Human–canine bond

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Human%E2%80%93canine_bond 

A two-year-old Laotian girl with her dog

The human–canine bond is rooted in the domestication of the dog, which began occurring through their long-term association with hunter-gatherers more than 30,000–40,000 years ago. The earliest known relationship between dogs and humans is attested by the 1914 discovery of the Bonn–Oberkassel dog, who was buried alongside two humans in modern-day Oberkassel, Germany, approximately 15,000 years ago. For centuries, the phrase "man's best friend" has commonly been used to refer to dogs, as they were the first species and the only large carnivore to have been domesticated. This companionship is most evident in Western countries, such as the United States, where 44% of households were found to be keeping at least one dog as a pet.

On average, female humans tend to have more positive attitudes towards dogs than male humans do, but studies have demonstrated that both dogs and humans release oxytocin while spending quality time together. This release of oxytocin is correlated with the formation of a strong social bond. Canines are capable of distinguishing between positive and negative human facial expressions and will react accordingly. Dogs appear in religions all over the world, particularly in Mesoamerican folklore and myth, thus signifying the deep reverence that humans all over the world have had and continue to have for them. Despite this relationship's significance throughout history, it is not necessarily always a positive one; dogs can be viewed in an extremely negative light, depending on the region.

Attachment

A child pushing a dog in a carriage, early 20th century

Psychologists believe that the relationship between human and canine is a bidirectional attachment bond, which resembles that of the typical human caretaker/infant relationship, and shows all of the usual hallmarks of a typical bond. Some examples of behaviors that led scientists to this conclusion is the display of proximity seeking behavior where the canine will seek out its caretaker as a means to cope with stress, and consequently the absence of the caretaker will trigger separation anxiety to a varying degree. Another such behavior is the safe haven effect, which describes when the canine more freely explores novel objects in the caretaker's presence. Canines are capable of assessing humans' emotional states, as well as discriminating humans by levels of familiarity.

Studies have demonstrated that shelter dogs benefit from interacting with complete strangers. These interactions result in a reduction in plasma cortisol, which is correlated to an overall reduction in stress. These results demonstrate the canines' innate desire to form an attachment with a human, and also demonstrate the positive health effects for the canine associated with the relationship.

Upon loss, due to death or retirement, the majority of caregivers report intense feelings of grief.

Research

Frederick II of Gonzaga petting a dog, by Titian in Portrait of Federico II Gonzaga (c. 1529)

Human–canine bonding was recognized by Boris M. Levinson, who greatly influenced the establishment of the field of study. Levinson accidentally discovered the benefits of assisted pet therapy when he found that withdrawn and uncommunicative children would interact positively whenever he brought his dog, Jingles, to their therapy sessions. His discovery was further reinforced by Sam and Elizabeth Corson, who were among the first to research and evaluate pet-facilitated therapy.

In the early 1980s the term 'human–animal bond' was officially coined by Leo K. Bustad, who delivered a summary lecture on the Human–Pet Relationship on October 28, 1983, at the International Symposium in Vienna. This symposium was held in honour of Konrad Lorenz, and during his lecture, Bustad praised him for his work on the human–animal bond and encouraged others to build on Lorenz's work on the subject. In the early 1970s, Konrad Lorenz had developed the field of ethology with his landmark research on the imprinting of behaviors in geese.

Bustad and other pet therapy advocates formed the Delta Society, which was built on the earlier work of Levinson and Croson. In the 1970s and 1980s, national and international conferences led to greater recognition of the human–animal bond. Since then, there has been widespread media coverage of animal-assisted activity and therapy programs and service dog training.

Types of relationships

Man with dog in India

Today dogs are mostly kept as household pets, although there still remains a sizeable population of working dogs worldwide. Working dogs today perform a wider variety of jobs than ever before in history, working in fields such as drug and explosive detection, therapy, hunting, and invasive species detection. Dogs are used for service due to their highly developed sense of smell. Research shows they can smell human emotions. A strong canine-human bond is formed between the dog and the handler while performing jobs together; a strong bond is required to safely and quickly perform their jobs. Many of the people who work with a canine partner will also live with them, which facilitates a strong bond between both partners. Many military dogs have also been adopted by their former handlers once they have been retired. Canine-human jobs span fields including hunting, herding, military, medical, and search.

