Enterocytozoon bieneusi and Encephalitozoon intestinalis (microsporidia) in HIV-positive patients in central Spain.

Microsporidia are fungi-related eukaryotic intracellular parasites that opportunistically infect immunocompromised individuals such as those infected by the human immunodeficiency virus (HIV). Among them, Enterocytozoon bieneusi and Encephalitozoon spp. are the most clinically relevant species. We investigated the occurrence and genetic diversity of microsporidial and protist infections in mostly immunocompetent HIV-positive patients in Madrid, Spain. A structured questionnaire was used to retrieve data on factors potentially associated with an increased risk of infection, including sexual attitudes and sex-risk behaviour. Faecal samples (n = 96) from 81 HIV-positive patients were collected and analysed by molecular (PCR and Sanger sequencing) methods. Two microsporidial pathogens were detected: Ent. bieneusi (2.5%, 95% CI: 0.3-8.6) and Enc.intestinalis (4.9%, 95% CI: 1.4-12.2). The two Ent. bieneusi isolates were identified as zoonotic genotype A. Among protists, Entamoeba dispar was the species most prevalently found (33.3%, 95% CI: 23.2-44.7), followed by Blastocystis spp. (19.8%, 95% CI: 11.7-30.1), Giardia duodenalis (13.6%, 95% CI: 7.0-23.0), and Cryptosporidium spp. and Entamoeba histolytica (2.5%, 95% CI: 0.3-8.6 each). Cyclospora cayetanensis and Cystoisospora belli were not detected. Subtypes ST1 (70.6%, 12/17) and ST3 (29.4%, 5/17) were identified within Blastocystis sp., sub-assemblages AII and BIII (50%, 1/2 each) within G. duodenalis, and Cry. parvum and canine-adapted Cry. canis (50%, 1/2 each) within Cryptosporidium spp. Microsporidial and protist parasites were frequent in well-controlled, mostly immunocompetent HIV-positive patients and should be included in diagnostic algorithms when diarrhoea is present.

Opportunistic microsporidial and protist intestinal infections were relatively common in well-controlled HIV-positive patients in Madrid, Spain. These agents should be suspected and appropriately diagnosed in HIV-positive patients presenting with diarrhoea regardless of their immunological status.

Microsporidia infection in patients with autoimmune diseases.

Purpose: Microsporidium is a spore-forming intracellular parasite that affects a wide range of hosts including humans. The tumor necrosis factor alpha (TNF-α) plays a key role in the immunity to infection with microsporidia. Recently, the TNF-α antagonists have proven successful in treating variable autoimmune diseases. In the current study, we aimed to investigate the impact of using TNF-α antagonists as a therapeutic regimen in the prevalence of infections with microsporidia. Materials and Methods: Diarrheal patients with distinct autoimmune diseases (n = 100) were assigned to the study. Patients taking anti-TNF-α medications (n = 60) were allocated to Group 1A and those undergoing non-TNF-α inhibitor treatment (n = 40) to Group 1B. Furthermore, patients with diarrhea without autoimmune disorders (n = 20) were allocated as controls. Stool specimens, 3 per patient, were collected and microscopically examined for microsporidia spores. A microsporidia-specific stool polymerase chain reaction was used to confirm the microscopic findings. Results: Microsporidia infection was identified in 28.3% (17/60), 10% (4/40), and in 5% (1/20) of patients in Group 1A, Group 1B, and in the control group, respectively. Overall, infection was significantly high in cases compared to the controls and in patients receiving TNF-α antagonists compared to patients not given TNF-α inhibitors (P < 0.05). Finally, infection was significantly higher in cases treated with TNF-α antagonists for ≥2 months compared to cases treated for <2 months of duration (P < 0.05). Conclusion: There was a significant increase in microsporidia infection in autoimmune disease patients undergoing treatment with TNF-α antagonists, and the duration of treatment is one of the risk factors. The study highlights the importance of microsporidia testing in immunocompromised patients, particularly those undergoing treatment with anti-TNF-α drugs and emphasises the need for awareness among clinicians regarding this opportunistic parasite.

Cryptosporidiosis and microsporidiosis as causes of diarrhea in kidney and/or pancreas transplant recipients.

