Detection of Blastocystis hominis: a controversial human pathogen

Occurrence and genotypic identification of Blastocystis sp., Enterocytozoon bieneusi, and Giardia duodenalis in dairy cattle in Heilongjiang Province, China

Blastocystis sp., Enterocytozoon bieneusi, and Giardia duodenalis are three common zoonotic intestinal parasites, and cattle are important hosts of these three intestinal protozoa. In this study, 1632 fecal samples were collected from dairy farms in Heilongjiang Province, China, and screened for Blastocystis sp., E. bieneusi, and G. duodenalis using polymerase chain reaction. Of these, 149 (9.13%) were positive for three zoonotic pathogens, including 104 (6.40%), 22 (1.35%), and 23 (1.41%) for Blastocystis sp., E. bieneusi, and G. duodenalis, respectively. Based on partial SSU rRNA gene sequencing analysis, 104 positive samples of Blastocystis sp. were found, and a total of nine known subtypes were identified, including ST10 (61), ST3 (18), ST14 (6), ST26 (7), ST24 (3), ST25 (2), ST1 (2), ST5 (2), and ST21 (1). Among these, three subtypes (ST1, ST3, and ST5) were recognized as zoonotic subtypes, and two subtypes (ST10 and ST14) were specific to animals. All 23 Giardia duodenalis-positive samples belonged to assemblage E (n = 23) based on sequenced beta-giardin (bg) and triosephosphate isomerase (tpi) genes. Three known genotypes of E. bieneusi, namely J (n = 9), I (n = 6), and BEB4 (n = 7), were identified by sequence analysis of the internal transcriptional spacer region gene. Our study provides basic data for prevention and control in Heilongjiang Province; however, further research is required to better understand the prevalence and public health significance of these pathogens in the Heilongjiang region.

The Application of 3base™ Technology to Diagnose Eight of the Most Clinically Important Gastrointestinal Protozoan Infections

Globally, over 3.5 billion people are infected with intestinal parasites each year, resulting in over 200,000 deaths. Three of the most common protozoan pathogens that affect the gastrointestinal tract of humans are Cryptosporidium spp., Giardia intestinalis, and Entamoeba histolytica. Other protozoan agents that have been implicated in gastroenteritis in humans include Cyclospora cayetanensis, Dientamoeba fragilis, Blastocystis hominis, and the microsporidia Enterocytozoon bieneusi and Encephalitozoon intestinalis. Genetic Signatures previously developed a 3base™ multiplexed Real-Time PCR (mRT-PCR) enteric protozoan kit (EP001) for the detection of Giardia intestinalis/lamblia/duodenalis, Cryptosporidium spp., E. histolytica, D. fragilis, and B. hominis. We now describe improvements to this kit to produce a more comprehensive assay, including C. cayetanensis, E. bieneusi, and E. intestinalis, termed EP005. The clinical performance of EP005 was assessed using a set of 380 clinical samples against a commercially available PCR test and other in-house nucleic acid amplification tests where commercial tests were not available. All methods provided at least 90% agreement. EP005 had no cross-reactivity against 82 organisms commonly found in the gut. The EP005 method streamlines the detection of gastrointestinal parasites and addresses the many challenges of traditional microscopic detection, resulting in cost savings and significant improvements in patient care.

Systematic Review and Meta-Analysis: Epidemiology of Human Blastocystis spp. Infection in Malaysia

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

Association of Blastocystis hominis with colorectal cancer: A systematic review of in vitro and in vivo evidences

BACKGROUND

Recently, there have been several findings that showed intestinal colonisation of Blastocystis hominis (Blastocystis) as a risk factor to the worsening of colorectal cancer (CRC). However, studies have shown controversial results in the pathogenicity of Blastocystis.

AIM

To review systematically the evidence available on the association between CRC and Blastocystis and the prevalence of Blastocystis in CRC patients and to investigate cytopathic and immunological effects of Blastocystis in in vitro and in vivo studies.

METHODS

PRISMA guidelines were utilised in conducting this systematic review. Original articles published before February 2, 2020 were included. PubMed, Science Direct, Scopus and Google scholar databases were searched. Manual searching was carried out to find articles missed during the online search.

RESULTS

Out of 12 studies selected for this systematic review, seven studies confirmed the prevalence of Blastocystis and found it to be between 2%-28% in CRC patients, whereby subtype 1 and subtype 3 were predominantly seen. A total of four studies employing in vitro human colorectal carcinoma cell line study models showed significant cytopathic and immunological effects of Blastocystis. In addition, one in vivo experimental animal model study showed that there was a significant effect of infection with Blastocystis on exacerbation of colorectal carcinogenesis.

