel and family members who had cared for them. The first people infected had been exposed to African green monkeys or their tissues. In Marburg, the monkeys had been imported for research and to prepare polio vaccine. The Soviet Union weaponized Marburg virus.

Monkeypox
Monkeypox is a viral disease with a clinical presentation in humans similar to that seen in the past in smallpox patients. The virus responsible for monkeypox is related to the virus that used to cause smallpox (both are orthopoxviruses). Monkeypox has a case-fatality rate of 11 percent in humans not vaccinated against smallpox. However, pneumonia due to monkeypox has approximately a 50 percent mortality rate.

Rift Valley Fever Virus
Rift Valley fever (RVF) is an acute, fever-causing viral disease that affects domestic animals (such as cattle, buffalo, sheep, goats and camels) and humans. RVF is most commonly associated with mosquito-borne epidemics during years of heavy rainfall. The RVF virus, a member of the genus Phlebovirus in the family Bunyaviridae, causes the disease Rift Valley Fever. Veterinary officers in Kenya first reported the disease among livestock in the early 1900s. Rift Valley Fever is generally found in regions of eastern and southern Africa where sheep and cattle are raised. However, the RVF virus also exists in most countries of sub-Saharan Africa and Madagascar. The United States conducted BW-related research with RVF.

Sin Nombre Virus
Sin Nombre virus is a member of the Hantavirus genus. The virus is highly infectious via the aerosol route, and can cause a disease called hantavirus pulmonary syndrome (HPS). Sin Nombre virus was first identified in the early 1990s in the Four Corners region of the United States, and has since emerged throughout the Americas. The virus is carried by the deer mouse.

Smallpox Virus
Smallpox virus, an orthopoxvirus with a narrow host range confined to humans, was an important cause of morbidity and mortality in the developing world until recent times. Eradication of the natural disease was completed in 1977 and the last human cases (laboratory infections) occurred in 1978. The virus officially exists today in only two laboratory repositories-in the United States (at the Centers for Disease Control and Prevention) and in Russia (at Vector). Appearance of human cases outside the laboratory would signal use of the virus as a biological weapon. Under natural conditions, the virus is transmitted by direct (face-to face) contact with an infected case, by fomites, and occasionally by aerosols. The Soviet Union weaponized smallpox and the United States conducted BW-related research with the smallpox virus.

Tick-borne (Russian Spring-Summer) Encephalitis
Tick-borne encephalitis is a viral infection of the central nervous system transmitted by tick bites. The disease typically begins as a flu-like illness, including fever, headache and vomiting, followed by the development of neurologic symptoms, including neck stiffness, dizziness, tremors, drowsiness, delirium and coma. Neurologic damage may be permanent, causing chronic headaches, difficulty concentrating, muscle weakness or loss of balance. A small percentage of cases are fatal. The Soviet Union conducted BW-related research with Tick-borne Encephalitis.

Venezuelan Equine Encephalitis Virus
Venezuelan equine encephalitis (VEE) virus is an arthropod-borne alphavirus that is endemic in northern South America, Trinidad, Central America, Mexico and Florida. Natural infections are acquired by the bites of a wide variety of mosquitoes. Horses, mules, donkeys and burros serve as amplifying hosts and source of mosquito infection. Immunity after infection is probably lifelong to the homologous serotype, but cross-immunity is weak or nonexistent to heterologous serotypes. Thus, when viewed either as an endemic disease threat or as a potential biological warfare threat, adequate immunization will require polyvalent vaccines. The United States and the Soviet Union weaponized VEE.

Western Equine Encephalitis Virus
Western equine encephalitis (WEE) is a disease that is spread to horses and humans by infected mosquitoes. It is one of a group of mosquito-borne virus diseases that can affect the central nervous system and cause severe complications and even death. Western equine encephalitis is found in North, Central and South America, but most cases have been reported from the plains regions of the western and central United States. The WEE virus is less virulent for adult humans than it is for equines and children, with lower rates of fatalities and neurological after effects.

Yellow Fever
Yellow fever is a viral disease that has caused large epidemics in Africa and the Americas. It can be recognized from historic texts stretching back 400 years. The disease is caused by the yellow fever virus, which belongs to the flavivirus group. Yellow fever is stable as an aerosol, making it a candidate as a biological weapon. The Soviet Union, Germany, Canada and the United States conducted BW-related research with yellow fever.