INTRODUCTION: Gastrointestinal disorders in solid organ recipients may have various origins including cryptosporidiosis and microsporidiosis. The prevalence of these infections is poorly known in solid organ transplant (SOT) patients in industrialized countries. METHODS: We prospectively assessed the infectious causes of diarrhea in SOT patients. Secondary objectives were to gain further insight into the main characteristics of cryptosporidiosis, and to assess risk factors for this infection. All adult kidney and/or pancreas recipients presenting with diarrhea and admitted to our facility between May 1, 2014 and June 30, 2015 were enrolled. A stool sample was analyzed using a standardized protocol including bacteriological, virological, and parasitological investigations. Data related to clinical symptoms, immunosuppression, and environmental potential risk factors were collected through a self-administered questionnaire and computerized medical records. RESULTS: Out of 73 enrolled patients, 36 had infectious diarrhea (49.3%). Viruses ranked first (17/36), followed by parasites and fungi (11/17). Cryptosporidiosis was the most common parasitic disease (n=6 patients). We observed four microsporidiosis cases. The estimated prevalence of cryptosporidiosis and microsporidiosis in this cohort was 3.7 and 2.40/00, respectively. No significant risk factor for cryptosporidiosis or microsporidiosis, neither environmental nor immunological, could be evidenced. CONCLUSION: Both cryptosporidiosis and microsporidiosis represent a significant cause of diarrhea in kidney transplant recipients.

Dual infection of urinary tract with Enterocytozoon bieneusi and Encephalitozoon cuniculi in HIV/AIDS patients

Microsporidia are emerging pathogens which cause an opportunistic infections in immunocompromised patients, especially those with AIDS. Intestinal microsporidiosis is the most recognized infection, whereas urinary tract infections caused by microsporidia are rarely paid attention to either due to their subclinical course or diagnostic difficulties. In this report dual microsporidial infection of urinary tract, caused by Enterocytozoon bieneusi and Encephalitozoon cuniculi was described in HIV/AIDS patients under cART therapy. Since microsporidiosis can cause severe complications or even death in immunosuppressed patients, our results suggest that microsporidial infection should be included in routine investigation of HIV-positive patients, even asymptomatic.

Coexistence of herpes simplex virus infection in microsporidial stromal keratitis associated with granulomatous inflammation.

BACKGROUND: Microsporidial stromal keratitis poses several diagnostic challenges. Patients may present with corneal ulceration, marked stromal thinning, or even as a quite corneal scar. The presentation of microsporidial stromal keratitis commonly mimics viral keratitis. Microbiology scrapings are usually helpful; however, scraping and culture-negative cases pose a significant diagnostic dilemma. Histopathological examination is diagnostic but shows varying degree of inflammation, predominantly composed of polymorphonuclear leukocytes. Granulomatous inflammation, in microsporidial stromal keratitis, is never well described, and the authors in this article aim to describe the presence of granulomatous inflammation in microsporidial stromal keratitis, in patients with associated herpes simplex virus (HSV) keratitis. METHODS: This was a retrospective and observational study conducted at a tertiary eye care center. RESULTS: Of 263 patients who underwent therapeutic penetrating keratoplasty for infectious keratitis, during 2011-2013, seven patients were diagnosed as microsporidial stromal keratitis. Microsporidial spores could be demonstrated on microbiological scrapings in 5/7 (71%) of cases, but identified on histopathological examination and also confirmed on polymerase chain reaction (PCR) for microsporidium in 100% of cases. There was evidence of diffuse stromal necrosis with markedly severe degree of polymorphonuclear leukocytic infiltrates, with granulomatous inflammation in 42% of cases. Interestingly, these were positive for HSV-1 DNA on PCR. Review of medical records revealed much severe clinical presentations in patients with granulomatous inflammation, in comparison to cases without granulomatous inflammation. CONCLUSIONS: The authors hereby recommend that severe clinical presentation in patients with microsporidial stromal keratitis, markedly dense polymorphonuclear leukocytic infiltrates or the presence of granulomatous inflammation on the histopathological examination, should be investigated further for the presence of HSV-1 DNA for better patient management and good visual outcome.

Reactive arthritis following a Microsporidia infection.