Pets

In the Western world, dogs are most commonly found as household pets. The overwhelming majority of American dog owners report that they feel as if their dog is a member of their family. Many Western owners allow their dogs to sleep in their beds with them and report lessened anxiety. Almost universally positive outcomes are reported among those who keep dogs as pets. The human-canine bond is strengthened, or diminished, depending on the quantity and quality of the time spent with the canine and through activities such as routine walking, feeding, grooming, and play.

In Muslim cultures the dog is regarded as unclean, and keeping a dog as a pet is generally seen as impure.

Herding

Main article: Herding dog

Kazakh shepherd with his herding dogs

The herding dog has long worked alongside humans, with the start of herding activities roughly being around the time of the domestication of sheep. Today's herding dogs have evolved a unique set of traits and mannerisms that makes them ideal for the job. Herding dogs may generally fall into several categories: protectors, drivers, headers, and heelers. Herding dogs rely on many predator skills such as posture and eye contact rather than brute force.

Hunting

Main article: Hunting dog

Hunting is one of the oldest jobs that dogs have performed alongside humans. Cave art dating back to the Neolithic age depicting dogs and humans hunting together has been found. In particular, a mural discovered in Saudi Arabia that is more than 9000 years old depicts a domesticated dog being used for hunting. Today hunting dogs generally fall into one of three categories; Terriers, gun dogs, and hounds. Terriers are smaller dogs which can be used to hunt small animals such as birds and rabbits. Gun dogs are mostly used during upland and wetland hunting to retrieve downed game. Hounds typically specialize in the chase and utilize a variety of noises to flush out game, used in hunting larger mammals such as deer, coyote, boar, and foxes.

Guarding

A German Shepherd dog guarding property

Main article: Guard dog

A guard dog or watchdog is a dog used to watch for and guard people or property against unwanted human or animal intruders.

Dogs have been used as guardians since ancient times. The ancient Romans placed Cave canem mosaics at the entrance of homes to warn visitors and intruders of the presence of dangerous dogs at the property.

Controlling vermin

A working Jack Russell Terrier exits a den pipe.

Dogs may be used to hunt vermin. A working terrier is a type of terrier dog bred and trained to hunt vermin including a badger, fox, rat and other small mammals. This may require the working terrier pursuing the vermin into an underground warren.

A ratter is any dog used for catching and killing rats and similar vermin. Specialized rat-catching breeds are found in many countries. A typical ratter is small to medium-sized and has a short and smooth coat, however a wide range of dog breeds and landraces may be used.

Sledding

Main articles: Sled dog and Sled dog racing

A sled dog team of 11 in Denali National Park and Preserve

Dog sledding began as a formal sport in North America in 1908, however the practice of using dogs to pull sleds dates back to at least 6000 BC. Remnants of sleds and harnesses has been found with canine remains in Siberia which carbon-dated to 7800–8000 years ago. A dog musher will need to develop a close bond sometimes with as many as 20 or more dogs in their kennel in order to keep a highly responsive and loyal team. The musher will need to cultivate a particularly strong relationship with their lead dog. The lead dog will ultimately decide which path the team takes.

Military

Main article: Dogs in warfare

A combat tracker dog with his handler

Canines are employed worldwide in various militaries around the world where they perform a variety of jobs on land, sea, and in the air. In the United States of America the Army Veterinary Corps and the 341st Training Squadron provide the training and logistics for many of the handlers and canines. Lackland AFB has around 900 canines at any given time. The commander of the 341st Training Squadron, William Roberts, states their mission is "to produce a dog that patrols and detects, either narcotics or explosives". In the past, military working dogs in the US were often euthanized after they retired, especially if they were deemed unfit for home life or showed aggressive behaviors. However, today, the military makes every effort to adopt out these dogs to qualified families. Only dogs with serious medical conditions are euthanized.

In the UK the 1st Military Working Dog Regiment provides trained dogs and handlers to support the armed forces in various operations, comprising 299 Regular soldiers and officers with the ability to surge to a maximum capacity of 384 Military Working Dogs.

The relationship between a soldier and his dog is often cited as deeply rooted and unshakable, with the result being that the handler and the dog can read almost imperceptible changes in each other's body language. In the United States military, the working dog is traditionally one rank higher than his handler so that he is afforded the respect they deserve.