CONCLUSION

Blastocystis is a commonly identified microorganism in CRC patients. These studies have provided supportive data that Blastocystis could exacerbate existing CRC via alteration in host immune response and increased oxidative damage. Future studies of CRC and Blastocystis should attempt to determine the various stages of CRC that are most likely to be associated with Blastocystis and its relationship with other intestinal bacteria.

Prevalence, subtypes and risk factors of Blastocystis spp. infection among pre- and perimenopausal women

Background

Blastocystis spp. are considered pathogenic or commensal organisms, although the majority of researchers suggest that these are neglected pathogens. The main aim of this study was to determine the prevalence and subtype distribution of Blastocystis spp. in pre- and perimenopausal women, with respect to socio-demographic (age and place of residence), and epidemiological factors, as well as drinking tap water, contact with domestic animals, traveling abroad, health status, and presence of gastrointestinal symptoms. Additionally, the objective was to compare hematological and biochemical parameters of Blastocystis spp. infected and uninfected women.

Methods

The study included 425 women aged 45–60. Their stool samples were examined microscopically and analyzed by a conventional polymerase chain reaction (cPCR).

Results

Blastocystis spp. were detected in 6.1% of pre- and perimenopausal women. Molecular analysis of the stool samples identified seven Blastocystis subtypes (ST1–ST4, ST6, ST7, and ST9). Blastocystis subtypes 2 and 3 were the most prevalent. The presence of Blastocystis spp. was not significantly related to socio-demographic and epidemiological factors. There were also no significant associations between Blastocystis spp. and blood parameters, or gastrointestinal symptoms.

Conclusion

This study complements the limited available data on the prevalence of Blastocystis spp. in pre- and perimenopausal women. It is also the first report showing the presence of Blastocystis subtype 9 in Poland.

Prevalence and associated risk factors of intestinal parasitic infections among Egyptian patients with inflammatory bowel disease

The global prevalence of inflammatory bowel disease (IBD) is continuously rising, however, a little is known concerning intestinal parasitic infections (IPIs) and (IBD). We aimed to evaluate the prevalence of IPIs among IBD patients, through a case-control study and also, to correlate the positive cases to the socio-demographic risk factors of IPIs among the study groups. A 1-year case-control study included patients with IBD (n=125) and healthy controls (n=125). The fecal samples were examined with the classical parasitological methods for intestinal parasites. Also, in-vitro culture (for Blastocystis sp.) and Immuno-chromatography technique (for Cryptosporidium / Giardia /Entamoeba) were done. IBD patients had significant higher positivity rate of IPIs compared to healthy controls (Adjusted OR= 9.60, 95% CI: 4.51-20.41, P = 0.0001), with Blastocystis sp., Entamoeba dispar/ histolytica and Cryptosporidium sp. being highly significant in IBD patients. In addition to IBD, living in rural area, with low socio-economic stander, and consumed raw/contaminated food and age group > 50 years old were significant risk factors for IPIs. In conclusion, our results support a possible link between IPIs and IBD.

Molecular epidemiology and genotype/subtype distribution of Blastocystis sp., Enterocytozoon bieneusi, and Encephalitozoon spp. in livestock: concern for emerging zoonotic infections

Intestinal parasitic infections have high prevalence rate in many regions especially in developing countries. The aim of this study was to determine the presence and genotype/subtype of some intestinal protozoa in livestock in Iran. Stool samples were collected from cattle, sheep, chickens, and horses. The presence of targeted parasites was evaluated using real-time PCR. Genotyping/subtyping of positive samples was characterized using sequencing of the ITS and barcoding region, respectively. Blastocystis sp., 27.7% (48/173) and Enterocytozoon bieneusi 26.0% (45/173) were the most frequent protozoa followed by Encephalitozoon spp., 0.57% (1/173). Cryptosporidium spp. were not detected among samples. Encephalitozoon spp., was detected only in chickens 2.2% (1/45). A statistically correlation was seen between animals and the prevalence of targeted protozoa. E. bieneusi genotypes I (9/38; 23.68%), BEB6 (22/38; 57.89%), D (6/38; 15.79%), and horse1 (1/38; 2.63%) were detected among samples. A statistically significant correlation was seen between the genotypes and animals (P ≤ 0.05). Blastocystis sp., ST1 (1/45; 2.22%), ST5 3/45; 6.66%), ST7 (1/45; 2.22%), ST10 (24/45; 53.33%), and ST14 (16/45; 35.55%) were characterized among samples. There was no significant correlation between certain subtypes and animals (P = 0.173). The presence of zoonotic potential genotypes of E. bieneusi in animals and zoonotic potential subtypes ST1 and ST7 among our samples provide a clue about the transmission dynamic of E. bieneusi and Blastocystis sp. between animals–animals and humans–animals.

