Current epidemiology of Pneumocystis pneumonia

Host Factors and Outcomes in Hospitalizations for Pneumocystis Jirovecii Pneumonia in the United States

OBJECTIVE

To assess host factors in pneumocystis jirovecii pneumonia (PCP)-related hospitalizations and compare outcomes between HIV and non-HIV patients.

METHODS

Using the National Inpatient Sample database, we identified 3384 hospitalizations with PCP (International Classification of Diseases, Ninth Revision, Clinical Modification code: 136.3) as the primary discharge diagnosis from 2005 to 2014. We evaluated hospitalizations for the following host factors: HIV, malignancies, organ transplantation, rheumatologic diseases, and vasculitides. We compared the prevalence of individual host factors among PCP hospitalizations over time, and compared intervention rates and outcomes between HIV and non-HIV patients with PCP.

RESULTS

Among all hospitalizations for PCP, malignancy was the most prevalent host factor (46.0%, n=1559), followed by HIV (17.8%, n=604); 60.7% (n=946) of malignancies were hematologic. The prevalence of HIV among hospitalizations for PCP decreased from 25.1% in 2005 to 9.2% in 2014 (P<.001), whereas the prevalence of non-HIV immunocompromising conditions increased. Compared with HIV patients, PCP patients without HIV had higher rates of bronchoscopy (52.3% vs 26.7%, P<.001) and endotracheal intubation (17.0% vs 7.9%, P<.001), prolonged hospitalizations (11.5 vs 8.7 days, P<.001), higher hospitalization costs (86.8 vs 48.2×10³ USD, P<.001) and increased in-hospital mortality (16.0% vs 5.0%, P<.001). After adjusting for age, sex, and smoking status, there was no difference in mortality between non-HIV and HIV patients with PCP (adjusted odds ratio, 1.4; 95% CI, 0.9 to 2.3).

CONCLUSION

The epidemiology of PCP has shifted with an increase in the prevalence of non-HIV patients who have higher intubation rates and prolonged hospitalizations compared with matched HIV patients.

Pneumocystis pneumonia with hypogammaglobulinemia in a pediatric patient who underwent heart transplantation

A 23-month-old Caucasian female who had heart transplantation (HT) at 11 days of age was diagnosed with Pneumocystis pneumonia (PCP) in the setting of secondary hypogammaglobulinemia (HGG). She was diagnosed with HGG at 5 months of age and had been receiving monthly intravenous immunoglobulin infusion. This is the first case report describing the clinical course of PCP in a pediatric patient with HGG. She developed PCP 23 months after HT even when she was off steroids and was receiving timely IVIG. The case posed some clinical questions regarding PCP prophylaxis and HGG management.

Diagnosing Pneumocystis jirovecii pneumonia: A review of current methods and novel approaches

Pneumocystis jirovecii can cause life-threatening pneumonia in immunocompromised patients. Traditional diagnostic testing has relied on staining and direct visualization of the life-forms in bronchoalveolar lavage fluid. This method has proven insensitive, and invasive procedures may be needed to obtain adequate samples. Molecular methods of detection such as polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), and antibody-antigen assays have been developed in an effort to solve these problems. These techniques are very sensitive and have the potential to detect Pneumocystis life-forms in noninvasive samples such as sputum, oral washes, nasopharyngeal aspirates, and serum. This review evaluates 100 studies that compare use of various diagnostic tests for Pneumocystis jirovecii pneumonia (PCP) in patient samples. Novel diagnostic methods have been widely used in the research setting but have faced barriers to clinical implementation including: interpretation of low fungal burdens, standardization of techniques, integration into resource-poor settings, poor understanding of the impact of host factors, geographic variations in the organism, heterogeneity of studies, and limited clinician recognition of PCP. Addressing these barriers will require identification of phenotypes that progress to PCP and diagnostic cut-offs for colonization, generation of life-form specific markers, comparison of commercial PCR assays, investigation of cost-effective point of care options, evaluation of host factors such as HIV status that may impact diagnosis, and identification of markers of genetic diversity that may be useful in diagnostic panels. Performing high-quality studies and educating physicians will be crucial to improve the rates of diagnosis of PCP and ultimately to improve patient outcomes.

