Blastocystis Research Foundation

Researchers from Clermont Universite’ and the Pasteur Institut have published an updated review on Blastocystis infection, genotyping, and clinical characteristics, entitled, “Blastocystis, an unrecognized parasite: an overview of pathogenesis and diagnosis”.    A full text of the review is available in Therapeutic Advances in Infectious Diseases

In a study of 200 shelter dogs and cats, and 100 client-owned dogs and cats, researchers from Oregon State University (Oregon, USA) report that roughly 10% of shelter dogs and cats carry Blastocystis, while none of the client owned animals were found to be infected.  Dogs and cats infected with Blastocystis had similar reported rates of diarrhea as those not infected.  The full text of the study is available from PLOS-One.

Researchers in Denmark report that roughly 50% of healthy individuals were found to be parasitized with Blastocystis or D. fragilis.  D. fragilis was detected in 35% of healthy controls vs. 23% of IBS patients, while Blastocystis was found in 22% of controls vs. 15% of IBS patients.  Surprisingly, individuals who drank bottled water, had no animals in the house, or had a higher income were more likely to be infected with Blastocystis.  For more information, refer to the NIH Pubmed abstract.

Researchers working with children in Morocco report an overall prevalence of parasitic infection of 51%.  Of the children positive for parasites, the most common infection was Blastocystis (64%), followed by Giardia at 20% (24% in rural areas, 16% in urban).    Researchers noted three different assemblage types of Giarida infection in the study population.  Full text available at

Russian researchers report on the extra-intestinal infection of an immunocompromised patient, noting that large quantities of Blastocystis organisms were found in the patient’s liver.  Examination of disintegrated portions of the patients liver showed the organism through staining.  The researchers report the patient made a full recovery following treatment with antibiotics and an antifungal drug, and note that physicians should be aware of the potential for disseminated Blastocystis infection in immunocompromised hosts.  Abstract available in Pubmed online.

A study of cecal scrapings from 24 broiler chickens, 4 turkeys, and 1 piglet showed organisms consistent with Blastocystis in most of the animals.  Specifically all of the chickens, 3 of the 4 turkeys, and the piglet showed infections, albeit in small numbers.  Researchers suggested that the infections may not have been the cause of death in the animals, since the organisms were present in low prevalence in scrapings.  Researchers suggested that the study suggested that there may be health significance in the transmission of Blastocystis from animals to humans.  Full text in the Journal of Parasitic Diseases.

Researchers evaluating a triple-antibiotic therapy for treatment of Blastocystis infection report the results of a trial with 10 patients.  Blastocystis carriage was evaluated both by stool culture and RT-PCR Testing.  Of the 10 patients studied, 6 reported clearance at 6 weeks.  All patients (n=2) reporting dramatic clinical improvement (>4 points)  cleared the organism, and both were multiply infection with ST3 and ST4.  The remaining 4 patients who reported clearance had varying degrees of non-statistically significant improvement, while some of the patients who did not clear the organism also reported improvement.  A significant proportion of patients studied reported low IgA levels.  A full text of the study is available in Gut Pathogens.

Researchers studyng fecal samples collected at random from 382 children age 2-15 years report that 93% of the samples tested positive for at least one parasitic infection.  Females were more likely to present with multiple parasitic infections (85.4%, 326/382, p=0.001).  Rural background and age status (6-11) were also positively associated with infection probability, as were drinking river water.  Walking barefoot was positively associated with hookworm infection.  Abstract available at NIH Pubmed server.

Researchers used fecal samples and post code information from patients at four public hospitals in Sydney to determine that Blastocystis infection is more likely to occur in certain geographic regions.  A total of 910 records were examined for patients seen from 2007-2010, and 580 cases with post code data were examined.  Blastocystis was found in 57% of the samples, Giardia in 27%, and D. fragailis in 12%.  Age prevalnece decreased up to age 24, but increased from age 25 onward.  The full text text of the paper is available in the Journal of Public Health Research.

Researchers studying Blastocystis isolated from animal cadavers in Channai, India report that scrapings from cecal sections, but not duodenal sections, are a reliable method for identifying Blastocystis infection.  Of 24 animals found positive for Blastocystis, cecal scrapings were positive in all cases, but duodenal scrapings were positive in only 6 cases.  The full text of the paper is available from the Journal of Parasitological Infections.