High prevalence of Pneumocystis jirovecii colonization among HIV-positive patients in southern Brazil.

A high prevalence of Pneumocystis jirovecii colonization was observed in patients positive for the human immunodeficiency virus (HIV) admitted to a tertiary hospital in southern Brazil between August 2012 and December 2012. Amplification of the mitochondrial large subunit ribosomal RNA gene in oropharyngeal samples through nested polymerase chain reaction identified P. jirovecii colonization in 26 of 58 (44.8%) HIV-positive patients admitted for causes other than Pneumocystis pneumonia. Colonization was more frequent among patients with an absolute CD4 count ≤200 cells/µl. These findings suggest that the HIV-infected population is a major reservoir and source of P. jirovecii infection and that identification of such individuals may contribute to future strategies for improving management of HIV-infected patients.

Pneumocystis and Pneumocystosis: first meeting of experts from Latin-American and Portuguese-speaking countries - a mini-review.

The Pneumocystis and Pneumocystosis: first meeting of experts from Latin-American and Portuguese-speaking countries was held in Lisbon, Portugal, on 24-26 October 2013. A total of 20 speakers from Latin America, Africa and Europe participated in the meeting. The epidemiological studies presented in this meeting begin to change the misconception that since the AIDS epidemic, Pneumocystis pneumonia (PcP) has become an infrequent disease, showing that today PcP remains a major opportunistic infection in HIV-infected patients in both developed and developing countries and an emerging problem in immunocompromised patients without HIV infection worldwide. PcP management remains a challenge. Right now, the combination of caspofungin and trimethoprim-sulfamethoxazole (TMP-SMX) is a promising therapeutic approach that needs to be assessed in controlled clinical trials.

Detection of Treponema pallidum by semi-nested PCR in the cerebrospinal fluid of asymptomatic HIV-infected patients with latent syphilis.

BACKGROUND: Neurosyphilis diagnosis is frequently dependent upon the results of serological tests and cerebrospinal fluid abnormalities, but the reliability of findings in patients with HIV-1 infection has been questioned, especially in asymptomatic patients with latent syphilis. In this study, we present the data on the presence of T. pallidum DNA in CSF from asymptomatic HIV-infected patients with the diagnosis of syphilis. METHODS: CSF and serum samples were collected from 12 HIV-infected patients attending a tertiary care clinic located in southern Brazil, during the period 2012 to 2013. RESULTS: In CSF samples from five of 12 patients (40%), we detected T. pallidum DNA. Unexpectedly, in these patients, the CSF cell count, protein and glucose levels were normal. In addition, none of these 5 CSF samples presented a positive VDRL reaction. Serum VDRL titers were similar between patients with positive and negative CSF T. pallidum DNA. Most patients with detectable T. pallidum DNA presented low serum VDRL titers. A higher serum VDRL titer of 1:64 was observed in only one patient. CONCLUSIONS: Our results have shown that asymptomatic HIV-infected patients with evidence of latent syphilis and normal CSF might present detectable T. pallidum DNA in the CSF. The detection of T. pallidum DNA by our seminested PCR provides additional information beyond conventional CSF analysis for the diagnosis of neurosyphilis. The detection of T. pallidum DNA in CSF despite normal CSF findings in HIV-infected patients could also provide a different therapeutic approach including the use of intravenous aqueous crystalline penicillin.

Pneumocystis jirovecii pneumonia in Latin America. A public health problem?

Pneumocystis jirovecii pneumonia (PcP) is a well-recognized major opportunistic infection in HIV-infected patients. During the 1980s, the HIV pandemic turned PcP into a major worldwide medical and public health problem. With the introduction of Pneumocystis chemoprophylaxis and the development of highly active antiretroviral therapy (ART) for the treatment of HIV infection, there has been a decrease in PcP incidence in developed countries. However, the prevalence of AIDS-related PcP in developing countries remains high because a lot of people do not have access to ART or ignore their HIV infection status. This article discusses the information available about PcP among Latin American countries where there is a great regional heterogeneity in the prevalence of HIV infection and in ART coverage, as well as in the observed frequencies of PcP that range from 5.9 to 55% in this area.

High prevalence of Pneumocystis jirovecii colonization in Brazilian cystic fibrosis patients.

