Treatment failure in patients with chronic Blastocystis infection
Roberts T., Ellis J., Harkness J., Marriott D., Stark D.
<jats:p>This article reports long-term infection and treatment failure in 18 symptomatic individuals infected with <jats:italic>Blastocystis</jats:italic> spp<jats:italic>.</jats:italic> Patients were initially treated with either metronidazole, iodoquinol or triple combination therapy consisting of nitazoxanide, furazolidone and secnidazole. Following treatment, resolution of clinical symptoms did not occur and follow-up testing revealed ongoing infection with the same subtype. Patients then underwent secondary treatment with a variety of antimicrobial agents but remained symptomatic with <jats:italic>Blastocystis</jats:italic> spp. still present in faeces. Sequencing of the SSU rDNA was completed on all isolates and four subtypes were identified in this group: ST1, ST3, ST4 and ST5. This study highlights the lack of efficacy of several commonly used antimicrobial regimens in the treatment of <jats:italic>Blastocystis</jats:italic> and the chronic nature of some infections. It also demonstrates the need for further research into treatment options for <jats:italic>Blastocystis</jats:italic> infection.</jats:p>