Blastocystis sp. Infection in Gabon: Prevalence and Association with Sociodemographic Factors, Digestive Symptoms and Anaemia

Abstract

Introduction: Blastocystis sp. is an intestinal protozoan that is commonly reported, but whose clinical significance remains controversial. Clinical forms of this infection range from asymptomatic carriage to clinical signs, specifically gastrointestinal ones. There is a lack of data on the epidemiology of this protist in Gabon. This study was carried out to provide data on the frequency of Blastocystis sp. infection and its association with clinical signs and the haemoglobin rate. Methods: A cross-sectional study was conducted between September 2018 and November 2019. Stool samples were collected in five of the nine provinces of Gabon from children and adults. Sociodemographic and clinical data were recorded using a standardised pre-tested questionnaire. Haematological parameters and temperature were reported in a laboratory register. Parasitological diagnosis was performed using stool direct examination and a Merthiolate-Iodine-Formaldehyde (M.I.F) concentration to detect Blastocystis sp. Results: In total, 843 participants were interviewed and examined; 414 brought back stool samples. The frequency of Blastocystis sp. infection was 45.2% (n = 187/414), and it increased with age: from 20.0% in young children to 49.5% in adults (P = 0.0057). Being a male (P = 0.08) tended to be associated with Blastocystis sp. carriage. In the multivariate logistic regression, only males were associated with Blastocystis sp. infection and had a 4.3-fold higher risk of being infected than females did (adjusted odds ratio = 4.3; 95% CI = 1.2–15.6; P = 0.03). Diarrhoea, abdominal pain and colitis were observed in some patients with Blastocystis sp. monoinfection. No relation between Blastocystis sp. carriage and anaemia was found. Conclusion: The frequency of Blastocystis sp. infection was high. Males were more at risk of being infected. Blastocystis sp. could be used as indicator in the improvement of environmental sanitation and hygiene, coupled with improved housing. Additional investigations in a population with clinical symptoms should be performed.