zoonoses and communicable diseases common to ... - PAHO/WHO

ACTINOMYCOSISICD-10 A42.9Synonyms: Actinostreptotrichosis, mandibular cancer, ray fungus disease.Etiology: Actinomyces israelii is the principal etiologic agent in man, and A.bovis the main one in animals. A. naeslundi, A. viscosus, A. odontolytical, A. meyeriand Arachnia propionica (A. propionicus) are isolated less often, although A. viscosusplays an important role in canine actinomycosis. Some reports indicate isolationof A. israelii from animals (Georg, 1974) and A. bovis from man (Brunner et al.,1973). Actinomyces are higher bacteria with many characteristics of fungi. They aregram-positive, do not produce spores, are non–acid-fast, range from anaerobic tomicroaerophilic, and are part of the normal flora of the mouth and of women’s genitaltract (Burden, 1989).Geographic Distribution: Worldwide.Occurrence in Man: Infrequent; however, data are very limited. Fewer than 100cases of the disease are recorded each year by the Public Health LaboratoryService’s Communicable Disease Surveillance Centre in Great Britain (Burden,1989). According to older data, 368 cases were recorded in Wales and England over12 years (1957–1968), with an incidence of 0.665 per million inhabitants, with ahigher incidence among industrial workers (Wilson, 1984). In Scotland, the annualincidence was three per million and the rate of attack was 10 times higher in agriculturalworkers than among others.The historical ratio of two cases in men to one in women is probably no longervalid because of the number of cases of genital actinomycosis in women usingintrauterine contraceptive devices (IUDs).Occurrence in Animals: The frequency of the disease varies widely amongregions and is also influenced by different livestock management practices. The diseaseusually appears as sporadic cases. Small outbreaks have occurred in somemarshy areas of the United States and the former Soviet Union.The Disease in Man: A. israelii, the main causal agent in man, is a normal componentof the flora of the mouth. As a result of wounds or surgery, it can enter thesoft tissues and bones, where it causes a suppurative granulomatous process thatopens to the surface through fistulas. Several clinical forms have been identifiedaccording to their location: cervicofacial, thoracic, abdominal, and generalized.Cervicofacial, which is the most common (from 50% to more than 70% of cases), isusually caused by a tooth extraction or a jaw injury; it begins with a hard swellingunder the mucous membrane of the mouth, beneath the periosteum of the mandible,or in the skin of the neck. At a later stage, softened areas, depressions, and openingsto the exterior with a purulent discharge are evident. These secretions usually containthe characteristic “sulphur granules,” which are actinomyces colonies. The thoracicform is generally caused by breathing the etiologic agent into the bronchialtubes where it establishes a chronic bronchopneumonia that affects the lower portionsof the right lung (Burden, 1989), with symptoms similar to pulmonary tuberculosis.As the disease progresses, invasion of the thoracic wall and its perforation3