Reactive arthritis may be caused by both sexually transmissible and enteric organisms, though Microsporidia is not currently recognised as a causative agent. This case report describes the development of reactive arthritis following Microsporidia infection in an immunocompetent man.

[Prevalence of Encephalitozoon intestinalis and Enterocytozoon bieneusi in cancer patients under chemotherapy]. / Kemoterapi alan kanserli hastalarda Encephalitozoon intestinalis ve Enterocytozoon bieneusi prevalansi

Microsporidia species are obligate intracellular parasites and constitute one of the most important opportunistic pathogens that can cause severe infections especially in immunocompromised patients. Enterocytozoon bieneusi and Encephalitozoon intestinalis are the most common species among 14 microsporidia species identified as human pathogens. The aim of this study was to investigate the prevalence of E.intestinalis and E.bieneusi in cancer patients under chemotherapy by immunofluorescent antibody and conventional staining methods. A total of 123 stool samples obtained from 93 patients (58 male, 35 female) with cancer who were followed in oncology and hematology clinics of our hospital and 30 healthy volunteers (13 male, 17 female) were included in the study. Fifty-one (55%) of the patients had complain of diarrhea. The presence of E.intestinalis and E.bieneusi were investigated by a commercial immunofluorescence antibody test using monoclonal antibodies (IFA-MAbs; Bordier Affinity Products, Switzerland) in all of the samples, and 50 of the samples were also investigated by modified trichrome, acid-fast trichrome and calcofluor staining methods. A total of 65 (69.9%) patients were found positive with IFA-MAbs method, including 43 (46.2%) E.intestinalis, 9 (9.7%) E.bieneusi and 13 (14%) mixed infections. In the control group, 5 (16.7%) subjects were positive with IFA-MAbs method, including 2 (6.7%) E.intestinalis, 1 (3.3%) E.bieneusi and 2 (6.7%) mixed infections. The difference between the positivity rate of the patient and control groups was statistically significant (p< 0.05). Of the patients with diarrhea, 68.6% (35/51) were infected with microsporidia, and the difference between cases with and without (48.6%) diarrhea was statistically significant (p< 0.05). When 50 samples in which all of the methods could be performed were evaluated, the frequency of microsporidia were detected as follows; 66% (n= 33) with IFA-MAbs, 34% (n= 17) with modified trichrome staining, 24% (n= 12) with acid-fast trichrome staining and 42% (n= 21) with calcofluor staining methods. Our data indicated that the use of IFA-MAbs method along with the conventional staining methods in diagnosis of microsporidia will increase the sensitivity. As a conclusion, the prevalence of E.intestinalis and E.bieneusi in cancer patients under chemotherapy was detected quite high (69.9%) in our study, it would be appropriate to screen these patients regularly in terms of microsporidian pathogens.

Microsporidial polymyositis in human immunodeficiency virus-infected patients, a rare life-threatening opportunistic infection: clinical suspicion, diagnosis, and management in resource-limited settings.

INTRODUCTION: Microsporidial myositis is a rare opportunistic infection that has been reported in HIV-infected and HIV-uninfected immunocompromised patients. METHODS: In this study we present a retrospective analysis of 5 cases of microsporidial myositis in HIV-infected patients, including the clinical, laboratory, and histologic features, and a review of the literature. RESULTS: Five young men with HIV infection [median CD4 count of 20 cells (range 14-144)/mm(3) ] who presented with signs and symptoms suggestive of myositis underwent EMG-NCV and muscle biopsy, which revealed signs compatible with microsporidial myositis. Early and aggressive treatment led to improvement in 3 patients. Two of the 5 patients died due to a delay in diagnosis, because the spores were mistaken for Candida without confirmatory stains or a high index of suspicion. CONCLUSIONS: Myositis in HIV-infected patients with low CD4 counts should be evaluated using muscle biopsy. A high index of suspicion is required for early diagnosis of microsporidial myositis in HIV-infected patients. Early diagnosis and immediate, aggressive treatment are the keys to favorable outcomes in these patients.

Hepatic steatosis associated with microsporidiosis in teleost fishes from Marajó Island, Brazil.

