Tularemia, also known as rabbit fever, is an
infectious disease
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...
caused by the
bacterium
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
''
Francisella tularensis
''Francisella tularensis'' is a pathogenic species of Gram-negative coccobacillus, an aerobic bacterium. It is nonspore-forming, nonmotile, and the causative agent of tularemia, the pneumonic form of which is often lethal without treatment. It is ...
''.
Symptoms may include
fever
Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...
,
skin ulcers
An ulcer is a sore on the skin or a mucous membrane, accompanied by the disintegration of tissue. Ulcers can result in complete loss of the epidermis and often portions of the dermis and even subcutaneous fat. Ulcers are most common on the skin ...
, and
enlarged lymph nodes
Lymphadenopathy or adenopathy is a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of an inflammatory type (the most common type) is lymphadenitis, producing swollen or enlarged lymph nodes. In cl ...
.
Occasionally, a form that results in
pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...
or a throat infection may occur.
[
The bacterium is typically spread by ]tick
Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...
s, deer flies
Deer flies (also known in some parts of the mid-Atlantic United States as sheep flies) are Hematophagy, bloodsucking insects considered Pest (organism), pests to humans and cattle. They are large flies with large brightly-coloured compound eyes, ...
, or contact with infected animals.[ It may also be spread by drinking contaminated water or breathing in contaminated dust.][ It does not spread directly between people. Diagnosis is by blood tests or ]cultures
Culture () is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups.Tylo ...
of the infected site.
Prevention is by using insect repellent
An insect repellent (also commonly called "bug spray") is a substance applied to skin, clothing, or other surfaces to discourage insects (and arthropods in general) from landing or climbing on that surface. Insect repellents help prevent and cont ...
, wearing long pants, rapidly removing ticks, and not disturbing dead animals. Treatment is typically with the antibiotic streptomycin
Streptomycin is an antibiotic medication used to treat a number of bacterial infections, including tuberculosis, ''Mycobacterium avium'' complex, endocarditis, brucellosis, ''Burkholderia'' infection, plague, tularemia, and rat bite fever. F ...
.[ Gentamicin, ]doxycycline
Doxycycline is a broad-spectrum tetracycline class antibiotic used in the treatment of infections caused by bacteria and certain parasites. It is used to treat bacterial pneumonia, acne, chlamydia infections, Lyme disease, cholera, typhus, an ...
, or ciprofloxacin
Ciprofloxacin is a fluoroquinolone antibiotic used to treat a number of bacterial infections. This includes bone and joint infections, intra abdominal infections, certain types of infectious diarrhea, respiratory tract infections, skin inf ...
may also be used.[
Between the 1970s and 2015, around 200 cases were reported in the United States a year.] Males are affected more often than females.[ It occurs most frequently in the young and the middle aged.][ In the United States, most cases occur in the summer.][ The disease is named after ]Tulare County, California
Tulare County ( ) is a county located in the U.S. state of California. As of the 2020 census, the population was 473,117. The county seat is Visalia. The county is named for Tulare Lake, once the largest freshwater lake west of the Great Lake ...
, where the disease was discovered in 1911. A number of other animals, such as rabbits, may also be infected.[
]
Signs and symptoms
Depending on the site of infection, tularemia has six characteristic clinical variants: ulceroglandular (the most common type representing 75% of all forms), glandular, oropharyngeal, pneumonic, oculoglandular, and typhoidal.
The incubation period for tularemia is one to 14 days; most human infections become apparent after three to five days. In most susceptible mammals, the clinical signs include fever
Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...
, lethargy, loss of appetite
Anorexia is a medical term for a loss of appetite. While the term in non-scientific publications is often used interchangeably with anorexia nervosa, many possible causes exist for a loss of appetite, some of which may be harmless, while others i ...
, signs of sepsis
Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...
, and possibly death. Nonhuman mammals rarely develop the skin lesions seen in people. Subclinical infection
A subclinical infection—sometimes called a preinfection or inapparent infection—is an infection that, being subclinical, is nearly or completely asymptomatic (no signs or symptoms). A subclinically infected person is thus a paucisymptomatic ...
s are common, and animals often develop specific antibodies to the organism. Fever is moderate or very high, and tularemia bacilli can be isolated from blood cultures at this stage. The face and eyes redden and become inflamed. Inflammation spreads to the lymph nodes, which enlarge and may suppurate (mimicking bubonic plague). Lymph node involvement is accompanied by a high fever.
