scholarly journals Pneumocystis jirovecii detection in asymptomatic patients: what does its natural history tell us?

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 739 ◽  
Author(s):  
Alexandre Alanio ◽  
Stéphane Bretagne
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Pneumocystis Pneumonia ◽  
Pneumocystis Jirovecii ◽  
Immunocompromised Patients ◽  
Healthy Individuals ◽  
Real Time Quantitative Pcr ◽  
Asymptomatic Patients ◽  
Fungal Load ◽  
Invasive Infections ◽  
Life Threatening

Pneumocystis jiroveciiis an unusual ascomycetous fungus that can be detected in the lungs of healthy individuals. Transmission from human to human is one of its main characteristics in comparison with other fungi responsible for invasive infections.P. jiroveciiis transmitted through the air between healthy individuals, who are considered to be the natural reservoir, at least transiently. In immunocompromised patients,P. jiroveciimultiplies, leading to subacute infections and acute life-threatening pneumonia, called Pneumocystis pneumonia [PCP]. PCP is caused by genotypically distinct mixtures of organisms in more than 90% of cases, reinforcing the hypothesis that there is constant inhalation ofP. jiroveciifrom different contacts over time, although reactivation of latent organisms from previous exposures may be possible. Detection ofP. jiroveciiDNA without any symptoms or related radiological signs has been called “colonization”. This situation could be considered as the result of recent exposure toP. jiroveciithat could evolve towards PCP, raising the issue of cotrimoxazole prophylaxis for at-risk quantitative polymerase chain reaction (qPCR)-positive immunocompromised patients. The more accurate way to diagnose PCP is the use of real-time quantitative PCR, which prevents amplicon contamination and allows determination of the fungal load that is mandatory to interpret the qPCR results and manage the patient appropriately. The detection ofP. jiroveciiin respiratory samples of immunocompromised patients should be considered for potential risk of developing PCP. Many challenges still need to be addressed, including a better description of transmission, characterization of organisms present at low level, and prevention of environmental exposure during immunodepression.

scholarly journals Development of a Droplet Digital Polymerase Chain Reaction for Sensitive Detection of Pneumocystis jirovecii in Respiratory Tract Specimens

2021 ◽  
Vol 8 ◽  
Author(s):  
Jie Yi ◽  
Nan Wang ◽  
Jie Wu ◽  
Yueming Tang ◽  
Jingjia Zhang ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Digital Pcr ◽  
Absolute Quantification ◽  
Pneumocystis Pneumonia ◽  
Pneumocystis Jirovecii ◽  
Immunocompromised Patients ◽  
Balf Sample ◽  
Bronchoalveolar Fluid ◽  
Life Threatening ◽  
Digital Polymerase Chain Reaction

Background:Pneumocystis jirovecii is a human-specific opportunistic fungus that causes Pneumocystis pneumonia (PCP), a life-threatening opportunistic lung infection that affects immunocompromised patients. P. jirovecii colonization may be linked to the transmission of the infection. The detection of P. jirovecii in immunocompromised patients is thus especially important. The low fungal load and the presence of PCR inhibitors limit the usefulness of quantitative PCR (qPCR) for accurate absolute quantification of P. jirovecii in specimens. Droplet digital PCR (ddPCR), however, presents a methodology that allows higher sensitivity and accuracy. Here, we developed a ddPCR method for detecting P. jirovecii DNA in respiratory specimens, and evaluated its sensitivity against qPCR.Materials and Methods: One bronchoalveolar fluid (BALF) sample each was collected from 82 patients with potential PCP to test the presence of P. jirovecii DNA using both ddPCR and qPCR, and samples with inconsistent results between the two methods were further tested by metagenomic next generation sequencing (mNGS). In addition, 37 sputum samples from 16 patients diagnosed with PCP, as well as continuous respiratory tract specimens from nine patients with PCP and treated with sulfonamides, were also collected for P. jirovecii DNA testing using both ddPCR and qPCR.Results: ddPCR and qPCR gave the same results for 95.12% (78/82) of the BALF samples. The remaining four specimens tested positive using ddPCR but negative using qPCR, and they were found to be positive by mNGS. Detection results of 78.37% (29/37) sputum samples were consistent between ddPCR and qPCR, while the other eight samples tested positive using ddPCR but negative using qPCR. The P. jirovecii load of patients with PCP decreased to undetectable levels after treatment according to qPCR, but P. jirovecii was still detectable using ddPCR.Conclusions: ddPCR was more sensitive than qPCR, especially at detecting low-pathogen-load P. jirovecii. Thus, ddPCR represents a useful, viable, and reliable alternative to qPCR in P. jirovecii testing in patients with immunodeficiency.

