giardiasis

Giardiasis: description

Like malaria, giardiasis is triggered by small creatures that are not bacteria or viruses. Giardia (Lamblia) belongs to the parasitic group of protozoa, also called single cell nucleus. Giardia are transmitted fecally-orally. This means that food or drinking water must be contaminated with traces of stool for someone to become infected. Often this happens when preparing food through “dirty hands” or contaminated drinking water.

Giardiasis is widespread worldwide, but is particularly common in southern countries. Depending on the hygienic conditions of the general population, up to one third of the population is infected. In Germany, more than 4,000 cases were diagnosed in 2013.

Especially travelers return the parasites from their vacation, so that nearly half of all diagnoses are directly related to a trip abroad. Particularly common are southern holiday regions such as India, Egypt, Turkey or Africa origin of the infection.

Lifecycle: Giardiasis

The Giardiasis has a very simple transmission path and life cycle. The adult parasites (trophozoites) live in the furrows of the small intestine wall. Only in case of previous damage or a weak defense system, they break through the intestinal wall and it can lead to body-wide complications.

As a rule, the giardia does not leave the mucous membrane and the infection is limited only to the intestine. However, they change the intestinal surface, so it can lead to recording problems and deficiency symptoms. Although the Lambliens are not bacteria, they can reproduce asexually by simply dividing and producing offspring. Some adult pathogens migrate down the intestine and become cysts (inactive stage). In doing so, they form a shell that allows them to survive in the outside world so that they can be transferred from one person to the next. Without the capsule, the trophozoites die off very quickly in the outside world. In water, the cysts can remain infectious for up to three months. When the cysts are ingested by a human through food or drinking water, the cysts in the gut revert to adult trophozoites and the cycle begins again.

Giardiasis: symptoms

In giardiasis, many people do not have any symptoms at all, so they never seek medical advice or treatment. If it comes to symptoms, the recurring, weeks-long diarrhea is usually the main problem. Unclear stomach pain and feeling of fullness are also common. The following symptoms are also typical for Giardia infection:

• Nausea and vomiting
• Colicky abdominal pain
• Moderate, often frothy-watery diarrhea, possibly with Blutbeimengungen
• bloating
• Water accumulation in the tissue (edema, in lengthy cases)
• In severe cases malnutrition, because too little nutrients are absorbed through the intestine
• Pancreatitis or bile duct inflammation in massive infestations or in immunocompromised people

Since many people have no symptoms, or never see the doctor, many people are infected for a long time and thus provide a source of infection for others.

Giardiasis: causes and risk factors

The cause of Giardiasis is the infection with the protozoan Giardia intestinalis. Some sources call the parasite by its old name: Giardia Lamblia. In addition to humans, the parasite also infects other mammals. Bieber, cats and dogs represent an important reservoir. Reservoirs are those animals that harbor the pathogen in nature and thus ensure the survival of the pathogen, even if all humans were treated efficiently.

Because the parasite is particularly transmitted through contaminated drinking water or food, one of the main risk factors is poor food hygiene. There are approximately 200 million new infections per year worldwide.

It is a potential cause of traveler’s diarrhea, but giardiasis tends to cause prolonged, moderate discomfort. Typical is rather long-lasting, relatively mild diarrhea even weeks after the return home.

Countries and living conditions with low hygienic standards are particularly risky. But there is also a risk of infection in southern and eastern Europe. Even in Germany or the US, the parasite is native and a contagion possible.

Children are affected more often. Infants who are breastfed are almost never infected. Visits the child a day care (kindergarten, crib) increases the risk. With puberty, the likelihood of infection falls again.

Overall, giardiasis is a non-dangerous disease that can be treated well, and only in rare, extreme cases is a greater risk. In these cases, there is usually a pre-existing disease that influences the course of the disease.

Giardiasis examinations and diagnosis

The causative agents of giardiasis can often be detected in the (fresh) stool. This is mostly done by a sensitive, immunological test on surface molecules of Giardia Lamblia. Rarely is searched for the unicellulars by means of a microscope. As a rule, three stool samples are required for this, which have to be dispensed at different times. This increases the likelihood of actually recognizing an infection with Giardiasis.

If the diagnosis of giardiasis in the stool fails, intestinal biopsy may be required; Here, the doctor takes a sample of the small intestinal mucosa. In almost all cases the pathogen is detectable in it.

Giardiasis: treatment

The Giardiasis can be treated by certain antibiotics and anti-worm remedies, although it is not a bacterium or a worm. Nevertheless, these two substances interfere with the metabolism of the parasite and lead to his death. The doctor usually prescribes the active ingredient metronidazole or albendazole. If the person has lost a lot of fluids as a result of diarrhea, special electrolyte solutions help. A Giardien infection should be treated even if no symptoms occur because those affected excrete the pathogen and thus constitute a source of infection. Only in this way can the risk of infection for society be reduced.

Disease course and prognosis

Giardiasis is a harmless but common parasite infection. Many patients do not notice their condition. Therefore, the efficient control of the parasite is so difficult. In patients with pre-existing conditions, such as immunodeficiencies or cystic fibrosis, where the intestinal barrier does not provide adequate protection, there is a risk that the giardia will continue to invade the body and make it seriously ill. However, this is the exception. As a rule, there is no danger to life and there are no further serious symptoms. Due to the infection, however, it can lead to nutrient uptake disorders or deficiency symptoms, if the infection is not diagnosed for a very long time and treated efficiently. The parasite is the most common single-celled intestinal parasite in many developed and developing countries. To guarantee a cure and to avoid the risk of infection is a consistent therapy of the giardiasis unavoidable.