Acute gastroenteritis due to Blastocystis hominis in an adolescent boy

Acute gastroenteritis with persistent vomiting, high degree fever and blood streaking stools often suggests bacterial aetiology in children. Authors report a 13-year-old boy presenting with acute watery diarrhoea with persistent vomiting, fever of 103°F, abdominal cramps and blood streaking stools who failed to show any response to parenteral third-generation cephalosporin for 72 hours. The stool examination revealed numerous cystic and amoeboid forms of Blastocystis hominis Metronidazole was started and the boy promptly responded within 24 hours. There was no recurrence of symptoms then onwards. The case highlights the crucial stool examination in case of acute diarrhoeal disease for rare aetiology.

Distribution and molecular analysis of Blastocystis subtypes from gastrointestinal symptomatic and asymptomatic patients in Iran

INTRODUCTION

Blastocystis is a common intestinal parasite of human and animal hosts. The parasite has 17 subtypes, and among those at least nine subtypes (ST1-ST9) are found in human hosts.

OBJECTIVE

The aim of the present study was to investigate the presence of different subtypes of Blastocystis spp. among the patients referred to Velayat hospital of Qazvin province, Iran.

METHODS

Overall, 864 stool samples were examined by using formalin-ethyl acetate concentration method and Trichrome staining. All specimens were cultured in clotted fetal bovine medium. Later, DNA extraction and PCR amplification of 18S ribosomal RNA gene region was conducted and phylogenetic tree constructed.

RESULTS

The results revealed 7.9% (68/864) of the study population were infected with Blastocystis. Intestinal symptoms were observed in 61% (36/59) of individuals positive for Blastocystis, with abdominal pain in 58% (21/36) of cases which was more frequent than other intestinal signs. No significant relationship was observed among the study variables. By molecular and phylogenetic analysis, three subtypes ST1 (45%), ST2 (30%) and ST3 (23%) of parasite were identified.

CONCLUSION

This study showed ST1 subtype was the predominant subtype among the positive specimens, meanwhile the highest haplotype and nucleotide diversity were clarified in ST3 subtype.

Evaluation of a Flotation Adapted Parasep® for Stool Ova and Parasite Examination

Stool ova and parasite examination using concentration methods remains the gold standard for the investigation of digestive parasitosis. Recently, single-use filtration devices have been marketed for stool concentration sedimentation methods such as MIF or Bailenger, which improve the analytical quality by avoiding contact with feces. In this study, the Parasep® device was adapted to the Faust technique flotation method. In addition, the performance between conventional techniques (MIF concentration and Faust) and techniques using this device was evaluated on 25 formalin-preserved stools and 3 fresh stools. With the Parasep device, the main parasites (protozoa or helminths) were isolated, and the technical requirements such as hygiene control for the operator and realization according to good laboratory practice were improved due to the filtration device.

Prevalence of non-pathogenic types of gastrointestinal protozoa in population in Slovakia and their potential importance in the aspect of public health

The aim of the research was to determine the prevalence of non-pathogenic protozoa circulating in the human population of Slovakia. We particularly focused on the socially deprived areas with poor sanitation conditions, as they are one of the factors affecting the transmission of these infections. Within this study, 2760 people were coprologically screened for the presence of protozoan cysts. The analyzed group comprised 1173 men and 1587 women from different regions of Slovakia. The total prevalence (2.03%) of non-pathogenic protozoa species was determined. The prevalence of Entamoeba coli was 0.80%, the prevalence of Endolimax nana 0.58%, and the prevalence of Blastocystis hominis was 0.65%. The presence of non-pathogenic protozoa was more frequent in women than that in men, in all age groups. The highest incidence of Entamoeba coli was found in children aged one month - seven years (0.79%), the lowest in the age group of 19-88 years (0.66%). Endolimax nana was most frequent in 8-18 year-olds (0.95%), where the statistical significance was found (p<0.05). The prevalence of Blastocystis hominis by the age group ranged from 0.39 to 0.95%. We did not find any statistical significance (p>0.05) for Entamoeba coli, and similarly for Blastocystis hominis associated with the sex and age. Although the circulation of non-pathogenic protozoa in the human population is far from being limited to the developing countries, their occurrence is also frequent in the population of developed countries. Despite their controversial pathogenicity, they should not be neglected, particularly in the patients with gastrointestinal symptoms.

Blastocystis hominis transmission by non-potable water: a case report in Italy

In the reported case, a 41-year-old Italian man came to the clinician's observation reporting cramps, bloating and watery diarrhoea a few days after drinking water indicated as unpotable from a fountain in a farm area. The medical suspicion was directed at both gluten intolerance and enteric infection, eventually of waterborne origin. Gluten intolerance was investigated by intestinal biopsy and excluded, while stool analyses ruled out infective bacteriological or viral agents and parasites. Subsequently, a persistent eosinophilia was revealed and a parasitological analysis was again suggested, planning for a more sensitive molecular method. Therefore, a multiplex-PCR of enteric protozoa species DNA was performed on an intestinal biopsy and faecal samples revealing only Blastocystis hominis protozoa, subsequently typed as subtype 1 by RFLP-PCR method. B. hominis is an anaerobic protozoa found in the human and animal intestinal tract, recently associated with a pathogenic role characterized by chronic development. Since blastocystosis has been demonstrated as a waterborne infection, a sample of water matrix was analysed, revealing the B. hominis subtype 1 DNA inside. A probable water transmission of Blastocystis infection has been demonstrated in this case report. Only a probiotic treatment based on Saccharomyces boulardii was administered to the patient and this apparently resolved the infection. In summary, the case described here is a chronic blastocystosis of possible waterborne origin, controlled by assuming a yeast treatment.

Intestinal parasitic infections: Current prevalence and risk factors among schoolchildren in capital area of the Republic of Marshall Islands

Intestinal parasitic infections (IPIs) among schoolchildren in Republic of Marshall Islands (RMI) largely remains unknown, thus investigation on IPIs status to establish the baseline data is urgently needed. This cross-sectional study intended to investigate the current IPIs status and associated risk factors among schoolchildren at capital of RMI. Single stool sample from 400 schoolchildren (207 boys and 193 girls) aged 9.73±2.50 yrs old was examined by employing merthiolate-iodine-formaldehyde concentration method. Demographic characteristics, uncomfortable symptoms and risk factors were obtained by questionnaires investigation. The overall prevalence of IPIs in schoolchildren was 22.8% (91/400), of them 24.2% harbored at least 2 different parasites. Notably, the majority was infected by waterborne protozoan parasites (82.4%, 75/91). Nine different intestinal parasites have been identified, of which six were pathogenic including Hook worm, Trichuris trichiura, Enterobius vermicularis, Entamoeba histolytica/dispar, Giardia intestinalis and Blastocystis hominis. Schoolchildren who ever complained dizziness or headache showed a significant higher prevalence of pathogenic IPIs than those who did not (p<0.05). Schoolchildren who lived in urban area than rural area had higher chance to acquire pathogenic IPIs (p=0.03). However, none of risk factors were identified to be associated with pathogenic IPIs.