scholarly journals Pneumocystis jirovecii Pneumonia Prophylaxis for Cancer Patients during Chemotherapy

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 237
Author(s):  
Kazuto Takeuchi ◽  
Yoshihiro Yakushijin
Keyword(s):  
Cancer Treatment ◽  
Treatment Outcomes ◽  
Cancer Patients ◽  
Potential Problem ◽  
Corticosteroid Treatment ◽  
Pneumocystis Jirovecii ◽  
Pneumocystis Jirovecii Pneumonia ◽  
Immunocompromised Patients ◽  
Healthy Individuals ◽  
Life Threatening

Pneumocystis jirovecii pneumonia (PJP) is one type of life-threatening pneumonia in immunocompromised patients. PJP development should be considered in not only immunocompromised individuals, but also patients undergoing intensive chemotherapies and immunotherapies, organ transplantation, or corticosteroid treatment. Past studies have described the clinical manifestation of PJP in patients during chemotherapy and reported that PJP affects cancer treatment outcomes. Therefore, PJP could be a potential problem for the management of cancer patients during chemotherapy, and PJP prophylaxis would be important during cancer treatment. This review discusses PJ colonization in outpatients during cancer chemotherapy, as well as in healthy individuals, and provides an update on PJP prophylaxis for cancer patients during chemotherapy.

scholarly journals Detection of Pneumocystis jirovecii by Quantitative PCR To Differentiate Colonization and Pneumonia in Immunocompromised HIV-Positive and HIV-Negative Patients

2016 ◽  
Vol 54 (6) ◽  
pp. 1487-1495 ◽  
Author(s):  
T. Fauchier ◽  
L. Hasseine ◽  
M. Gari-Toussaint ◽  
V. Casanova ◽  
P. M. Marty ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Quantitative Pcr ◽  
Pneumocystis Jirovecii ◽  
Hiv Positive ◽  
Immunocompromised Patients ◽  
Infection Status ◽  
Content Type ◽  
Fungal Burden ◽  
Life Threatening ◽  
Hiv Negative

Pneumocystisjiroveciipneumonia (PCP) is an acute and life-threatening lung disease caused by the fungusPneumocystis jirovecii. The presentation of PCP in HIV-positive patients is well-known and consists of a triad of dyspnea, fever, and cough, whereas the presentation of PCP in HIV-negative patients is atypical and consists of a sudden outbreak, O2desaturation, and a rapid lethal outcome without therapy. Despite the availability of direct and indirect identification methods, the diagnosis of PCP remains difficult. The cycle threshold (CT) values obtained by quantitative PCR (qPCR) allow estimation of the fungal burden. The more elevated that the fungal burden is, the higher the probability that the diagnosis is pneumonia. The purposes of the present study were to evaluate theCTvalues to differentiate colonization and pneumonia in a population of immunocompromised patients overall and patients stratified on the basis of their HIV infection status. Testing of bronchoalveolar lavage (BAL) fluid samples from the whole population of qPCR-positive patients showed a meanCTvalue for patients with PCP of 28 (95% confidence interval [CI], 26 to 30) and a meanCTvalue for colonized patients of 35 (95% CI, 34 to 36) (P< 10−3). For the subgroup of HIV-positive patients, we demonstrated that aCTvalue below 27 excluded colonization and aCTvalue above 30 excluded PCP with a specificity of 100% and a sensitivity of 80%, respectively. In the subgroup of HIV-negative patients, we demonstrated that aCTvalue below 31 excluded colonization and aCTvalue above 35 excluded PCP with a specificity of 80% and a sensitivity of 80%, respectively. Thus, qPCR of BAL fluid samples is an important tool for the differentiation of colonization and pneumonia inP. jirovecii-infected immunocompromised patients and patients stratified on the basis of HIV infection status with differentCTvalues.

scholarly journals Immunization with Pneumocystis Cross-Reactive Antigen 1 (Pca1) Protects Mice against Pneumocystis Pneumonia and Generates Antibody to Pneumocystis jirovecii

