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Background Protection against Plasmodium falciparum is observed in a population deficient in glucose-6-phosphate dehydrogenase (G6PD), particularly in African and Mediterranean regions. However, such protection remains unknown among G6PD-deficient individuals in Southeast Asia. Methods In this study, we assessed the invasion and maturation of P falciparum K1 in a culture of erythrocytes isolated from Thai subjects carrying Viangchan (871G > A) and Mahidol (487G > A). Results We found that the parasites lost their ability to invade hemizygous and homozygous G6PD-deficient erythrocytes of Viangchan and Mahidol variants in the second and third cycles of intraerythrocytic development. It is interesting to note that P falciparum parasites selectively grew in erythrocytes from hemi- and homozygous genotypes with normal G6PD activity. Moreover, externalization of phosphatidylserine upon P falciparum infection was significantly increased only in Viangchan hemizygous variant cells. Conclusions This study is the first to show that blockage of invasion in long-term culture and potentially enhanced removal of parasitized erythrocytes were observed for the first time in erythrocytes from Viangchan and Mahidol G6PD-deficient individuals.

ObjectiveTo compare the diagnostic performance of 10 mathematical formulae for identifying thalassemia trait in blood donors.MethodsCompete blood counts were conducted on peripheral blood specimens using the UniCel DxH 800 hematology analyzer. Receiver operating characteristic curves were used to evaluate the diagnostic performance of each mathematical formula.ResultsIn the 66 donors with thalassemia and 288 subjects with no thalassemia analyzed, donors with thalassemia trait had lower values for mean corpuscular volume and mean corpuscular hemoglobin than subjects without thalassemia donors (77 fL vs 86 fL [P ConclusionsOur data indicate that the Shine and Lal formula has remarkable diagnostic performance in identifying donors with underlying thalassemia trait.

Objective To address the effects of storage duration on red blood cell (RBC)–derived microparticles (RMPs) in packed RBCs from donors who have thalassemia. Materials and Methods Packed RBCs were prepared according to laboratory routine. The quantity of RMPs was determined using FACSCalibur and counting beads. Results Across durations of storage, the packed RBCs from donors with thalassemia (n = 28) and healthy volunteers (n = 104) showed average RMPs to be 47,426 (10,139‒127,785) particles/μL vs 49,021 (13,033‒126,749) particles/μL, respectively (P = .63). The peak RMP levels in donors with thalassemia and healthy volunteers, respectively, were shown in products from storage days 34 and 38. Both groups showed a trend toward a positive association between RMP concentration and the duration of storage in packed RBC bags stored under blood bank conditions. Conclusion Our results suggest that storage-induced RMP release has similar effects in stored packed RBCs obtained from both donors with thalassemia and healthy volunteers.

Manual examination of faecal smear samples to identify the existence of parasitic eggs is very time-consuming and can only be done by specialists. Therefore, an automated system is required to tackle this problem since it can relate to serious intestinal parasitic infections. This paper reviews the ICIP 2022 Challenge on parasitic egg detection and classification in microscopic images. We describe a new dataset for this application, which is the largest dataset of its kind. The methods used by participants in the challenge are summarised and discussed along with their results., Comment: The 29th IEEE International Conference on Image Processing

Distinguishing glomerular hematuria (GH) from non-glomerular hematuria (NGH) is important for treating the cause of hematuria. We aimed to determine red blood cell-derived microparticles (RMPs) and phosphatidylserine (PS)-exposing red blood cells (RBCs) and evaluate their use for diagnosing GH and NGH patients.All patients received a physical assessment and urological examination. Dysmorphic RBCs (dRBCs) and acanthocytes were examined using a light microscope. The urinary RMPs and PS-exposing RBCs were determined using flow cytometry.The ratio of RMPs to RBCs was higher in GH patients (n = 29) than in NGH patients (n = 29) (1.06 vs. 0.18). The value of the sum of the PS-exposing RBCs plus RMPs divided by the number of RBCs was higher in GH patients than in NGH patients (48.3% vs. 19.4%). The percentage of RBCs was higher in GH patients than in NGH patients (54.5% vs. 21.8%). Similarly, both the percentages of acanthocytes and of non-acanthocytes were higher in GH patients than in NGH patients (29% vs. 7.7% and 25.4% vs. 14.2%, respectively). The ROC-AUC of the number of PS-exposing RBCs plus RMPs divided by the number of RBCs was 0.9 (95% CI, 0.82-0.97), and the RMPs:RBCs ratio was 0.88 (95% CI, 0.79-0.98). The ROC-AUCs of the dRBCs and acanthocytes were 0.85 (95% CI, 0.78-0.95) and 0.88 (95% CI, 0.8-0.97), respectively.Patients with GH have higher numbers of urinary RMPs and PS-exposing RBCs. These parameters have the potential to be predictive tools for classifying GH in the future.

