Systematic review and meta-analysis: Epidemiology of human 'Blastocystis' spp. Infection in Malaysia

'Blastocystis' spp. is a unicellular enteric protozoan parasite in humans with a controversial role in disease etiology. It is common in developing countries among immunocompromised patients and people who have close contact with animals. In this study, we have systematically reviewed previous studies on the distribution and genotypes of human 'Blastocystis' infection in Peninsular Malaysia. Studies examining the prevalence of 'Blastocystis' in diverse demographics, including rural, urban, comorbid conditions, and high-risk populations, were taken into consideration. The infection has been reported in nine states; the total percentage of infection was 17.8% (1671/9397), with the most cases in Pahang (27.3%) and the least in Johor (3.4%). Molecular studies revealed the presence of six subtypes: ST1, ST2, ST3, ST4, ST5, and ST6. ST3 was reported as the predominant subtype in all the states, with a prevalence of 54.7% (338/618). The findings provide greater clarity on the epidemiology of 'Blastocystis' in Malaysia, which will help in policy making towards planning and strategizing control measures against the parasite.