A total of 40 specimens of the teleost fish Gobioides grahamae Palmer & Wheeler, 1955 were obtained from the municipality of Salvaterra on Marajó Island in the Brazilian state of Pará. Their livers were removed and processed for light microscopy. Overall, 90% of the specimens presented some degree of steatosis of the liver, which was invariably associated with the presence of Microsporidium sp. The present study confirms the occurrence of steatosis in G. grahamae associated with parasitic infections by Microsporidium. The findings indicate that the condition of otherwise healthy fishes in their natural environment may be affected negatively by parasites.

Prevalencia de microsporidios intestinales y otros enteroparásitos en pacientes con VIH positivo de Maracaibo, Venezuela / Prevalence of intestinal microsporidia and other intestinal parasites in hiv positive patients from Maracaibo, Venezuela.

Introducción. Desde 1985, los microsporidios se consideran parásitos causantes de infecciones emergentes y oportunistas en individuos inmunocomprometidos en todo el mundo. Objetivo. Detectar la presencia de microsporidios y otros enteroparásitos en pacientes con VIH/sida del Servicio Autónomo Hospital Universitario de Maracaibo (SAHUM), donde no existían estudios previos en este campo. Materiales y métodos. Las muestras fecales se analizaron mediante examen directo, método de concentración con formol-éter, coloración de Kinyoun y coloración Gram-cromotropo rápida. Se realizaron PCR separadas para diferenciar Entamoeba histolytica o Entamoeba dispar , cuando se observó el complejo E. histolytica/dispar al microscopio. Mediante historia clínica se obtuvo información del paciente. Resultados. De los 56 individuos participantes, 38 (67,86 %) presentaron alguna especie parasitaria comensal o patógena en su muestra fecal. Predominaron los individuos portadores de especies parásitas patógenas (26/38). Fueron diagnosticados protozoos como Isospora belli (17,65 %), Blastocystis spp .(17,65 %), Cryptosporidium spp. (7,84 %), complejo Entamoeba histolytica/dispar (5,88 %) , Entamoeba coli (3,92 %) , Giardia lamblia (3,92 %) , Endolimax nana (3,92 %) , Cyclospora cayetanensis (3,92 %) y Chilomastix mesnili (1,96 %). Entre los helmintos, Ascaris lumbricoides, Trichuris trichiura y Strongyloides stercoralis, presentaron un porcentaje de 27,27 % cada uno, e Hymenolepis nana , de 18,18 %. Solo se detectó E. histolytica en uno de los tres casos que presentaron el complejo al examen microscópico. Mediante Gram-cromotropo, 17 muestras evidenciaron esporas del filo Microsporidia, lo que equivale a un 33,33 % de prevalencia. Conclusión. Los microsporidios pueden ocupar el primer lugar de prevalencia en pacientes con VIH positivo, cuando se utilizan técnicas diagnósticas específicas.

Objective: To detect the presence of microsporidia and other enteric parasites in patients with HIVAIDS of the Autonomous Services University Hospital of Maracaibo (SAHUM), where there are no previous studies in this field. Materials and methods: Fecal samples were analyzed by means of direct exam, concetration method with formal-ether, Kinyoun coloration and fast Gram-Chromotrope coloration. Separate PCR were perfomed to differentiate Entamoeba histolytica and Entamoeba dispar , when the E. histolytica/E. dispar complex was observed in the microscope. Information on the patient was obtained trough clinical history. Results: Of 56 individuals that participated, 38 (67.86%) presented some commensal parasite and/ or pathogenic species in their fecal sample. Carriers of pathogenic species were predominat (26/38). Protozoa such as Isospora belli protozoa (17.65%), Blastocystis spp. (17.65%), Cryptosporidium spp. (7.84%), E. histolytica/E. dispar (5.88%), Entamoeba coli (3.92%), Giardia lamblia (3.92%), Endolimax nana (3.92%), Cyclospora cayetanensis (3.92%), and Chilomastix mesnilli (1.96%) were diagnosed. Among the helminths, Ascaris lumbricoides, Trichuris trichiura and Strongyloides stercoralis , had a percentage of 27.27% each, and Hymenolepis nana , 18.18%. Entamoeba histolytica was only detected in one of three cases presenting complex microscopic examination. By Gram-chromotrope, 17 samples showed spores of the Microsporidia phylum, equivalent to 33.33% prevalence. Conclusion: Microsporidia may be first prevalente in HIV positive patients when specific diagnostic techniques are used.

