Giardiasis
A common parasitic disease causing diarrhoea and malabsorption worldwide.
Giardiasis is a parasitic disease caused by the protist enteropathogen Giardia duodenalis (also known as G. lamblia and G. intestinalis). It is especially common in children and travelers and is one of the most common parasitic human diseases worldwide, with infection rates as high as 7% in the developed world and 30% in the developing world. The World Health Organization classifies giardiasis as a neglected disease, and it is popularly known as beaver fever in North America.
Quick Facts
- Field
- Infectious disease, gastroenterology
- Symptoms
- Diarrhoea, abdominal pain, weight loss, nausea
- Onset
- 1 to 3 weeks after exposure
- Causes
- Giardia duodenalis spread mainly through contaminated food or water
- Risks
- Hypogammaglobulinemia
- Diagnosis
- Stool testing
- Differential
- Irritable bowel syndrome
- Prevention
- Improved sanitation
- Treatment
- Antiprotozoal medications
- Medication
- Tinidazole, metronidazole
- Frequency
- Up to 7% (developed world), up to 30% (developing world)
Facts from the source article.
Lore & Background
Prevention may be improved through proper personal hygiene practices and by cooking and sanitizing food. Asymptomatic cases often do not need treatment. When symptoms are present, treatment is typically provided with either tinidazole or metronidazole. Other drugs, such as nitazoxanide, albendazole, quinacrine, chloroquine, paromomycin, and other drug combinations are also used in clinics. Refractory giardiasis and resistant strains are reported more and more often. Infection may cause a person to become lactose intolerant, so it is recommended to temporarily avoid lactose following an infection or use lactase supplements.
Reader's Guide
Giardiasis is significant as one of the most common parasitic human diseases, affecting millions worldwide, with symptomatic cases estimated at 280 million in 2013. Its classification by the World Health Organization as a neglected disease highlights the need for continued attention in public health, especially in developing regions where infection rates reach 30%. The disease's impact is particularly severe in children, where prolonged infection can cause failure to thrive and impair mental development. The emergence of refractory giardiasis and resistant strains poses a growing challenge to treatment, as drugs like tinidazole and metronidazole become less effective. The disease also has economic and social implications for travelers and outdoor enthusiasts, as it is popularly known as beaver fever in North America. Understanding its transmission via the fecal-oral route and the resilience of cysts in cold water underscores the importance of sanitation and hygiene in prevention. The legacy of giardiasis research includes advances in diagnostic methods, though the gold standard remains microscopic identification, and ongoing study of antigenic variation and immune evasion by Giardia duodenalis.
Did You Know?
- Cysts of Giardia can survive for nearly three months in cold water.
- Infection may cause a person to become lactose intolerant, which is usually temporary but may become permanent.
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