Consensus Multilocus Sequence Typing Scheme for Pneumocystis jirovecii

Pneumocystis jirovecii is an opportunistic human pathogenic fungus causing severe pneumonia mainly in immunocompromised hosts. Multilocus sequence typing (MLST) remains the gold standard for genotyping of this unculturable fungus. However, the lack of a consensus scheme impedes a global comparison, large scale population studies and the development of a global MLST database. To overcome this problem this study compared all genetic regions (19 loci) currently used in 31 different published Pneumocystis MLST schemes. The most diverse/commonly used eight loci, β-TUB, CYB, DHPS, ITS1, ITS1/2, mt26S and SOD, were further assess for their ability to be successfully amplified and sequenced, and for their discriminatory power. The most successful loci were tested to identify genetically related and unrelated cases. A new consensus MLST scheme consisting of four genetically independent loci: β-TUB, CYB, mt26S and SOD, is herein proposed for standardised P. jirovecii typing, successfully amplifying low and high fungal burden specimens, showing adequate discriminatory power, and correctly identifying suspected related and unrelated isolates. The new consensus MLST scheme, if accepted, will for the first time provide a powerful tool to investigate outbreak settings and undertake global epidemiological studies shedding light on the spread of this important human fungal pathogen.

Evaluation of a commercial Loop-mediated Isothermal Amplification (LAMP) assay for rapid detection of Pneumocystis jirovecii

BACKGROUND

Various tools are obtainable for the detection of Pneumocystis jirovecii, among them qPCR promising highest sensitivity. A novel molecular method is commercially available, the loop-mediated isothermal amplification (LAMP) assay.

OBJECTIVES

We compared the performance of the LAMP eazyplex^® Pneumocystis jirovecii with the RealStar Pneumocystis jirovecii PCR 1.0 qPCR.

MATERIAL/METHODS

Overall, 162 lower respiratory tract specimens from 146 critically ill patients were investigated. LAMP assay and qPCR were carried out according to the manufacturer's recommendations. Positive results of the LAMP were described as time to positivity (TTP). The limit of detection (LOD) of the LAMP was analysed using 10-fold serial dilutions of a high positive P jirovecii respiratory sample. For each serial dilution, TTP of the LAMP was plotted against cycle threshold (Ct) values of the qPCR.

RESULTS

The LOD of the LAMP was determined to be approximately 4 × 10³ copies/mL. While the LAMP revealed 28 (17%) positive signals from 20 patients, by using qPCR 41 (25%) positive samples from 28 patients were identified. Overall agreement with qPCR was 92%. Five false-negative, one false-positive and nine invalid results were detected by the LAMP. Positive and negative predictive values were 96% each, and sensitivity and specificity were 84% and 99%, respectively. There was a low correlation between the TTP and the fungal load.

CONCLUSION

The LAMP is a time-saving and easy-to-perform method. It can be used as an alternative diagnostic method. However, for quantification purposes the qPCR is still the gold standard.

Influenza-like illness is associated with high pneumococcal carriage density in Malawian children

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Influenza-like illness (ILI) in children is associated with high pneumococcal carriage density.

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Children with ILI harboured more viral organisms than asymptomatic healthy children.

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Children with ILI patients had higher IL-8 levels in nasal aspirates than asymptomatic healthy children.

Background

High pneumococcal carriage density is a risk factor for invasive pneumococcal disease (IPD) and transmission, but factors that increase pneumococcal carriage density are still unclear.

Methods

We undertook a cross-sectional study to evaluate the microbial composition, cytokine levels and pneumococcal carriage densities in samples from children presenting with an influenza-like illness (ILI) and asymptomatic healthy controls (HC).

Results

The proportion of children harbouring viral organisms (Relative risk (RR) 1.4, p = 0.0222) or ≥ 4 microbes at a time (RR 1.9, p < 0.0001), was higher in ILI patients than HC. ILI patients had higher IL-8 levels in nasal aspirates than HC (median [IQR], 265.7 [0 – 452.3] vs. 0 [0 – 127.3] pg/ml; p = 0.0154). Having an ILI was associated with higher pneumococcal carriage densities compared to HC (RR 4.2, p < 0.0001).