Objective To quantitate the microparticles (MPs) in whole blood and blood products obtained from blood donors who are deficient in glucose-6-phosphate dehydrogenase (G6PD). Methods The current study analyzed whole blood and blood components prepared from 49 blood donors with G6PD deficiencies and 98 with G6PD-normal results. Packed red blood cells (PRBCs), platelet concentrate (PC), and plasma were prepared according to transfusion laboratory procedures. MP concentrations were determined using a flow cytometer. Results Blood components prepared from donors with G6PD deficiency were characterized by higher red blood cell-derived MP (RMP) concentration in PRBCs (25,526 vs 18,738 particles/µL) but lower concentrations of platelet-derived MPs (PMPs; in whole blood and PC), leukocyte-derived MPs (LMP; in whole blood and plasma) and total MP (in PC), compared with those from donors with G6PD-normal test results. Conclusions These results suggest that differences in G6PD status may account for variation in RMP levels during processing.

Thalassemia trait and G6PD deficiency are asymptomatic and volunteers with these variants are eligible for blood donation.This study aimed to investigate prevalence and hematologic profiles of blood donors with thalassemia trait and G6PD deficiency and the influence of these abnormalities have on donor retention and blood component preparation.Prospectively recruited blood donors were investigated for thalassemia and G6PD deficiency. Characteristic data, hematologic profiles, proportions of prepared blood components, donor return rate within 12 months and adverse reactions in patients receiving red cell transfusions were compared among thalassemia trait, G6PD deficiency, and normal donors.In Thai blood donors, thalassemia trait prevalence was 21.1% and G6PD deficiency prevalence based on G6PD activity was 7.7%. Blood donors with thalassemia trait had significantly lower hemoglobin, MCV, and MCH than blood donors without thalassemia trait (Hb 13.55 ± 1.00 vs. 13.96 ± 1.25 g/dL, MCV 76.70 ± 6.69 vs. 87.01 ± 5.10 fL, and MCH 25.06 ± 2.17 vs. 28.67 ± 1.91 pg, all respectively and all p 0.01). However, the hematologic profiles of blood donors with G6PD deficiency were not significantly different from the hematologic profiles of blood donors with normal G6PD activity. No significant difference was observed among thalassemia trait, G6PD deficiency, and normal donors relative to donor retention and blood component preparation.The high prevalence of thalassemia trait and G6PD deficiency in Thai blood donors observed in this study does not adversely affect donor retention and blood component preparation.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy in humans. More than 400 million people worldwide are affected by this genetic condition. Testing for G6PD deficiency before drug administration is essential for patient safety. Rapidly ascertaining the G6PD status of a person is desirable for proper treatment. The device described in this study, the G6PD diaxBOX, was developed to quantify G6PD deficiency using paper-based analytical devices (PADs) and a colorimetric assay. The G6PD diaxBOX is a straightforward, affordable, portable, and instrument-free analytical system. The major components of the G6PD diaxBox are a banknote-checking UV fluorescent lamp and camera that are easy to access and analysis software. When N A D P H is generated, it absorbs at UV 340 nm and emits colored light that is detected with the camera. The determined Pearson's coefficient shows that the color intensity measured from the G6PD diaxBOX correlated with G6PD activity level. Also, a Bland-Altman analysis indicated that more than 95% of the measurement error was in the upper and lower boundaries (±2 SD) and the error from the severe and moderate deficiency group was less than ± 1 SD. Therefore, the error from G6PD diaxBOX was within the limit boundary and the overall accuracy was more than 80%. The G6PD diaxBOX facilitates the effective and efficient quantification of G6PD deficiency and as such represents a clinically well-suited, rapid point-of-care test.