A high rate of Pneumocystis jirovecii colonization was observed in Brazilian cystic fibrosis (CF) patients (13 out of 34; 38.2%) who underwent bronchoscopy between March 2006 and August 2009 at the Hospital de Clinicas de Porto Alegre, Brazil. Bronchoalveolar lavage samples were collected from these patients and studied by nested PCR amplification of the mitochondrial gene coding for the large subunit ribosomal RNA (mtLSUrDNA). The observed rate of colonization was higher than that reported in European populations. Genotypic characterization of the mtLSUrDNA locus revealed a predominance of the polymorphisms 85C/248C (genotype 1) and 85T/248C (genotype 3), with all samples possessing the wild-type genotype of dihydropteroate synthase. These findings suggest that cystic fibrosis patients could be an important reservoir and source of P. jirovecii infection. Further studies are required to elucidate the role of this common fungal colonization in the evolution of CF patients.

Pneumocystis jirovecii colonization in patients treated with infliximab.

BACKGROUND: Infliximab, a chimeric antitumour necrosis factor (TNF) monoclonal antibody, has become an established effective therapy for inflammatory rheumatic disease. However, TNF is a critical factor in host defence, and the suppression of its biological activity may be associated with the increased risk of opportunistic infections. The frequent use of infliximab in clinical practice has identified Pneumocystis jirovecii pneumonia (PcP) as a serious complication. Individuals colonized with Pneumocystis may be at high risk of development of PcP when they have undergone immunosuppression. Hence, we addressed the question of the frequency of Pneumocystis colonization among patients treated with infliximab. DESIGN: We examined 125 oropharyngeal washes collected from 78 individuals with rheumatoid arthritis, 30 with ankylosing spondylitis and 17 with psoriatic arthritis, half of them underwent infliximab therapy, using a real-time polymerase chain reaction assay that employs specific primers from a portion of the mitochondrial large-subunit rRNA gene of P. jirovecii. RESULTS: Pneumocystis jirovecii colonization was detected in 32 (25·6%) patients. In a multivariate regression model, only duration of infliximab treatment for more than 3 years and use of corticosteroid were significantly and independently associated with risk of Pneumocystis colonization. However, the effect of corticosteroid on P. jirovecii colonization rate was not linearly dose dependent as showed other logistic regression analysis. CONCLUSIONS: There is a high rate of P. jirovecii colonization among patients with rheumatologic diseases treated with infliximab. The identification of patients colonized by P. jirovecii before starting the treatment with infliximab could be a strategy for PcP prevention.

[Human reservoirs of Pneumocystis]. / El ser humano como reservorio de Pneumocystis.

Pneumocystis jirovecii, the fungal agent that causes Pneumocystis pneumonia (PCP), is known to exclusively infect humans. Molecular studies have enabled detection of this fungus in individuals who have been colonized by P. jirovecii. Such colonization, found in several populations, seems to act as a human reservoir for the fungus. Various studies have reported mutations associated with sulfa resistance in P. jirovecii strains isolated from colonized patients, who can transmit the mutant genotype to PCP-susceptible individuals. The growing interest in P. jirovecii colonization may prompt the design of new prevention and management strategies for PCP.

Absence of dihydropteroate synthase mutations in Pneumocystis jirovecii from Brazilian AIDS patients.

Several studies from developed countries have documented the association between trimethoprim-sulfamethoxazole prophylaxis failure and mutations in the Pneumocystis jirovecii gene coding for dihydropteroate synthase (DHPS). DNA was extracted from Giemsa-stained smears of 70 patients with P. jirovecii pneumonia seen in Porto Alegre, Brazil, from 1997 to 2004. Successful PCR amplification of the DHPS locus was obtained in 57 of 70 cases (81.4%), including five cases (8.7%) that had used sulfa prophylaxis. No DHPS gene mutations were seen. These results suggest that DHPS mutations are currently as rare in Brazil as in other developing countries.

Sensitivity and specificity of nested and real-time PCR for the detection of Pneumocystis jiroveci in clinical specimens.

A polymerase chain reaction (PCR)-based test for Pneumocystis jiroveci (formerly Pneumocystis carinii f. sp. hominis) might be an alternative to histologic diagnoses of P. jiroveci pneumonia (PCP). However, previously developed nested PCR methods tend to have low specificities (high false-positive rates). In this study, nested and quantitative real-time PCR methods for the amplification of the P. jiroveci DHPS (dihydropteroate synthase) gene were evaluated in a variety of stored clinical samples from Spain, South Africa, and Brazil. The sensitivities of both assays were high, ranging from 62.5% to 100% depending on the type of specimen. In a subset of 71 microscopically confirmed PCP cases and 70 negative cases, the sensitivities and specificities were 94% and 81% for nested PCR and 94% and 96% for real-time PCR, respectively. Real-time PCR has a statistically significantly better specificity than nested PCR (P = .015) and is likely to generate fewer false positives.