GIARDIASIS

General Information

DEFINITION--Bowel infection caused by a parasite found in contaminated water. It is becoming increasingly common among day care and preschool children.

BODY PARTS INVOLVED--Gastrointestinal tract, especially the small bowel.

SEX OR AGE MOST AFFECTED--All ages, but most common in children.

SIGNS & SYMPTOMS

• Often no symptoms are present.
• Sudden diarrhea and abdominal cramping. Some persons have only mild diarrhea and indigestion.
• Loose, bulky, bad-smelling stools.
• Slight fever (uncommon).
• Weight loss.
• Occasionally persistent symptoms over weeks and months.

CAUSES--Infestation by a microscopic parasite, giardia lamblia. Giardia parasites enter the body through food or water and multiply in the small intestine. Local inflammation, causing diarrhea and other symptoms, occurs in 1 to 3 weeks.

RISK INCREASES WITH

• Crowded or unsanitary living conditions, especially a substandard water supply and poor sanitation system.
• Drinking stream water while camping.
• Previous stomach surgery. Stomach acid normally provides some protection against this infection.
• Oral-anal sexual practices.
• Day care centers; preschools.
• Institutional living.

HOW TO PREVENT

• Boil water that is not known to be safe or treat it with commercial chemical purifiers.
• Avoid uncooked foods that may have been rinsed in contaminated water.
• Wash hands often, especially before meals, to avoid catching infection from other persons.
• Isolate children until infection has cleared.

What To Expect

DIAGNOSTIC MEASURES--

• Your own observation of symptoms.
• Medical history and physical exam by a doctor. Tell your doctor if you have been traveling or camping in the previous month.
• Laboratory stool studies to detect parasites. May need to be repeated if early studies are negative. Antibody tests may soon be available.
• Since stool examinations are frequently false-positive, your doctor may treat on the basis of clinical history and examination.

APPROPRIATE HEALTH CARE

• Home-care.
• Doctor's treatment.
• Hospitalization may be required for patients with severe diarrhea to replace lost fluids.

POSSIBLE COMPLICATIONS

• Malabsorption and weight loss.
• Dehydration.

PROBABLE OUTCOME--Spontaneous recovery in about 1 month for most persons. Medication hastens recovery.

How To Treat

GENERAL MEASURES--

• Prevention is the best treatment. Be cautious when away from normal water supplies.
• Practice careful personal hygiene if you have diarrhea or are around those who do.

MEDICATION--

• Don't use non-prescription drugs for gastrointestinal problems. These can mask symptoms.
• Your doctor may prescribe an antiparasitic drug such as quinacrine or metronidazole. Alcohol interacts with metronidazole to cause abdominal cramps and nausea, so don't drink alcohol during treatment.

ACTIVITY--No restrictions.

DIET--Maintain an adequate fluid intake (at least 8 glasses of water or liquid a day).

Call Your Doctor If

• You have symptoms of giardiasis.
• New, unexplained symptoms develop. Drugs used in treatment may produce side effects.