In giardiasis (Lambliasis; synonyms: Diarrhea due to Giardia intestinalis; Diarrhea due to Giardia lamblia; Diarrhea due to Lamblia intestinalis; Infection due to Giardia lamblia; Infection due to Lamblia intestinalis; Lambliasis; Lambliosis; Lamblial dysentery; ICD-10-GM A07. 1: Giardiasis [Lambliasis]) is an infection of the small intestine caused by Giardia lamblia (Giardia duodenalis, Giardia intestinalis, Lamblia intestinalis).
Giardia lamblia is a protozoan (single-celled organism).
The disease is one of the parasitic zoonoses (animal diseases).
Pathogen reservoirs are cattle and domestic animals (dogs) in addition to humans.
Occurrence: The infection occurs worldwide. It is most common in southern countries. Giardia lamblia is a possible causative agent of traveler’s diarrhea. In Germany, the disease is often seen in people returning from vacation. Particularly affected are:
- Egypt
- India
- Italy
- Spain
- Tanzania
- Thailand
- Turkey
- Tropics (tropical countries)
Seasonal variations are not observed.
The transmission of the pathogen (route of infection) is fecal-oral (infections in which pathogens excreted with feces (fecal) are absorbed through the mouth (oral)), through direct contact, food or drinking water.
The incubation period (time from infection to onset of disease) is usually 7-10 days.
The duration of illness is untreated to several months or even years; there is almost always a transition to chronic diarrhea (diarrhea).
Sex ratio: males are more commonly affected than females. There is a marked difference in 1-year-olds.
Frequency peak: An age peak is in childhood and adolescence. The highest age-specific incidences occurred in 1- to 4-year-old children. A second incidence peak occurred in the 20- to 49-year-old age groups.
The incidence (frequency of new cases) is approximately 5 cases per 100,000 population per year.
Course and prognosis: Infection with Giardia lamblia can be inconspicuous, but can also lead to long-lasting, recurrent diarrhea (diarrhea), accompanied by upper abdominal discomfort with weight loss and meteorism (flatulence).
In Germany, the disease is notifiable under the Infection Protection Act (IfSG) if the pathogen is detected in combination with an acute infection. Infected persons are not allowed to work in establishments that handle food or drinking water. Infected children younger than six years of age may not return to community facilities until further spread has been ruled out.