Study of opportunistic intestinal parasitic infections in human immunodeficiency virus/acquired immunodeficiency syndrome patients

Emerging and Reemerging Parasitic Diseases in Taiwan: A Retrospective Study of Clinical Case Reports in 2001~2018

Emerging and re-emerging parasitic diseases can cause significant economic burdens at national and global levels. However, governments often underestimate or ignore these diseases, especially in developed countries. This retrospective, case-oriented study analyzed parasitic diseases reported in Taiwan between 2001 and 2018. One hundred and thirty-two eligible clinical profiles of Taiwanese patients obtained from the NCBI, Scopus, Google Scholar, and Web of Science databases and local journals according to age, sex, source of infection, symptoms, risk factors, and geographical regions were analyzed. The analysis results showed that the number/frequency of cases caused by nematodes (46.97%) or protozoa (37.88%) was significantly higher than that of trematodes (9.85%) or cestodes (5.30%) (p < 0.0001). Northern Taiwan (46.97%) had a significantly higher rate than Southern Taiwan (33.33%), Central Taiwan (8.33%), and Eastern Taiwan (5.30%) (p < 0.05). The 15-65 age group (68.94%) had a significantly higher rate than the 65-90 age group (22.73%) and the 0-15 age group (8.33%) (p < 0.0001). Males (70.46%) had a significantly higher number/frequency of cases than females (29.54%) (p < 0.0001). People who acquired the infection through the food/soil route (32.58%) or who had a low immune status (32.58%) had a higher rate than travel-related infections (15.15%) (p < 0.001). The present study showed that emerging/reemerging parasitic infections continue to be of great concern to the lives and health of Taiwanese citizens and, if ignored, will threaten the health of the Taiwanese people; therefore, the delineation of preventive measures by health authorities is urgently warranted.

Prevalence of intestinal parasites in HIV/AIDS-infected patients with correlation to CD4+ T-cell count at hospital in Eastern India

Introduction

In developing nations, one of the most common reasons for death and illness is due to infections that are brought on by intestinal parasites. People who have HIV are more likely to contract parasites that are either well-established intestinal pathogens, like Entamoeba histolytica, Giardia lamblia and Strongyloidesstercoralis, or an opportunistic pathogen like Cryptosporidium, Isospora, Cyclospora and Microsporidia. Higher prevalence of intestinal parasitic infections occurs in patients with low CD4+ cell counts. Hence, this study had been performed to know the correlation of intestinal parasitic infection in HIV/AIDS patients with reference to CD4+ cell count.

Materials and Methods

The study comprised 1477 HIV-positive patients who were treated at ART Centre of Rajendra Institute of Medical Sciences (RIMS), Ranchi. All participants provided verbal informed consent before specimens were collected. Blood and stool sample were used for the identification of parasite and CD4+ T-Cell count.

Results

In patients living with HIV, the prevalence of intestinal parasite infection was 12.59 per cent. In a manner parallel, the prevalence of parasitic infections was found to be 10.29% among male HIV-positive patients and 2.31% among female HIV-positive patients.

Conclusions

This study has shed light that low CD4+ T-cell count appears to be a factor for intestinal parasitic infections and development of diarrhoea. Regular screening and treatment of intestinal parasitic infections is very important in overall improvement in quality of life of HIV/AIDS patients. Nevertheless, sanitary hygiene practices and deworming are needed to enhance the control of infection in the affected areas.

Microsporidia in HIV-Positive and HIV-Negative Pediatric Patients with Diarrhea at a Tertiary Care Hospital

Background  Human microsporidiosis presents as an important and rapidly emerging opportunistic infection. However, the exact burden of this infection especially in the pediatric population of Northern India remains unknown. In this study, we investigated the prevalence of microsporidia among human immunodeficiency virus (HIV)-positive and HIV-negative pediatric patients who presented with diarrhea. Methods  A total of 263 children were recruited consisting of 98 HIV seropositive with diarrhea and 165 HIV seronegative but with diarrhea. Morning stool samples were collected and both direct and formol ether concentrated samples were examined for the presence of intestinal parasites. The modified acid-fast staining was done for coccidian parasites and trichrome stain for microsporidia detection. Further, the species were detected using a real-time polymerase chain reaction (PCR) targeting a conserved region of the small ribosomal subunit rRNA gene of Enterocytozoon bieneusi , Encephalitozoon hellem , Encephalitozoon intestinalis , and Encephalitozoon cuniculi . Results  Overall, one or more parasites were detected in 52.04% (51/98) of HIV seropositive and 53.33% (88/165) of seronegative children ( p  = 0.8391). However, coccidian parasites were detected in a significantly huge number of HIV seropositive children (21.43% [21/98]) as compared with HIV seronegative children (4.24% [7/165]). Microsporidial DNA could be detected in HIV seropositive with diarrhea children (17.35% [17/98]) by PCR. A significant correlation between low CD4 count (≤ 200/μL) and intestinal parasite positivity could be established. Conclusion  Microsporidia is a significant cause of diarrhea in HIV seropositive pediatric patients and should be kept in mind as one of the differential diagnoses in such patients.