Diabetes mellitus (DM) is a major global public health problem with an increasing prevalence. DM increases the risk of infections caused by bacteria, fungi, viruses, and parasites. We examined the prevalence, subtypes, and risk factors of Blastocystis infection in patients with and without DM in central Thailand. Stool samples and questionnaires were obtained from 130 people in the DM group and 100 people in the non-DM group. Blastocystis infection was identified via a nested polymerase chain reaction and subtyped via sequencing of the partial small-subunit ribosomal RNA (SSU rRNA) gene. Analysis of potential risk factors was conducted via binary logistic regression. The overall prevalence of Blastocystis infection was 10.8%, including rates of 9% and 12.3% in the non-DM and DM groups, respectively. The most prevalent subtype was ST3, followed by ST1, and ST4. Factors that potentially increased the risk of Blastocystis infection include patients being &gt, 65 years old, the presence of DM, a DM duration of &ge, 10 years, a low level of education, and animal ownership. In conclusion, this is the first study of Blastocystis infection in DM, and a high prevalence was found among this population. Therefore, health education promoting sanitation and hygiene is necessary to reduce and prevent infection in the community.

Diabetes mellitus (DM) is a major global public health problem with an increasing prevalence. DM increases the risk of infections caused by bacteria, fungi, viruses, and parasites. We examined the prevalence, subtypes, and risk factors of Blastocystis infection in patients with and without DM in central Thailand. Stool samples and questionnaires were obtained from 130 people in the DM group and 100 people in the non-DM group. Blastocystis infection was identified via a nested polymerase chain reaction and subtyped via sequencing of the partial small-subunit ribosomal RNA (SSU rRNA) gene. Analysis of potential risk factors was conducted via binary logistic regression. The overall prevalence of Blastocystis infection was 10.8%, including rates of 9% and 12.3% in the non-DM and DM groups, respectively. The most prevalent subtype was ST3, followed by ST1, and ST4. Factors that potentially increased the risk of Blastocystis infection include patients being >65 years old, the presence of DM, a DM duration of ≥10 years, a low level of education, and animal ownership. In conclusion, this is the first study of Blastocystis infection in DM, and a high prevalence was found among this population. Therefore, health education promoting sanitation and hygiene is necessary to reduce and prevent infection in the community.