2016 ◽  
Vol 85 (4) ◽  
Author(s):  
Brenda L. Tesini ◽  
Terry W. Wright ◽  
Jane E. Malone ◽  
Constantine G. Haidaris ◽  
Martha Harber ◽  
...  
Keyword(s):  
Pneumocystis Carinii ◽  
Surface Protein ◽  
Pneumocystis Pneumonia ◽  
Negative Control ◽  
Cross Reactivity ◽  
Pneumocystis Jirovecii ◽  
Content Type ◽  
Life Threatening ◽  
Potential Vaccine ◽  
Preventive Methods

ABSTRACT Pneumocystis pneumonia (PcP) is a life-threatening infection that affects immunocompromised individuals. Nearly half of all PcP cases occur in those prescribed effective chemoprophylaxis, suggesting that additional preventive methods are needed. To this end, we have identified a unique mouse Pneumocystis surface protein, designated Pneumocystis cross-reactive antigen 1 (Pca1), as a potential vaccine candidate. Mice were immunized with a recombinant fusion protein containing Pca1. Subsequently, CD4+ T cells were depleted, and the mice were exposed to Pneumocystis murina. Pca1 immunization completely protected nearly all mice, similar to immunization with whole Pneumocystis organisms. In contrast, all immunized negative-control mice developed PcP. Unexpectedly, Pca1 immunization generated cross-reactive antibody that recognized Pneumocystis jirovecii and Pneumocystis carinii. Potential orthologs of Pca1 have been identified in P. jirovecii. Such cross-reactivity is rare, and our findings suggest that Pca1 is a conserved antigen and potential vaccine target. The evaluation of Pca1-elicited antibodies in the prevention of PcP in humans deserves further investigation.

scholarly journals An overview of Pneumocystis jirovecii pneumonia for the African generalist practitioner

1970 ◽  
Vol 19 (4) ◽  
pp. 3200-3207
Author(s):  
I Govender ◽  
O M Maphasha ◽  
S Rangiah ◽  
C Steyn
Keyword(s):  
Pneumocystis Pneumonia ◽  
Diagnostic Methods ◽  
Pneumocystis Jirovecii ◽  
Causative Organism ◽  
Pneumocystis Jirovecii Pneumonia ◽  
Immunocompromised Patients ◽  
Productive Cough ◽  
First Line ◽  
Duration Of Symptoms ◽  
Uninfected Patient

Introduction: Pneumocystis jirovecii is the causative organism of Pneumocystis pneumonia (PCP) in humans, which is more common among immunocompromised patients. Classically patients present with fever, non-productive cough, and dyspnoea. In the HIV-infected individuals the symptoms may be subtle at first, but gradually progress over several weeks. In the HIV-uninfected patient, however, the duration of symptoms is shorter and more severe, mainly due to the increased inflammatory response of the HIV-uninfected patient.Methods: This article focuses on the diagnostic methods and then the management and prophylaxis principles of PCP by reviewing the best current practices and guidelines in Africa.Conclusion: This overview is presented by clinicians who have experience with PCP and is directed mainly at first-line healthcare providers.Keywords: Pneumocystis jirovecii pneumonia, african generalist practitioner.

Endemic Fungal Infection

Chest Imaging ◽  
2019 ◽  
pp. 203-207
Author(s):  
Sonia L. Betancourt
Keyword(s):  
Lung Cancer ◽  
Fungal Infection ◽  
Superior Vena ◽  
Vena Cava ◽  
Immunocompromised Patients ◽  
Healthy Individuals ◽  
Cavitary Disease ◽  
Life Threatening ◽  
Vena Cava Syndrome ◽  
Endemic Fungi

Endemic fungi (EF) live in soil as saprophytes, infect humans when their spores are inhaled, and often affect healthy individuals that live in or have visited certain areas. EF infection should be suspected in patients from endemic areas who present with pulmonary opacities and/or cavitary disease on imaging. However, disseminated life-threatening disease may affect also immunocompromised patients (e.g. AIDS). Consider EF infection in patients with bronchopneumonia associated with lymphadenopathy that does not respond to antibiotics. Fungal infection may mimic tuberculosis, metastatic disease, lung cancer. Immunosupression is frequently associated with disseminated EF infection. Chronic mediastinal histoplasmosis is a common benign etiology of superior vena cava syndrome.

scholarly journals Evaluation of the corticosteroid dose at Pneumocystis pneumonia onset in non-HIV patients receiving steroids and the period from the discontinuation of trimethoprim-sulfamethoxazole prophylaxis to the onset of Pneumocystis pneumonia