Multiple protozoal infections in a single immunocompromised patient: A case report

Immunocompromised patients with human immunodeficiency virus (HIV) infection are prone to multiple infections, of which parasitic infections are an important cause. Parasitic protozoal infections - both by common and rare protozoa are documented in such patients. Here, we report a rare and interesting case of five protozoal infections affecting a single HIV-infected person at the same time of initial presentation. A 64-years-male came to us with complaints of chronic diarrhea for 6 months. He was investigated and found to be positive for HIV I. His stool examination revealed cysts of Entameba histolytica and Giardia lamblia and oocysts of Cryptosporidium species and Cystoisospora species. His toxoplasma IgG was also positive in high titer. The patient was medically diagnosed and was treated with medications as clinically prescribed - antiretroviral therapy was initiated and he was discharged in due course. A total of five protozoal infections were documented affecting a single person - newly diagnosed immunocompromised male, which by sheer qualitative count of patient case histories, indeed is a rare case reported in the medical literature.

Development of a Molecular Marker Based on the Mitochondrial Genome for Detection of Cyclospora cayetanensis in Food and Water Samples

Cyclospora cayetanensis is a coccidian parasite that causes diarrheal illness outbreaks worldwide. The development of new laboratory methods for detection of C. cayetanensis is of critical importance because of the high potential for environmental samples to be contaminated with a myriad of microorganisms, adversely impacting the specificity when testing samples from various sources using a single molecular assay. In this study, a new sequencing-based method was designed targeting a specific fragment of C. cayetanensis cytochrome oxidase gene and developed as a complementary method to the TaqMan qPCR present in the U.S. FDA BAM Chapter 19b and Chapter 19c. The comparative results between the new PCR protocol and the qPCR for detection of C. cayetanensis in food and water samples provided similar results in both matrices with the same seeding level. The target region and primers in the protocol discussed in this study contain sufficient Cyclospora-specific sequence fidelity as observed by sequence comparison with other Eimeriidae species. The sequence of the PCR product appears to represent a robust target for identifying C. cayetanensis on samples from different sources. Such a sensitive method for detection of C. cayetanensis would add to the target repertoire of qPCR-based screening strategies for food and water samples.

Global Burden of Cyclospora cayetanensis Infection and Associated Risk Factors in People Living with HIV and/or AIDS

Cyclospora cayetanensis infections remain one of the most common protozoan opportunistic causes of gastrointestinal diseases and diarrhea among people living with HIV and/or AIDS (PLWHA). This study was conducted to provide a summary of the evidence on the global burden of C. cayetanensis infection and associated risk factors among PLWHA. Scopus, PubMed, Science Direct, and EMBASE were searched up to February 2022. All original peer-reviewed original research articles were considered, including descriptive and cross-sectional studies describing C. cayetanensis in PLWHA. Incoherence and heterogeneity between studies were quantified by I index and Cochran’s Q test. Publication and population bias were assessed with funnel plots and Egger’s asymmetry regression test. All statistical analyses were performed using StatsDirect. The pooled prevalence of C. cayetanensis infection among PLWHA was 3.89% (95% CI, 2.62–5.40). The highest prevalence found in South America was 7.87% and the lowest in Asia 2.77%. In addition, the prevalence of C. cayetanensis was higher in PLWHA compared to healthy individuals. There was a relationship between a higher C. cayetanensis prevalence in PLWHA with a CD4 cell count below 200 cells/mL and people with diarrhea. The results show that PLWHA are more vulnerable to C. cayetanensis infection and emphasizes the need to implement the screening and prophylaxis tailored to the local context. Owing to the serious and significant clinical manifestations of the parasite, an early identification of seropositivity is recommended to initiate prophylaxis between PLWHA with a CD4 count ≤200 cells/mL and PLWHA who do not receive antiviral therapy.

