Rat-bite fever
Encyclopedia
Rat-bite fever is an acute, febrile
human illness caused by bacteria transmitted by rodent
s, rat
s in most cases, which is passed from rodent to human via the rodent's urine or mucous secretions. Alternative names for rat bite fever include streptobacillary fever, streptobacillosis, spirillary fever, sodoku, and epidemic arthritic erythema. It is a rare disease spread by infected rodents and can be caused by two specific types of bacteria. Most cases occur in Japan, but specific strains of the disease are present in the United States, Europe, Australia, and Africa.
Some cases are diagnosed after patients were exposed to the urine or bodily secretions of an infected animal. These secretion
s can come from the mouth, nose, or eyes of the rodent. The majority of cases are due to the animal's bite. It can also be transmitted throughout food or water that is contaminated with rat feces or urine. Rats are not the only type of animal that can be infected with this disease. Others include weasels, gerbils, and squirrels. Household pets such as dogs or cats that are exposed to these animals can also carry the disease and infect humans.
If a person is bitten by a rodent, it is important to quickly wash and cleanse the wound area thoroughly with antiseptic solution to reduce the risk of infection.
facultatively anaerobic bacteria can cause the infection.
Spirillum minus
is more rare, and is found most often in Asia
. In Japan
the disease is called Sodoku. Symptoms do not manifest for two to four weeks after exposure to the organism, and the wound through which it entered exhibits slow healing and marked inflammation
. The fever lasts longer and is recurring, for months in some cases. Rectum pain and gastrointestinal symptoms are less severe or are absent. Penicillin is the most common treatment.
and epidemic arthritic erythema. It is a severe disease caused by Streptobacillus
moniliformis, transmitted either by rat bite or ingestion of contaminated products (Haverhill fever). After an incubation period of 2-10 days, Haverhill fever begins with high prostrating fevers, rigors, headache and polyarthralgia. Soon an exanthem appears, either maculopapular or petechial and arthritis of large joints can be seen. The organism can be cultivated in blood or articular fluid. The disease can be fatal if untreated in 20% of cases due to malignant endocarditis, meningoencephalitis or septic shock. Treatment is with penicillin or tetracycline.
rat bite fever and streptobacillary rat bite fever have a few individual symptoms although most symptoms are crossovers. Streptobacillary is most commonly found in the United States and spirillary rat bite fever is generally diagnosed in patients in Africa and other countries.
Rat bite symptoms are visually seen in most cases and include inflammation around the open sore
. A rash
can also spread around the area and appear red or purple. Other symptoms associated with streptobacillary rat bite fever include chills, fever
, vomiting, headaches, and muscle aches. Joints can also become painfully swollen and pain can be experienced in the back. Along with rash and swollen joints, skin irritations like ulcers or inflammation can develop on the hands and feet. Wounds will heal slowly, so it is possible that symptoms will come and go over the course of a few months. It is important to contact a physician
and report these symptoms immediately.
Symptoms associated with spirillary rat bite fever include issues with the lymph node
s. The lymph nodes which lie in the lymphatic system
will often swell or inflame as a reaction to the disease or infection. The most common locations of lymph node swelling are in the neck, groin and underarm. Symptoms generally appear within two to ten days of exposure to the affected animal. It will begin with the fever and will progress to the rash that will appear on the hands and feet within two to four days. Rash will appear all over the body with this form of the infection and will rarely cause symptoms of joint pain.
To diagnosis streptobacillary rat bite fever, blood or joint fluid is extracted and the organisms living in it are cultured. Diagnosis for spirillary rat bite fever is by direct visualization or culture of spirillum from blood smears or tissue from lesions or lymph nodes. Treatment of antibiotics is the same for both types of infection.
antibiotics or where allergic to this erythromycin
or tetracyclines for respectively streptobacillary or spirillary infections.
is positive. Without treatment, the infection usually resolves on its own, although it may take up to a year to do so. A particular strain of rat bite fever that is located in the United States can progress and cause serious complications that can be potentially fatal. Before antibiotic
s were used for the treatment of rat bite fever, many cases resulted in death. If left untreated, streptobacillary can result in infection in the lining of the heart, covering over the spinal cord and brain, or in the lungs. Any tissue or organ throughout the body may develop a pocket of infection and pus, called an abscess
.
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
human illness caused by bacteria transmitted by rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s, rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s in most cases, which is passed from rodent to human via the rodent's urine or mucous secretions. Alternative names for rat bite fever include streptobacillary fever, streptobacillosis, spirillary fever, sodoku, and epidemic arthritic erythema. It is a rare disease spread by infected rodents and can be caused by two specific types of bacteria. Most cases occur in Japan, but specific strains of the disease are present in the United States, Europe, Australia, and Africa.
Some cases are diagnosed after patients were exposed to the urine or bodily secretions of an infected animal. These secretion
Secretion
Secretion is the process of elaborating, releasing, and oozing chemicals, or a secreted chemical substance from a cell or gland. In contrast to excretion, the substance may have a certain function, rather than being a waste product...
s can come from the mouth, nose, or eyes of the rodent. The majority of cases are due to the animal's bite. It can also be transmitted throughout food or water that is contaminated with rat feces or urine. Rats are not the only type of animal that can be infected with this disease. Others include weasels, gerbils, and squirrels. Household pets such as dogs or cats that are exposed to these animals can also carry the disease and infect humans.
If a person is bitten by a rodent, it is important to quickly wash and cleanse the wound area thoroughly with antiseptic solution to reduce the risk of infection.
Causes
Two types of gram-negativeGram-negative
Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...
facultatively anaerobic bacteria can cause the infection.
Spirillosis
Rat-bite fever transmitted by the gram-negative spirochaeteSpirochaete
Spirochaetes belong to a phylum of distinctive Gram-negative bacteria, which have long, helically coiled cells...
