Encephalitozoon hellem in a patient with CD4+ T-cell prolymphocytic leukemia: case report and genomic identification.

Five cases of microsporidioses among leukemic patients, 4 in myeloid-leukemic patients and 1 in a chronic lymphocytic leukemia, have been described until now. We report a case of microsporidiosis and the genomic identification of Encephalitozoon hellem in a patient with CD4(+) T-cell prolymphocytic leukemia.

Evidence of airborne excretion of Pneumocystis carinii during infection in immunocompetent rats. Lung involvement and antibody response.

To better understand the role of immunocompetent hosts in the diffusion of Pneumocystis in the environment, airborne shedding of Pneumocystis carinii in the surrounding air of experimentally infected Sprague Dawley rats was quantified by means of a real-time PCR assay, in parallel with the kinetics of P. carinii loads in lungs and specific serum antibody titres. Pneumocystis-free Sprague Dawley rats were intratracheally inoculated at day 0 (d0) and then followed for 60 days. P. carinii DNA was detected in lungs until d29 in two separate experiments and thereafter remained undetectable. A transient air excretion of Pneumocystis DNA was observed between d14 and d22 in the first experiment and between d9 and d19 in the second experiment; it was related to the peak of infection in lungs. IgM and IgG anti-P. carinii antibody increase preceded clearance of P. carinii in the lungs and cessation of airborne excretion. In rats receiving a second challenge 3 months after the first inoculation, Pneumocystis was only detected at a low level in the lungs of 2 of 3 rats at d2 post challenge and was never detected in air samples. Anti-Pneumocystis antibody determinations showed a typical secondary IgG antibody response. This study provides the first direct evidence that immunocompetent hosts can excrete Pneumocystis following a primary acquired infection. Lung infection was apparently controlled by the immune response since fungal burdens decreased to become undetectable as specific antibodies reached high titres in serum. This immune response was apparently protective against reinfection 3 months later.

Prevalence of opportunistic intestinal parasitic infections among HIV-infected patients with low CD4 cells counts in France in the combination antiretroviral therapy era.

BACKGROUND: The use of combination antiretroviral therapy (cART) has dramatically reduced the prevalence of opportunistic infections, however data on the prevalence of intestinal parasitic infections in HIV-infected patients with low CD4 cell counts in the cART era are scarce. METHODS: We performed a prospective cohort study among HIV-infected patients with CD4 cell counts <100/mm(3) seen at a university hospital in Paris. Medical records were reviewed and stool samples were obtained for macroscopic examination and detection of parasites including cryptosporidia and microsporidia, whether or not the patient had diarrhea. Stool cultures were performed for patients with diarrhea. Factors associated with the detection of parasites were then identified. RESULTS: Stools samples from 143 consecutive patients were analyzed. Patients were mostly men (76%), and the median patient age was 41 years. The median CD4 cell count was 32/mm(3), and 59% were receiving cART. Diarrhea was present in 85 patients (59%), 19 of whom (22%) had intestinal parasites detected in stools. Three patients with diarrhea were diagnosed with Salmonella typhimurium, Campylobacter coli, and Clostridium difficile infections. Among the 58 patients without diarrhea, parasitic intestinal pathogens were still identified in six (10%). The overall prevalence of intestinal parasites was 17%, with cryptosporidia (n=8), microsporidia (n=6), and Giardia duodenalis (n=5) being the most frequent pathogens. Patients with intestinal parasites had diarrhea more often (76% vs. 56%, p=0.025) and were more often at US Centers for Disease Control and Prevention (CDC) clinical stage C (84% vs. 69%, p=0.024) than patients without parasites. CONCLUSIONS: The prevalence of intestinal parasitic infections remains significant in HIV-infected patients with low CD4 counts in the cART era. A systematic search for parasitic pathogens including microsporidia, cryptosporidia, and G. duodenalis should be performed even in the absence of diarrhea.

Evaluation of four commercial rapid immunochromatographic assays for detection of Cryptosporidium antigens in stool samples: a blind multicenter trial.

In a multicenter study, potassium dichromate-preserved stools from patients infected with Cryptosporidium parvum (n = 20), C. hominis (n = 20), and other Cryptosporidium species (n = 10) and 60 controls were examined using four immunochromatographic assays. Assay sensitivity ranged between 50.1% and 86.7% for C. parvum and C. hominis but was <35% for other species.

Quantification and spread of Pneumocystis jirovecii in the surrounding air of patients with Pneumocystis pneumonia.