Intestinal microsporidiosis in India: a two year study.

Intestinal parasitic pathogens in HIV/AIDS patients include Cryptosporidium sp, Cystoisospora sp, microsporidia and less commonly other parasites. The two most common microsporidia causing intestinal infection are Enterocytozoon bieneusi and Encephalitozoon intestinalis. Most of the Indian studies for intestinal parasitic infections in HIV/AIDS patients have not included microsporidia, due to difficult staining and identification of the parasite. The aim of the present study was to find the prevalence of intestinal microsporidiosis and their species identification along with correlation of CD4 count with parasite positivity and diarrhoea in HIV positive individuals. Stool samples of 363 individuals including 125 HIV seropositive patients with diarrhoea, 158 HIV seropositive patients without diarrhoea, 55 HIV seronegative patients with diarrhoea and 25 healthy controls were obtained from various out-patient departments and in-patients admitted to a tertiary care hospital from August 2008 to October 2009. The stool samples were subjected to examination by wet mount, modified acid fast stain for coccidian parasites and multiplex nested PCR for microsporidia. The overall prevalence of all intestinal parasites among HIV patients in our study was 26.5%. The prevalence of intestinal parasitic pathogens in HIV positive patients with diarrhoea was 43.2%. Microsporidia were the most common parasites detected (14%) in all patients, while in HIV infected patients 15.9% patients had microsporidia infection. The most common species causing intestinal microsporidiosis in our study was E. intestinalis (10.5%). In HIV seropositive individuals with diarrhoea, E. intestinalis was 20.8% and E. bieneusi 8.0% while in HIV-seropositive individuals without diarrhoea, E. intestinalis was 3.8% and E. bieneusi 1.9%. E. intestinalis was present in 10.9% of HIV negative individuals with diarrhoea in whom E. bieneusi was not found. There was a significant association between CD4 count ≤200/µl and intestinal parasite positivity. Thus, it can be concluded that intestinal microsporidiosis is under reported but an important disease in India. The predominant species in our study is E. intestinalis , in contrast to other parts of the world where E. bieneusi is more common.

[Prevalence of intestinal microsporidia and other intestinal parasites in hiv positive patients from Maracaibo, Venezuela]. / Prevalencia de microsporidios intestinales y otros enteroparásitos en pacientes con VIH positivo de Maracaibo, Venezuela.

OBJECTIVE: To detect the presence of microsporidia and other enteric parasites in patients with HIVAIDS of the Autonomous Services University Hospital of Maracaibo (SAHUM), where there are no previous studies in this field. MATERIALS AND METHODS: Fecal samples were analyzed by means of direct exam, concetration method with formal-ether, Kinyoun coloration and fast Gram-Chromotrope coloration. Separate PCR were perfomed to differentiate Entamoeba histolytica and Entamoeba dispar , when the E. histolytica/E. dispar complex was observed in the microscope. Information on the patient was obtained trough clinical history. RESULTS: Of 56 individuals that participated, 38 (67.86%) presented some commensal parasite and/ or pathogenic species in their fecal sample. Carriers of pathogenic species were predominat (26/38). Protozoa such as Isospora belli protozoa (17.65%), Blastocystis spp. (17.65%), Cryptosporidium spp. (7.84%), E. histolytica/E. dispar (5.88%), Entamoeba coli (3.92%), Giardia lamblia (3.92%), Endolimax nana (3.92%), Cyclospora cayetanensis (3.92%), and Chilomastix mesnilli (1.96%) were diagnosed. Among the helminths, Ascaris lumbricoides, Trichuris trichiura and Strongyloides stercoralis , had a percentage of 27.27% each, and Hymenolepis nana , 18.18%. Entamoeba histolytica was only detected in one of three cases presenting complex microscopic examination. By Gram-chromotrope, 17 samples showed spores of the Microsporidia phylum, equivalent to 33.33% prevalence. CONCLUSION: Microsporidia may be first prevalente in HIV positive patients when specific diagnostic techniques are used.

Diarrhea in the immunocompromised patient.