Examples of Military working dogs include:

• Guard dog
• Attack dog
• Mascot dog
• Detection dog
• Law Enforcement dog

Search

Main articles: Search and rescue dog and Police dog

Search and rescue dog with handler

Because of their highly developed sense of smell, many canines today work with their handlers to search for many things, including drugs, invasive species, and people. The first search and rescue dogs were the Saint Bernards who were trained to locate lost or stranded travelers in the Swiss Alps.

Dogs and their handlers will have formed a close bond allowing each other to interpret each other's body language correctly leading to the successful detection of the desired object or person.Examples of body language to look for when the dog begins to "hit" on a scent cone are small pauses, tail flicks, and puffing air with the nose. Every dog is different and will present different signals that will take lots of dedicated training from the handler to learn how to correctly interpret.

Assistance

Main article: Assistance dog

Assistance dog

People who suffer from isolation, depression, and other mental illness to the point where it significantly interferes with day-to-day life may find security in an emotional support animal, however it is important to remember that usually dogs who fall into the emotional support animal category do not require any specific training. As a result of the studies by Dr. Samuel Corson pets have become commonplace in nursing homes where they can provide comfort and affection to people. Therapy dogs are used in hospitals around the world where they can have a positive impact on a variety of diagnoses, including cancer.

examples of assistances dogs include:

• Guide dogs
• Hearing dogs
• Mobility assistance dogs
• Medical response dogs
  • Seizure response dogs
  • Autism assistance dogs
  • Psychiatric response dogs

Health benefits

Further information: Human–animal bonding

A dog companion in the arms of its human owner.

Canines' social impact on humans is especially significant for those who tend to be more isolated, such as children with no siblings or elderly persons. In this view, the animal is part of our community and is an important determinant for psychological well-being.

According to self psychology, an animal can be a "self-object" that gives a sense of cohesion, support, or sustenance to a person's sense of self. Self-psychology explains why some animals are so crucial to a person's sense of self and well-being. Dog companionship often helps people to develop a daily routine and gives them something to look forward to each day. Studies also show owning a dog reduces stress, alleviates anxiety, and even can prolong a human's lifespan.

Abuse

Further information: Cruelty to animals

Despite the normally positive relationship, there are instances where dogs have turned on their owner or other humans. There are also instances where a normally positive relationship can result in a human abusing their canine, either psychologically or physically. The reasons for a human or a dog turning on their companion are diverse and poorly understood, but may be generally boiled down to improper socialization or underlying mental health issues for either party.

Plague (disease)

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Plague_(disease) 

 

Plague
Yersinia pestis seen at 200× magnification with a fluorescent label.
Specialty	Infectious disease
Symptoms	Fever, weakness, headache
Usual onset	1–7 days after exposure
Types	Bubonic plague, septicemic plague, pneumonic plague
Causes	Yersinia pestis
Diagnostic method	Finding the bacterium in a lymph node, blood, sputum
Prevention	Plague vaccine
Treatment	Antibiotics and supportive care
Medication	Gentamicin and a fluoroquinolone
Prognosis	≈10% risk of death (with treatment)
Frequency	≈600 cases a year

Plague is an infectious disease caused by the bacterium Yersinia pestis. Symptoms include fever, weakness, headache and black lips. Usually, this begins one to seven days after exposure. There are three forms of plague, each affecting a different part of the body and causing associated symptoms. Pneumonic plague infects the lungs, causing shortness of breath, coughing and chest pain; bubonic plague affects the lymph nodes, making them swell; and septicemic plague infects the blood and can cause tissues to turn black and die.

The bubonic and septicemic forms are generally spread by flea bites or handling an infected animal, whereas pneumonic plague is generally spread between people through the air via infectious droplets. Diagnosis is typically made by finding the bacterium in fluid from a lymph node, blood or sputum.

Vaccination is recommended only for people at high risk of exposure to plague. Those exposed to a case of pneumonic plague may be treated with preventive medication. If infected, treatment is with antibiotics and supportive care. Typically antibiotics include a combination of gentamicin and a fluoroquinolone. The risk of death with treatment is about 10% while without it is about 70%.

Globally, about 600 cases are reported a year. In 2017, the countries with the most cases include the Democratic Republic of the Congo, Madagascar and Peru. In the United States, infections occasionally occur in rural areas, where the bacteria are believed to circulate among rodents. It has historically occurred in large outbreaks, with the best known being the Black Death in the 14th century, which resulted in more than 50 million deaths in Europe.