BACKGROUND: Airborne transmission of Pneumocystis has been demonstrated in animal models and is highly probable in humans. However, information concerning burdens of Pneumocystis jirovecii (human-derived Pneumocystis) in exhaled air from infected patients is lacking. Our objective is to evaluate P. jirovecii air diffusion in patients with Pneumocystis pneumonia. METHODS: Patients admitted with Pneumocystis pneumonia were prospectively enrolled from 9 January 2008 to 21 July 2009. Air samples (1.5 m(3)) were collected on liquid medium with a commercial sampler at 1-, 3-, 5-, and 8-m distances from patients' heads. Air control samples were collected away from Pneumocystis pneumonia patient wards and outdoors. Samples were examined for P. jirovecii detection and quantification using a real-time polymerase chain reaction assay targeting the mitochondrial large subunit ribosomal RNA gene. RESULTS: Forty patients were diagnosed as having Pneumocystis pneumonia. Air sampling was performed in the environment for 19 of them. At a 1-m distance from patients' heads, P. jirovecii DNA was detected in 15 (79.8%) of 19 patients, with fungal burdens ranging from 7.5 X 10³ to 4.5 X 106 gene copies/m(3). These levels decreased with distance from the patients (P < .002). Nevertheless, 4 (33.3%) of the 12 samples taken at 8 m, in the corridor adjacent to their room, were still positive. Forty control samples were collected and remained negative. CONCLUSION: This study provides the first quantitative data on the spread of P. jirovecii in exhaled air from infected patients. It sustains the risk of P. jirovecii direct transmission in close contact with patients with Pneumocystis pneumonia and leads the way for initiating a quantitative risk assessment for airborne transmission of P. jirovecii.

Disseminated infection with a new genovar of Encephalitozoon cuniculi in a renal transplant recipient.

Disseminated microsporidiosis is a life-threatening opportunistic infection. Here, we report about a previously undescribed genovar of Encephalitozoon cuniculi causing disseminated infection in a non-HIV-infected renal transplant recipient. Disseminated microsporidiosis must be considered in the differential diagnosis of chronic fever in renal allograft recipients, even those without urinary symptoms.

Failure of atovaquone/proguanil to prevent Plasmodium ovale malaria in traveler returning from Cameroon.

We report a case of a patient returning from Cameroon who developed Plasmodium ovale malaria, despite atovaquone/proguanil (AP, Malarone) prophylaxis, which is widely used for the prevention of chloroquine-resistant malaria. AP is indeed active only on schizont blood forms of P. ovale but not against liver-stage hypnozoites and does not realize effective prophylaxis against delayed onset of P. ovale malaria. Hence, this case illustrates the risk of failure with Malarone for the prophylaxis of P. ovale infection for travelers in endemic regions. Travelers returned from risk areas with symptoms suggestive of malaria, should not have the diagnosis of P. ovale (or P. vivax) infection discounted, despite a history of compliance with a standard chemoprophylactic regimen.

Clinical picture of Pneumocystis jiroveci pneumonia in cancer patients.

BACKGROUND: Pneumocystis pneumonia (PCP) is common in patients with HIV infection but may also occur in patients with other causes of immunodeficiency, including hematologic and solid malignancies. METHODS: To better describe the clinical picture of PCP as to maintain a high level of suspicion in adequate cases, we studied 56 cancer patients with PCP and compared them to 56 cancer patients with bacterial pneumonia. RESULTS: Among 56 PCP patients, 44 patients (78.6%) had hematologic malignancies (18 recipients of bone marrow transplantation) and 12 patients had solid tumors. The time since diagnosis was 24 months (range, 4 to 49 months). All patients with solid tumors and 20 patients (45.4%) with hematologic malignancies were receiving steroids. Only six patients were receiving PCP prophylaxis. The main symptoms were fever (85.7%), dyspnea (78.6%), and cough (57.1%). Time from symptom onset was 7 days (range, 3 to 14 days). PCP presented as severe pneumonia (Pao(2), 58 mm Hg [range, 50 to 70 mm Hg]) with bilateral interstitial infiltrates (80.4%) and bilateral ground-glass attenuation (89.3%) by CT. Of the 24 ICU patients (42.9%), 16 patients (19.6%) required mechanical ventilation. Eleven patients (19.6%) died. Compared to 56 patients with bacterial pneumonia, PCP patients were more likely to have non-Hodgkin lymphoma and be receiving long-term steroids; they had longer times since diagnosis, longer symptom duration, higher frequencies of fever and of diffuse lung disease (diffuse crackles, bilateral infiltrates, and hypoxemia), higher frequency of ground-glass opacities, and lower frequency of pleural involvement. CONCLUSIONS: PCP presents as subacute, febrile, hypoxemic, and diffuse pulmonary involvement in patients with solid tumors or hematologic malignancies receiving long-term steroids.

Healing of Old World cutaneous leishmaniasis in travelers treated with fluconazole: drug effect or spontaneous evolution?