Influence of Proton Pump Inhibitors and Histamine Receptor 2 Antagonists on Blastocystis ST3 and Selected Microorganisms of Intestinal Microbiota In Vitro

INTRODUCTION

Proton pump inhibitors (PPIs) and histamine receptor 2 (H2) antagonists are commonly prescribed medications. Association between PPIs and alteration of the gut microbiota has been reported. Blastocystis, the most common intestinal protozoan worldwide, occurs in both healthy and symptomatic people with gastrointestinal or cutaneous disorders, with controversial pathogenicity. The current study was aimed to investigate the influence of PPIs and H2 blockers on the in vitro proliferation of selected intestinal bacteria, fungi, and protozoa.

METHODS

Cultures of Lactobacillus rhamnosus, Escherichia coli, Enterococcus faecium, Candida albicans, and Blastocystis subtype 3 were treated with different concentrations of respective medications in vitro, and the numbers of microorganisms were quantified and compared.

RESULTS

Pantoprazole and esomeprazole exerted a significant inhibition on Blastocystis and C. albicans, especially at higher concentrations, which were even more effective than metronidazole. On the other hand, treatment with pantoprazole caused an increase in proliferation of L. rhamnosus and E. coli. There was no influence of H2 blockers on the examined microorganisms.

DISCUSSION

PPIs, such as pantoprazole, can be a potential treatment in the prophylaxis or eradication of Blastocystis and C. albicans.

Strongyloides stercoralis and other intestinal parasites in patients receiving immunosuppressive drugs in northern Iran: a closer look at risk factors

OBJECTIVES

The objective of this study was to evaluate the prevalence of Strongyloides stercoralis and other intestinal parasites in patients receiving immunosuppressive drugs in northern Iran and to investigate related risk factors.

METHODS

This cross-sectional study was conducted among 494 patients receiving immunosuppressive drugs, including cancer patients undergoing chemotherapy (n=188) and those treated with prolonged corticosteroid administration (n=306). All fresh fecal samples were examined using the direct wet-mount, formalin ethyl acetate concentration, and agar plate culture techniques.

RESULTS

In total, 16.8% of patients were positive for at least 1 intestinal parasite; the helminthic and protozoan infection rates were 5.1% and 12.3%, respectively. The infection rate was significantly higher in corticosteroid-treated individuals (19.6%) than cancer patients (12.2%) (p<0.05). The prevalence rate of S. stercoralis among patients receiving chemotherapy and those treated with corticosteroids were 4.3% and 5.2%, respectively. The prevalence rate of S. stercoralis infection was significantly higher in older patients (p<0.05).

CONCLUSIONS

Strongyloidiasis is one of the most common parasites among patients receiving immunosuppressive drugs in northern Iran. Early diagnosis and proper treatment of these patients are necessary to minimize the complications of severe strongyloidiasis.

Blastocystis infection frequency and subtype distribution in university students

Blastocystis is a parasite commonly found in the gut of humans and animals; there are 22 known subtypes (STs). STs 1-9 and 12 have been found in humans. This parasite has a faecal-oral route of transmission; its high infection prevalence in developing countries is due to poor hygiene practices, exposure to infected animals, and intake of contaminated water or food. Its pathogenicity has not been established, because it has been found in symptomatic and asymptomatic patients. The goal of this study was to analyze the frequency of Blastocystis and its subtypes (1, 2, 3, 4, 5, and 7), and assess the relationship between these subtypes and abdominal pain and distension. 202 university students participated in this study. A questionnaire was applied to assess the gastrointestinal symptoms, and subsequently the students were asked to provide faecal samples. The presence of parasites was determined by optical microscopy. Blastocystis-positive samples had their DNA extracted and end-point PCR was performed to corroborate the presence of Blastocystis and determine its subtypes. Among the samples, 47.03% were positive according to PCR analysis. The most prevalent subtypes were ST3 (29.79%), ST4 (16.84%), and ST1 (14.89%). We found a relationship between ST1 and abdominal pain (OR = 0.196; CI = 0.0533-0.7318; p = 0.015), and between ST4 and abdominal distension (OR = 0.2928; CI = 0.1017-0.8429; p = 0.023). However, the presence of this parasite and the probable relationship with gastrointestinal symptoms suggest the need to determine its role within intestinal microbiota in order to confirm whether its eradication is really necessary or not.