Conclusion

These findings suggest that children with an ILI have an increased propensity for high pneumococcal carriage density. This could in part contribute to increased susceptibility to IPD and transmission in the community.

Safety and efficacy of reduced-dose pentamidine as second-line treatment for HIV-related pneumocystis pneumonia

OBJECTIVES

Parenteral pentamidine isethionate (PM) 4 mg/kg/day is recommended as an alternative therapeutic regimen after failure of first-line treatment for pneumocystis pneumonia (PCP). However, the dose is often reduced to 3 mg/kg/day in clinical settings because of high rates of adverse events and drug toxicity. Although considered equally efficacious, this lower dose has not been well evaluated.

METHODS

This was a single-center, retrospective cohort study that analyzed 75 patients with HIV-PCP who were treated with trimethoprim-sulfamethoxazole, but discontinued treatment because of treatment failure or adverse events; they were then administered 3 mg/kg/day of intravenous PM as a salvage therapy. The primary outcomes were the regimen completion rate with the reduced PM dose.

RESULTS AND CONCLUSIONS

In total, 40 (53.3%) of the eligible patients completed PCP therapy with reduced-dose PM salvage treatment. The overall survival rate of PCP was 73 (97.3%). The median duration of second-line PM treatment was 8.0 days (interquartile range: 6.0-10.0). Although, the adverse events with reduced-dose PM were observed in 41 (54.7%), including 35 treatment-limiting adverse events, grade 3 or 4 adverse events occurred in only three patients (thrombocytopenia, one patient; neutropenia, two patients). Life-threating adverse events, such as hypoglycemia and arrhythmia, were not observed with reduced-dose PM. Salvage therapy with reduced-dose PM for patients with HIV-PCP is relatively safe and effective; moreover, life-threating adverse events did not occur. This therapy could be recommended for patients with HIV-PCP who fail to respond to first-line treatment with trimethoprim-sulfamethoxazole.

Possible Diagnostic Delays and Missed Prevention Opportunities in Pneumocystis Pneumonia Patients Without HIV: Analysis of Commercial Insurance Claims Data-United States, 2011-2015

Background

Pneumocystis pneumonia (PCP) is a life-threatening but treatable and preventable fungal infection in immunocompromised persons. Previous studies suggest that persons without HIV who develop PCP (PCPHIV-) experience more acute, severe illness than persons with HIV who develop PCP (PCPHIV+). We analyzed health insurance claims data to compare demographics, underlying conditions, symptoms, and prescriptions for PCPHIV+ and PCPHIV-.

Methods

We used the IBM MarketScan Research Databases to identify patients diagnosed with PCP during 2011-2015. We analyzed claims 1 year before to 3 months after diagnosis to compare PCPHIV+ and PCPHIV-.

Results

Among 3938 patients, 70.4% were PCPHIV-. Compared with PCPHIV+, PCPHIV- were more likely to be older (median, 60 vs 45 years; P < .0001), female (51.5% vs 20.2%; P < .0001), hypoxemic (13.5% vs 7.1%; P < .0001), and to die within 90 days (6.6% vs 4.2%; P < .0001). The most common underlying conditions among PCPHIV- included chronic pulmonary diseases (54.6%), solid tumors (35.1%), hematologic malignancies (20.1%), and rheumatologic conditions (14.0%). The median time between the first visit for PCP-related symptoms and PCP diagnosis was longer for PCPHIV- than PCPHIV+ (25 vs 16 days; P < .0001). In the 3 months before PCP diagnosis, PCPHIV- were less likely to have an outpatient prescription for PCP prophylaxis than PCPHIV+ (6.9% vs 10.6%; P = .0001).

Conclusions

PCPHIV- may experience a prolonged illness course and diagnostic delays compared with PCPHIV+. Clinicians should maintain a high index of suspicion for PCP in immunocompromised patients with compatible symptoms, regardless of HIV status.