Intestinal parasitic infections in different groups of immunocompromised patients in Kashan and Qom cities, central Iran

INTRODUCTION

Intestinal parasitic infections (IPIs) are important causes of morbidity and mortality in patients with immunocompromising conditions.

OBJECTIVE

The aim of this study was to determine the prevalence of IPIs in different groups of immunocompromised patients, including hemodialysis patients (HD), renal transplant recipients (RTR), cancer and HIV/AIDS patients in comparison with healthy individuals in two central cities of Iran (Kashan and Qom).

METHODS

In this case-control study, the stool samples of 135 HD, 50 RTR, 60 cancer patients, 20 HIV/AIDS patients and 120 healthy subjects were tested using direct-smear, formol-ether concentration, Ziehl-Neelsen staining and Agar plate method.

RESULTS

The overall infection rate was 11.7% (31/265) in patient groups and 0% (0/120) in the control group. The frequency of parasites was 25% in HIV/AIDS patients, 11.9% (16/135) in HD, 12.0% (6/50) in RTR and 6.7% (4/60) in cancer patients. Blastocystis hominis (4.2%) and Giardia lamblia (3.0%) were the most prevalent parasites in patient groups. The infection rate was significantly higher in male (17.6%) than female (5.4%) patients (p = .002), but no statistically significant association was observed according to the age and educational levels.

CONCLUSIONS

This study showed a high prevalence of IPIs in immunocompromised patients. The results of this study suggest that periodic stool examinations for screening of IPIs should be included as a part of routine medical care in these patients.

MODIFIED CULTURE METHODOLOGY FOR SPECIFIC DETECTION OF BLASTOCYSTIS HOMINIS IN STOOL SAMPLES

Blastocystis hominis provides major challenges for laboratory diagnosis due to its polymorphic nature in wet mounts which can result in confusion with other protozoa, yeast or even fat globules. Studies revealed that simple smears were less sensitive than in vitro cultivation using different media for the detection of B. hominis in stool specimens. Cultures of B. hominis are usually enriched by different types of sera to enhance growth and multiplication of the parasite. The aim of this study is to assess the use of two sera types other than horse serum that is commonly used in culture media for the growth, multiplication and detection of B. hominis in examined stool samples and comparing the results with those obtained using horse serum. Fifty stool samples were collected from patients suffering from different colonic manifestations attending Cairo University Hospitals. The samples were freshly cultured in three different culture media using horse serum (in Jones' medium), donkey serum (as a modification ii Jones' medium) and human plasma (in modified Pavlova's medium) in adequate preparations. Cultures were then left for incubation and examined by direct microscopy to detect Blastocystis hominis. The result showed of 50 stool samples studied,. 18 samples (36%) were positive results for B. hominis. The number of positive results obtained by horse serum, donkey serum and human plasma were 13,18and 11 respectively. Paired comparisons were made between each 2 cultures with each culture set as a reference once to detect the most appropriate one for diagnosis When horse was set as the reference method, donkey serum showed a sensitivity of 100% and specificity of 86.5% with a 90% agreement between the 2 methods. While human plasma showed a sensitivity of 46.2% and specificity of 86.5% with an agreement of 76%. In addition, the vacuolar form was the commonest pattern observed in this study throughout all the three cultures.

Clinical significance and prevalence of Blastocystis hominis in Van, Turkey

Objectives:

To determine the associated clinical symptoms and prevalence of Blastocystis hominis (B. hominis).

Methods:

Stool samples of 50,185 patients (26,784 males and 23,401 females) who were received at the Parasitology Laboratory of Yuzuncu Yil University Faculty of Medicine, Van, Turkey in the last 5 years were inspected microscopically using saline and iodine-stained wet-mount preparations. Age, gender, and symptoms of patients were recorded and their significance was evaluated.

Results:

The prevalence of B. hominis in the total sample was 0.54% (275/50185). Out of 275 infected patients, 143 (52%) were males, and 132 (48%) were female (χ²=0.884; p=0.348). The distribution of B. hominis infection was high in 7-13 aged children (34.9%) (χ²=306.8; p=0.001). Blastocystis was higher among symptomatic patients (70.2%) compared with asymptomatic patients (29.8%) (χ²=107.13; p=0.001). The most frequent clinical symptoms associated with the disease were abdominal pain (27.3%) and diarrhea (19.6%) followed by anorexia, fever, saliva, anal itching, and nausea.

Conclusion:

Blastocystis hominis is considered a causative agent of human disease in patients with recurrent symptoms. Due to the significant risk for zoonotic transmission, molecular techniques must be used to determine the route and source of infection.

[Frequency and in vitro susceptibility antiparasitic of Blastocystis hominis from patients admitted to the Hospital Regional Lambayeque, Peru]

OBJECTIVE

To describe the frequency and antiparasitic in vitro susceptibility of Blastocystis hominis in patients admitted to theHospital Regional Lambayeque, Peru.

MATERIAL AND METHODS

A cross-sectional study was conducted from January to August 2015 at 313 patients of all ages. B. hominis detection was performed on serial fecal samples by direct microscopic examination and microculture in modified Locke solution. The in vitro susceptibility testing against the drug metronidazole, nitazoxanide, trimethoprim-sulfamethoxazole and erythromycin was performed in 24 strains of B. hominis, which grew up (microculture method) in 10 double concentrations of each antimicrobial (from 256 ug/ml to 0.5 ug/mL) plus a control.

RESULTS

46.3% (145/313) of the sample had B. hominis, also the age between 12 to 17 years and 60 years was associated with higher frequency of parasites (OR: 2.93 and 2.62). The minimum inhibitory concentration (MIC) 90 of metronidazole and nitazoxanide was 3.19 ug/mL and 11.19 ug/ml, respectively, whereas the MIC 90 of trimethoprim-sulfamethoxazole and erythromycin were above 256 ug/mL.