Worldwide prevalence of emerging parasite Blastocystis in immunocompromised patients: A systematic review and meta-analysis

BACKGROUND

Blastocystis is one of the most common pathogens of the human intestine, caused by an emerging parasite, which can lead to severe symptoms and even death in immunocompromised patients. We aimed to determine the global prevalence of Blastocystosis infection in people with immunodeficiency. A systematic literature search was conducted on Web of Science, Scopus, Google scholar, Science Direct and MEDLINE databases to select all observational studies reporting the prevalence of Blastocystosis infection in Worldwide, based on different diagnostic methods in immunocompromised patients of any age and published from inception to February 2019. Pooled estimates and 95% confidence intervals (95% CIs) were calculated using random effects models and in addition, the I² statistic was calculated. The geographic distribution of studies was evaluated and the diagnosis of Blastocystis was compared by various techniques. Electronic databases were reviewed for Blastocystosis infection in HIV/AIDS, cancer and other immunocompromised patients, and meta-analyses were conducted to calculate the overall estimated prevalence. Total68 eligible studies were included. The estimated pooled prevalence rate of Blastocystosis infection in immunocompromised patients was overall 10% (95% CI, 7-13%; I² 96.04%) (P < 0.001), of whom 21% [18-25] were in Australia, 12% [4-24] in America, 11% [6-17] in Europe and 10% [5-15], 7% [3-13] in Asia and Africa, respectively. It was calculated that the estimated pooled prevalence rate of Blastocystosis infection in immunocompromised patients was overall 10% and the prevalence estimates ranged from 0.44 to 72.39. Also, overall the prevalence of parasites co-infection in immunocompromised patients was detected as 0.024%. Our finding showed that immunocompromised people show a high prevalence of Blastocystosis infection compared to the control population. Adequate information on the prevalence rate is still missing from many countries. However, current information underscore that Blastocystis should not be neglected.

Blastocystis hominis: A Pathogenic Parasite

Background: Blastocystis hominis is recognized as a common intestinal parasite. Some studies have reported the effect of phenotypic, serologic, and biochemical indices on the parasites’ pathogenic characteristics. Objectives: This study aimed to introduce B. hominis as a pathogen, trying to change views about this parasite and introduce it as a parasite important in medical sciences. Methods: An open-ended, language-restricted (English) search was conducted in MEDLINE (PubMed), CINAHL, Scopus, and the Cochrane Library databases (from 1990 to 2018) using specific search criteria to identify Blastocystis spp. Results: The search of the literature retrieved 158 published articles on Blastocystis spp. Among these articles, the ones related to the pathogenicity of B. hominis were selected for further investigations. Results obtained in this study showed that the number of articles within five-year periods had an increasing trend. Also, studies of B. hominis have mainly investigated its pathogenic characteristics, accounting for 37.34% of the studies. Conclusions: This study showed comprehensive reasons for proving the pathogenesis of the parasite. It is hoped that further studies would fill the existing gaps regarding this parasite and identify its true identity as a medically important parasite.

Development and evaluation of high-resolution melting curve analysis for rapid detection and subtyping of Blastocystis and comparison the results with sequencing

Blastocystis is a prevalent parasite that has a wide distribution. In order to design HRM real-time PCR, primers were selected from SSU rRNA gene to amplify specific fragment with different melting temperatures for each subtype of Blastocystis. Subsequently, HRM real-time PCR was performed and melting curve analysis was done by Rotor-Gene Q software. The results of HRM real-time PCR was then compared with sequence results of "barcoding region" of SSU rRNA gene of Blastocystis. To evaluate sensitivity of test, 10-fold serial dilutions of the parasite were prepared from ~ 10⁶ to 1 parasite per mL of stool sample and were investigated by HRM real-time PCR. In order to determine specificity of method, HRM real-time PCR was done for some microorganisms and Blastocystis-negative stool samples. In silico analysis showed that all seventeen subtypes of Blastocystis were distinguish. In vitro analysis revealed that the test discriminated subtypes with specific melting temperatures.

