Blastocystis

Blastocystis (Blastocystis hominis) is a common infection that can be found all over the world and one that does not necessarily show any symptoms. It has previously been questioned whether Blastocystis really causes harm in humans. It is clear that some individuals get severe symptoms and others none at all, which can be due to a number of different reasons such as when other coexisting infections are ongoing and the immune system is impaired. 

Life cycle

These parasites live in the gastrointestinal tract from which they are also spread into waterways. Infection occurs through contaminated water and possibly also from contaminated crops. Blastocystis also occurs in most mammals, including monkeys, pigs and rodents, which can pass the infection to humans. 

Symptoms

An infection with Blastocystis may not cause any symptoms at all but occasionally the infection can manifest itselves through abdominal symptoms such as diarrhea or constipation, increased amount of flatulation, abdominal pain and weight loss.