CONCLUSIONS

B. hominis occurs in high frequency in patients admitted to the Hospital Regional in Lambayeque, proving to be an important problem of public health in the region. Also B. hominis isolated from these patients were shown to be susceptible in vitro to low concentrations of metronidazole and nitazoxanide so they could be chosen for treatment of this parasite.

Hypoalbuminemia as a predictor of diarrhea caused by blastocystis hominis

Blastocystis hominis is an intestinal protozoan found worldwide, particularly in developing countries, that may cause gastrointestinal symptoms, including diarrhea. We conducted a hospital-based study to identify clinical factors predictive of diarrhea caused by B. hominis. We studied patients with positive stool samples for B. hominis by formalin ethyl acetate concentration technique at Srinagarind Hospital, Khon Kaen University, Khon Kaen, Thailand between 2003 and 2010. Patients were divided into diarrhea and non-diarrhea groups. Diarrhea patients were categorized if the diarrhea was associated with B. hominis only. In total, 81 patients with isolated B. hominis infection were studied. Of those, 17 patients (21%) had diarrhea associated with B. hominis infection. Eight variables were included in the final model predicting diarrhea caused by B. hominis on multiple logistic regression analysis. Only serum albumin level was significantly associated with diarrhea cases in this study with an adjusted OR of 0.162 and a 95% CI of 0.027- 0.957. Hypoalbuminemia is associated with diarrhea associated with blastocystosis.

[Relationship between morphology and pathogenicity of Blastocystis hominis trophozoites]

Six hundred and eighty-six fresh fecal specimens were collected from outpatients (663 well-formed feces and 23 watery feces) during March 2011 to March 2012. All specimens were examined microscopically by direct smear and iodine stained method. B. hominis obtained from the human positive fecal specimens were cultured in LES medium, and inoculated into the abdominal cavity of 10 female mice of 6-8-week old. The abdominal fluid was examined with same methods. 103 of 686 patients were positive (80 well-formed feces and 23 watery feces). Micro-scopically, the granular form and vacuolated form of B. hominis trophozoites could be easily identified by direct smear and iodine staining in well-formed fecal specimens, showing ovoid in shape and about (13.2 +/- 0.2) microm in size. The trophozoites cultured in LES medium showed similar feature. But in the watery fecal specimens and mice ascites specimen, they were amorphous containing more granules. And their average size was (28.0 +/- 0.3) microm which was larger than the former. Moreover, the ameba form of B. hominis trophozoites was also detected in the 23 watery fecal specimen and mice ascites specimen. The trophozoites of B. hominis were varying in shape and size depending on their living environment.

[Blastocystis hominis in symptomatic celiac patients]

INTRODUCTION

Celiac disease (EC) not diagnosed or treated affect histological, immunological and nutritional status of patients who suffer it. These changes allow infection by parasites that cause no symptoms in immunocompetent patients, such as Blastocystis hominis (Bh). OBJETIVE. To analyze the presence of Bh in symptomatic celiac patients and describe the clinical, histological, immune and nutritional status in these patients. MATERIAL AND METHOD An observational descriptive cross sectional study was performed. Thirty symptomatic celiac patients (18 women, mean age 41 years old, range 19-68 years), assisted at the Institute of Gastroenterology of Cuba from January to December 2009, entered the study.

RESULTS

Diarrhea and chronic anemia were the most commonly reported clinical manifestations (22 and 4 patients, respectively). The analysis of more than five Bh per field was more frequent in the group ofpatients studied (63.3%), with statistically significant difference in patients with vilous atrophy and low weight (P < 0.03) compared to cases with less than five Bh per feld. No significant differences were found when the immune status of patients was analyzed. CONCLUSIONS. In symptomatic celiac patients with subtotal-total villous atrophy and low weight the finding of more than five Bh perfield should be considered as opportunistic.

[Survey on Blastocystis hominis infection in HIV positive individuals in Fuyang City, Anhui Province]

OBJECTIVE

To understand the epidemiological characteristics of co-infection of HIV and Blastocystis hominis and its risk factors.

METHODS

A total of 309 people with HIV positive in the development zone of Fuyang City were recruited, and the face to face questionnaires were conducted to collect the information of behavioral characteristics and sociodemographic data of the participants. Meanwhile, the samples of stool and blood were collected to test B. hominis, cytokines and CD4+/CD8+ T-lymphocyte. The influencing factors of co-infection of HIV and Blastocystis hominis were analyzed by the single factor analysis and Logistic regression analysis.

RESULTS

Among the 309 people involved, 302 accepted feces examinations, 286 accepted the questionnaire investigation, and 263 accepted both of them. The infection rate of B. hominis was 17.11%, that of the female was 21.90%, which was significantly higher than that of the male (11.90%) (P < 0.05). The results from the multivariate Logistic regression model showed that good nutrition was significantly associated with the co-infection of HIV and B. hominis (OR = 0.263, 95% CI: 0.073, 0.945).

CONCLUSIONS

The infection rate of B. hominis is high in people with HIV positive, and the nutrition situation of individuals may be one of the important risk factors associated with co-infection.

[Genotype analysis and isoenzyme patterns of ten isolates of Blastocystis hominis from Guangxi]

OBJECTIVE

To analyze genotypes and lactate dehydrogenase (LDH) and esterase (EST) patterns in 10 isolates of Blastocystis hominis collected from Guangxi.

METHODS

Ten B. hominis isolates (BhGX1-BhGX10) were obtained from the fecal specimens of patients and cultivated in vitro, and then the genomic DNA was extracted. The isolates were genotyped by PCR using seven pairs of known sequenced-tagged site (STS) primers. Isoenzyme patterns of LDH and EST were investigated by SDS-PAGE.

RESULTS

Out of the 10 isolates, 8 were identified as genotype I and the genotypes of the other two (BhGX4 and BhGX7) were unknown which were negative to all the STS primers. Among the ten isolates, 10 LDH bands were found, more with Rm37, Rm49, Rm57, Rm68 and Rm92. 12 bands showed in EST patterns: Rm14, Rm18, Rm23, Rm27, Rm35, Rm41, Rm45, Rm50, Rm55, Rm68, Rm77 and Rm82. Difference existed with the LDH and EST patterns among the isolates.

CONCLUSION

Genotype I is the major one in the 10 B. hominis isolates from Guangxi, and the isolates show different isoenzyme patterns for LDH and EST.