The influence of probiotic bacteria and human gut microorganisms causing opportunistic infections on Blastocystis ST3

BACKGROUND

Blastocystis subtype 3 is an intestinal protist present in humans throughout the world with a controversial pathogenic potential. It has been suggested that probiotic bacteria inhibit the multiplication of gut protozoans, while others are beneficial for their development. This study aimed to evaluate the efficacy of the lactic acid bacteria Lactobacillus rhamnosus, Lactococcus lactis and Enterococcus faecium in Blastocystis ST3 eradication and the relevance of the intestinal microorganisms Escherichia coli, Candida albicans and Candida glabrata in protozoan proliferation. Blastocystis xenic and axenic culture was co-incubated with the above-mentioned microorganisms and their cell free supernatants at different concentrations in vitro. The number of protozoan cells was counted every day.

RESULTS

Both experiments, with xenic and axenic cultures, showed Blastocystis inhibition by L. rhamnosus and L. lactis and their supernatants from the 2nd day of co-incubation. Furthermore, co-incubation with both E. faecium and E. coli showed a beneficial influence on Blastocystis during the first 2 days. Only after 3 days did the above-mentioned bacteria start to inhibit Blastocystis growth in both cultures. The supernatant containing the metabolites of E. coli was effective to a lesser degree. Compared to the control samples, co-incubation with both C. albicans and C. glabrata showed a faster decrease in Blastocystis proliferation, but this was not statistically significant.

CONCLUSIONS

This study has shown the potential of using L. rhamnosus and L. lactis, as well as E. faecium as a prophylactic treatment against Blastocystis colonization or as an additional treatment regimen in combination with standard drugs.

Blastocystis Hominis and Chronic Abdominal Pain in Children: Is there an Association between Them?

Chronic abdominal pain has many etiologies, one of them being parasites. The aim of this study was to find an association between chronic abdominal pain in children and Blastocystis hominis (Bh). Clinical files of patients with Bh and functional abdominal pain were reviewed. A comparison was made between patients who showed an improvement of their symptoms and those who did not. Out of the 138 patients who had functional abdominal pain and Bh, 37 patients did not receive any treatment (26.8%), while 101 received it and were treated with different antimicrobial agents (73.2%); regarding the improvement of symptoms, a statistically significant difference (p < 0.001) was observed. Chronic abdominal pain in children has different etiologies; however, we have documented through this work that it is appropriate to provide antimicrobial treatment for patients with Bh and chronic abdominal pain.

Detection of Blastocystis in clinical stool specimens using three different methods and morphological examination in Jones' medium

Background:

Blastocystis was identified almost a century ago, yet its biology and pathogenicity status in humans is obscure. Studies on Blastocystis in India are scanty and are mostly microscopy based. This study compared three detection modalities to determine their efficiency in the identification of Blastocystis in human feces.

Materials and Methods:

A total of 279 stool samples were screened using microscopy, culture (Jones' medium), and polymerase chain reaction (PCR)-based methods. Among the three, PCR is considered the gold standard test for detection of Blastocystis, as it helps to authenticate the sensitivity, specificity, and kappa agreement obtained by the other two tests. The morphological features of Blastocystis were recorded at 24, 48, and 72 h. After positive morphological identification, ten samples were cultured on Löwenstein–Jensen (LJ) medium and Locke's egg slant medium.

Results:

The sensitivity and specificity determined on the basis of microscopy were 36.2% and 99.4%, respectively. On the other hand, Jones' medium showed 67.6% sensitivity and 100% specificity. Further, we documented various morphological and reproductive features of Blastocystis using various staining techniques on cultures positive in Jones' medium. In addition, we also found that LJ medium was not equally efficacious as Jones' medium in assisting the growth of Blastocystis.

Conclusions:

Although molecular diagnosis is a necessary tool for understanding the true epidemiology of Blastocystis, in laboratories devoid of molecular detection facilities, stool microscopy in conjunction with stool culture on Jones' medium could serve as the best alternative tool for the detection of Blastocystis.

Blastocystis: how do specific diets and human gut microbiota affect its development and pathogenicity?