Intestinal Parasite Infestation in HIV Infected Patients in Tertiary Care Center

Every year, the number of people living with HIV rises as a consequence of advanced infections and the positive effects of highly active antiretroviral therapy (HAART). Gastrointestinal involvement is common, with 90% of patients seeking treatment for gastrointestinal problems as their HIV infection progresses. Nonetheless, identifying and characterization of infectious agents is important for patient management by excluding a clinical diagnosis and determining appropriate treatment, as well as determining public healthcare policy for true pathogen prevalence and yielding epidemiological risk factors for specific infections. The aim of this study is to evaluate the prevalence of symptomatic or asymptomatic intestinal parasitic infection among HIV or AIDS patients. For this study with 80 HIV seropositive patients being recruited from various wards and the Integrated Counseling and Testing Center (ICTC) affiliated to the microbiology department. Patients with acute and chronic diarrhea with abdominal disorder were taken as symptomatic whereas patients without these clinical complaints and who came for routine investigations were taken as asymptomatic. Firstly stool samples were analyzed by macroscopically for the presence of mucus, blood, larvae, segments of tapeworm and adult worms. The consistencies of stool were also recorded such as formed, watery or soft or loose with odor and color. It was examined microscopically after macroscopically for protozoan cysts and trophozoites, helminthic ova and larvae, as wet mount preparation by saline and iodine preparation as well as formal ether concentrated. For the detection of intestinal coccidian parasites, smears were prepared from stool samples and a modified Ziel-Nelseen (MZN) stain was also performed. Stool samples with the detection of parasites were informed for treatment. The prevalence of intestinal parasite was 23.75% with asymptomatic and symptomatic groups having a prevalence of 16.98% and 37.04% respectively. Out of total patients, 56.25% were male and 43.75% were female. Among the male patients, 11 (13.75%) were positive for an intestinal parasitic infection and 8 (10%) were positive among females. The age distribution data revealed that the age group 21-40 years old had the highest number of intestinal parasites, followed by 41-60, 61-80, and 0-20 years old. The most intestinal parasites were found in the young and middle-aged patients, according to this study. Different parasites were identified as Entamoeba histolytica, Taenia species, Ascaris lumbricoides, Cryptosporidium parvum and Isospora with one protozoan, two coccidian parasites and two helminthes. The most common parasite was Taenia species 6 (7.5%) followed by Entamoeba histolytica 5 (6.3%) and Cryptosporidium parvum 5 (6.3%). Intestinal parasitic infection is not uncommon in HIV seropositive patients. This study underscores the need for early diagnosis and treatment of these intestinal parasites in both symptomatic and asymptomatic HIV patients.

Dead-End Ultrafiltration and DNA-Based Methods for Detection of Cyclospora cayetanensis in Agricultural Water

Cyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne diarrheal illness outbreaks worldwide. Most of these outbreaks are associated with the consumption of fresh produce. Sensitive and specific methods to detect C. cayetanensis in agricultural water are needed to identify the parasite in agricultural water used to irrigate crops that have been implicated in outbreaks. In this study, a method to detect C. cayetanensis in water by combining dead-end ultrafiltration (DEUF) with sensitive and specific molecular detection was developed and evaluated. Triplicates of 10-liter agricultural water samples were seeded with 200, 100, 25, 12, and 6 C. cayetanensis oocysts. Surface water samples were also collected in the Mid-Atlantic region. All water samples were processed by DEUF and backflushed from the ultrafilters. DNA was extracted from concentrated samples and analyzed by quantitative PCR (qPCR) targeting the C. cayetanensis 18S rRNA gene. All water samples seeded with 12, 25, 100, and 200 oocysts were positive, and all unseeded samples were negative. Samples seeded with 6 oocysts had a detection rate of 66.6% (8/12). The method was also able to detect C. cayetanensis isolates in surface water samples from different locations of the Chesapeake and Ohio Canal (C&O Canal) in Maryland. This approach could consistently detect C. cayetanensis DNA in 10-liter agricultural water samples contaminated with low levels of oocysts, equivalent to the levels that may be found in naturally incurred environmental water sources. Our data demonstrate the robustness of the method as a useful tool to detect C. cayetanensis from environmental sources.IMPORTANCE Cyclospora cayetanensis is a protozoan parasite that causes foodborne and waterborne outbreaks of diarrheal illness worldwide. These foodborne outbreaks associated with the consumption of fresh produce and agricultural water could play a role in the contamination process. In this study, a method to detect C. cayetanensis in agricultural water by combining a robust filtration system with sensitive and specific molecular detection was developed and validated by the FDA. The results showed that this approach could consistently detect low levels of C. cayetanensis contamination in 10 liters of agricultural water, corresponding to the levels that may be found in naturally occurring environmental water sources. The method was also able to detect C. cayetanensis in surface water samples from a specific location in the Mid-Atlantic region. Our data demonstrate the robustness of the method to detect C. cayetanensis in agricultural water samples, which could be very useful to identify environmental sources of contamination.

Profile of intestinal parasitic infections in human immunodeficiency virus/acquired immunodeficiency syndrome patients in Northeast India

Introduction:

Diarrhea is one of the major complications occurring in over 90% of human immunodeficiency virus (HIV)-infected individuals in developing countries. Coccidian group of parasitic infections remain the standout opportunistic pathogens in many parts of the world.

Aim:

The objective was to understand the profile of diarrheagenic parasites in HIV/AIDS patients along with analysis of the changing trends in the profile of parasitic diarrhea with special context to coccidian parasitic infections.

Methodology:

A cross-sectional study was performed at “ID CENTRE FOR NORTHEAST,” Shillong, from January 2014 to October 2017. Stool samples collected were observed microscopically for parasites both on direct and concentrated stool samples under ×10 and ×40 magnification. Modified acid-fast staining was used for the detection of coccidian parasites. All statistical analyses were performed using IBM SPSS software, Version 24.0.