Background The radical cure of Plasmodium vivax and P. ovale requires treatment with primaquine or tafenoquine to clear dormant liver stages. Either drug can induce haemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, necessitating screening. The reference diagnostic method for G6PD activity is ultraviolet (UV) spectrophotometry; however, a universal G6PD activity threshold above which these drugs can be safely administered is not yet defined. Our study aimed to quantify assay-based variation in G6PD spectrophotometry and to explore the diagnostic implications of applying a universal threshold. Methods and findings Individual-level data were pooled from studies that used G6PD spectrophotometry. Studies were identified via PubMed search (25 April 2018) and unpublished contributions from contacted authors (PROSPERO: CRD42019121414). Studies were excluded if they assessed only individuals with known haematological conditions, were family studies, or had insufficient details. Studies of malaria patients were included but analysed separately. Included studies were assessed for risk of bias using an adapted form of the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Repeatability and intra- and interlaboratory variability in G6PD activity measurements were compared between studies and pooled across the dataset. A universal threshold for G6PD deficiency was derived, and its diagnostic performance was compared to site-specific thresholds. Study participants (n = 15,811) were aged between 0 and 86 years, and 44.4% (7,083) were women. Median (range) activity of G6PD normal (G6PDn) control samples was 10.0 U/g Hb (6.3–14.0) for the Trinity assay and 8.3 U/g Hb (6.8–15.6) for the Randox assay. G6PD activity distributions varied significantly between studies. For the 13 studies that used the Trinity assay, the adjusted male median (AMM; a standardised metric of 100% G6PD activity) varied from 5.7 to 12.6 U/g Hb (p < 0.001). Assay precision varied between laboratories, as assessed by variance in control measurements (from 0.1 to 1.5 U/g Hb; p < 0.001) and study-wise mean coefficient of variation (CV) of replicate measures (from 1.6% to 14.9%; p < 0.001). A universal threshold of 100% G6PD activity was defined as 9.4 U/g Hb, yielding diagnostic thresholds of 6.6 U/g Hb (70% activity) and 2.8 U/g Hb (30% activity). These thresholds diagnosed individuals with less than 30% G6PD activity with study-wise sensitivity from 89% (95% CI: 81%–94%) to 100% (95% CI: 96%–100%) and specificity from 96% (95% CI: 89%–99%) to 100% (100%–100%). However, when considering intermediate deficiency (, Daniel Pfeffer and coauthors report on the assessment of glucose-6-phosphate dehydrogenase activity, which is required for safe use of some malaria treatments., Author summary Why was this study done? Complete cure of vivax malaria, the most geographically widespread malaria species, requires the use of 8-aminoquinoline drugs to clear dormant liver stages of the parasite (‘radical cure’); however, these drugs can cause severe haemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Ultraviolet (UV) spectrophotometry is used as the reference test to measure G6PD activity, for validating new point-of-care diagnostics, and to determine population-specific definitions of G6PD deficiency. Currently, there is no universal threshold to define G6PD deficiency, and each laboratory must invest time and resources to derive site- and laboratory-specific definitions of G6PD deficiency. What did the researchers do and find? We pooled measurements of G6PD activity from studies conducted across different countries and laboratories worldwide. We assessed the comparability of spectrophotometry results between these laboratories to see whether a universal definition and diagnostic cutoff for G6PD deficiency could be determined. There was substantial variation in the performance and absolute measurements of spectrophotometry conducted in different laboratories, hindering the definition of a universal cutoff for G6PD deficiency. What do these findings mean? These findings highlight the importance of quality-control measures to minimise the influence of laboratory procedures on observed measurements. The data suggest that while a robust universal, assay-specific G6PD activity cutoff value can be established for diagnosis of severe G6PD deficiency (

Background Extracellular vesicles (EVs) have been broadly studied in malaria for nearly a decade. These vesicles carry various functional biomolecules including RNA families such as microRNAs (miRNA). These EVs-derived microRNAs have numerous roles in host-parasite interactions and are considered promising biomarkers for disease severity. However, this field lacks clinical studies of malaria-infected samples. In this study, EV specific miRNAs were isolated from the plasma of patients from Thailand infected with Plasmodium vivax and Plasmodium falciparum. In addition, it is postulated that these miRNAs were differentially expressed in these groups of patients and had a role in disease onset through the regulation of specific target genes. Methods EVs were purified from the plasma of Thai P. vivax-infected patients (n = 19), P. falciparum-infected patients (n = 18) and uninfected individuals (n = 20). EV-derived miRNAs were then prepared and abundance of hsa-miR-15b-5p, hsa-miR-16-5p, hsa-let-7a-5p and hsa-miR-150-5p was assessed in these samples. Quantitative polymerase chain reaction was performed, and relative expression of each miRNA was calculated using hsa-miR-451a as endogenous control. Then, the targets of up-regulated miRNAs and relevant pathways were predicted by using bioinformatics. Receiver Operating Characteristic with Area under the Curve (AUC) was then calculated to assess their diagnostic potential. Results The relative expression of hsa-miR-150-5p and hsa-miR-15b-5p was higher in P. vivax-infected patients compared to uninfected individuals, but hsa-let-7a-5p was up-regulated in both P. vivax-infected patients and P. falciparum-infected patients. Bioinformatic analysis revealed that these miRNAs might regulate genes involved in the malaria pathway including the adherens junction and the transforming growth factor-β pathways. All up-regulated miRNAs could potentially be used as disease biomarkers as determined by AUC; however, the sensitivity and specificity require further investigation. Conclusion An upregulation of hsa-miR-150-5p and hsa-miR-15b-5p was observed in P. vivax-infected patients while hsa-let-7a-5p was up-regulated in both P. vivax-infected and P. falciparum-infected patients. These findings will require further validation in larger cohort groups of malaria patients to fully understand the contribution of these EVs miRNAs to malaria detection and biology.