The pathogenic role of different Blastocystis hominis genotypes isolated from patients with irritable bowel syndrome

BACKGROUND AND STUDY AIMS

The pathogenic role of Blastocystis hominis is still regarded by some as controversial. Studies have been in progress for years to evaluate the role of blastocystosis in irritable bowel syndrome (IBS) and demonstrated that faecal carriage of B. hominis was frequent in these patients. This study attempted to distinguish different genotypes of B. hominis isolates obtained from patients with IBS and to evaluate their pathogenic potentials.

PATIENTS AND METHODS

One hundred subjects (51 patients with IBS and 49 asymptomatic infected subjects) harbouring B. hominis were investigated by a direct smear examination and in vitro culture of stool samples followed by genotyping of B. hominis by PCR using STS primers. Sigmoidoscopy was done in all subjects and biopsies were taken and subjected to histopathologic examination.

RESULTS

Genotyping proved that only four genotypes of B. hominis were identified. In patients with IBS, genotypes III, I, and IV were detected (28, 15 and 14 isolates, respectively). On the other hand, genotypes III, IV, and II were identified in asymptomatic infected individuals (21, 19 and 13 isolates, respectively). The degrees of chronic inflammatory changes in sigmoidoscopic biopsies caused by B. hominis genotypes among IBS patients revealed that severe inflammation was present mainly in patients harboring genotype I isolates (4/15) (26.66%), while genotype III caused severe inflammation only in 9.09%. Genotype II isolates were not detected in IBS cases. Asymptomatic infected individuals harboring genotypes II, III and IV exhibited mild to moderate inflammatory changes. Genotype I isolates were not detected in asymptomatic infected group. The correlation between different B. hominis genotypes and degree of inflammation was statistically insignificant.

CONCLUSION

Genotype I was the most pathogenic genotype of B. hominis isolates in patients with IBS while genotype II was not detected among those patients. Also, our results suggest the presence of pathogenic and non-pathogenic strains among genotypes III and IV.

In vitro sensitivity of Blastocystis hominis to garlic, ginger, white cumin, and black pepper used in diet

To determine the growth pattern and in vitro susceptibility of Blastocystis hominis to metronidazole (MTZ), garlic, ginger, white cumin, and black pepper. Stool specimens were collected from 16 irritable bowel syndrome (IBS) and 10 controls between July-November 2010. Stool microscopy and culture for B. hominis was performed. Drug susceptibility assays was done using 0.01 and 0.1 mg/ml of MTZ, garlic, ginger, white cumin, and black pepper. Effect was assessed on B. hominis culture after 48 h. Stool DNA was extracted using stool DNA extraction kit (Qiagen) and polymerase chain reaction (PCR) done using subtype-specific sequence-tagged-site primers. B. hominis genotype 3 and coinfection of 1 and 3 tended to grow well in culture compared to isolated type 1 infection. Exposed to MTZ at a concentration of 0.01 mg/ml, 38% (6/16) B. hominis from IBS did not grow in culture compared to 100% (10/10) of B. hominis from control (p = 0.001). When they were exposed to MTZ at 0.1 mg/ml, 56% (9/16) B. hominis from IBS did not grow in cultures compared to 100% (10/10) from control (p = 0.01). Forty-four percent (7/16) B. hominis from IBS did not grow in culture compared to 100% (10/10) B. hominis from control when exposed to garlic at a concentration of 0.01 mg/ml (p = 0.003) and following exposure to garlic at 0.1 mg/ml, 38% (6/16) B. hominis from IBS did not grow in cultures compared to 100% (10/10) from control (p = 0.001). B. hominis isolates from IBS had a cell count of 6,625 at a MTZ concentration of 0.01 mg/ml that reduced to 1,250 as MTZ concentration was increased to 0.1 mg/ml (p = 0.08). B. hominis from IBS with a mean cell count of 3 × 10(5) at baseline decreased to 1 × 10(4) when exposed to garlic at 0.01 mg/ml (p < 0.001) and to 1 × 10(3) (p < 0.001) when garlic was 0.1 mg/ml. B. hominis from IBS cell count decreased to 1 × 10(5) when exposed to white cumin at 0.01 mg/ml (p = 0.01) and to 1 × 10(5) (p < 0.001) when white cumin was 0.1 mg/ml. Exposed to black pepper at 0.1 mg/ml, cell count of B. hominis from IBS decreased to 1 × 10(5) (p = 0.01). B. hominis from IBS decreased to 1.3 × 10(5) exposed to ginger at 0.01 mg/ml (p = 0.001). B. hominis isolates were mostly genotypes 3, type 1 and 3 coinfection, and non-typeable B. hominis isolates. B. hominis isolates from IBS mostly genotype 1 demonstrated an increased sensitivity to garlic at 0.01 mg/ml with a B. hominis cell count of 3,714 compared to 6,142 when exposed to 0.01 mg/ml of MTZ. However, this sensitivity did not increase as garlic concentration was increased to 0.1 mg/ml, for B. hominis cell count was 6,000 compared to 1,428 as MTZ was increased to 0.1 mg/ml.

[Blastocystis hominis and nonpathogenic enteric protozoa in patients with pulmonary tuberculosis and those with HIV infection]

Blastocystis hominis and nonpathogenic enteric protozoa were diagnosed in 300 patients with pulmonary tuberculosis mainly of its infiltrative form and 500 with Stages II and III HIV infection; the patients received antituberculosis therapy (ATT) and antiretroviral therapy (ART), respectively. Control groups included 200 Tashkent dwellers and 350 patients with various noninfectious diseases of the gastrointestinal tract. Triple coproscopy was made. B. hominis was significantly more frequently detected in patients with pulmonary tuberculosis and those with HIV infection than in healthy individuals: in 53.6 +/- 2.9, 42.2 +/- 2.2, and 18.0 +/- 2.5, respectively (P < 0.01). Only did the tuberculosis or HIV-infected patients show a high intensity of B. hominis infection, which was accompanied by recurring diarrhea and nausea. The high activity of alanine aminotransferase and aspartate aminotransferase was observed in 20% of the patients with tuberculosis + blastocytosis; that of alkaline phosphatase was seen in 25%. The tuberculosis or HIV-infected patients were more frequently found to have Chylomastix mesnili, Jodamoeba butschlii, and Endolimax nana. The specific features of intestinal colonization seem to reflect changes in local immunity; the drugs included into ATT and ART have no substantial effects on the viability of protozoa.

