Irregular shedding of Blastocystis hominis

Abstract

The shedding pattern of the protozoan parasite, Blastocystis hominis, is investigated in man and in experimental animal infections. The shedding pattern of the vacuolar and cystic forms of Blastocystis hominis in infected individuals have been shown in the present study to be irregular. The study shows that there is marked fluctuation in the shedding of the parasite from day to day, varying from as high as 17 to 0 per x40 microscopic field. The cystic stages when estimated in 8 Blastocystis-infected individuals ranged from as high as 7.4x10(5) cysts per gram of stool to 0. The shedding of cystic and vacuolar forms observed over a period of 20 days in experimentally-infected Wistar rats were not only shown to be irregular but the amount varied from host to host. The study has important diagnostic implications in that the stool samples must be collected more than once from patients showing clinical signs and symptoms to eliminate the cause of it to Blastocystis. The study also shows that there are asymptomatic individuals who pass a large amount of cysts as such individuals should be treated to prevent transmission to others.

Development and Evaluation of a Genus-Specific, Probe-Based, Internal-Process-Controlled Real-Time PCR Assay for Sensitive and Specific Detection of Blastocystis spp

“…It is known that Blastocystis shedding exhibits day-to-day variation (39). The present data obtained by real-time PCR analysis confirmed that Blastocystis-positive fecal samples exhibit a range in C T values from 12 to 40.…”

Extreme anoxia tolerance in embryos of the annual killifishAustrofundulus limnaeus: insights from a metabolomics analysis

“…These forms reported from TEM studies of fresh stool samples were significantly smaller (5 to 8 m) than culture forms and were suggested to be the form that occurs in vivo (233,235). However, others observed typical vacuolar forms from fresh fecal samples (9,64,128,132,227,232,281,318). The central vacuole was absent in the avacuolar form, while the multivacuolar forms contained multiple small vacuoles.…”

Recent Developments in Blastocystis Research

“…Furthermore, shedding of Blastocystis may be cyclical (Vennila et al, 1999), yet it is unusual for more than one stool sample to be examined. However, when the aim is to explore links to disease, the main complication is again the selection of the populations -in this case, the definitions of symptomatic and asymptomatic and comparability of the symptomatic group and the asymptomatic controls.…”