Background Gold standard microscopic examination of Plasmodium falciparum intraerythrocytic stage remains an important process for staging and enumerating parasitized erythrocytes in culture; however, microscopy is laborious and its accuracy is dependent upon the skill of the examiner. Methods In this study, ViSafe Green (VSG), which is a nucleic acid-binding fluorescent dye, was used for assessing in vitro development of P. falciparum using flow cytometry. Results Fluorescence intensity of VSG was found to depend on the developmental stage of parasites. Specifically, multiple-nuclei-containing schizonts were observed in the VSGhigh population, and growing trophozoites and ring-shaped forms were observed in the VSGintermediate and VSGlow populations. The efficacy of VSG-based assay was found to be comparable to the microscopic examination method, and it demonstrated an ability to detect as low as 0.001% of the parasitaemia estimated by Giemsa staining. Moreover, when applying VSG for anti-malarial drug test, it was able to observe the growth inhibitory effect of dihydroartemisinin, the front-line drug for malaria therapy. Conclusions Taken together, the results of this study suggest the VSG-based flow cytometric assay to be a simple and reliable assay for assessing P. falciparum malaria development in vitro.

Additional file 2: Fig. S2. VSG-based flow cytometric analysis of gametocyte. Early schizonts and mature schizonts (left panel) and early stage gametocytes (right panel) were observed in VSGhigh fraction. In the VSGhigh fraction, parasitized erythrocytes have granular distribution of haemozoin, resembling stage IB. Moreover, some were elongated and D-shaped within erythrocytes, which are key characteristics of stage II gametocytes. Early schizonts having 2 and 6 divided nucleus, and mature schizonts consisting of 14 merozoites were also observed in the VSGhigh fraction, whereas ring forms and trophozoites were observed in the VSGlow and VSGintermediate fractions. Scale bar: 10 μm.

Additional file 3: Fig. S3. Giemsa stain of VSG+ cells sorted from non-synchronized and synchronized culture of P. falciparum. (A) Morphology of three distinct populations observed in the non-synchronized culture (Fig. 5b, left panel): (1) cells having small size with various granularity (approximately 0–45 K of FSC-A, and 30–170 K of SSC-A); (2) cells having a relatively large size with high granularity (approximately 45–185 K of FSC-A, and 75–170 K of SSC-A); and, (3) cells having a relatively larger size with low granularity (approximately 45–185 K of FSC-A, and 20–75 K of SSC-A). Based on the intensity of VSG and microscopic images, the population number 1, 2, and 3 in the upper panel of Fig. 5b are schizonts, trophozoites, and ring forms, respectively. (B) Morphology of one minor (indicated as 1) and one major (indicated as 2) population observed in the synchronized culture (Fig. 5b, right panel): (1) cells having high granularity (more than 160 K of SSC-A); and (2) cells having with low granularity (lower than 160 K of SSC-A). Both had a similar size (50–150 K of FSC-A). Based on microscopic images, majority of the VSG+ cells with more than 160-K SSC-A are infected erythrocytes containing multiple ring forms, and they had VSG intensity of 11,578; whereas, the majority of VSG+ cells with lower than 160 K SSC-A are infected erythrocytes with single ring forms and they had VSG intensity of 10,182.