[Blastocystis hominis infection in a baby with food allergy]

The paper describes a rare manifestation of Blastocystis hominis infection in a 3-month-old baby with food allergy that appeared as atopic dermatitis and coloproctitis induced by food proteins (cow's milk, hen's egg). The fact that food allergy may be one of the predisposing factors in the development of clinical manifestations of B. hominis infection is discussed. The assumption that the amoeboid form of blastocysts accompanies the clinical manifestation of the infection is confirmed.

Evaluation of the transmission mode of B. hominis by using PCR method

Blastocystis hominis is a common intestinal parasite observed in fecal examination. On the other hand, the transmission of this parasite is certainly unknown. The transmission of B. hominis can be realized by animal contact and the contamination by water and food with excreted cysts from the reservoir hosts. B. hominis isolated from 25 humans, their pets, and tap water was identified by polymerase chain reaction using sequenced tag site primers in this study. B. hominis isolates obtained from humans and pets were identified as subtype1, subtype2, and subtype3 while B. hominis isolates obtained from tap water were also identified as subtype1. The B. hominis isolates obtained from humans in this study were defined as the same as the subtypes of the B. hominis isolates obtained from the pets, of which these people keep at their homes, and the tap water. These findings reveal that the source of B. hominis infection could be pets and tap water.

Blastocystis hominis and Dientamoeba fragilis in patients fulfilling irritable bowel syndrome criteria

Studies have suggested a possible role for Blastocystis hominis and Dientamoeba fragilis in the etiology of irritable bowel syndrome (IBS). We studied the prevalence of B. hominis and D. fragilis in patients with IBS-diarrhea (IBS-D). Three hundred and thirty patients were enrolled, 171 (52%) with IBS-D and 159 (48%) were controls, respectively. Stool microscopy, culture, and polymerase chain reaction (PCR) for B. hominis and D. fragilis were done. B. hominis was positive by stool microscopy in 49% (83/171) of IBS compared to 24% (27/159) in control (p < 0.001). B. hominis culture was positive in 53% (90/171) in IBS compared to 16% (25/159) in control (p < 0.001). B. hominis PCR was positive in 44% (75/171) in IBS compared to 21% (33/159) in control (p < 0.001). D. fragilis microscopy was positive in 3.5% (6/171) in IBS-D compared to 0.6% (1/159) in control (p = 0.123). D. fragilis culture was positive in 4% (7/171) in IBS compared to 1.3% (2/159) in control (p = 0.176). D. fragilis PCR was positive in 4% (6/171) in IBS-D compared to 0% (0/159) in control (p = 0.030). B. hominis is common, while D. fragilis was less prevalent in our patients with IBS-D. B. hominis and D. fragilis culture had a better yield compared to stool microscopy and PCR.

A case-control study of Blastocystis hominis among Iranian population

OBJECTIVES

A case-control study was conducted to investigate the epidemiology and clinical features of Blastocystis hominis among Iranian patients with and without GI symptoms.

METHODS

Six hundred and seventy patients with GI and Six hundred and seventy patients without GI symptoms were enrolled as cases and controls respectively during 2006-07. Standard microscopic examinations following in vitro culture were used to examine the stool samples for presence of trophozoites and cysts of B. hominis.

RESULTS

Infection with B. hominis occurred most commonly in those with GI symptoms (5.67 %) compared with those patients without GI symptoms (3.43 %). The most common symptom in case group was abdominal pain (86.84 %). B. hominis was mostly found with Giardia lamblia in case group and with Entamoeba coli in control group. In addition, there was no significant relation between the presence of GI symptoms and the incidence of B. hominis.

CONCLUSION

B. hominis has long been described as a non-pathogenic protozoan parasite until recently, when claims have been made that it could result in pathogenic conditions. Thus, to confirm the complication is needed to additional study especially on molecular pathogenesis of this organism.

[Isoenzyme patterns of the isolates of Blastocystis hominis from Guangxi]

OBJECTIVE

To observe malate dehydrogenase and alkaline phosphatase patterns of ten isolates of Blastocystis hominis (Bh) from Guangxi.

METHODS

Blastocystis hominis agents were isolated from the fecal specimens of patients and cultivated in vitro. The samples were prepared for polyacrylamide gel slab electrophoresis (PAGSE). Sodium malate and 1-Naphthyl phosphoric acid sodium were used as substrates. NBT and fast blue RR salt were used to stain MDH and ALP respectively. The isoenzyme bands were recorded with relative mobility (Rm).

RESULTS

Among the 10 isolates, 7 MDH bands were found, more with Rm34, Rm47, Rm51, Rm55, and Rm59. All the isolates showed Rm34 and Rm51 bands. 5 bands showed ALP patterns: Rm22, Rm25, Rm28, Rm35, and Rm38. Difference existed with the MDH and ALP patterns among the isolates.

CONCLUSION

MDH and ALP patterns may indicate a genetic difference among the isolates, which might play a role in its classification.

[The distribution of intestinal parasites detected in The Dokuz Eylul University Medical Faculty Hospital between 2005 and 2008.]

A retrospective evaluation of the data from 14,246 patients with gastrointestinal complaints who presented at the parasitology laboratory of the Dokuz Eylul University Medical Faculty Hospital between January 2005 and December 2008 was carried out. Fecal samples of all patients were examined using native-Lugol and the trichrome and Kinyoun acid-fast staining method after sedimentation in fecal concentration tubes. One or more parasites were detected in 1320 (9.3%) of the patients. The distribution of the intestinal parasites was as follows: Blastocystis hominis, 689 (4.83%); nonpathogenic amoebas, 108 (21.82%); Giardia intestinalis, 320 (2.24%); Enterobius vermicularis, 23 (0.16%); Entamoeba histolytica/Entamoeba dispar, 34 (0.24%); and other rare parasites, 78 (0.54%). The results of this study emphasize the fact that intestinal parasitic infections are still an important public health problem.

[Blastocystis--an enigmatic parasite]

Blastocystis can be isolated from roughly 25% of patients suspected of intestinal parasitosis. At least ten subtypes (STs) have been isolated from humans and animals, and recent data demonstrate that the pathogenicity of the parasite is subtype-dependent. For instance, ST1 and ST7 are more prevalent among patients with symptoms than healthy individuals, whereas ST3 predominates among healthy carriers. The article sums up basic aspects of the parasite and gives an introduction to new data and points of criticism of previous studies seeking to unravel the pathogenicity of the parasite.