Signs and symptoms

There are several different clinical manifestations of plague. The most common form is bubonic plague, followed by septicemic and pneumonic plague. Other clinical manifestations include plague meningitis, plague pharyngitis, and ocular plague. General symptoms of plague include fever, chills, headaches, and nausea. Many people experience swelling in their lymph nodes if they have bubonic plague. For those with pneumonic plague, symptoms may (or may not) include a cough, pain in the chest, and haemoptysis.

Bubonic plague

Main article: Bubonic plague

Swollen inguinal lymph glands on a person infected with the bubonic plague. The swollen lymph glands are termed buboes from the Greek word for groin, swollen gland: bubo.

When a flea bites a human and contaminates the wound with regurgitated blood, the plague-causing bacteria are passed into the tissue. Y. pestis can reproduce inside cells, so even if phagocytosed, they can still survive. Once in the body, the bacteria can enter the lymphatic system, which drains interstitial fluid. Plague bacteria secrete several toxins, one of which is known to cause beta-adrenergic blockade.

Y. pestis spreads through the lymphatic vessels of the infected human until it reaches a lymph node, where it causes acute lymphadenitis. The swollen lymph nodes form the characteristic buboes associated with the disease, and autopsies of these buboes have revealed them to be mostly hemorrhagic or necrotic.

If the lymph node is overwhelmed, the infection can pass into the bloodstream, causing secondary septicemic plague, and if the lungs are seeded, it can cause secondary pneumonic plague.

Septicemic plague

Main article: Septicemic plague

Septicemic plague resulting in necrosis

Lymphatics ultimately drain into the bloodstream, so the plague bacteria may enter the blood and travel to almost any part of the body. In septicemic plague, bacterial endotoxins cause disseminated intravascular coagulation (DIC), causing tiny clots throughout the body and possibly ischemic necrosis, in which tissues die due to a lack of blood circulation. DIC results in depletion of the body's clotting resources so that it can no longer control bleeding. Consequently, there is bleeding into the skin and other organs, which can cause a red or black patchy rash, and coughing up and vomiting of blood. There are bumps on the skin that look somewhat like insect bites; these are usually red, and sometimes white in the centre. Untreated, the septicemic plague is usually fatal. Early treatment with antibiotics reduces the mortality rate to between 4 and 15 per cent.

Pneumonic plague

Main article: Pneumonic plague

The pneumonic form of plague arises from infection of the lungs. It causes coughing and thereby produces airborne droplets that contain bacterial cells and are likely to infect anyone inhaling them. The incubation period for pneumonic plague is short, usually two to four days, but sometimes just a few hours. The initial signs are indistinguishable from several other respiratory illnesses; they include headache, weakness, and spitting or vomiting of blood. The course of the disease is rapid; unless diagnosed and treated soon enough, typically within a few hours, death may follow in one to six days; in untreated cases, mortality is nearly 100%.

Cause

The Oriental rat flea (Xenopsylla cheopis) engorged with blood after a blood meal. This species of flea is the primary vector for the transmission of Yersinia pestis, the organism responsible for bubonic plague in most plague epidemics in Asia, Africa, and South America. Both male and female fleas feed on blood and can transmit the infection.

A child bitten by a flea infected with the bacterium Yersinia pestis. Y. pestis, a member of the family Yersiniaceae, has caused the bite to become ulcerated.

Transmission of Y. pestis to an uninfected individual is possible by any of the following means:

• droplet contact – coughing or sneezing on another person
• direct physical contact – touching an infected person, including sexual contact
• indirect contact – usually by touching soil contamination or a contaminated surface
• airborne transmission – if the microorganism can remain in the air for long periods
• fecal-oral transmission – usually from contaminated food or water sources
• vector borne transmission – carried by insects or other animals.

Yersinia pestis circulates in animal reservoirs, particularly in rodents, in the natural foci of infection found on all continents except Australia. The natural foci of plague are situated in a broad belt in the tropical and sub-tropical latitudes and the warmer parts of the temperate latitudes around the globe, between the parallels 55° N and 40° S. Contrary to popular belief, rats did not directly start the spread of the bubonic plague. It is mainly a disease in the fleas (Xenopsylla cheopis) that infested the rats, making the rats themselves the first victims of the plague. Rodent-borne infection in a human occurs when a person is bitten by a flea that has been infected by biting a rodent that itself has been infected by the bite of a flea carrying the disease. The bacteria multiply inside the flea, sticking together to form a plug that blocks its stomach and causes it to starve. The flea then bites a host and continues to feed, even though it cannot quell its hunger, and consequently, the flea vomits blood tainted with the bacteria back into the bite wound. The bubonic plague bacterium then infects a new person and the flea eventually dies from starvation. Serious outbreaks of plague are usually started by other disease outbreaks in rodents or a rise in the rodent population.