Diarrhea is a common problem in patients with immunocompromising conditions. The etiologic spectrum differs from patients with diarrhea who have a normal immune system. This article reviews the most important causes of diarrhea in immunocompromised patients, ranging from infectious causes to noninfectious causes of diarrhea in the setting of HIV infection as a model for other conditions of immunosuppression. It also deals with diarrhea in specific situations, eg, after hematopoietic stem cell or solid organ transplantation, diarrhea induced by immunosuppressive drugs, and diarrhea in congenital immunodeficiency syndromes.

Molecular characterizations of Cryptosporidium, Giardia, and Enterocytozoon in humans in Kaduna State, Nigeria.

The use of molecular diagnostic tools in epidemiological investigations of Cryptosporidium, Giardia, and Enterocytozoon has provided new insights into their diversity and transmission pathways. In this study, 157 stool specimens from 2-month to 70-year-old patients were collected, a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis of the small subunit (SSU) rRNA gene was used to detect and differentiate Cryptosporidium species, and DNA sequence analysis of the 60 kDa glycoprotein (gp60) gene was used to subtype Cryptosporidium hominis and Cryptosporidium parvum. Giardia duodenalis, and Enterocytozoon bieneusi in the specimens were detected using PCR and sequence analysis of the triosephosphate isomerase (tpi) gene and internal transcribed spacer (ITS), respectively. C. hominis and C. parvum were found in two (1.3%) and one (0.6%) specimen respectively, comprising of Ia and IIe (with 8 nucleotide substitutions) subtype families. The G. duodenalis A2 subtype was detected in five (3.2%) specimens, while four genotypes of E. bieneusi, namely A, type IV, D and WL7 were found in 10 (6.4%) specimens. Children aged two years or younger had the highest occurrence of Cryptosporidium (4.4%) and Enterocytozoon (13.0%) while children of 6 to 17 years had the highest Giardia infection rate (40.0%). No Cryptosporidium, Giardia, and Enterocytozoon were detected in patients older than 60 years. Enterocytozoon had high infection rates in both HIV-positive (3.3%) and HIV-negative (8.3%) patients. Results of the study suggest that anthroponotic transmission may be important in the transmission of Cryptosporidium spp. and G. duodenalis while zoonotic transmissions may also play a role in the transmission of E. bieneusi in humans in Kaduna State, Nigeria.

Detection of concurrent infection of dairy cattle with Blastocystis, Cryptosporidium, Giardia, and Enterocytozoon by molecular and microscopic methods.

Of fecal specimens examined from 47 dairy cattle ranging in age from neonates to multiparous cows, 9, 10, 24, and 17 were positive for Blastocystis spp., Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi, respectively, as determined by PCR. Eight 3- to 5-month-old cattle were concurrently infected with three or four of these parasites. This is the first report to identify multiple concurrent infections with these four potentially zoonotic protist pathogens in cattle. None of the cattle exhibited signs of illness or effects of infection on growth and are regarded as healthy carriers. A commercially available immunofluorescence (IFA) microscopic test confirmed six of seven available PCR-positive Blastocystis specimens and identified one IFA-positive cow that was PCR negative.

Myositis due to the microsporidian Anncaliia (Brachiola) algerae in a lung transplant recipient.

Microsporidia are obligate intracellular parasites, more closely related to fungi than protozoa on molecular phylogenetic analysis, and are known to be a rare cause of opportunistic infection in immune compromised patients including human immunodeficiency virus-positive patients and solid organ transplant recipients. We report the first case to our knowledge of microsporidial myositis in a lung transplant recipient. He was 49 years old and had received a lung transplant in 2000 for cystic fibrosis. He presented in 2009 with fevers, chronic diarrhea, myalgia, and pancytopenia, and developed progressive weakness and neurological symptoms before his death 35 days after hospital admission. Multiple investigations, including stool culture, rectal biopsy, colonoscopy, cerebrospinal fluid examination, bone marrow biopsy, lung biopsy, and bronchoalveolar lavage, failed to reveal a definite cause for the patient's deterioration. The diagnosis of microsporidial infection was made on post-mortem light microscopic examination of tissue sections of the tongue and deltoid muscle. Light microscopy diagnosed a microsporidial myositis, confirmed by transmission electron microscopy, which suggested that the organism was Brachiola species. The identity of the organism was confirmed by polymerase chain reaction as Brachiola algerae (recently renamed Anncaliia algerae). The case highlights the need to consider protozoal organisms in the differential diagnosis of myalgia and multisystemic infections in immune compromised patients.