Additional file 1: Fig. S1. Effect of cell debris on analysis of VSG+ cells by flow cytometry. (A) In flow cytometry, cell debris has a lower level of forward scatter (FSC), and it can be observed at the bottom left corner of the density plot [32]. To remove cell debris, the threshold of FSC was set at 10,000 for all experiments. The presence of debris in three independent experiments was examined and shown. Cells having characteristics of FSClow and that are located at bottom left (circles) of the density plot are considered debris. There is 0.64±0.2% of debris, suggesting that the majority of analysed cells are not debris. Moreover, the presence of cell debris in VSG+ cells was checked by examining VSG+ cells according to FSC-A and SSC-A (lower panels). There was 0.69±0.13% of VSG+ cells that had characteristics of FSClow at bottom left corner of the density plot. Therefore, more than 95% of cells analysed by VSG-based flow cytometry were unlikely to be cell debris. (B) Morphology of cells having characteristics of FSClow (< 50 K). P. falciparum-infected erythrocytes were subjected to flow cytometric analysis. The gated single cells were sorted according to intensity of FSC. There were ring forms and schizonts observed in the FSClow cells. Thus, inclusion of the FSClow cells is required. Microscopic images were captured using a microscope with objective lens of 100x magnification.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a genetic haemolytic disorder. Most persons with G6PD deficiency are asymptomatic, but exposure to oxidant drugs, such as the anti-malarial drug primaquine, may induce haemolysis, which is commonly found in Asian countries. A reliable test is necessary for diagnosing the deficiency to prevent an acute haemolytic crisis. This study proposes a novel quantitative method to detect G6PD deficiency using paper-based analytical devices (G6PDD-PAD). Wax printing was utilized for fabricating circular reaction zone patterns in paper. The colorimetric assay is based on the formation of formazan via a reduction of tetra-nitro blue tetrazolium (TNBT) by the G6PD enzyme on G6PDD-PAD. Detection was achieved by capturing the colour using a desktop scanner and the colour intensity was analysed with Adobe Photoshop C56. The results showed that the G6PD activity analysed by G6PDD-PAD was highly correlated with the standard biochemical assay (SBA) (r2=0.87, p

Background Phosphatidylserine (PS) plays important roles in platelets’ pro-coagulant function. However, little is known about assessing this molecule in platelet concentrates (PCs) prepared for routine blood transfusion service. Aim To quantitate the number of PS-exposing platelets in PCs prepared in a routine transfusion laboratory. Methods PC products were prepared according to routine laboratory procedure. The numbers of PS-exposing platelets in the PCs and in unprocessed whole blood were determined using flow cytometry. Results A cross-sectional study of 253 PCs found that they had significantly increased numbers of PS-exposing platelets compared to unprocessed whole blood (47,439 ± 26,500 cells/μL; 5903‒166,156 cells/μL) vs. 30,058 ± 12,958 cells/μL; 8,154-86,606 cells/μL). A heterogeneity study demonstrated that 6% and 2% of the measured PCs and of unprocessed donor whole blood, respectively, showed an increase in the number of PS-exposing platelets that was greater than 2 fold. Conclusions The study suggested that the number PS-exposing platelets in PC prepared in a routine transfusion laboratory differs. However, assessment of the number of PS-exposing platelets in platelet products could be a valid measure to use in managing the quality of platelet processing in routine laboratories.

Background Cell-derived microparticles (MPs) are currently of great interest to screening transfusion donors and blood components. However, the current approach to counting MPs is not affordable for routine laboratory use due to its high cost. Aim The current study aimed to investigate the potential use of flow-rate calibration for counting MPs in whole blood, packed red blood cells (PRBCs), and platelet concentrates (PCs). Methods The accuracy of flow-rate calibration was investigated by comparing the platelet counts of an automated counter and a flow-rate calibrator. The concentration of MPs and their origins in whole blood ( n = 100), PRBCs ( n = 100), and PCs ( n = 92) were determined using a FACSCalibur. The MPs’ fold-changes were calculated to assess the homogeneity of the blood components. Results Comparing the platelet counts conducted by automated counting and flow-rate calibration showed an r 2 of 0.6 ( y = 0.69 x + 97,620). The CVs of the within-run and between-run variations of flow-rate calibration were 8.2% and 12.1%, respectively. The Bland–Altman plot showed a mean bias of −31,142 platelets/μl. MP enumeration revealed both the difference in MP levels and their origins in whole blood, PRBCs, and PCs. Screening the blood components demonstrated high heterogeneity of the MP levels in PCs when compared to whole blood and PRBCs. Conclusions The results of the present study suggest the accuracy and precision of flow-rate calibration for enumerating MPs. This flow-rate approach is affordable for assessing the homogeneity of MPs in blood components in routine laboratory practice.