Results:

The prevalence of intestinal parasitic infections was 40.99%, coccidian parasitic infection accounted for 85.13% of total intestinal parasitic infections. Cryptosporidium parvum was the most common cause of diarrhea (70.64%), followed by Cystoisospora belli (23.81%) and Cyclospora spp. (5.55%). Trend analysis of coccidian etiology during the study revealed a significant rise in the positivity of Cryptosporidium spp. and a decrease in the Cystoisosporiasis belli infection. The common noncoccidian parasites identified include hookworm (8.1%) followed by Ascaris lumbricoides (4.7%).

Conclusion:

The magnitude of parasitic infections is considerably high among the HIV/AIDS patients in Northeast India, and it is essential for screening and periodic monitoring of all the HIV patients for coccidian parasites by stool microscopy.

Cryptosporidiosis in HIV-positive patients and related risk factors: A systematic review and meta-analysis

Cryptosporidium is one of the major causes of diarrhea in HIV-positive patients. The aim of this study is to systematically review and meta-analyze the prevalence of Cryptosporidium in these patients. PubMed, Science Direct, Google Scholar, Web of Science, Cochrane and Ovid databases were searched for relevant studies dating from the period of 1 January 2000 to 31 December 2017. Data extraction for the included studies was performed independently by two authors. The overall pooled prevalence was calculated and subgroup analysis was performed on diagnostic methods, geographical distribution and study population. Meta-regression was performed on the year of publication, proportion of patients with diarrhea, and proportion of patients with CD4 < 200 cells/mL. One hundred and sixty-one studies and 51,123 HIV-positive participants were included. The overall pooled prevalence of Cryptosporidium infection in HIV-positive patients was 11.2% (CI95%: 9.4%–13.0%). The pooled prevalence was estimated to be 10.0% (CI95%: 8.4%–11.8%) using staining methods, 13.5% (CI95%: 8.9%–19.8%) using molecular methods, and 26.3% (CI95%: 15.0%–42.0%) using antigen detection methods. The prevalence of Cryptosporidium in HIV patients was significantly associated with the country of study. Also, there were statistical differences between the diarrhea, CD4 < 200 cells/mL, and antiretroviral therapy risk factors with Cryptosporidiosis. Thus, Cryptosporidium is a common infection in HIV-positive patients, and safe water and hand-hygiene should be implemented to prevent cryptosporidiosis occurrence in these patients.

Cystoisospora belli infections in humans: the past 100 years

Cystoisospora belli is a coccidian parasite of humans, with a direct fecal-oral transmission cycle. It is globally distributed, but mainly found in tropical and subtropical areas. Many cases of C. belli infections have been reported in patients with HIV, and in patients undergoing immunosuppressive therapy for organ transplants or those treated for tumours worldwide. Unsporulated or partially sporulated oocysts of C. belli are excreted in feces. When sporulated oocysts in contaminated water or food are ingested, asexual and sexual stages of C. belli are confined to the epithelium of intestines, bile ducts and gallbladder. Monozoic tissue cysts are present in extra-intestinal organs (lamina propria of the small and large intestine, lymph nodes, spleen, and liver) of immunosuppressed humans. However, a paratenic host has not been demonstrated. Cystoisospora belli infections can be persistent, lasting for months, and relapses are common; the mechanism of relapse is unknown. Recently, the endogenous stages of C. belli were re-examined and attention was drawn to cases of misidentification of non-protozoal structures in the gallbladder of patients as C. belli. Here, we review all aspects of the biology of C. belli, including morphology, endogenous stages, prevalence, epidemiology, symptoms, diagnosis and control.

Cyclospora cayetanensis and Cyclosporiasis: An Update

Cyclospora cayetanensis is a coccidian parasite of humans, with a direct fecal-oral transmission cycle. It is globally distributed and an important cause of foodborne outbreaks of enteric disease in many developed countries, mostly associated with the consumption of contaminated fresh produce. Because oocysts are excreted unsporulated and need to sporulate in the environment, direct person-to-person transmission is unlikely. Infection by C. cayetanensis is remarkably seasonal worldwide, although it varies by geographical regions. Most susceptible populations are children, foreigners, and immunocompromised patients in endemic countries, while in industrialized countries, C. cayetanensis affects people of any age. The risk of infection in developed countries is associated with travel to endemic areas and the domestic consumption of contaminated food, mainly fresh produce imported from endemic regions. Water and soil contaminated with fecal matter may act as a vehicle of transmission for C. cayetanensis infection. The disease is self-limiting in most immunocompetent patients, but it may present as a severe, protracted or chronic diarrhea in some cases, and may colonize extra-intestinal organs in immunocompromised patients. Trimetoprim-sulfamethoxazole is the antibiotic of choice for the treatment of cyclosporiasis, but relapses may occur. Further research is needed to understand many unknown epidemiological aspects of this parasitic disease. Here, we summarize the biology, epidemiology, outbreaks, clinical symptoms, diagnosis, treatment, control and prevention of C. cayetanensis; additionally, we outline future research needs for this parasite.