Blastocystis is an enteric parasite that inhabits the gastrointestinal tract of humans and many animals. This emerging parasite has a worldwide distribution. It is often identified as the most common eukaryotic organism reported in human fecal samples. This parasite is recognized and diagnosed more often than ever before. Furthermore, some strains develop resistance against currently recommended drugs, such as metronidazole; therefore, the use of natural remedies or special diets has many positive aspects that may address this problem. The goal of this review is to compare natural treatments and various diets against the efficacy of drugs, and describe their influence on the composition of the gut microbiota, which affects Blastocystis growth and the occurrence of symptoms. This article reviews important work in the literature, including the classification, life cycle, epidemiology, pathogenesis, pathogenicity, genetics, biology, and treatment of Blastocystis. It also includes a review of the current knowledge about human gut microbiota and various diets proposed for Blastocystis eradication. The literature has revealed that garlic, ginger, some medical plants, and many spices contain the most effective organic compounds for parasite eradication. They work by inhibiting parasitic enzymes and nucleic acids, as well as by inhibiting protein synthesis. The efficacy of any specific organic compound depends on the Blastocystis subtype, and, consequently, on its immunity to treatment. In conclusion, the article discusses the findings that human gut microbiota composition triggers important mechanisms at the molecular level, and, thus, has a crucial influence on the parasitic pathogenicity.

Distribution and phylogenetic analysis of Blastocystis sp. subtypes isolated from IBD patients and healthy individuals in Iran

Blastocystis is a single-celled intestinal parasite commonly found in humans and a broad range of animals all over the world. In humans, its role in health and disease remains unsettled. The aim of our study was to investigate the distribution of Blastocystis and Blastocystis subtypes (ST) in patients with inflammatory bowel disease (IBD) and control subjects. A total of 71 stool samples were collected from IBD patients, 69 and 2 of whom had ulcerative colitis (UC) and Crohn's Disease (CD), respectively. Moreover, 166 stool samples from healthy subjects were included as control samples. All stool samples were cultivated, and 550-bp fragments of the small subunit ribosomal RNA gene was amplified from Blastocystis-positive cultures. All PCR-positive samples were sequenced. Blastocystis was observed in 9 (12.67%) and 35 (21.1%) IBD patients and healthy controls, respectively. There was no statistically significant correlation between IBD and presence of Blastocystis (P = 0.147). There was a statistically significant correlation between age and Blastocystis colonization in the IBD group (P < 0.05), but not among healthy controls. No significant correlation between gender and colonization was observed. ST1 and ST3 were obtained from 1 (12.5%) and 7 (87.5%) IBD patients, respectively, while in the healthy control group, subtypes 1, 2, and 3 were found in 14 (40%), 12 (34.28%), and 9 (25.72%), respectively. Phylogenetic analysis showed no variation in the distribution of subtypes nor intra-subtype genetic diversity between samples acquired from IBD patients and healthy controls. This study showed a trend towards a lower prevalence of Blastocystis in IBD patients than in control subjects. ST3 sequences isolated from IBD patients and control individuals did not appear to differ genetically.

Geospatial distribution of intestinal parasitic infections in Rio de Janeiro (Brazil) and its association with social determinants

BACKGROUND

Intestinal parasitic infections remain among the most common infectious diseases worldwide. This study aimed to estimate their prevalence and provide a detailed analysis of geographical distribution of intestinal parasites in the metropolitan region of Rio de Janeiro, considering demographic, socio-economic, and epidemiological contextual factors.

METHODS/PRINCIPAL FINDINGS

The cross-section survey was conducted among individuals attending the Evandro Chagas National Institute of Infectious Diseases (FIOCRUZ, RJ) during the period from April 2012 to February 2015. Stool samples were collected and processed by sedimentation, flotation, Kato-Katz, Baermann-Moraes and Graham methods, iron haematoxylin staining and safranin staining. Of the 3245 individuals analysed, 569 (17.5%) were infected with at least one parasite. The most common protozoa were Endolimax nana (28.8%), Entamoeba coli (14.8%), Complex Entamoeba histolytica/Entamoeba dispar (13.5%), Blastocystis hominis (12.7%), and Giardia lamblia (8.1%). Strongyloides stercoralis (4.3%), Schistosoma mansoni (3.3%), Ascaris lumbricoides (1.6%), and hookworms (1.5%) were the most frequent helminths. There was a high frequency of contamination by protozoa (87%), and multiple infections were observed in 141 participants (24.8%). A positive association between age (young children) and gender (male) with intestinal parasites was observed. Geospatial distribution of the detected intestinal parasitic infections was not random or homogeneous, but was influenced by socioeconomic conditions (through the material deprivation index (MDI)). Participants classified in the highest levels of deprivation had higher risk of having intestinal parasites.

