5-41
Objective: Signs
Using Basic Tools: Watery diarrhea
Using Advanced Tools: Lab: Look for organism in stool O&P samples (repeat at least 3 times before
considering negative).
Assessment:
Prolonged watery diarrhea and sulfuric belching suggest giardia.
Differential Diagnosis: Other causes of watery diarrhea: cholera, salmonella, etc.
Plan:
Treatment: Metronidazole 250 mg tid x 5-7 days, oral rehydration.
NOTE: Avoid metronidazole use in first trimester of pregnancy.
Patient Education
General: Maintain oral fluids to avoid volume depletion.
Activity: As tolerated
Diet: Giardia infection can result in transient lactose intolerance, so patients should avoid lactose-containing
foods such as milk or cheese.
Medications: Avoid alcohol use while taking metronidazole.
Prevention and Hygiene: Boiling is probably the best water treatment. Most commercial water filters will not
remove giardia from water. If using iodine or chlorine, treat water with iodine or chlorine for at least 20 minutes
before use. Avoid fecal-oral contamination with good hygiene.
No Improvement/Deterioration: Return for reevaluation
Follow-up Actions
Return evaluation: Consider alternative causes of diarrhea.
Consultation Criteria: Condition not responding to treatment.
Zoonotic Disease Considerations
Agent: Giardia lamblia
Principal Animal Hosts: Dogs
Clinical Disease in Animals: May be asymptomatic; chronic diarrhea, steatorrhea, weight loss
Probable Mode of Transmission: Water
Known Distribution: Worldwide; common
ID: Hookworm and Cutaneous Larva Migrans
LTC Glenn Wortmann, MC, USA & MAJ Daniel Schissel, MC, USAIntroduction: Several species of hookworm can infect humans, most commonly Necator americanus or
Ancylostoma duodenale. An estimated one fourth of the world’s population is infected, and the geographic
distribution is in the tropical and subtropical zones. Eggs in feces from infected people and animals are
deposited on the ground and hatch into larvae. Larvae infect by direct penetrating skin, migrating to the lungs
and up to the esophagus. They are then swallowed and travel to the small intestine. Symptoms become
evident weeks to months after infection. Eosinophilia is common. Cutaneous larva migrans (CLM) is a unique
serpentine lesion created by a canine or feline hookworm, A. caninum, A. braziliense, which migrates through
the skin but is unable to penetrate the dermis. The lesions are very pruritic; thread-like; found most commonly
on the feet, hands, and buttocks; and become progressively larger with time. The larvae usually die, but
may require treatment.
Subjective: Symptoms
“Ground itch” (an itchy, red rash at the site of larval penetration through the skin), cough, abdominal pain,