Prevalence of enteric parasitic infections among people living with HIV in Abeokuta, Nigeria

INTRODUCTION

Enteric parasitic infections have been increasingly recognized as etiology of life-threatening chronic diarrhea in PLWHA in sub-Saharan Africa. This study investigated the prevalence and burden of intestinal parasitic infection among PLWHA in Abeokuta, southwest Nigeria.

METHODS

Freshly passed stool samples were collected from PLWHA. Detection of Cryptosporidium spp and Microsporidium spp was carried out with Kinyoun's stain and Weber's Chromotrope-based stain respectively. Investigation of other intestinal parasites was done using the direct saline preparation and formol-ether concentration methods. CD4+ T cell count was measured using Partec flow cytometry technique.

RESULTS

A total of 231 (males: females 96:135; mean age 31.81±11.40 years) PLWHA were recruited into the study, among whom 84 (36.4%) were infected with at least one intestinal parasites. Fifty two (22.5%) individuals were positive for Cryptosporidium spp and a significant association between Cryptosporidium sppand diarrhea was observed (p=0.006). Seven (3.0%) were positive for Microsporidium spp. Helminths recovered included Ascaris lumbricoides (20.8%), hookworm (6.5%), Strongyloides stercoralis (4.3%), Trichuris trichiura (5.6%) and Taenia spp. (5.6%). Cryptosporidium spp, Microsporidium spp and S. stercoralis were significantly associated with CD4+ count ≥ 200 cells/mm3 (p<0.05). Cryptosporidium sppand A. lumbricoides were significantly observed among patients that are anti-retroviral therapy (ART) naive.

CONCLUSION

High prevalence of opportunistic parasitic infection was significantly correlated with diarrhea, low CD4+ count and ART naïve individuals in the study. These findings re-emphasize the need for early diagnosis of opportunistic parasites and appropriate intervention among PLWHA.

The role of HIV infection in the etiology and epidemiology of diarrheal disease among children aged 0-59 months in Manhiça District, Rural Mozambique

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HIV prevalence was higher among cases with moderate-to-severe diarrhea (MSD) than controls.

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Mortality was higher among HIV-infected children with diarrhea than HIV-uninfected ones.

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HIV-infected children were more likely to have MSD.

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Cryptosporidium was the most common pathogen in HIV-infected children with MSD.

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Escherichia coli producing heat-stable toxin (enterotoxigenic Escherichia coli, any sequence type) was the most common pathogen in HIV-infected children with less severe diarrhea.

Background

Diarrhea is an important health problem among HIV-infected patients. This study evaluated the role of HIV in the epidemiology, etiology, and severity of diarrheal disease among children.

Methods

The Global Enteric Multicenter Study enrolled children with moderate-to-severe diarrhea (MSD) and less-severe diarrhea (LSD) between December 2007 and November 2012. One to three controls for MSD cases and one per LSD case were enrolled and matched by age, sex, and neighborhood. All children were tested for HIV. Clinical data, anthropometric data, and stool samples were collected. Follow-up was performed at 60 days.

Results

Two hundred and fourteen MSD cases and 418 controls, together with 349 LSD cases and 214 controls were tested. HIV prevalence was 25% among MSD cases (4% for matched controls) and 6% among LSD cases (6% among matched controls). HIV-infected children were more likely to have MSD (odds ratio 5.6, p < 0.0001).

Mortality rates were higher among HIV-infected children than among the uninfected (34 vs. 5 per 1000 child-weeks at risk; p = 0.0039). Cryptosporidium, Giardia, and enteroaggregative Escherichia coli (aatA only) were more prevalent among HIV-infected MSD cases than among uninfected ones.

Conclusion

HIV is an important risk factor for MSD. The high mortality rate implies that children with MSD should be screened for HIV and managed accordingly.

Metabarcoding analysis of eukaryotic microbiota in the gut of HIV-infected patients