Cause
Tularemia is caused by the bacteria ''Francisella tularensis
''Francisella tularensis'' is a pathogenic species of Gram-negative coccobacillus, an aerobic bacterium. It is nonspore-forming, nonmotile, and the causative agent of tularemia, the pneumonic form of which is often lethal without treatment. It is ...
'' which is typically spread by tick
Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...
s, deer flies
Deer flies (also known in some parts of the mid-Atlantic United States as sheep flies) are Hematophagy, bloodsucking insects considered Pest (organism), pests to humans and cattle. They are large flies with large brightly-coloured compound eyes, ...
, and contact with infected animals.[
]
Bacteria
The bacteria can penetrate into the body through damaged skin, mucous membranes, and inhalation. Humans are most often infected by tick/deer fly bite or through handling an infected animal. Ingesting infected water, soil, or food can also cause infection. Hunters are at a higher risk for this disease because of the potential of inhaling the bacteria during the skinning process. It has been contracted from inhaling particles from an infected rabbit ground up in a lawnmower ( see below). Tularemia is not spread directly from person to person.["WHO Guidelines on Tularemia"](_blank)
Published 2007 Humans can also be infected through bioterrorism attempts.
''Francisella tularensis
''Francisella tularensis'' is a pathogenic species of Gram-negative coccobacillus, an aerobic bacterium. It is nonspore-forming, nonmotile, and the causative agent of tularemia, the pneumonic form of which is often lethal without treatment. It is ...
'' can live both within and outside the cells of the animal it infects, meaning it is a facultative intracellular bacterium. It primarily infects macrophage
Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cel ...
s, a type of white blood cell, and thus is able to evade the immune system. The course of disease involves the spread of the organism to multiple organ systems, including the lung
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of t ...
s, liver
The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...
, spleen
The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes . , and lymphatic system. The course of disease is different depending on the route of exposure. Mortality in untreated (before the antibiotic era) patients has been as high as 50% in the pneumoniac and typhoidal forms of the disease, which however account for less than 10% of cases.
Spread
The most common way the disease is spread is via arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
vector
Vector most often refers to:
*Euclidean vector, a quantity with a magnitude and a direction
*Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism
Vector may also refer to:
Mathematic ...
s. Ticks involved include ''Amblyomma
''Amblyomma'' is a genus of hard ticks. Some are disease vectors, for example the Rocky Mountain spotted fever in Brazil or ehrlichiosis in the United States.
This genus is the third largest in the family Ixodidae, with its species primarily o ...
'', ''Dermacentor
''Dermacentor'' is a genus of ticks in the family Ixodidae, the hard ticks. The genus has a cosmopolitan distribution, with native species on all continents except Australia. Most occur in the Nearctic realm.
Hosts of ''Dermacentor'' ticks incl ...
'', ''Haemaphysalis
''Haemaphysalis'' is a genus of ticks, containing these species:
*'' Haemaphysalis aborensis'' Warburton, 1913
*'' Haemaphysalis aciculifer'' Warburton, 1913
*'' Haemaphysalis aculeata'' Lavarra, 1904
*'' Haemaphysalis adleri'' Feldman-Muhsam, 1 ...
'', and ''Ixodes
''Ixodes'' is a genus of hard-bodied ticks (family Ixodidae). It includes important disease vectors of animals and humans ( tick-borne disease), and some species (notably '' Ixodes holocyclus'') inject toxins that can cause paralysis. Som ...
''. Rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...
s, rabbits, and hares often serve as reservoir hosts, but waterborne infection accounts for 5 to 10% of all tularemia in the United States. Tularemia can also be transmitted by biting flies, particularly the deer fly '' Chrysops discalis''. Individual flies can remain infectious for 14 days and ticks for over two years. Tularemia may also be spread by direct contact with contaminated animals or material, by ingestion of poorly cooked flesh of infected animals or contaminated water, or by inhalation of contaminated dust.
Diagnosis
Pathology
In lymph node biopsies, the typical histopathologic pattern is characterized by geographic areas of necrosis with neutrophils and necrotizing granulomas. The pattern is non specific and similar to other infectious lymphadenopathies.
