How should Blastocystis hominis be reported?
In the past there was some agreement that the number of organisms present (mod, many, packed) were more likely to be associated with symptoms. However, in the past few years, there have been anecdotal reports of patients being symptomatic with rare or few organisms, as well. The current recommendation is to report the organism and quantitate per rare, few, mod, many, packed (using your proficiency testing quantitation scheme). It is important to confirm the physicians know what the report means and understand the controversial issues surrounding this organism – they can then correlate the numbers with symptoms. If rare or few, there is no solid data per numbers relevance other than the anecdotal case reports (many of which are word of mouth). Per the pathogenicity issue, there’s still a lot of controversy. However, many physicians are treating if the patient is symptomatic and no other organisms are found (including coccidia and/or microsporidia). Blastocystis hominis may actually be a