Co-infection of HIV and tropical infectious agents that affect the nervous system.

Tropical infections refer to a group of diseases usually located in regions with a warm climate, particularly affecting developing countries, partly because of the conditions that allow them to thrive. However, due to the increased international travel, infectious agents that were previously limited to tropical regions pose an increasing threat to populations at risk for opportunistic infection (OI), especially those infected with the HIV. Tropical infections can facilitate HIV transmission and accelerate the progression of asymptomatic HIV infection to AIDS. Some have the potential to alter the epidemiology, natural history, and/or response to treatment of the other. The introduction of highly active antiretroviral therapy has provided a huge benefit for the vast majority of patients infected with the HIV, by allowing the immune system to recover, improving the clinical and radiological results and reducing the number of OI. On the other hand, some patients have developed various disorders of immune reconstitution, resulting in either hyper-immune inflammatory response to an exogenous antigen or autoimmunity. A significant proportion of these cases have been reported in immigrants from tropical countries to high-income countries, therefore awareness of these phenomena is needed since clinical presentations are often atypical and pose diagnostic challenges. This article reviews some of the key diagnostic aspects of tropical infections associated with HIV infection.

Molecular epidemiologic characterization of Enterocytozoon bieneusi in HIV-infected persons in Benin City, Nigeria.

Molecular characterization of Enterocytozoon bieneusi has led to better understanding of microsporidiosis transmission in humans. This study aimed to detect and genotype E. bieneusi in human immunodeficiency virus (HIV)-infected persons. Stool specimens were collected from 463 HIV-infected patients and analyzed for E. bieneusi by polymerase chain reaction (PCR) and DNA sequence analysis of the internal transcribed spacer. E. bieneusi was detected in 77 HIV patients. CD4 cell counts < 200 cells/µL was associated with E. bieneusi infection (P = 0.09). E. bieneusi was significantly associated with weight loss (P < 0.0001), diarrhea (P = 0.006), fever (P < 0.0001), not being married (P < 0.0001), and flush type of toilet (P = 0.0007). Six known genotypes of D, A, IV, CAF2, EbpA, and Peru 8 in 31, 22, 14, 2, 1, and 1 patients, respectively, five novel genotypes of E. bieneusi, and one infection with mixed genotypes were observed in this study. Three of the novel genotypes were genetically distant to the genotypes commonly found in humans.

[Contribution of PCR for detection and identification of intestinal microsporidia in HIV-infected patients]. / Apport de la PCR dans la recherche et l'identification des microsporidies intestinales chez les sujets infectés par le VIH.

AIM: Intestinal microsporidiosis are among the most frequent opportunistic diseases in immunocompromised subjects. This study aimed to evaluate the contribution of PCR for a better detection and species identification of microsporidia in stool specimens of HIV-infected patients. PATIENTS AND METHODS: Stool samples obtained from 119 HIV-infected Tunisian subjects were screened for intestinal microsporidiosis by light microscopy using Weber's modified Trichrome stain and by a PCR method using universal primers V1/PMP2 which amplified a common fragment of the small subunit rRNA gene of microsporidia. The obtained PCR products were then sequenced using an ABI PRISM 377 DNA sequencer. RESULTS: The results showed a better sensitivity of PCR in the detection of microsporidia with an infection rate of 14.3% significantly higher than that of 6.7% obtained by light microscopy (p=0.03). As previously described, intestinal microsporidiosis was associated with low CD4 cell counts; 23.9% infection rate in patients having CD4 cell count under 200/mm(3) against 5.6% in patients with higher CD4 cell count (p=0.008). The sequencing of 15 out of the 17 positive PCR products has confirmed in all cases the species identified based on the PCR fragment size i.e., 250pb for Enterocytozoon bieneusi (seven cases) and about 270pb for Encephalitozoon intestinalis (nine cases); one case revealed a double infection. CONCLUSION: PCR proved to be more effective than classical Trichrome stain for the diagnosis of intestinal microsporidiosis. Moreover, the ability of PCR to identify the species involved could also be useful for cases management.