[The effect of trimethoprim-sulfamethoxazole in Blastocystis hominis infection]

The aim of this study was to investigate clinical findings and the effects of trimethoprim-sulfamethoxazole (TMP-SMX) in cases of blastocystosis. A total of 37 cases whose stool specimens were sent to the parasitology laboratory from the outpatient clinics of our hospital for various reasons were included in the study. Only five or more Blastocystis hominis were found during examination with direct wet mount using the 40x objective. The stool specimens were tested for other agents (Salmonella spp., Shigella spp., Escherichia coli H157:07, rotavirus) and cases with one of these were excluded from the study. The cases with blastocystosis were given TMP-SMX for 7 days. After the treatment, the cases were questioned as to symptoms once again, the stool specimen examinations were repeated with the same methods, and the results were evaluated. In 34 (91.89%) out of the 37 cases where B. hominis was found, various clinical symptoms such as stomach ache, flatulence, diarrhea, itching and fever were observed singly and/or together. After the treatment it was found that 36 (97.3%) out of 37 cases improved. This study supports the premise that TMP-SXT is effective in the treatment of B. hominis.

[The distribution of intestinal parasites among children in Denizli]

Intestinal parasitic disease appears to be an important national health problem in our country. Parasitic infection distribution is related to the socioeconomic status and environmental factors. The aim of this study was to determine the distribution of intestinal parasites among children in the 1-15 age group in the Denizli province. Parasitic infection was observed in 256 (10.2%) out of 2518 children. The highest rate of 31.4% was that of Giardia intestinalis. The rates of Enterobius vermicularis and Blastocystis hominis were found to be 29.6% and 14% respectively.

[The role of protozoan parasites in etiology of urticaria]

In order to investigate a possible link between parasites and chronic urticaria, the prevalence of intestinal protozoans in stool samples of individuals with chronic urticaria (n=55) and healthy controls (n=43) were evaluated with native lugol, formol-ethyl acetate concentration and trichrom dye, modified acid fast. In the case of Giardia intestinalis (G. intestinalis) ELISA was also used. In the study 29.1% of the patients were found to have protozoan (Blastocystis hominis + G.intestinalis) infections. On the other hand, only 11.6% of the patients in healthy group were having a protozoon infection, all of which were B. hominis. There was no statistically significant difference between the patient group and control group regarding the frequency of B. hominis presence. Also, the number of G.intestinalis positive patients were also statistically different in patient group from those of healthy controls. In patients whom were positive for protozoan infections, agent specific therapy was used. In 7 of these patients symptoms of the disease were subsided with this therapy while six continued to have relapses. Three patients had missed the control visits therefore the course of the disease was not evaluated. As a conclusion, protozoans should be considered in the etiology of chronic urticaria and stool examination should be done in these patients routinely.

[Staining improvement for Blastocystis hominis specimen]

Schaudinn solution was used to fix the Blastocystis hominis specimen and an improved Harris hematoxylin staining was applied to stain it. The method shows clearer internal structure of the parasite, simpler and less time-consuming than the traditional iron hematoxylin solution.

Cytologic diagnosis of blastocystis hominis in peritoneal fluid: a case report

BACKGROUND

Blastocystis hominis is the most common parasite identified in s worldwide. Although it is commonly identified in stool preparations, unusual to encounter B hominis in abdominal fluid.

CASE

A 46-year-old woman presented with the clinical impression of acute peritonitis. The initial radiologic evaluation showed free air in the abdominal cavity and an abdominal mass. Abdominal fluid submitted for cytologic examination was diagnostic of acute inflammation with mixed bacteria and abundant cystlike forms of B hominis. The patient underwent an exploratory laparotomy that revealed a poorly differentiated adenocarcinoma involving her bowel and peritoneum.

CONCLUSION

The present case highlights the unusual identification ofextraintestinal forms of B hominis in a peritoneal fluid sample from a patient with invasive, poorly differentiated adenocarcinoma and associated bowel perforation.

Bacterial, archaeal, and eukaryal diversity in the intestines of Korean people

The bacterial, archaeal, and eukaryal diversity in fecal samples from ten Koreans were analyzed and compared by using the PCR-fingerprinting method, denaturing gradient gel electrophoresis (DGGE). The bacteria all belonged to the Firmicutes and Bacteroidetes phyla, which were known to be the dominant bacterial species in the human intestine. Most of the archaeal sequences belonged to the methane-producing archaea but several halophilic archarea-related sequences were also detected unexpectedly. While a small number of eukaryal sequences were also detected upon DGGE analysis, these sequences were related to fungi and stramenopiles (Blastocystis hominis). With regard to the bacterial and archaeal DGGE analysis, all ten samples had one and two prominent bands, respectively, but many individual-specific bands were also observed. However, only five of the ten samples had small eukaryal DGGE bands and none of these bands was observed in all five samples. Unweighted pair group method and arithmetic averages clustering algorithm (UPGMA) clustering analysis revealed that the archaeal and bacterial communities in the ten samples had relatively higher relatedness (the average Dice coefficient values were 68.9 and 59.2% for archaea and bacteria, respectively) but the eukaryal community showed low relatedness (39.6%).

Protein profile and morphometry of cultured human Blastocystis hominis from children with gastroenteritis and healthy ones

A total of 180 children of age group 5-12 years old in both sexes, of whom 90 were symptomatic and negative for other parasites, rotavirus or pathogenic bacteria. Another 90 children were asymptomatic, but with B. hominis in stools. Direct smear, formaline-ethyl acetate sedimentation concentration, kinyon carbol-fuchin stain, stool culture, enzyme immunoassay, culturing, morphometric study, gel electrophoresis and experimental infection of mice were done. The results showed that the central body cysts (CB), granular and multivacuolar forms isolated from symptomatic patients were larger than those from asymptomatic ones. The CB form was common compared to other forms and isolated from 104 cases. B. hominis infection was prevalent among males rather than females (60.5% versus 39.5%). The clinical data showed that diarrhea was the most common symptom (58.9%). The infection intensity had a direct relation with illness duration. The polyacrylamide gel electrophoresis showed that isolates from symptomatic and asymptomatic patients ranged between 24-130 kDa. All isolates showed similar banding patterns. Only minor differences was in low MW (30, 50 kDa) and in high MW (118 kDa) in samples from symptomatic patients. The histopathological examination of caecum, colon and small intestine of B. hominis mice infected from symptommatic patients showed infiltration with inflammatory cells and tissue invasion by the parasite.

Clinical significance of Blastocystis hominis: experience from a medical center in northern Taiwan

BACKGROUND AND PURPOSE

Blastocystis hominis is an intestinal protozoan. The pathogenic role of this organism in human beings is still controversial and has varied among reports from different geographic areas. The purpose of this study was to determine the clinical significance of B. hominis in northern Taiwan.

