ORGANISM 2--Spirometra species
Organisms (plerocercoid larvae) of the genus Spirometra and also other species
of Diphyllobothrium, parasites of cats and other mammals which are unable to mature in
an abnormal host (man), are responsible for the disease known as sparganosis.
Infections are initiated when man swallows infected copepods in drinking water which
then develop into the sparganum; they may be initiated when fish, amphibians (frogs,
tadpoles) or snakes are consumed raw, transferring the sparganum larva; or they may
be introduced when the flesh of frogs or snakes is used as a poultice applied to a lesion
or wound. As the sparganum larvae localize in the abnormal site, they cause a painful
inflammatory reaction in adjacent tissues. Depending upon the site, these organisms
may cause intense and serious disease processes, particularly in certain species which
seem to proliferate by budding or splitting and result in many individual larvae.
Diagnosis is made by recognition of larval forms from tissue biopsies.
COMMON NAME: Sparganosis.
GEOGRAPHICAL DISTRIBUTION: Worldwide.
PATHOGENESIS: Inflammatory edema and necrosis of adjacent tissues; conjunctivitis;
ocular inflammation; eosinophilia.
HABITAT: Small intestine of cats, dogs, tissues of man.
SECOND: Frogs, tadpoles, snakes.
ABNORMAL HOST: Man.
INFECTIVE FORM: Plerocercoid larva (sparganum).
MODE OF INFECTION: Poultices, ingestion.
SPECIMEN OF CHOICE: Biopsy.