Research on the relationship between changes in the gut microbiota and human disease, including AIDS, is a growing field. However, studies on the eukaryotic component of the intestinal microbiota have just begun and have not yet been conducted in HIV-infected patients. Moreover, eukaryotic community profiling is influenced by the use of different methodologies at each step of culture-independent techniques. Herein, initially, four DNA extraction protocols were compared to test the efficiency of each method in recovering eukaryotic DNA from fecal samples. Our results revealed that recovering eukaryotic components from fecal samples differs significantly among DNA extraction methods. Subsequently, the composition of the intestinal eukaryotic microbiota was evaluated in HIV-infected patients and healthy volunteers through clone sequencing, high-throughput sequencing of nuclear ribosomal internal transcribed spacers 1 (ITS1) and 2 (ITS2) amplicons and real-time PCRs. Our results revealed that not only richness (Chao-1 index) and alpha diversity (Shannon diversity) differ between HIV-infected patients and healthy volunteers, depending on the molecular strategy used, but also the global eukaryotic community composition, with little overlapping taxa found between techniques. Moreover, our results based on cloning libraries and ITS1/ITS2 metabarcoding sequencing showed significant differences in fungal composition between HIV-infected patients and healthy volunteers, but without distinct clusters separating the two groups. Malassezia restricta was significantly more prevalent in fecal samples of HIV-infected patients, according to cloning libraries, whereas operational taxonomic units (OTUs) belonging to Candida albicans and Candida tropicalis were significantly more abundant in fecal samples of HIV-infected patients compared to healthy subjects in both ITS subregions. Finally, real-time PCR showed the presence of Microsporidia, Giardia lamblia, Blastocystis and Hymenolepis diminuta in different proportions in fecal samples from HIV patients as compared to healthy individuals. Our work revealed that the use of different sequencing approaches can impact the perceived eukaryotic diversity results of the human gut. We also provide a more comprehensive view of the eukaryotic community in the gut of HIV-infected patients through the complementarity of the different molecular techniques used. Combining these various methodologies may provide a gold standard for a more complete characterization of the eukaryotic microbiome in future studies.

Multiple parasitic and viral infections in a patient living with HIV/AIDS on antiretroviral therapy

Patients with human immunodeficiency virus (HIV) infection are more prone for gastrointestinal infections causing diarrhoea, particularly with parasites. Parasitic infections have been regularly reported in such patients. A female patient confirmed positive for HIV 1 on antiretroviral therapy came with complaints of chronic diarrhoea for the past 7 months. Her initial CD4 count was 89 cells/μl of blood, and antibodies to cytomegalovirus and herpes simplex virus 1 and 2 virus were found to be positive in the patient's serum, but there was no HIV-associated retinopathy. Her stool examination showed decorticated fertilised eggs of Ascaris lumbricoides, cysts of Blastocystis sp. and Entamoeba species in the unconcentrated sample and oocysts of Cystoisospora species, egg of Schistosoma haematobium and eggs of Trichuris trichiura in the concentrated. The patient responded well to cotrimoxazole and albendazole, and repeat samples were negative for all these parasites.

The Prevalence of Cyclospora cayetanensis and Cryptosporidium spp. in Turkish patients infected with HIV-1

Opportunistic infections such as cryptosporidiosis and cyclosporiasis are commonly encountered in patients with acquired immunodeficiency syndrome (AIDS). We investigated the existence of opportunistic protozoans that significantly affect the quality of life in HIV-1 infected patients using conventional and molecular methods. The study group comprised 115 HIV-1 positive patients. In the identification of Cyclospora cayetanensis and Cryptosporidium, the formol-ether precipitation method was used and smears were evaluated in optical microscope by staining modified Ziehl-Neelsen (ZN). The primers and probes used for PCR were Heat shock protein 70 for C. cayetanensis and the oocysts wall protein for Cryptosporidium spp.. Cyclospora and Cryptosporidium spp. oocysts were detected in one and two patients, respectively, by staining, whereas we detected C. cayetanensis in three patients out of 115 (2.6%) by PCR, and Cryptosporidium spp. in a further three patients (2.6%). C. cayetensis was detected in patients with CD4 counts of 64 cells/μm, 182 cells/μm and 287 cells/μm, respectively. Cryptosporidium spp. was detected in patients with CD4 counts of 176 cells/μm, 241 cells/μm and 669 cells/μm. As conclusion, PCR method is faster and more sensitive than microscopic methods and to screen intestinal pathogens routinely in patients infected with HIV should not be neglected in developing countries like Turkey.

Respiratory Failure Associated with Ascariasis in a Patient with Immunodeficiency

In industrialized countries, risk groups for parasitic diseases include travelers, recent immigrants, and patients with immunodeficiency following chemotherapy and radiotherapy and AIDS. A 66-year-old Polish male was admitted in December 2012 to the Department of Haematology in a fairly good general condition. On the basis of cytological, cytochemical, immunophenotypic, and cytogenetic analysis of bone marrow, the patient was diagnosed with acute myeloblastic leukemia. On the 7th day of hospitalization in the Department of Haematology, patient was moved to the Intensive Care Unit (ICU) due to acute respiratory and circulatory failure. In March 2013, 3 months after the onset of respiratory failures, a mature form of Ascaris spp. appeared in the patient's mouth. This report highlights the importance of considering an Ascaris infection in patients with low immunity presenting no eosinophilia but pulmonary failure in the central countries of Europe.