A 21st-century study of a 1665 outbreak of plague in the village of Eyam in England's Derbyshire Dales – which isolated itself during the outbreak, facilitating modern study – found that three-quarters of cases are likely to have been due to human-to-human transmission, especially within families, a much larger proportion than previously thought.

Diagnosis

Symptoms of plague are usually non-specific, necessitating laboratory testing to definitively diagnose the disease. Y. pestis can be identified through both a microscope and by culturing a sample and this is used as a reference standard to confirm that a person has a case of plague. The sample can be obtained from the blood, mucus (sputum), or aspirate extracted from inflamed lymph nodes (buboes). a person is administered antibiotics before a sample is taken or if there is a delay in transporting the person's sample to a laboratory and/or a poorly stored sample, there is a possibility for false negative results.

Polymerase chain reaction (PCR) may also be used to diagnose plague, by detecting the presence of bacterial genes such as the pla gene (plasmogen activator) and caf1 gene, (F1 capsule antigen). PCR testing requires a very small sample and is effective for both alive and dead bacteria. For this reason, if a person receives antibiotics before a sample is collected for laboratory testing, they may have a false negative culture and a positive PCR result.

Blood tests to detect antibodies against Y. pestis can also be used to diagnose plague, however, this requires taking blood samples at different periods to detect differences between the acute and convalescent phases of F1 antibody titres.

In 2020, a study about rapid diagnostic tests that detect the F1 capsule antigen (F1RDT) by sampling sputum or bubo aspirate was released. Results show rapid diagnostic F1RDT test can be used for people who have suspected pneumonic and bubonic plague but cannot be used in asymptomatic people. F1RDT may be useful in providing a fast result for prompt treatment and fast public health response as studies suggest that F1RDT is highly sensitive for both pneumonic and bubonic plague. However, when using the rapid test, both positive and negative results need to be confirmed to establish or reject the diagnosis of a confirmed case of plague and the test result needs to be interpreted within the epidemiological context as study findings indicate that although 40 out of 40 people who had the plague in a population of 1000 were correctly diagnosed, 317 people were diagnosed falsely as positive.

Prevention

Main article: Plague vaccine

Vaccination

Bacteriologist Waldemar Haffkine developed the first plague vaccine in 1897. He conducted a massive inoculation program in British India, and it is estimated that 26 million doses of Haffkine's anti-plague vaccine were sent out from Bombay between 1897 and 1925, reducing the plague mortality by 50–85%.

Since human plague is rare in most parts of the world as of 2023, routine vaccination is not needed other than for those at particularly high risk of exposure, nor for people living in areas with enzootic plague, meaning it occurs at regular, predictable rates in populations and specific areas, such as the western United States. It is not even indicated for most travellers to countries with known recent reported cases, particularly if their travel is limited to urban areas with modern hotels. The United States CDC thus only recommends vaccination for (1) all laboratory and field personnel who are working with Y. pestis organisms resistant to antimicrobials: (2) people engaged in aerosol experiments with Y. pestis; and (3) people engaged in field operations in areas with enzootic plague where preventing exposure is not possible (such as some disaster areas). A systematic review by the Cochrane Collaboration found no studies of sufficient quality to make any statement on the efficacy of the vaccine.

Early diagnosis

Diagnosing plague early leads to a decrease in transmission or spread of the disease.

Prophylaxis

Pre-exposure prophylaxis for first responders and health care providers who will care for patients with pneumonic plague is not considered necessary as long as standard and droplet precautions can be maintained. In cases of surgical mask shortages, patient overcrowding, poor ventilation in hospital wards, or other crises, pre-exposure prophylaxis might be warranted if sufficient supplies of antimicrobials are available.

Postexposure prophylaxis should be considered for people who had close (<6 feet), sustained contact with a patient with pneumonic plague and were not wearing adequate personal protective equipment. Antimicrobial postexposure prophylaxis also can be considered for laboratory workers accidentally exposed to infectious materials and people who had close (<6 feet) or direct contact with infected animals, such as veterinary staff, pet owners, and hunters.