METHODS

A total of 100 patients who had a positive B. hominis stool examination during the period April to December of 2001 were retrospectively identified from Taipei Veterans General Hospital. The demographic and clinical characteristics of these patients were reviewed from the medical records.

RESULTS

All of the patients were adults. Fifty nine patients had more than one underlying diseases, including malignancies. Twenty one patients presented with fever and 10 patients had gastrointestinal symptoms, including diarrhea and/or abdominal pain. However, all of the patients had other conditions that might have contributed to the clinical presentation, and they improved without specific treatment for B. hominis. Furthermore, there were no significant differences in clinical symptoms and white blood cell count between patients with malignancy or diabetes mellitus and those without. Six patients had hypereosinophilia that could not be attributed to other causes. Among 34 patients who had a further stool examination within one year, B. hominis was undetectable in 31 patients (91.2%), despite their having no specific antiprotozoal treatment.

CONCLUSIONS

The association of clinical symptoms and B. hominis could not be delineated from our study, even in immunocompromised patients. All of the patients improved without receiving any specific therapy. More studies from different areas are needed in order to delineate the clinical significance B. hominis.

[The prevalence of Microsporidium among patients given a diagnosis of cancer]

The aim of this study was to determine the frequency of Microsporidium among patients given a diagnosis of cancer. For this purpose fecal samples from 320 patients aged 23.60+/-23.00 years were examined using native-Lugol and sedimentation methods and evaluated with modified trichrome, trichrome, and calcofluor dyes. Moreover a control group of 320 non-cancer patients was set up. While 10.9% of the patient group was found to have Microsporidium, only 5.6% of the control group did. Comparison between the control and patient groups in terms of presence of Microsporidium revealed a statistically significant difference. The analysis of a possible relation between intestinal parasites and the presence of Microsporidium revealed a statistically significant correlation between Microsporidium and Blastocystis hominis (P < 0.05). The frequencies of intestinal parasites in the control group and the patient group were found to be 17.8% and 18.1%, respectively. From the findings it was concluded that presence of intestinal parasites and Microsporidium in cancer patients can cause critical problems and adversely affect the therapy. Moreover it was suggested that cancer patients should be informed about regular feces examination and protection against parasites in order to improve their life standards and protect them against parasite infections during treatment.

[The prevalence of intestinal parasites according to the distribution of the patients' gender and parasite species for five years at the Osmangazi University Medical Faculty]

In this study, patients (outpatients and inpatients) with various gastrointestinal system complaints presenting at various clinics of the Eskisehir Osmangazi University Medical Faculty, from February 2003-December 2007 were investigated for the presence of intestinal parasites. The prevalence of intestinal parasites was evaluated according to parasite species, gender of the patients and the years, in which cases were seen. A total of 34,733 stool samples were prepared by formal-ethyl acetate concentration and examined in saline and iodine preparations microscopically with 10x and 40x magnifications. Also trichrome stained preparations of non-pathogenic amoebas and modi-fied Erlich-Ziehl-Nielsen stained preparations for Cryptosporidium spp were examined by oil-immersion objectives (100x). One or more parasites were found in 1252 of the 34,733 stool samples (including nonpathogenic protozoa).the overall prevalence of intestinal parasitic infection rate was 3.6%, of these patients, 52.5% were female and 47.5% male. Predominant parasites were Entamoeba histolytica/dispar group amoebas (31% (397/1252), followed by Giardia intestinalis 19% (236/1252), Blastocystis hominis 7% (108/1252), and Cryptosporid-ium parvum %4.5 (56/1252). Since the cellophane type method was only used in a few cases; the rates detected in helminth cases in this study were different from other studies. The ratio of E. vermicularis was found to be 2.3% (29/1252), Taenia saginata 0.8% (10/1252) and Strongyloides stercoralis 0.4% (5/1252). In comparison to a previous 10 year retrospective study which was performed in our hospital, we detected an important decrease in prevalence of parasites. But the presence of intestinal parasites is still an important problem.

[The distribution of intestinal parasites and their causative factors in children]

Intestinal parasitic infection prevalence in children who had been brought to our hospital together with related factors. The study was carried out in 400 children who were chosen at random among those brought to our hospital. All stool samples were examined with nativelugol, formol-ether, Kinyon acid-fast, methods. The cellophane tape preparations and hemoglobin concentration measurement were used. Intestinal parasites found in 156 of 400 (39%) children were Giardia intestinalis (19.8%) Enterobius vermicularis (15%), Blastocystis hominis (5.8%). Socio-economic and educational level of patient's family, living in urban area, having abdominal pain, anal itching, salivation during sleep, and nasal itching had been found related with the prevalence of parasitic infection. No relationship were found in the other factors. Because WHO guidelines favor routine screening and treatment of parasitic infections of school-age children when the prevalence of parasitic infections in community exceeds 50%, all children should be evaluated for parasitic infections if they have one or more risk factors.

Significance of intraepithelial lymphocytes in appendix

The aim of this study was to investigate the importance of the increase in intraepithelial lymphocytes (IELs) in the mucosa of the appendix. One hundred and four retrospective appendectomy specimens were examined to evaluate the IELs. Intraepithelial lymphocytosis was identified in 11.5% (12 cases) of the specimens. Of these 12 cases, 6 cases with intraepithelial lymphocytosis were associated with parasitic infection. No increase in IELs was found in the 36 appendices that were removed in other primary operations. A wide range of immunologic stimuli can raise IELs in the gastrointestinal system. However, in appendectomies with clinical signs of acute appendicitis, an increase in IELs is more likely to be related to parasitic infection. This increase should be considered for the diagnosis of parasitic infections.

Prevalence of Blastocystis hominis and Strongyloides stercoralis infection in Okinawa, Japan

This study was conducted to clarify the prevalence of Blastocystis hominis and Strongyloides stercoralis infection in Ryukyu University Hospital, Okinawa, Japan, between January 2004 and November 2006. Stool samples collected from 3,292 patients were examined by the direct smear method, formalin-ether sedimentation method, and agar plate culture method. The prevalence rate of B. hominis and S. stercoralis infection was 1.0 and 3.4%, respectively. The prevalence rate of B. hominis infection in patients aged >80 years old was significantly higher than that in patients <80 years old (P < 0.001). The prevalence rate of S. stercoralis infection was significantly higher in patients with B. hominis infection compared with those without (P < 0.001). This study demonstrated a prevalence rate for B. hominis and S. stercoralis infection and an association between B. hominis and S. stercoralis infection in Okinawa, Japan.