Combination Immunotherapy with Passive Antibody and Sulfasalazine Accelerates Fungal Clearance and Promotes the Resolution of Pneumocystis-Associated Immunopathogenesis

The pulmonary immune response protects healthy individuals against Pneumocystis pneumonia (PcP). However, the immune response also drives immunopathogenesis in patients who develop severe PcP, and it is generally accepted that optimal treatment requires combination strategies that promote fungal killing and also provide effective immunomodulation. The anti-inflammatory drug sulfasalazine programs macrophages for enhanced Pneumocystis phagocytosis and also suppresses PcP-related immunopathogenesis. Anti-Pneumocystis antibody opsonizes Pneumocystis organisms for greater phagocytosis and may also mask antigens that drive immunopathogenesis. Thus, we hypothesized that combining antibody and sulfasalazine would have the dual benefit of enhancing fungal clearance while dampening immunopathogenesis and allow the rescue of severe PcP. To model a clinically relevant treatment scenario in mice, therapeutic interventions were withheld until clear symptoms of pneumonia were evident. When administered individually, both passive antibody and sulfasalazine improved pulmonary function and enhanced Pneumocystis clearance to similar degrees. However, combination treatment with antibody and sulfasalazine produced a more rapid improvement, with recovery of body weight, a dramatic improvement in pulmonary function, reduced lung inflammation, and the rapid clearance of the Pneumocystis organisms. Accelerated fungal clearance in the combination treatment group was associated with a significant increase in macrophage phagocytosis of Pneumocystis Both passive antibody and sulfasalazine resulted in the suppression of Th1 cytokines and a marked increase in lung macrophages displaying an alternatively activated phenotype, which were enhanced by combination treatment. Our data support the concept that passive antibody and sulfasalazine could be an effective and specific adjunctive therapy for PcP, with the potential to accelerate fungal clearance while attenuating PcP-associated immunopathogenesis.

An overview of Pneumocystis jirovecii pneumonia for the African generalist practitioner

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.

Myeloid C-type lectin receptors that recognize fungal mannans interact with Pneumocystis organisms and major surface glycoprotein

Myeloid C-type lectin receptors (CLRs) are innate immune recognition molecules that bind to microorganisms via their carbohydrate recognition domains. In this study, we utilized a library of CLRs that recognize fungal mannans. We used this library to screen against Pneumocystis carinii (Pc) homogenates or purified Pc major surface glycoprotein (Msg) present on Pneumocystis. The results demonstrated that all of the mammalian CLR hFc-fusions tested displayed significant interaction/binding with Pc organisms, and furthermore to isolated Msg. Highest Pc organism and Msg binding activities were with CLR members Mincle, Dectin-2, DC-SIGN and MCL. An immunofluorescence assay with the respective CLR hFc-fusions against whole Pc life forms corroborated these findings. Although some of these CLRs have been implicated previously as important for Pneumocystis pathogenesis (Dectin-1/Dectin-2/Mincle), this is the first analysis of head-to-head comparison of known fungal mannan binding CLR-hFc fusions with Pc. Lastly, heat treatment resulted in reducted CLR binding.

A multi-centered study of Pneumocystis jirovecii colonization in patients with respiratory disorders: Is there a colonization trend in the elderly?

Background and Purpose:

Pneumocystis jirovecii colonization plays a key role in the progression of pulmonary infection. However, there are limited data regarding the colonization of these fungi in the patients residing in different regions of Iran. Regarding this, the present study was conducted to evaluate the prevalence of P. jirovecii colonization in non-HIV-infected patients with respiratory failure introduced by physicians using nested polymerase chain reaction (PCR).

Materials and Methods:

This study was conducted on 136 samples obtained from 136 patients with respiratory disorders referring to different hospitals in the capital and north of Iran during 2013-2015. The samples were collected using bronchoalveolar lavage (BAL; n=121) and sputum induction (n=15). Nested PCR method targeting mtLSU rRNA gene was used for the detection of P. jirovecii DNA in the specimens.

