Murine typhus
Encyclopedia
Murine typhus is a form of typhus
transmitted by flea
s (Xenopsylla cheopis), usually on rat
s. (This is in contrast to epidemic typhus, which is usually transmitted by lice
.) Murine typhus is an under-recognized entity, as it is often confused with viral illnesses. Most people who are infected do not realize that they have been bitten by fleas.
, and is transmitted by the flea
s that infest rat
s. While rat fleas are the most common vectors, cat fleas and mouse fleas are less common modes of transmission. These fleas are not affected by the infection. Human infection occurs because of flea-fecal contamination of the bites on human skin. Rats, cats, possums maintain the ricketssia colonization by providing it with a host for its entire life cycle. Rats can develop the infection, and help spread the infection to other fleas that infect them, and help multiply the number of infected fleas that can then infect humans.
Less often, endemic typhus is caused by Rickettsia felis
and transmitted by fleas carried by cats or opossums.
Murine typhus is found most commonly in southern California, Texas and Hawaii. In some studies, up to 13% of children were found to have serological evidence of infection.
, nausea
, vomiting
, and cough.
Symptoms may resemble those of measles
, rubella
, or possibly Rocky Mountain spotted fever
. These symptoms are likely caused by a vasculitis caused by the rickettsia.
Typhus
Epidemic typhus is a form of typhus so named because the disease often causes epidemics following wars and natural disasters...
transmitted by flea
Flea
Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...
s (Xenopsylla cheopis), usually on 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. (This is in contrast to epidemic typhus, which is usually transmitted by lice
Louse
Lice is the common name for over 3,000 species of wingless insects of the order Phthiraptera; three of which are classified as human disease agents...
.) Murine typhus is an under-recognized entity, as it is often confused with viral illnesses. Most people who are infected do not realize that they have been bitten by fleas.
Causes
It is caused by the bacteria Rickettsia typhiRickettsia typhi
Rickettsia typhi is a species of the genus Rickettsia.It is the causative agent of Murine typhus.The genome is similar to that of Rickettsia prowazekii.-References:...
, and is transmitted by the flea
Flea
Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...
s that infest 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. While rat fleas are the most common vectors, cat fleas and mouse fleas are less common modes of transmission. These fleas are not affected by the infection. Human infection occurs because of flea-fecal contamination of the bites on human skin. Rats, cats, possums maintain the ricketssia colonization by providing it with a host for its entire life cycle. Rats can develop the infection, and help spread the infection to other fleas that infect them, and help multiply the number of infected fleas that can then infect humans.
Less often, endemic typhus is caused by Rickettsia felis
Rickettsia felis
Rickettsia felis or cat-flea typhus is a species of Rickettsia that causes flea-borne spotted fever in cats. The bacteria can also infect humans and cause illness. Fleas are the vector carriers of the bacteria and it has been found in cat flea populations of North and South America, Southern...
and transmitted by fleas carried by cats or opossums.
Murine typhus is found most commonly in southern California, Texas and Hawaii. In some studies, up to 13% of children were found to have serological evidence of infection.
Symptoms
Symptoms of endemic typhus include headache, fever, chills, myalgiaMyalgia
Myalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
, nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
, and cough.
Symptoms may resemble those of measles
Measles
Measles, also known as rubeola or morbilli, is an infection of the respiratory system caused by a virus, specifically a paramyxovirus of the genus Morbillivirus. Morbilliviruses, like other paramyxoviruses, are enveloped, single-stranded, negative-sense RNA viruses...
, rubella
Rubella
Rubella, commonly known as German measles, is a disease caused by the rubella virus. The name "rubella" is derived from the Latin, meaning little red. Rubella is also known as German measles because the disease was first described by German physicians in the mid-eighteenth century. This disease is...
, or possibly Rocky Mountain spotted fever
Rocky Mountain spotted fever
Rocky Mountain spotted fever is the most lethal and most frequently reported rickettsial illness in the United States. It has been diagnosed throughout the Americas. Some synonyms for Rocky Mountain spotted fever in other countries include “tick typhus,” “Tobia fever” , “São Paulo fever” or “febre...
. These symptoms are likely caused by a vasculitis caused by the rickettsia.