Microscopy technique is widely used in the detection of Blastocystis sp. infection. This study was performed to compare two microscopy-based techniques; in vitro cultivation of faecal specimens in Jones' medium (IVC) followed by Wheatley Trichrome staining and fixed-PVA faecal specimens (PVA) followed by Wheatley Trichrome staining with single-round polymerase chain reaction (PCR) as the reference technique. Examination was performed on 466 faecal samples obtained from Orang Asli community in Pahang, Malaysia. Detection rate of Blastocystis sp. was highest in IVC (35.6%) followed by PVA (20.0%). Single-round PCR detected 41.0% of the faecal specimens. The sensitivity and specificity of PVA and IVC compared to the reference technique were 75.3% (95% CI: 65.2-83.6) and 68.5% (CI: 63.7-73.3), and 88.6% (CI: 82.7-93.0) and 86.3% (CI: 81.9-90.0) respectively. The agreement between the reference technique and PVA showed fair statistically significant agreement by Cohen Kappa statistics of (K=0.318, p<0.001), meanwhile substantial statistically significant agreement was observed between PCR and IVC by Cohen Kappa (K=0.727, p<0.001). Therefore, in vitro cultivation in Jones' medium followed by Wheatley Trichrome staining of faecal specimens should be used as a screening technique in the detection Blastocystis sp. infections. � 2017 Oriental Scientific Publishing Company. Al rights reserved.

Background: Alternating wet and dry seasons may play an important role in the acquisition and distribution of Blastocystis subtype infection in the tropics. This cross-sectional study was therefore conducted to provide the prevalence of Blastocystis and to determine the potential risk factors associated with each subtype during the wet and dry seasons in the Aboriginal community, Pahang, Malaysia. Methods: A total of 473 faecal samples were collected: 256 (54.1%) and 217 (45.9%) samples were obtained during the wet (October-November 2014) and the dry season (June 2015), respectively. All fresh faecal samples were subjected to molecular analysis for subtype and allele identification. Results: Of the 473 samples, 42.6% and 37.8% were positive for Blastocystis ST1, ST2, ST3 and ST4 during wet and dry seasons, respectively. Prevalence of Blastocystis ST1 was significantly higher during the wet season compared to the dry season (Z = 2.146, P < 0.05). Analysis of the association of each Blastocystis subtype with socioeconomic characteristics showed the presence of other family members infected with Blastocystis ST3 and the use of stored river water for domestic activities were the significant risk factors for Blastocystis ST3 infections during both seasons. Untreated water supply and low monthly household income (less or equal to RM 500) were the other significant risk factors for Blastocystis ST3 infections during wet and dry season, respectively. The presence of other family members with Blastocystis ST1 and ST2 was the only significant risk factor associated with ST1 and ST2 infections during both seasons. We hypothesise that transmission of Blastocystis ST1, ST2 and ST3 occurred from person to person during both seasons. The waterborne transmission was also identified as a mode of transmission of Blastocystis ST3. Conclusion: The significant risk factors identified in this study were important in the dynamic transmission of Blastocystis infections during both seasons. Provision of treated water supply and health education are affirmative actions to be taken to control Blastocystis infections in this community. 2017 The Author(s).