The laboratorial isolation of ''F. tularensis'' requires special media such as buffered charcoal yeast extract agar Buffered charcoal yeast extract (BCYE) agar is a selective growth medium used to culture or grow certain types of bacteria, particularly the Gram-negative species '' Legionella pneumophila''. It has also been used for the laboratory diagnosis of ...
. It cannot be isolated in the routine culture media because of the need for sulfhydryl group donors (such as cysteine). The microbiologist must be informed when tularemia is suspected not only to include the special media for appropriate isolation, but also to ensure that safety precautions are taken to avoid contamination of laboratory personnel. Serological tests (detection of antibodies in the serum of the patients) are available and widely used. Cross reactivity with ''Brucella
''Brucella'' is a genus of Gram-negative bacteria, named after David Bruce (1855–1931). They are small (0.5 to 0.7 by 0.6 to 1.5 µm), non encapsulated, non motile, facultatively intracellular coccobacilli.
''Brucella'' spp. are the caus ...
'' can confuse interpretation of the results, so diagnosis should not rely only on serology. Molecular methods such as PCR are available in reference laboratories.
Prevention
There are no safe, available, approved vaccines against tularemia. However, vaccination research and development continues, with live attenuated vaccines being the most thoroughly researched and most likely candidate for approval. Sub-unit vaccine candidates, such as killed-whole cell vaccines, are also under investigation, however research has not reached a state of public use.
Optimal preventative practices include limiting direct exposure when handling potentially infected animals by wearing gloves and face masks (importantly when skinning deceased animals).
Treatment
If infection occurs or is suspected, treatment is generally with the antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
s streptomycin
Streptomycin is an antibiotic medication used to treat a number of bacterial infections, including tuberculosis, ''Mycobacterium avium'' complex, endocarditis, brucellosis, ''Burkholderia'' infection, plague, tularemia, and rat bite fever. F ...
or Gentamicin. Doxycycline
Doxycycline is a broad-spectrum tetracycline class antibiotic used in the treatment of infections caused by bacteria and certain parasites. It is used to treat bacterial pneumonia, acne, chlamydia infections, Lyme disease, cholera, typhus, an ...
was previously used. Gentamicin may be easier to obtain than streptomycin.[ There is also tentative evidence to support the use of quinolone antibiotics.][
]
Prognosis
Since the invention of antibiotics, the rate of death associated with tularemia has decreased from 60% to less than 4%.
Epidemiology
Tularemia is most common in the Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
, including North America and parts of Europe and Asia. It occurs between 30º and 71º north latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...
.
In the United States, although records show that tularemia was never particularly common, incidence rates continued to drop over the course of the 20th century. Between 1990 and 2000, the rate dropped to less than 1 per one million, meaning the disease is extremely rare in the United States today.
In Europe, tularemia is generally rare, though outbreaks with hundreds of cases occur every few years in neighboring Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...
and Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...
. In Sweden over a period from 1984 to 2012 a total of 4,830 cases of tularemia occurred (most of the infections were acquired within the country). About 1.86 cases per 100,000 persons occur each year with higher rates in those between 55 and 70.
Outbreaks
From May to October 2000, an outbreak of tularemia in Martha's Vineyard
Martha's Vineyard, often simply called the Vineyard, is an island in the Northeastern United States, located south of Cape Cod in Dukes County, Massachusetts, known for being a popular, affluent summer colony. Martha's Vineyard includes the s ...
, , resulted in one fatality, and brought the interest of the United States Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...
(CDC) as a potential investigative ground for aerosolised ''Francisella tularensis''. For a time, Martha's Vineyard was identified as the only place in the world where documented cases of tularemia resulted from lawn mowing. However, in May 2015 a resident of Lafayette, Colorado, died from aerosolised ''F. tularensis'', which was also connected to lawn mowing, highlighting this new vector of risk.
An outbreak of tularemia occurred in Kosovo
Kosovo ( sq, Kosova or ; sr-Cyrl, Косово ), officially the Republic of Kosovo ( sq, Republika e Kosovës, links=no; sr, Република Косово, Republika Kosovo, links=no), is a partially recognised state in Southeast Euro ...
in 1999–2000.