Drug Development Against the Major Diarrhea-Causing Parasites of the Small Intestine, Cryptosporidium and Giardia

Diarrheal diseases are among the leading causes of morbidity and mortality in the world, particularly among young children. A limited number of infectious agents account for most of these illnesses, raising the hope that advances in the treatment and prevention of these infections can have global health impact. The two most important parasitic causes of diarrheal disease are Cryptosporidium and Giardia. Both parasites infect predominantly the small intestine and colonize the lumen and epithelial surface, but do not invade deeper mucosal layers. This review discusses the therapeutic challenges, current treatment options, and drug development efforts against cryptosporidiosis and giardiasis. The goals of drug development against Cryptosporidium and Giardia are different. For Cryptosporidium, only one moderately effective drug (nitazoxanide) is available, so novel classes of more effective drugs are a high priority. Furthermore, new genetic technology to identify potential drug targets and better assays for functional evaluation of these targets throughout the parasite life cycle are needed for advancing anticryptosporidial drug design. By comparison, for Giardia, several classes of drugs with good efficacy exist, but dosing regimens are suboptimal and emerging resistance begins to threaten clinical utility. Consequently, improvements in potency and dosing, and the ability to overcome existing and prevent new forms of drug resistance are priorities in antigiardial drug development. Current work on new drugs against both infections has revealed promising strategies and new drug leads. However, the primary challenge for further drug development is the underlying economics, as both parasitic infections are considered Neglected Diseases with low funding priority and limited commercial interest. If a new urgency in medical progress against these infections can be raised at national funding agencies or philanthropic organizations, meaningful and timely progress is possible in treating and possibly preventing cryptosporidiosis and giardiasis.

Continuous culture of Cryptosporidium parvum using hollow fiber technology

Diarrheal disease is a leading cause of pediatric death in economically low resource countries. Cryptosporidium spp. are the second largest member of this group and the only member for which no treatment exists. One of the handicaps to developing chemotherapy is the lack of a reproducible long-term culture method permitting in vitro drug screening beyond 48 h. We have adapted the well-established hollow fiber technology to provide an environment that mimics the gut by delivering nutrients and oxygen from the basal layer upwards while allowing separate redox and nutrient control of the lumen for parasite development. Using this technique, oocyst production was maintained for >6 months, producing approximately 1×10(8)oocysts ml(-1)day(-1), compared with 48 h with a yield of 1×10(6)oocysts ml(-1) in two-dimensional cultures. Oocysts, after 4 and 20 weeks in culture, produced a chronic infection in a TCR-α-deficient mouse model. In vivo infectivity of oocysts was confirmed using oocysts from a 6 week culture in a dexamethasone immunosuppressed mouse model.

Clinical and Microbiology Profile and Outcome of Diarrhea by Coccidian Parasites in Immunocompetent Children

BACKGROUND

Several studies have reported prevalence of pediatric coccidian parasitic diarrhea, but there is little information about their clinical profile, management and outcome. This study reviews the clinical profile and treatment outcome of coccidian parasitic diarrhea in immunocompetent children.

METHODS

Five thousand one hundred and twenty-three immunocompetent children younger than 15 years of age presenting with acute diarrhea to a tertiary care pediatric hospital during a period of 4 years (2009-2012) were included in the study. Their demographic details and clinical course were recorded, and feces specimens received in the microbiology laboratory were subject to microbiology culture, wet mount microscopy, modified Ziehl-Neelsen staining to detect intestinal coccidian parasites and rotavirus sandwich enzyme-linked immunosorbent assay test (if age less than 2 years).

RESULTS

The prevalence of coccidian parasitic diarrhea in immunocompetent children was 1.13% (58 cases) with Cryptosporidium spp. accounting for 1.09% (56 cases). Most Cryptosporidium infections were in children younger than 2 years [38 (67.85%)] and during the monsoon season [32 (57.14%)] with common clinical features being watery or liquid feces [44 (78.57%)], vomiting [40 (71.43%)] and fever [35 (62.5%)]. Thirteen (81.25%) of the 16 cases of cryptosporidiosis with dehydration were less than 2 years of age. Fifty-one (87.93%) of the 58 children were hospitalized. Thirty-eight (67.85%) children with cryptosporidiosis received empiric antimicrobial agents for suspected enteric bacterial and protozoan parasitic infection, which were discontinued after coccidian parasites were detected. Median duration of hospitalization was 2 days with no mortality reported.

CONCLUSIONS

Coccidian parasitic diarrhea affects immunocompetent children of all age groups. Unnecessary administration of antimicrobial agents to these children can be avoided by routinely screening pediatric diarrheal fecal specimens for coccidian parasites by a cost-effective method such as modified Ziehl-Neelsen staining.

Cyclospora cayetanensis infection in transplant traveller: a case report of outbreak

BACKGROUND

Cyclospora cayetanensis is a protozoan parasite causing intestinal infections. A prolonged course of infection is often observed in immunocompromised individuals. In Europe, less than 100 cases of C. cayetanensis infection have been reported to date, almost all of which being diagnosed in individuals after travelling abroad.

