| Actinomycosis | |
|---|---|
 | |
| A man with actinomycosis on the right side of his face | |
| Specialty | Infectious disease |
Actinomycosis is a rare and chronicinfectiousbacterial disease caused by thegram-positiveActinomyces species.[1] The name refers to ray-like appearance of the organisms in the granules. About 70% of infections are due to eitherActinomyces israelii orA. gerencseriae.[1] Infection can also be caused byStreptomyces somaliensis andPropionibacterium propionicus. The condition is likely to be a polymicrobialanaerobic infection.[2]
The disease is characterised by the formation of painfulabscesses in themouth,lungs,[3][4]breast,[5] orgastrointestinal tract.[2] Actinomycosis abscesses grow larger as the disease progresses, often over months. In severe cases, they may penetrate the surrounding bone and muscle to the skin, where they break open and leak large amounts ofpus, which often contains characteristic granules filled with progeny bacteria. These granules are often called "sulfur granules" due to their yellow appearance, although they may also be white, gray or brown.[6]
Actinomycosis is primarily caused by any of several members of the bacterialgenusActinomyces. These bacteria are generallyanaerobes.[7] In animals, they normally live in the small spaces between the teeth and gums, causing infection only when they can multiply freely inanoxic environments. An affected human often has recently haddental work, poororal hygiene,periodontal disease,radiation therapy, or trauma (broken jaw) causing local tissue damage to theoral mucosa, all of which predispose the person to developing actinomycosis.A. israelii is a normalcommensal species part ofthe microbiota species of the lower reproductive tract of women.[8] They are also normal commensals among thegut flora of thecaecum; thus, abdominal actinomycosis can occur following removal of theappendix. The three most common sites of infection are decayed teeth, the lungs, and theintestines. Actinomycosis infections are typicallypolymicrobial, containing additional bacterial species; asActinomyces itself has little invasive ability, these other species often aid in the infection process.[9]
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The diagnosis of actinomycosis can be a difficult one to make. In addition to microbiological examinations,magnetic resonance imaging andimmunoassays may be helpful.[10]
Actinomyces bacteria are generally sensitive topenicillin, which is frequently used to treat actinomycosis. In cases of penicillin allergy,doxycycline is used.Sulfonamides such as sulfamethoxazole may be used as an alternative regimen at a total daily dosage of 2–4 grams. Response to therapy is slow and may take months.Hyperbaric oxygen therapy may also be used as an adjunct to conventional therapy when the disease process is refractory to antibiotics and surgical treatment.[11][12]
Disease incidence is greater in males between the ages of 20 and 60 years than in females.[13] Before antibiotic treatments became available, the incidence in the Netherlands and Germany was one per 100,000 people/year. Incidence in the U.S. in the 1970s was one per 300,000 people/year, while in Germany in 1984, it was estimated to be one per 40,000 people/year.[13] The use ofintrauterine devices (IUDs) has increased incidence of genitourinary actinomycosis in females. Incidence of oral actinomycosis, which is harder to diagnose, has increased.[13]
In 1877,pathologistOtto Bollinger described the presence ofA. bovis in cattle, and shortly afterwards,James Israel discoveredA. israelii in humans. In 1890,Eugen Bostroem isolated the causative organism from a culture of grain, grasses, and soil. After Bostroem's discovery, a general misconception existed that actinomycosis was amycosis that affected individuals who chewed grass or straw. The pathogen is still known as the “great masquerader".[14]Bergey's Manual of Systematic Bacteriology classified the organism as bacterial in 1939,[15] but the disease remained classified as a fungus in the 1955 edition of theControl of Communicable Diseases in Man.[16]
ViolinistJoseph Joachim died of actinomycosis on 15 August 1907.The Norwegian painterHalfdan Egedius died from actinomycosis on 2 February 1899.
Actinomycosis occurs rarely in humans, but rather frequently incattle as a disease called "lumpy jaw". This name refers to the largeabscesses that grow on the head and neck of the infected animal. It can also rarely affect sheep, swine, horses, dogs, and other mammals.[17]
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