The efficacy of fluconazole was evaluated in 35 travelers with parasitologically proven imported Old World cutaneous leishmaniasis (CL). Leishmania major (mainly MON-25) was identified in 15 patients and strongly suspected given the transmission area in 12 of these patients. Daily oral fluconazole (200 mg/day for adults and 2.5 mg/kg/day for children) was prescribed for six weeks. Outcome definition was based on re-epithelialization rate at day 50. Of the 27 L. major-infected patients, 12 (44.4%) were cured. This cure rate is similar to the placebo cure rate from trials in L. major CL in which, as in the present report, the definition of outcome relied exclusively on re-epithelialization. These data question the assumption that oral fluconazole is consistently effective for treatment of CL caused by L. major.

Use of enzyme-linked immunosorbent assay and dipstick assay for detection of Strongyloides stercoralis infection in humans.

A homemade enzyme-linked immunosorbent assay (ELISA) (Academic Medical Center ELISA [AMC-ELISA]) and a dipstick assay for the detection of anti-Strongyloides stercoralis antibodies in serum were developed and evaluated together with two commercially available ELISAs (IVD-ELISA [IVD Research, Inc.] and Bordier-ELISA [Bordier Affinity Products SA]) for their use in the serodiagnosis of imported strongyloidiasis. Both commercially available ELISAs have not been evaluated previously. The sensitivities of the assays were evaluated using sera from 90 patients with parasitologically proven intestinal strongyloidiasis and from 9 patients with clinical larva currens. The sensitivities of the AMC-ELISA, dipstick assay, IVD-ELISA, and Bordier-ELISA were 93, 91, 89, and 83%, respectively, for intestinal strongyloidiasis. In all tests, eight of nine sera from patients with larva currens were positive. The specificity was assessed using a large serum bank of 220 sera from patients with various parasitic, bacterial, viral, and fungal infectious diseases; sera containing autoimmune antibodies; and sera from healthy blood donors. The specificities of AMC-ELISA, dipstick assay, IVD-ELISA, and Bordier-ELISA were 95.0, 97.7, 97.2, and 97.2%, respectively. Our data suggest that all four assays are sensitive and specific tests for the diagnosis of both intestinal and cutaneous strongyloidiasis.

Prevalence of intestinal parasites including microsporidia in human immunodeficiency virus-infected adults in Cameroon: a cross-sectional study.

To assess the prevalence of intestinal parasites in a cohort of human immunodeficiency virus (HIV)-infected adults in Cameroon, a cross-sectional study was conducted. Detection of parasites was performed in 181 stool samples from 154 HIV-infected patients with a mean CD4 cell count of 238 cells/mm(3). Only 35 patients (22%) were receiving antiretroviral therapy at the time of stool sampling, and 46 (29%) had diarrhea. Opportunistic protozoa were found in 15 patients (9.7%), 8 of whom (53%) had diarrhea. Enterocytozoon bieneusi was found in eight patients, C. parvum in six patients, and Isospora belli in three patients. All E. bieneusi isolates tested belonged to the same genotype. The prevalence of opportunistic protozoa among patients with CD4 cell counts less than 50/mm(3) was 32%.

Inhibitory activity of human immunodeficiency virus aspartyl protease inhibitors against Encephalitozoon intestinalis evaluated by cell culture-quantitative PCR assay.

Immune reconstitution might not be the only factor contributing to the low prevalence of microsporidiosis in human immunodeficiency virus (HIV)-infected patients treated with protease inhibitors, as these drugs may exert a direct inhibitory effect against fungi and protozoa. In this study, we developed a cell culture-quantitative PCR assay to quantify Encephalitozoon intestinalis growth in U-373-MG human glioblastoma cells and used this assay to evaluate the activities of six HIV aspartyl protease inhibitors against E. intestinalis. A real-time quantitative PCR assay targeted the E. intestinalis small-subunit rRNA gene. HIV aspartyl protease inhibitors were tested over serial concentrations ranging from 0.2 to 10 mg/liter, with albendazole used as a control. Ritonavir, lopinavir, and saquinavir were able to inhibit E. intestinalis growth, with 50% inhibitory concentrations of 1.5, 2.2, and 4.6 mg/liter, respectively, whereas amprenavir, indinavir, and nelfinavir had no inhibitory effect. Pepstatin A, a reference aspartyl protease inhibitor, could also inhibit E. intestinalis growth, suggesting that HIV protease inhibitors may act through the inhibition of an E. intestinalis-encoded aspartyl protease. These results showed that some HIV protease inhibitors can inhibit E. intestinalis growth at concentrations that are achievable in vivo and that the real-time quantitative PCR assay that we used is a valuable tool for the in vitro assessment of the activities of drugs against E. intestinalis.

Detection of cryptosporidium and identification to the species level by nested PCR and restriction fragment length polymorphism.

