Contents
Blastocystosis is a parasitic disease of the gastrointestinal tract caused by Blastocystis hominis. Most infections do not show any characteristic symptoms – chronic diarrhea, abdominal pain, weakness and weight loss appear. Blastocystosis is treated pharmacologically, the prognosis is very good.
Blastocystoza — epidemiology
Blastocystosis is one of the most common parasitoses in humans. The infection occurs via the fecal-oral route. Traveling to countries with low sanitary and hygienic standards is a factor contributing to contagion. Refugees from developing countries are often a reservoir of Blastocystis hominis. Congenital or acquired immunodeficiency is believed to contribute to the clinical manifestation, but no correlation has been established between the degree of immune system damage and the occurrence of symptomatic blastocystosis.
Blastocystosis — etiology
The etiological factor is Blastocystis hominis. The protozoan comes in several forms (amoebic, granular, vacuolar, cyst). An invasive form for another person are thick-walled cysts. Thin-walled cysts are responsible for autoinvasion. The source of blastocystosis infection is contaminated water or food. Currently, it is believed that there are non-pathogenic and pathogenic strains of Blastocystis hominis. The latter are responsible for symptomatic blastocystosis. The existence of strains of different virulence is supported by the fact that the incidence of blastocystosis is comparable in HIV-infected and uninfected.
Blastocystosis – pathophysiology
She is not well understood. After infection, the release of the parasite from the cysts (excitement) takes place in the large intestine.
Symptoms of blastocystosis
Most infections with blastocystosis are asymptomatic. In clinical cases, invasion of Blastocystis hominis is characterized by chronic, less frequently acute diarrhea. In addition, abdominal pain, a fine blotchy rash, weakness, weight loss and headaches may occur. It is likely that the invasion of Blastocystis hominis may contribute to the development of colon irritabile syndrome.
Blastocystosis – diagnosis
The method of choice is stool parasitological examination. Microscopic diagnosis can be difficult due to the variety of forms and sizes of Blastocystis hominis. The trichrome staining of the slides facilitates the identification of the protozoan. Finding trophozoites and / or protozoan cysts in the faeces confirms blastocystosis. Blastocystosis should be differentiated from other parasitic infestations of the gastrointestinal tract and functional disorders of the intestines.
Treatment of blastocystosis
The therapeutic effect is obtained after the administration of metronidazole at a dose of 500 mg 3 times a day for 10 days. Other nitroimidazole derivatives (tinidazole, ornidazole, secnidazole) are also effective. Alternatively, nitazoxanide at a dose of 500 mg twice daily for 2 days or cotrimoxazole at a dose of 3 mg twice daily for 960 days can be used.
Blastocystosis – how to prevent it?
The preventive treatment of blastocystosis consists in following the basic rules of hygiene, consuming safe (pathogen-free) water and food.
Source: J. Cianciara, J. Juszczyk, Infectious and parasitic diseases; Czelej Publishing House