Spirillum minus
Spirillum minus
Spirillum minus is a species of Spirillum.Spirillum minus is associated with rat-bite fever....
is more rare, and is found most often in Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
. In Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
the disease is called Sodoku. Symptoms do not manifest for two to four weeks after exposure to the organism, and the wound through which it entered exhibits slow healing and marked inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
. The fever lasts longer and is recurring, for months in some cases. Rectum pain and gastrointestinal symptoms are less severe or are absent. Penicillin is the most common treatment.
Streptobacillosis
The Streptobacillosis form of rat-bite fever is known by the alternative names Haverhill FeverHaverhill fever
In rat-bite fever transmitted by the gram-negative rod Streptobacillus moniliformis, symptoms begin to appear two to ten days after a rat bite injury. The illness resembles a severe influenza, with a moderate fever , chills, joint pain, and a diffuse red rash, located mostly on the hands and feet...
and epidemic arthritic erythema. It is a severe disease caused by Streptobacillus
Streptobacillus
Streptobacillus is a genus of aerobic, gram-negative facultative anaerobe bacteria, which grow in culture as rods in chains.Species associated with infection - S. moniliformisReported susceptibilities and therapies - penicillin, erythromycin-Diseases:...
moniliformis, transmitted either by rat bite or ingestion of contaminated products (Haverhill fever). After an incubation period of 2-10 days, Haverhill fever begins with high prostrating fevers, rigors, headache and polyarthralgia. Soon an exanthem appears, either maculopapular or petechial and arthritis of large joints can be seen. The organism can be cultivated in blood or articular fluid. The disease can be fatal if untreated in 20% of cases due to malignant endocarditis, meningoencephalitis or septic shock. Treatment is with penicillin or tetracycline.
Symptoms
Symptoms will be different for every person and will be different depending on the type of rat bite fever that a person is infected with. Both spirillarySpirillum
Spirillum in microbiology refers to a bacterium with a cell body that twists like a spiral. It is the third distinct bacterial cell shape type besides coccus and bacillus cells.-Taxonomic:...
rat bite fever and streptobacillary rat bite fever have a few individual symptoms although most symptoms are crossovers. Streptobacillary is most commonly found in the United States and spirillary rat bite fever is generally diagnosed in patients in Africa and other countries.
Rat bite symptoms are visually seen in most cases and include inflammation around the open sore
Sore
Sore may refer to:* A mild pain or ache* A small skin ulcer, usually open from skin infection* A slang term for angry* Sore , an Indonesian rock band* Sore, Landes, a village in the Landes département of France* Sore , by Buzzov*en...
. A rash
Rash
A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
can also spread around the area and appear red or purple. Other symptoms associated with streptobacillary rat bite fever include chills, fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
, vomiting, headaches, and muscle aches. Joints can also become painfully swollen and pain can be experienced in the back. Along with rash and swollen joints, skin irritations like ulcers or inflammation can develop on the hands and feet. Wounds will heal slowly, so it is possible that symptoms will come and go over the course of a few months. It is important to contact a physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
and report these symptoms immediately.
Symptoms associated with spirillary rat bite fever include issues with the lymph node
Lymph node
A lymph node is a small ball or an oval-shaped organ of the immune system, distributed widely throughout the body including the armpit and stomach/gut and linked by lymphatic vessels. Lymph nodes are garrisons of B, T, and other immune cells. Lymph nodes are found all through the body, and act as...
s. The lymph nodes which lie in the lymphatic system
Lymphatic system
The lymphoid system is the part of the immune system comprising a network of conduits called lymphatic vessels that carry a clear fluid called lymph unidirectionally toward the heart. Lymphoid tissue is found in many organs, particularly the lymph nodes, and in the lymphoid follicles associated...
will often swell or inflame as a reaction to the disease or infection. The most common locations of lymph node swelling are in the neck, groin and underarm. Symptoms generally appear within two to ten days of exposure to the affected animal. It will begin with the fever and will progress to the rash that will appear on the hands and feet within two to four days. Rash will appear all over the body with this form of the infection and will rarely cause symptoms of joint pain.
Test and diagnosis
This condition is diagnosed by detecting the bacteria in skin, blood, joint fluid, or lymph nodes. Blood antibody tests may also be used. To get a proper diagnosis for rat bite fever, different tests are run depending on the type of symptoms that are being experienced.To diagnosis streptobacillary rat bite fever, blood or joint fluid is extracted and the organisms living in it are cultured. Diagnosis for spirillary rat bite fever is by direct visualization or culture of spirillum from blood smears or tissue from lesions or lymph nodes. Treatment of antibiotics is the same for both types of infection.
Treatment
Responds to penicillinPenicillin
Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....
antibiotics or where allergic to this erythromycin
Erythromycin
Erythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma and...
or tetracyclines for respectively streptobacillary or spirillary infections.
Prevention
Whilst obviously preventable by staying away from rodents, otherwise hands and face should be washed after contact and any scratches both cleaned and antiseptics applied.Prognosis
When proper treatment is provided for patients with rat bite fever, the prognosisPrognosis
Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...
is positive. Without treatment, the infection usually resolves on its own, although it may take up to a year to do so. A particular strain of rat bite fever that is located in the United States can progress and cause serious complications that can be potentially fatal. Before antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s were used for the treatment of rat bite fever, many cases resulted in death. If left untreated, streptobacillary can result in infection in the lining of the heart, covering over the spinal cord and brain, or in the lungs. Any tissue or organ throughout the body may develop a pocket of infection and pus, called an abscess
Abscess
An abscess is a collection of pus that has accumulated in a cavity formed by the tissue in which the pus resides due to an infectious process or other foreign materials...
.