Blastocystis sp. infection in patients with gastrointestinal complaints: a Cuban study.

Objective: This study is aimed to determine the association between the presence of Blastocystis sp. and gastrointestinal complaints in adults. Method: A descriptive study was carried out from January to December 2011 at the Centre of Hygiene, Epidemiology and Microbiology in Matanzas City, Cuba. A total of 749 adults (aged from 20 to 69 years old, mean age 38) had the opportunity to be included. Patients who had positive stool results for pathogenic bacteria, parasites and those with positive result to rotavirus were excluded from the study. A total of 240 adults were finally included, 128 (53.3%) male and 112 (46.67%) female with a mean age of 40 years old. To facilitate the comparison patients were divided into two groups: 110 adults with gastrointestinal complains and a second group of 130 adults without gastrointestinal disturbances. Sex distribution was homogenous in both groups. The fresh fecal samples were examined to determine the presence of Blastocystis sp. using the direct wet mount. Formalin-ether (Ritchie) technique was used to avoid the misdiagnosis of other intestinal parasites. In both techniques, the fresh samples were examined under light microscope. Results: Blastocystis sp. was detected in 49 patients (44.5%) in the symptomatic group and 28 (22.4%) in the asymptomatic one. Abdominal pain (52.7%) or distension (38.2%), acute diarrhea (26.4%), loss of appetite (18.2%), and dyspepsia (16.4%) were the gastrointestinal complains notified by patients included on the symptomatic group. The probability to identify Blastocystis sp. in patients with gastrointestinal complains was 2.9 times higher than in asymptomatic patients. Conclusion: Current results support those authors considering Blastocystis sp. as pathogen. [ABSTRACT FROM AUTHOR]