2021 ◽  
Author(s):  
Daiki Inoue ◽  
Hirotaka Tamesada ◽  
Tomoki Maetani ◽  
Sho Yamada ◽  
Yujiro Kikuchi ◽  
...  
Keyword(s):  
Clinical Information ◽  
Pneumocystis Pneumonia ◽  
Equivalent Dose ◽  
Immunocompromised Patients ◽  
Hiv Patients ◽  
Corticosteroid Dose ◽  
Immunodeficiency Virus ◽  
Median Period ◽  
Life Threatening ◽  
Prophylactic Use

Abstract Background Pneumocystis pneumonia (PCP) is a life-threatening opportunistic infection among non-human immunodeficiency virus (non-HIV) immunocompromised patients. The prophylactic use of trimethoprim-sulfamethoxazole (TMP-SMX) reduces PCP incidence. However, it remains unclear when TMP-SMX can be safely discontinued among patients for whom corticosteroid tapering is underway, and occasionally, PCP develops after TMP-SMX discontinuation despite tapering of corticosteroids to considerably lower dose. Methods We retrospectively reviewed non-HIV immunocompromised patients who were diagnosed with PCP in our institution during a 12-year period (January 2007 to December 2018). We analysed the clinical information including corticosteroid doses when PCP developed and the period from TMP-SMX discontinuation to PCP onset for these patients. Results In all, 39 patients were included. The median patient age was 70 years (range: 27–92 years), and 18 patients (46.2%) were female. Thirty-two patients (82.1%) were administered corticosteroids. The median daily corticosteroid dose converted to the prednisolone equivalent dose was 14 mg (range: 2–60 mg). Further, six (15.4%) patients were treated with a dose of 5 mg or less. Twenty-eight patients (71.8%) were never administered TMP-SMX, and TMP-SMX was discontinued before PCP development in the remaining 11 patients. The median period from TMP-SMX discontinuation to PCP development was 95 days (range: 44–175 days), and in nine patients, PCP developed 14 ± 2 weeks after TMP-SMX discontinuation. Conclusions PCP developed in non-HIV patients treated with corticosteroids at doses considerably lower than the daily 20 mg prednisolone equivalent dose. Non-HIV immunocompromised patients are more likely to develop PCP approximately 3 months after TMP-SMX discontinuation.

scholarly journals Detection of Pneumocystis jirovecii in Hospitalized Children Less Than 3 Years of Age

2021 ◽  
Vol 7 (7) ◽  
pp. 546
Author(s):  
Estelle Menu ◽  
Jean-Sélim Driouich ◽  
Léa Luciani ◽  
Aurélie Morand ◽  
Stéphane Ranque ◽  
...  
Keyword(s):  
Severe Combined Immunodeficiency ◽  
Hyaline Membrane Disease ◽  
Relevant Information ◽  
Underlying Disease ◽  
Pneumocystis Pneumonia ◽  
Pneumocystis Jirovecii ◽  
Respiratory Pathogens ◽  
Respiratory Sample ◽  
Few Data ◽  
Underlying Diseases

Few data are available in the literature regarding Pneumocystis jirovecii infection in children under 3 years old. This retrospective cohort study aimed to describe medically relevant information among them. All children under 3 years old treated in the same medical units from April 2014 to August 2020 and in whom a P. jirovecii evaluation was undertaken were enrolled in the study. A positive case was defined as a child presenting at least one positive PCR for P. jirovecii in a respiratory sample. Medically relevant information such as demographical characteristics, clinical presentation, microbiological co-infections, and treatments were collected. The objectives were to describe the characteristics of these children with P. jirovecii colonization/infection to determine the key underlying diseases and risk factors, and to identify viral respiratory pathogens associated. The PCR was positive for P. jirovecii in 32 children. Cardiopulmonary pathologies (21.9%) were the most common underlying disease in them, followed by severe combined immunodeficiency (SCID) (18.8%), hyaline membrane disease (15.6%), asthma (9.4%) and acute leukaemia (6.3%). All SCID children were diagnosed with pneumocystis pneumonia. Co-infection with Pj/Rhinovirus (34.4%) was not significant. Overall mortality was 18.8%. Paediatric pneumocystis is not restricted to patients with HIV or SCID and should be considered in pneumonia in children under 3 years old.

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