CONCLUSIONS/SIGNIFICANCE

This study provides the first epidemiological information on the prevalence and distribution of intestinal parasitic infections in the Rio de Janeiro metropolitan area. Intestinal parasites, especially protozoa, are highly prevalent, indicating that parasitic infections are still a serious public health problem. MDI showed that intestinal parasites were strongly associated with the socioeconomic status of the population, thus making it possible to identify social vulnerable areas.

OCCURRENCE OF Blastocystis spp. IN UBERABA, MINAS GERAIS, BRAZIL

Intestinal parasites are a problem for public health all over the world. The infection with Blastocystis, a protozoan of controversial pathogenicity, is one of the most common among them all. In this study, the occurrence of intestinal parasites, with emphasis on Blastocystis, in patients at the Universidade Federal do Triângulo Mineiro was investigated in Uberaba (MG) through microscopy of direct smears and fecal concentrates using Ritchie’s method. Feces of 1,323 patients were examined from April 2011 to May 2012. In 28.7% of them at least one intestinal parasite was identified, and the most frequent organisms were Blastocystis spp. (17.8%) and Giardia intestinalis (7.4%). The occurrence of parasitism was higher in children aged 6 -10 years old, and the infection with Blastocystis spp. was higher above the age of six (p < 0.001). The exclusive presence of G. intestinalis and of Blastocystis spp. was observed in 5.4% and 12.2% of the patients, respectively. Regarding patients with diarrheic feces, 8% revealed unique parasitism of Blastocystis spp. Other intestinal parasites observed in children were Ascaris lumbricoides(0.3%) and Entamoeba histolytica/dispar/moshkovskii (1.4%). The Ritchie’s method was more sensitive (92.8%) when compared to direct microscopy (89.8%), with high agreement between them (97.7%, kappa = 0.92). In conclusion, the occurrence of Blastocystis spp. in Uberaba is high and the presence of diarrheic feces with exclusive presence of the parasite of Blastocystis spp. was observed.

Quantitative Methodologies Reveal a Diversity of Nutrition, Infection/Illness, and Psychosocial Stressors During Pregnancy and Lactation in Rural Mam-Mayan Mother–Infant Dyads From the Western Highlands of Guatemala

Background:

The nature and severity of 3 categories of maternal stressors (nutritional, infectious, and psychosocial) that may impact maternal health and early infant growth are not often considered together.

Objectives:

To describe quantitative methodologies; assess construct validity of questionnaires; report variability in sociodemographic, obstetric, nutritional, infectious, and psychosocial characteristics; and compare characteristics between pregnancy and lactation and between study cohorts of Mam-Mayan mother–infant dyads.

Methods:

Grounded in participatory action research and a socioecological framework, this observational study enrolled a longitudinal cohort of 155 women, followed during pregnancy (6-9 months), early (0-6 weeks), and later (4-6 months) postpartum, and 2 cross-sectional cohorts (60 early and 56 later postpartum). Household and social factors; obstetric history; nutritional, infectious, and psychosocial stressors; and infant characteristics were explored.

Results:

Diet diversity (3.4 ± 1.3) and adult food security (38%) were low. Urinary and gastrointestinal infections were rare (<5%), whereas experience of local idioms of distress was frequent (20%-50%). Participants reported low maternal autonomy (81%), high paternal support (70%), small social support networks (2.7 ± 1.3 individuals), and high trust in family (88%) and community-based institutions (61%-65%) but low trust in government services (6%). Domestic violence was commonly reported (22%). Infant stunting was common (36% early postpartum and 43% later postpartum) despite frequent antenatal care visits (7.5 ± 3.8). Participant engagement with the research team did not influence study outcomes based on comparisons between longitudinal and cross-sectional cohorts.

Conclusions:

The variability in sociodemographic, nutritional, and psychosocial variables, will allow exploration of factors that promote resilience or increase vulnerability of the mother–infant dyad.

Mysterious chronic urticaria caused by Blastocystis spp.?

Species of the genus Blastocystis, which are single-cell, intestinal protozoan parasites of humans and animals, remain mysterious, with unclear clinical and epidemiologic significance. In recent years, many researchers have suggested a possible connection between Blastocystis spp. infection and chronic urticaria. In the present article, we review the literature and discuss the possible associations between the clinical symptomatology and pathogenicity of this organism in terms of its subtypes, morphologic forms, genetic diversity, and interactions with other intestinal microbiota.

