Giardiasis

Giardia lamblia is a ubiquitous gastrointestinal protozoon that may be identified in individuals with asymptomatic colonization or acute or chronic diarrheal illness.

Infection is recognized more commonly in children than in adults.

Giardiasis occurs in temperate and tropical regions worldwide.

It continues to be the most frequently identified human protozoal enteropathogen.

Prevalence rates are higher in developing countries.

Also commoner in children.

• Trophozoite:
  • Colonizes the lumen of the small intestine
  • Alters the epithelial structure and function
• Cyst:
  • Person to person transmission
  • Resistant to gastric acidity and digestive enzymes

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• Fecal-oral transmission
• Direct contact with dirty hands, objects, surfaces
• Sexual contact

• Poor sanitation
• Daycare center attendees
• Institutionalized persons
• Malnutrition
• Immunodeficiency
• Cystic fibrosis
• Travelers to highly endemic areas
• Homosexuals

Multifactorial and not fully elucidated.

• Alter epithelial structure and function, leading to malabsorption
• Marked or moderate partial villous atrophy in the jejunum
• Effects are seen in the lumen

• Incubation period of 1-2 weeks
• Asymptomatic
• Diarrhea
• Malaise
• Abdominal distention
• Flatulence
• Abdominal cramps
• Nausea
• Malodorous and greasy stools
• Anorexia
• Weight loss
• Vomiting
• Low-grade fever (infrequent)
• Various neurologic symptoms
• Irritability
• Sleep disorder
• Mental depression
• Neuroasthenia
• Urticaria
• Malabsorption
• Failure to thrive

• Other causes of diarrhea
• Celiac disease

• Stool
• Light microscopy:
• Cyst or trophozoites
• ELISA
• Immunofluorescence assay
• Deoxyribonucleic acid (DNA) probes
• Entero-test and duodenal biopsy

Medical Care:

• Appropriate fluid and electrolyte therapy
• Drugs
• Nitroimidazole derivatives
• Acridine dyes (e.g., quinacrine)
• Nitrofurans (furazolidone)

• Chronic illness and weight loss
• Malabsorption syndrome in adults
• Disaccharidase deficiency
• Growth retardation

• Hand washing
• Proper handling of food, water, and sewage
• Implementation of chlorination, sedimentation, and filtration methods for public water supplies
• Avoidance of uncooked foods such as vegetables in endemic areas