Cryptosporidiosis is an emerging protozoan disease associated with large waterborne outbreaks. Diagnosis relies on microscopic examination of stools, but this method cannot identify the infecting species of Cryptosporidium. We have developed a test based on nested PCR and restriction fragment length polymorphism (RFLP) that offers simple identification of Cryptosporidium hominis, Cryptosporidium parvum, and most other human infective species in stool samples. Purified C. parvum oocysts were used for PCR development. Extracted DNA was amplified by nested PCR targeting a 214-bp fragment of the 18S RNA gene. Enzymatic restriction sites were identified by bioinformatic analysis of all published Cryptosporidium 18S rRNA sequences. Experiments with spiked stool samples gave an estimated PCR detection limit of one oocyst. Specificity was assessed by testing 68 stool samples from patients with microscopically proven cryptosporidiosis and 31 Cryptosporidium-negative stools. Sixty-seven (98.5%) of the 68 stool samples from patients with microscopically proven cryptosporidiosis and 2 of the other stool samples were positive by PCR and could be genotyped. RFLP analysis identified 36 C. hominis, 19 C. parvum, 8 Cryptosporidium meleagridis, and 6 Cryptosporidium felis or Cryptosporidium canis samples. Species determination in 26 PCR-positive cases was in full agreement with DNA sequencing of the 18S rRNA hypervariable region. The excellent sensitivity of PCR, coupled with the accuracy of RFLP for species identification, make this method a suitable tool for routine diagnosis and genotyping of Cryptosporidium in stools.

Development of a real-time PCR assay for quantitative detection of Encephalitozoon intestinalis DNA.

A new real-time PCR assay for quantitation of Encephalitozoon intestinalis DNA was developed which used a TaqMan fluorescent probe for specific detection. Serial dilutions of E. intestinalis spore suspensions obtained from tissue culture were used as external standards. The detection limit of the technique was 20 spores per ml, with a good interassay reproducibility (coefficient of variation of 7.1% for the suspension containing 20 spores/ml, 5.0% for the suspension containing 75 spores/ml and below 3.5% for higher concentrations). Quantitative detection of E. intestinalis DNA was similar whether the serial dilutions of spores were made in distilled water or in a stool suspension, allowing the use of the assay for stool specimens. The assay was then applied to 14 clinical specimens from 8 immunocompromised patients with proven E. intestinalis infection. The quantitation of the parasitic burden was achieved in stools, blood, urine, tissue biopsies, and bronchopulmonary specimens. The highest parasitic burdens were noted in stools, urine, and bronchopulmonary specimens, reaching 10(5) to 10(6) spores/g or ml. Dissemination of the infection was also evidenced in some patients by demonstration of E. intestinalis DNA in blood and serum. We conclude that real-time PCR is a valuable tool for quantitation of E. intestinalis burden in clinical specimens.

Prospective value of PCR amplification and sequencing for diagnosis and typing of old world Leishmania infections in an area of nonendemicity.

We assessed the prospective value of PCR amplification of a repetitive sequence from Leishmania nuclear DNA and sequencing for the diagnosis and typing of Old World Leishmania infection in an area of nonendemicity. During this 42-month study, 29 of 168 consecutive samples were examined and classified as positive for Leishmania by direct examination and/or in vitro culture. This molecular approach showed excellent sensitivity (97%) and specificity (100%) compared to direct examination (86 and 100%, respectively) and in vitro culture (72 and 100%, respectively). Isoenzymatic and molecular typing allowed similar identification for 12 samples. Besides, PCR and subsequent sequencing of DNA products permitted the species identification of 14 samples for which parasite culture remained negative or did not allow isoenzymatic characterization, indicating the complementarity of parasitological and molecular tools.

Development of a real-time polymerase-chain-reaction assay for quantitative detection of Enterocytozoon bieneusi DNA in stool specimens from immunocompromised patients with intestinal microsporidiosis.

A new real-time polymerase chain reaction (PCR) method was developed for quantitation of Enterocytozoon bieneusi DNA in sequential stool specimens from immunocompromised patients with intestinal microsporidiosis. Patients were treated with fumagillin (n=6) or with placebo (n=6), in a randomized comparative trial. At baseline, mean E. bieneusi DNA levels were not significantly different in stool specimens from the placebo group, compared with those from the fumagillin group (5.9+/-0.4 vs. 5.9+/-0.6 log(10) copies/microL of stool suspension, respectively; P=.96). In the placebo group, parasitic burden remained stable during follow-up (P=.46), whereas, in the fumagillin group, E. bieneusi DNA levels dropped below the lower limit of detection in all patients (mean reduction from baseline, -4.7 log(10) copies; P<.0001). Real-time PCR performed better than did semiquantitative assessments by microscopy, to measure parasitic burden. In conclusion, this real-time PCR assay is a reliable tool for quantitation of E. bieneusi DNA in stool specimens and for the monitoring of treatment efficacy.