[Observations on Blastocystis hominis and Cyclospora cayetanensis in routine parasitological examinations]

We report some observations made from routine parasitological examinations on feces. The methods of Faust et al. and of spontaneous sedimentation in water are not enough to identify Blastocystis hominis. Significant percentage presence of this protozoan was found, especially when staining with iron hematoxylin was performed. Cyclospora cayetanensis was found in 0.7% of the cases, which suggests that this parasite should also routinely be investigated by appropriate techniques.

[Dot enzyme-linked immunosorbent assay for detection of serum antibody to Blastocystis hominis in humans]

Serum and stool samples were collected from 322 undergraduate students in medical school. Using stool in vitro cultivation as golden standard, 178 cases were found Blastocystis hominis positive and 144 were negative. Dot-ELISA was used to examine the serum samples with a sensitivity of 92.1% (164/178) and specificity of 97.1% (141/144). This revealed that dot-ELISA can be used for antibody detection against Blastocystis hominis.

Prevalence of intestinal parasites among primary schoolchildren in Derna District, Libya

The prevalence of intestinal parasites and some hygienic factors was evaluated in primary schoolchildren in Derna District. A total of 1039 stool specimens were examined by direct smear and formaline-ether concentration methods. The results showed that 31% of the children were infected with at least one or two parasites. These parasites were Giardia lamblia (12.7%), Blastocystis hominis (6.7%), Entamoeba histolytica/ Entamoeba dispar (6.6%), Entamoeba coli (3.2%), E. hartmanni (1.0%), Enterobius vermicularis (0.6%), Ascaris lumbricoides (0.1%) and Hymenolepis nana (0.1%). A significant difference was between infection rate and parent's education (P = 0.000), socio-economic status of the family (P = 0.000), family size and number of rooms in houses (P = 0.000). Also, there was a significant differences between infection rate and source of water for human consumption (P = 0.05).

Prevalence of enteric protozoa in human immunodeficiency virus (HIV)-positive and HIV-negative men who have sex with men from Sydney, Australia

A prospective, comparative study of the prevalence of enteric protozoa was determined among human immunodeficiency virus (HIV)- positive and HIV-negative men who have sex with men (MSM) in Sydney, Australia. A total of 1,868 patients submitted stool specimens; 1,246 were from MSM (628 HIV positive and 618 HIV positive) and 622 from non-MSM were examined over a 36-month period. A total of 651 (52.2%) stool specimens from MSM were positive for protozoa compared with 85 (13%) from non-MSM. There was a significant difference in the prevalence of Blastocystis hominis, Endolimax nana, Entamoeba histolytica/dispar complex, Entamoeba hartmanni, Iodamoeba butschlii, and Enteromonas hominis detected between MSM and non-MSM (P<0.001). The only notable difference between HIV-negative and HIV-positive MSM was that HIV-infected MSM were found to more likely have a Cryptosporidium parvum infection. Entamoeba histolytica was found in 3 patients, E. dispar in 25, and E. moshkovskii in 17, all of whom were MSM. When compared with a control group, MSM were significantly more likely to harbor intestinal protozoa and have multiple parasites present. The results of this study show high rates of enteric parasites persist in MSM and highlight the importance of testing for intestinal parasites in MSM. This is the first report of E. moshkovskii from MSM.

[A preliminary study on preservation methods of Blastocystis hominis]

OBJECTIVE

To observe the effect of different cryoprotective agents and temperature factors on the viability of Blastocystis hominis so as to explore the ideal method for preservation of B. hominis.

METHODS

B. hominis agents were obtained from a patient's fecal specimen. Having washed by normal saline and divided into tubes, the samples were cryopreserved in -20 degrees C refrigerator or in -196 degrees C liquid nitrogen with 10% DMSO, 40% glycerol and 15% ethylene glycol respectively. The thawed B. hominis agents were then used for culture. By trypan blue staining and microscopy, the viability and proliferation of those resuscitative cells were investigated.

RESULTS

B. hominis survived for 3 weeks at 18 degrees C-20 degrees C while less than 1 week at 4 degrees C-6 degrees C. When stored in -20 degrees C refrigerator or liquid nitrogen with cryoprotective agents, they survived for more than 3 months. The cryopreservation with 40% glycerol at -196 degrees C for 6 months resulted in 41.7% viability of the revivified cells. Cleavage cells were easily observed after culturing for 72 hours.

CONCLUSION

Preserving B. hominis in liquid nitrogen with 40% glycerol is an optimal cryopreservation protocol.

Characteristics of Blastocystis hominis infection in a Turkish university hospital

In order to determine characteristics of Blastocystis (B.) hominis infection; 770 individuals' stool specimens were examined both by simple and concentration techniques and stained with iodine solution and trichrome in the Parasitology Laboratory of Hacettepe University Faculty of Medicine, Turkey. Among the examined 770 specimens, B. hominis was detected in 94 (12.2%). B. hominis was the most common intestinal parasite among the study group. It was mostly detected with Dientamoeba fragilis. Among the groups the incidence of B. hominis in allergic patients was higher than controls. Among the immunosuppressed patients, B. hominis was detected significantly higher in patients who had solid tumours. Of the 48 individuals who had only B. hominis in their stool the most common symptom was abdominal pain. Concentration technique with trichrome stain was more sensitive than simple smear with lugol solution for the detection of B. hominis. Studies with more patients must be planed to understand the B. hominis infection in solid tumour patients and coexistence of B. hominis and D. fragilis.

[Evaluation of intestinal parasites in a period of four years in the coprology laboratory of a training hospital]

Parasitological examination of stool samples of 9867 individuals, submitted from both inpatient and outpatient departments to the Microbiology Department of an 800-bed Training Hospital between 1.1.2003 and 31.12.2006, revealed that 582 individuals (5.9%) were infected with intestinal parasites. Different diagnostic methods were employed in two different periods, and Blastocystis hominis, Giardia intestinalis and Entamoeba histolytica/dispar were found to be the most common parasites, respectively. Patients were predominantly male (67% (n=336) male vs. 33% (n=165) female) and aged between 15-25 years (36%). In addition, 14% (81/582) patients had multiple parasitoses. Despite being labor-intensive, parasitological examination of stool samples with necessary staining methods by experienced staff will surely help determine both the diagnosis and exact prevalence of intestinal parasitic infections in Turkey.