OBJECTIVE To determine the polymorphisms in the 3' untranslated region (3'UTR) of the G6PD gene and analyze the specific SNPs or haplotypes that may affect messenger RNA (mRNA) secondary structure by in silico analysis. METHODS We studied the 3'UTR polymorphisms in 107 healthy subjects living in Thailand (ethnicities unknown). The haplotype was analyzed using Haploview software. mRNA secondary structure and microRNA binding of the G6PD gene were predicted by use of the CLC Main Workbench 6.9 and RegRNA 2.0 programs. RESULTS The results revealed 1 new variant in the 3'UTR of the G6PD gene (c.*99A > G). Haplotype ATCG showed significance by association-test results that yielded a high odds ratio (OR, 7.90; 95% confidence interval [CI], 3.15-19.81). Moreover, this haplotype affected G6PD mRNA secondary structure changes and microRNA binding via in silico analysis. CONCLUSIONS These results suggest that the haplotype ATCG is associated with reduction of G6PD enzyme expression, G6PD mRNA secondary structure changes, and microRNA binding via in silico analysis.

© 2016, Korean Society for Parasitology and Tropical Medicine. Blastocystis is a common zoonotic enteric protozoan that has been classified into 17 distinct subtypes (STs). A cross-sectional study was conducted to determine the prevalence and subtype distributions of Blastocystis in villagers living along the Chao Phraya River, Ayutthaya Province, Thailand, and to assess the risk of zoonotic infection. In total, 220 stool samples were collected, and DNA was extracted. PCR and sequencing were performed with primers targeting the small-subunit ribosomal RNA (SSU rRNA) genes. Blastocystis was present in 5.9% (13/220) of samples, and ST3 (5.0%; 11/220) was the predominant subtype, followed by ST2 (0.45%; 1/220) and ST6 (0.45%; 1/220). Phylogenetic trees were constructed with the maximum-likelihood method based on the Hasegawa–Kishino–Yano + G + I model, neighbor-joining, and maximum parsimony methods. The percentage of bootstrapped trees in which the associated taxa clustered together was relatively high. All the sequences of the Blastocystis-positive samples (KU051524–KU051536) were closely related to those from animals (pig, cattle, and chicken), indicating a zoonotic risk. Therefore, the villagers require proper health education, especially regarding the prevention of parasitic infection, to improve their personal hygiene and community health. Further studies are required to investigate the Blastocystis STs in the animals living in these villages.

SummaryIntroduction Heinz bodies are important to diagnosing and managing patients. However, microscopic examination of Heinz bodies has several disadvantages, demonstrating the need for a better method. We explored the potential use of flow cytometry to examine Heinz bodies. Methods Whole-blood samples were collected from patients deficient in G6PD and healthy volunteers. Acetylphenylhydrazine was used to induce formation of Heinz bodies in red blood cells (RBCs). Then, RBCs positive for Heinz bodies were examined using a FACSCanto II cytometer. Results RBCs treated with acetylphenylhydrazine formed Heinz bodies and emitted a broad spectrum of fluorescence that could be detected by flow cytometry. The maximum emission of fluorescence was observed at 45 min after the incubation with acetylphenylhydrazine. In addition, the fluorescence emitted was stable for at least 72 h. The flow cytometer could detect the RBCs positive for Heinz bodies even if they made up as little as 0.1% of the total RBC population. Furthermore, the percentage and number, respectively, of RBCs positive for Heinz bodies in G6PD-deficient patients and normal donors exhibited a mean ± standard deviation (SD) of 68.9 ± 27.5 vs. 50.9 ± 28.6 and 96 014 ±35 732 cells/μL vs. 74 688 ± 36 514 cells/μL. Conclusion Heinz bodies induced by acetylphenylhydrazine emit fluorescence, and this fluorescence could be examined using flow cytometry. Our study suggests the potential use of the developed method to investigate the formation of Heinz bodies in clinical samples.