Prevalence of Intestinal Protozoa among Saudi Patients with Chronic Renal Failure: A Case-Control Study

It has been hypothesized that chronic renal failure (CRF) predisposes patients to infection with intestinal protozoa. We tested this hypothesis with a matched case-control study to determine the prevalence of these protozoa and their diarrhea associated symptoms among 50 patients with CRF (cases) from Taif, western Saudi Arabia. Fifty diarrheal patients without CRF were recruited in the study as controls. Participants were interviewed by a structured questionnaire and stool samples were collected. Samples were thoroughly examined with microscopy and three coproantigens detection kits. Enteric protozoa were detected in 21 cases and 14 controls. Blastocystis spp. were the most predominant parasite (16% in cases versus 8% in controls), followed by Giardia duodenalis (10% in cases versus 12% in controls) and Cryptosporidium spp. (10% in cases versus 6% in controls). Cyclospora cayetanensis was identified in two cases, while Entamoeba histolytica was described in one case and one control. Intestinal parasitism was positively associated with the male gender, urban residence, and travel history. Clinical symptoms of nausea/vomiting and abdominal pain were significantly varied between the parasitized cases and controls (P value ≤ 0.05). Given the results, we recommend screening all diarrheal feces for intestinal protozoa in the study's population, particularly those with CRF.

The intestinal protozoa: emerging impact on global health and development

PURPOSE OF REVIEW

To highlight new findings on the relevance of gastrointestinal protozoan infections to global public health in low-income and middle-income countries and suggest new large-scale interventions.

RECENT FINDINGS

New disease burden assessments and epidemiological studies highlight the role of the major intestinal protozoa as important etiologic disease agents in low-income and middle-income countries. Despite their prevalence and adverse health impact, such information has not yet translated to the implementation of large-scale interventions as exist for helminth infections and other neglected tropical diseases. There are also several key research and development questions that must be addressed for intestinal protozoan infections and the potential need for new tools, for example, drugs, diagnostics, and vaccines. Additional studies have identified new and emerging species of intestinal protozoa relevant to global public health such as Dientamoeba fragilis and Blastocystis hominis and how they too might emerge as important gastrointestinal pathogens in the coming years.

SUMMARY

New and emerging information on intestinal protozoa are reviewed with emphasis on aspects considered relevant to global health policymakers including prospects for scaling up interventions against intestinal protozoan infections in resource-poor countries.

Do not forget the stool examination!-cutaneous and gastrointestinal manifestations of Blastocystis sp. infection

Blastocystis sp. is one of the most common parasites in the human intestinal tract. This infection commonly is accompanied by diarrhoea and abdominal pain, but extraintestinal symptoms, such as skin lesions, may also accompany the disease. In this study, our aim was to assess the frequency, clinical symptoms and skin manifestations of confirmed positive Blastocystis sp. infections. Data of 80 patients with confirmed positive Blastocystis sp. infections were assessed retrospectively. The average age of the patients was 46.3 years of age (with a range between 13 and 85 years of age). The number of female patients was higher than the number of males (48 vs. 32; 60 vs. 40%). Gastrointestinal and dermatological symptoms and the results of routine biochemical and haematological blood tests of enrolled patients were collected and analyzed. The skin manifestations were analyzed using the data available (including descriptions, photos and histologies). We discovered that 11.25% of our enrolled patients exhibited skin manifestations associated to Blastocystis sp., mainly on the females. The occurrence of Blastocystis sp. was 6% in symptomatic patients who required medical attendance in the time period between 2005 and 2013. Of the 80 patients, 73.75% indicated that they had gastrointestinal symptoms: 40 patients complained of abdominal pain and 17 with blood in their stool, while other symptoms, such as meteorism (15 subjects), weigh loss (8 subjects), perianal pain or itching (6 subjects), passing stool with mucus (5 subjects), vomiting (2 subjects) and fever (2 subjects) were less frequent. The prevalence of abdominal pain in the cohort without skin lesions was higher compared to those patients with skin problems (p = 0.007). The mean value of C-reactive protein showed elevated levels, but eosinophils were within a normal range. In addition, we did not find significant difference in eosinophilia between patients with vs. without skin manifestations. Thus, we suggest that eosinophilia is not an obligatory laboratory finding in protozoon infections, such as Blastocystis sp. In the light of our results, we suggest a stool parasite examination for patients with skin lesions of unknown origin.