Specific recommendations on pre- and post-exposure prophylaxis are available in the clinical guidelines on treatment and prophylaxis of plague published in 2021.

Treatments

If diagnosed in time, the various forms of plague are usually highly responsive to antibiotic therapy. The antibiotics often used are streptomycin, chloramphenicol and tetracycline. Amongst the newer generation of antibiotics, gentamicin and doxycycline have proven effective in monotherapeutic treatment of plague. Guidelines on treatment and prophylaxis of plague were published by the Centers for Disease Control and Prevention in 2021.

The plague bacterium could develop drug resistance and again become a major health threat. One case of a drug-resistant form of the bacterium was found in Madagascar in 1995. Further outbreaks in Madagascar were reported in November 2014 and October 2017.

Epidemiology

Main article: Epidemiology of plague

Distribution of plague-infected animals 1998

Globally about 600 cases are reported a year. In 2017, the countries with the most cases include the Democratic Republic of the Congo, Madagascar and Peru. It has historically occurred in large outbreaks, with the best known being the Black Death in the 14th century which resulted in more than 50 million dead. In recent years, cases have been distributed between small seasonal outbreaks which occur primarily in Madagascar, and sporadic outbreaks or isolated cases in endemic areas. In 2022, the possible origin of all modern strains of Yersinia pestis was found in DNA in human remains in three graves located in Kyrgyzstan, dated to 1338 and 1339. The first recorded occurrence of the Black Death occurred shortly thereafter during the siege of Caffa in Crimea in 1346, and was carried to Europe by boat by people attempting to escape the disease. The strain was identified as the most recent common ancestor of both strains found in historic graves and currently existing strains. Bacteria affecting marmots in modern-day Kyrgyzstan are the closest genetically (compared to samples from infected rodents worldwide) to the strain found in the graves, suggesting this is also the location where plague transferred from animals to humans.

Biological weapon

The plague has a long history as a biological weapon. Historical accounts from ancient China and medieval Europe details the use of infected animal carcasses, such as cows or horses, and human carcasses, by the Xiongnu/Huns, Mongols, Turks and other groups, to contaminate enemy water supplies. Han dynasty general Huo Qubing is recorded to have died of such contamination while engaging in warfare against the Xiongnu. Plague victims were also reported to have been tossed by catapult into cities under siege.

In 1347, the Genoese possession of Caffa, a great trade emporium on the Crimean peninsula, came under siege by an army of Mongol warriors of the Golden Horde under the command of Jani Beg. After a protracted siege during which the Mongol army was reportedly withering from the disease, they decided to use the infected corpses as a biological weapon. The corpses were catapulted over the city walls, infecting the inhabitants. This event might have led to the transfer of the Black Death via their ships into the south of Europe, possibly explaining its rapid spread.

During World War II, the Imperial Japanese Army developed weaponized plague, based on the breeding and release of large numbers of fleas. During the Japanese occupation of Manchuria, Unit 731 deliberately infected Chinese, Korean and Manchurian civilians and prisoners of war with the plague bacterium. These subjects, termed "maruta" or "logs", were then studied by dissection, others by vivisection while still conscious. Members of the unit such as Shirō Ishii were exonerated from the Tokyo tribunal by Douglas MacArthur but 12 of them were prosecuted in the Khabarovsk War Crime Trials in 1949 during which some admitted having spread bubonic plague within a 36-kilometre (22 mi) radius around the city of Changde.

Ishii innovated bombs containing live mice and fleas, with very small explosive loads, to deliver the weaponized microbes, overcoming the problem of the explosive killing the infected animal and insect by the use of a ceramic, rather than metal, casing for the warhead. While no records survive of the actual usage of the ceramic shells, prototypes exist and are believed to have been used in experiments during WWII.

After World War II, both the United States and the Soviet Union developed means of weaponising pneumonic plague. Experiments included various delivery methods, vacuum drying, sizing the bacterium, developing strains resistant to antibiotics, combining the bacterium with other diseases (such as diphtheria), and genetic engineering. Scientists who worked in USSR bio-weapons programs have stated that the Soviet effort was formidable and that large stocks of weaponised plague bacteria were produced. Information on many of the Soviet and US projects is largely unavailable. Aerosolized pneumonic plague remains the most significant threat.

The plague can be easily treated with antibiotics. Some countries, such as the United States, have large supplies on hand if such an attack should occur, making the threat less severe.