In 2004, three researchers at Boston Medical Center
Boston Medical Center (BMC) is a non-profit 514-bed academic medical center in Boston, Massachusetts. It is the largest safety-net hospital and Level I trauma center in New England.
BMC employs 1,466 physicians—including 711 residents and f ...
, in Massachusetts, were accidentally infected with ''F. tularensis'', after apparently failing to follow safety procedures.
In 2005, small amounts of ''F. tularensis'' were detected in the National Mall
The National Mall is a Landscape architecture, landscaped park near the Downtown, Washington, D.C., downtown area of Washington, D.C., the capital city of the United States. It contains and borders a number of museums of the Smithsonian Institut ...
area of Washington, D.C.
)
, image_skyline =
, image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, ...
, the morning after an antiwar demonstration on September 24, 2005. Biohazard sensors were triggered at six locations surrounding the Mall. While thousands of people were potentially exposed, no infections were reported. The detected bacteria likely originated from a natural source, not from a bioterror attempt.
In 2005, an outbreak occurred in Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
amongst participants in a hare hunt. About 27 people came into contact with contaminated blood and meat after the hunt. Ten of the exposed, aged 11 to 73, developed tularemia. One of these died due to complications caused by chronic heart disease.
Tularemia is endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...
in the Gori region of the Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago a ...
n country of Georgia
Georgia most commonly refers to:
* Georgia (country), a country in the Caucasus region of Eurasia
* Georgia (U.S. state), a state in the Southeast United States
Georgia may also refer to:
Places
Historical states and entities
* Related to the ...
. The last outbreak was in 2006. The disease is also endemic on the uninhabited Pakri Islands
, image_name =
, image_caption =
, image_size =
, map_image = Pakri location map.svg
, map_caption =
, native_name = Pakri saared
, native_name_link =
, sobriquet =
, location = Baltic Sea
, ...
off the northern coast of Estonia
Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, a ...
. Used for bombing practice by Soviet
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nation ...
forces, chemical and bacteriological weapons may have been dropped on these islands.
In July 2007, an outbreak was reported in the Spanish
Spanish might refer to:
* Items from or related to Spain:
**Spaniards are a nation and ethnic group indigenous to Spain
**Spanish language, spoken in Spain and many Latin American countries
**Spanish cuisine
Other places
* Spanish, Ontario, Can ...
autonomous region of Castile and León
Castile and León ( es, Castilla y León ; ast-leo, Castiella y Llión ; gl, Castela e León ) is an autonomous community in northwestern Spain.
It was created in 1983, eight years after the end of the Francoist regime, by the merging of the ...
and traced to the plague of vole
Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of lo ...
s infesting the region. Another outbreak had taken place ten years before in the same area.
In January 2011, researchers searching for brucellosis
Brucellosis is a highly contagious zoonosis caused by ingestion of unpasteurized milk or undercooked meat from infected animals, or close contact with their secretions. It is also known as undulant fever, Malta fever, and Mediterranean fever.
The ...
among feral pig
The feral pig is a domestic pig which has gone feral, meaning it lives in the wild. They are found mostly in the Americas and Australia. Razorback and wild hog are Americanisms applied to feral pigs or boar-pig hybrids.
Definition
A feral ...
populations in Texas
Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...
discovered widespread tularemia infection or evidence of past infection in feral hog populations of at least two Texas counties, even though tularemia is not normally associated with pig
The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous, domesticated, even-toed, hoofed mammal. It is variously considered a subspecies of ''Sus ...
s at all. Precautions were recommended for those who hunt, dress, or prepare feral hogs. Since feral hogs roam over large distances, concern exists that tularemia may spread or already be present in feral hogs over a wide geographic area.
In November 2011, it was found in Tasmania
)
, nickname =
, image_map = Tasmania in Australia.svg
, map_caption = Location of Tasmania in AustraliaCoordinates:
, subdivision_type = Country
, subdi ...
. Reports claimed it to be the first in the Southern Hemisphere. However, the causative organism was documented to have been isolated from a foot wound in the Northern Territory
The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...
in 2003.
In 2014, at least five cases of tularemia were reported in Colorado
Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...
and at least three more cases in early 2015, including one death as a result of lawn mowing, as noted above. In the summer of 2015, a popular hiking area just north of Boulder was identified as a site of animal infection and signs were posted to warn hikers.
