0521779407-19 CUNY1086/Karliner 0 521 77940 7 June 6, 2007 17:50
1386 Strongyloidiasiscirculation to lungs, go to alveolae, migrate up bronchial tree and are
swallowed, and mate in small intestine.
■Exposure: by contact of skin with feces, contaminated soil, or inges-
tion of food contaminated with larvae. Autoinfection occurs con-
tinuously through bowel wall and perianal skin. Massive autoin-
fection (hyperinfection syndrome) occurs in immunocompromised
patients (steroids, hematologic malignancies, starvation, immuno-
suppressive drugs, transplant patients, etc.)Signs & Symptoms
■Penetration phase (skin): local itching, sometimes subcutaneous lar-
val tracts visible, especially on buttocks or perianal area.
■Migratory phase: In heavy infections may have cough, wheeze,
eosinophilia, and transient pulmonary infiltrates (Loeffler’s syn-
drome).
■Intestinal Phase: may have no symptoms, or may have varying
degrees of epigastric pain, dyspepsia, bloating, diarrhea, sometimes
with passage of blood in heavy infections. Allergic symptoms or
urticaria, asthma may occur at any time. AIDS patients usually have
standard syndromes, but sometimes hyperinfection.
■Hyperinfection syndrome: this may give exaggerated intestinal
symptoms such as diarrhea, bloating, abdominal pain. If sufficient
tissue invasion has occurred there may be fever, hypotension, ina-
nition, pulmonary infiltrates, meningeal signs.tests
■Basic tests: blood: CBC almost always shows eosinophilia, some-
times anemia. In severe disease eosinophilia may be absent.
■Basic tests: urine: normal
■Specific tests: Stool O&P shows the larvae in 50–70% of cases. Organ-
ism more easily seen using concentration methods: (1) the Baer-
mann method (putting stool in gauze in funnel over warm water,
larvae migrate to water), or, (2) a similar method using filter paper
(Harada-Mori technique), or, (3) culture on nutrient agar (probably
most sensitive but not readily available).
■Other tests: Larvae may be seen in duodenal juices using the
Enterotest, or intubation. Serology is sensitive, positive in 95% of
cases, done at CDC, may cross-react with filariasis and may be
false-negative in immunocompromised host. Occasionally larvae
are coughed up or seen at bronchoscopy. In hyperinfection syn-
drome larvae are plentiful in stool, blood cultures often positive for