FINDINGS

We described cases of three businessmen who developed acute traveller's diarrhoea after they returned to Poland from Indonesia. One of the travellers was a renal transplant recipient having ongoing immunosuppressive treatment. In each case, acute and prolonged diarrhoea and other intestinal disorders occurred. Oocysts of C. cayetanensis were identified in faecal smears of two of the travellers (one immunosuppressed and one immunocompetent). Diagnosis was confirmed by the successful amplification of parasite DNA (18S rDNA). A co-infection with Blastocystis hominis was identified in the immunocompetent man.

CONCLUSIONS

Infection of C. cayetanensis shall be considered as the cause of prolonged acute diarrhoea in immunocompromised patients returning from endemic regions.

Chronic cholecystitis with Cystoisospora belli in an immunocompetent patient

A 47-year-old woman presented with a history of vague abdominal pain for several years, which worsened over the past 2 months, with pain more prominent in the right upper quadrant. She also had a history of peptic ulcer disease. The ultrasound scan of right upper quadrant revealed normal gallbladder and oesophagogastroduodenoscopy was unremarkable. A (99m)technetium labelled hepato iminodiacetic acid (HIDA) scan with cholecystokinin provocation demonstrated a decreased gallbladder ejection fraction (EF) of 32%. On this basis, the patient was diagnosed with biliary dyskinesia and underwent an elective laparoscopic cholecystectomy. Histopathological analysis revealed chronic cholecystitis with Cystoisospora belli identified in the gallbladder wall. Cystoisospora has been identified to cause an opportunistic acalculous cholecystitis among immunocompromised hosts, especially those with AIDS. This is the first case report of chronic cholecystitis due to C. belli in an immunocompetent patient.

Sensitization of enteric neurons to morphine by HIV-1 Tat protein

BACKGROUND

Gastrointestinal (GI) dysfunction is a major cause of morbidity in acquired immunodeficiency syndrome (AIDS). HIV-1-induced neuropathogenesis is significantly enhanced by opiate abuse, which increases proinflammatory chemokine/cytokine release, the production of reactive species, glial reactivity, and neuronal injury in the central nervous system. Despite marked interactions in the gut, little is known about the effects of HIV-1 in combination with opiate use on the enteric nervous system.

METHODS

To explore HIV-opiate interactions in myenteric neurons, the effects of Tat ± morphine (0.03, 0.3, and 3 μM) were examined in isolated neurons from doxycycline- (DOX-) inducible HIV-1 Tat(1-86) transgenic mice or following in vitro Tat 100 nM exposure (>6 h).

KEY RESULTS

Current clamp recordings demonstrated increased neuronal excitability in neurons of inducible Tat(+) mice (Tat+/DOX) compared to control Tat-/DOX mice. In neurons from Tat+/DOX, but not from Tat-/DOX mice, 0.03 μM morphine significantly reduced neuronal excitability, fast transient and late long-lasting sodium currents. There was a significant leftward shift in V(0.5) of inactivation following exposure to 0.03 μM morphine, with a 50% decrease in availability of sodium channels at -100 mV. Similar effects were noted with in vitro Tat exposure in the presence of 0.3 μM morphine. Additionally, GI motility was significantly more sensitive to morphine in Tat(+) mice than Tat(-) mice.

CONCLUSIONS & INFERENCES

Overall, these data suggest that the sensitivity of enteric neurons to morphine is enhanced in the presence of Tat. Opiates and HIV-1 may uniquely interact to exacerbate the deleterious effects of HIV-1-infection and opiate exposure on GI function.

Effects of HIV-1 Tat on enteric neuropathogenesis

The gastrointestinal (GI) tract presents a major site of immune modulation by HIV, resulting in significant morbidity. Most GI processes affected during HIV infection are regulated by the enteric nervous system. HIV has been identified in GI histologic specimens in up to 40% of patients, and the presence of viral proteins, including the trans-activator of transcription (Tat), has been reported in the gut indicating that HIV itself may be an indirect gut pathogen. Little is known of how Tat affects the enteric nervous system. Here we investigated the effects of the Tat protein on enteric neuronal excitability, proinflammatory cytokine release, and its overall effect on GI motility. Direct application of Tat (100 nm) increased the number of action potentials and reduced the threshold for action potential initiation in isolated myenteric neurons. This effect persisted in neurons pretreated with Tat for 3 d (19 of 20) and in neurons isolated from Tat(+) (Tat-expressing) transgenic mice. Tat increased sodium channel isoforms Nav1.7 and Nav1.8 levels. This increase was accompanied by an increase in sodium current density and a leftward shift in the sodium channel activation voltage. RANTES, IL-6, and IL-1β, but not TNF-α, were enhanced by Tat. Intestinal transit and cecal water content were also significantly higher in Tat(+) transgenic mice than Tat(-) littermates (controls). Together, these findings show that Tat has a direct and persistent effect on enteric neuronal excitability, and together with its effect on proinflammatory cytokines, regulates gut motility, thereby contributing to GI dysmotilities reported in HIV patients.