History
The tularemia bacterium was first isolated by G.W. McCoy of the United States Public Health Service
The United States Public Health Service (USPHS or PHS) is a collection of agencies of the Department of Health and Human Services concerned with public health, containing nine out of the department's twelve operating divisions. The Assistant S ...
plague lab and reported in 1912. Scientists determined tularemia could be dangerous to humans; a human being may catch the infection after contacting an infected animal. The ailment soon became associated with hunters, cooks and agricultural workers.
Biological weapon
The Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency, under the Department of Health and Human Services, and is headquartered in Atlanta, Georgi ...
(CDC) regard ''F. tularensis'' as a viable biological warfare
Biological warfare, also known as germ warfare, is the use of biological toxins or infectious agents such as bacteria, viruses, insects, and fungi with the intent to kill, harm or incapacitate humans, animals or plants as an act of war. ...
agent, and it has been included in the biological warfare programs of the United States, Soviet Union and Japan at various times. A former Soviet biological weapons scientist, Ken Alibek
Kanatzhan "Kanat" Alibekov ( kk, Қанатжан Байзақұлы Әлібеков, Qanatjan Baizaqūly Älıbekov; russian: Канатжан Алибеков, Kanatzhan Alibekov; born 1950), known as Kenneth "Ken" Alibek since 1992, is a Kazak ...
, has alleged that an outbreak of tularemia among German soldiers shortly before the Battle of Stalingrad was due to the release of ''F. tularensis'' by Soviet forces. Others who have studied the pathogen "propose that an outbreak resulting from natural causes is more likely". In the United States, practical research into using rabbit fever as a biological warfare agent took place in 1954 at Pine Bluff Arsenal
The Pine Bluff Arsenal is a United States Army installation in Jefferson County, Arkansas, about eight miles northwest of Pine Bluff and thirty miles southeast of Little Rock.
Pine Bluff Arsenal is one of nine Army installations in the United ...
, Arkansas
Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage ...
, an extension of the Fort Detrick
Fort Detrick () is a United States Army Futures Command installation located in Frederick, Maryland. Historically, Fort Detrick was the center of the U.S. biological weapons program from 1943 to 1969. Since the discontinuation of that program, it ...
program. It was viewed as an attractive agent because:
* it is easy to aerosolize
* it is highly infective; between 10 and 50 bacteria are sufficient to infect victims
* it is nonpersistent and easy to decontaminate (unlike anthrax)
* it is highly incapacitating to infected persons
* it has comparatively low lethality, which is useful where enemy soldiers are in proximity to noncombatants, e.g. civilians
The Schu S4 strain was standardized as "Agent UL" for use in the United States M143 bursting spherical bomblet. It was a lethal biological warfare agent with an anticipated fatality rate of 40 to 60%. The rate-of-action was around three days, with a duration-of-action of one to three weeks (treated) and two to three months (untreated), with frequent relapses. UL was streptomycin resistant. The aerobiological stability of UL was a major concern, being sensitive to sunlight, and losing virulence over time after release. When the 425 strain was standardized as "agent JT" (an incapacitant rather than lethal agent), the Schu S4 strain's symbol was changed again to SR.
Both wet and dry types of ''F. tularensis'' (identified by the codes TT and ZZ) were examined during the "Red Cloud" tests, which took place from November 1966 to February 1967 in the Tanana Valley
The Tanana Valley is a lowland region in central Alaska in the United States, on the north side of the Alaska Range, where the Tanana River emerges from the mountains. Traditional inhabitants of the valley are Tanana Athabaskans of Alaskan Athab ...
, Alaska.
Other animals
Cats and dogs can acquire the disease from the bite of a tick or flea that has fed on an infected host, such as a rabbit or rodent. For treatment of infected cats, antibiotics are the preferred treatment, including tetracycline, chloramphenicol or streptomycin. Long treatment courses may be necessary as relapses are common.
References
External links
*
{{Authority control
Bacterium-related cutaneous conditions
Zoonotic bacterial diseases
Biological weapons
Zoonoses
Tick-borne diseases
Rabbit diseases
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Sheep and goat diseases
Atypical pneumonias