Results:

The nested PCR analysis resulted in the detection of P. jirovecii DNA in 32 (23.5%) patients. The mean age of the participants was 49.04±11.94 years (age range: 14-90 years). The results revealed no correlation between Pneumocystis colonization and gender. The studied patients were divided into two groups of immunocompromised and immunocompetent patients. In the regard, 25.4% of the patients with detectable P. jirovecii DNA were immunocompromised and had cancer, organ transplantation, asthma, sarcoidosis, dermatomyositis, chronic obstructive pulmonary disease, bronchiectasis, and pulmonary vasculitis. On the other hand, Pneumocystis DNA was detected in 21.8% of the immunocompetent patients. Frequencies of P. jirovecii DNA detection in the patients with tuberculosis, hydatid cyst, and unknown underlying diseases were obtained as 20.8%, 25%, and 22%, respectively. The prevalence of Pneumocystis colonization varied based on age. In this regard, P. jirovecii colonization was more prevalent in patients aged above 70 years.

Conclusion:

As the findings indicated, non-HIV-infected patients, especially the elderly, had a high prevalence of P. jirovecii colonization. Therefore, these patients are probably a potential source of infection for others. Regarding this, it is of paramount importance to adopt monitoring and prophylactic measures to reduce this infection.

Changing Trends in the Epidemiology and Risk Factors of Pneumocystis Pneumonia in Spain

Objective: The information about the epidemiology of Pneumocystis pneumonia (PcP) in Europe is scarce, and in Spain there are only data nationwide on patients with HIV infection. This study has been carried out with the aim of knowing in our country the current epidemiological spectrum and the risk factors of PcP.

Methods: Observational, descriptive transversal study that included all patients admitted in Spain with diagnosis upon discharge of PcP registered in the National Health System's Hospital Discharge Records Database of Spain, between 2008 and 2012.

Results: Four thousand five hundred and fifty four cases of PcP were reported, 1,204 (26.4%) in HIV-negative patients. During the study period, mean annual incidence (cases per million) was 19.4, remaining globally stable, increasing from 4.4 to 6.3 in HIV-negative patients and decreasing from 15.5 to 13.4 among HIV-infected patients. Risk factors were identified in 85.5% of HIV-negative cases, the most frequent being hematological neoplams (29%), chronic lung diseases (15.9%), and non-hematological cancers (14.9%). Mean mortality and hospitalization cost were high (25.5% and 12,000 euros, respectively).

Conclusions: The results of this first nationwide study in Spain allow a change in the misconception that, after the AIDS epidemic, PcP is an infrequent disease, showing that today it is an emerging problem in patients without HIV infection. These findings underlines the need for increased efforts toward a better characterization of risk groups to improve prophylactic strategies and reduce the burden of disease.

Pneumocystis pneumonia in patients with rheumatic diseases receiving prolonged, non-high-dose steroids-clinical implication of primary prophylaxis using trimethoprim-sulfamethoxazole

OBJECTIVES

To investigate the incidence of pneumocystis pneumonia (PCP) and its risk factors in patients with rheumatic disease receiving non-high-dose steroid treatment, along with the risks and benefits of PCP prophylaxis.

METHODS

This study included 28,292 treatment episodes with prolonged (≥ 4 weeks), non-high-dose steroids (low dose [< 15 mg/day, n = 27,227] and medium dose [≥ 15 to < 30 mg/day, n = 1065], based on prednisone) over a 14-year period. Risk factors for PCP and prophylactic effect of trimethoprim-sulfamethoxazole (TMP-SMX) were investigated if the 1-year incidence rate (IR) of PCP in each dose group was > 0.1/100 person-years. Cox regression with LASSO was used for analysis.

RESULTS

One-year PCP IR in the low-dose group was 0.01 (95% CI 0.001-0.03)/100 person-years, and only the medium-dose group showed eligible PCP IR for further analysis. In the medium-dose group, prophylactic TMP-SMX was administered in 45 treatment episodes while other episodes involved no prophylaxis (prophylaxis group vs. control group). In 1018.0 person-years, 5 PCP cases occurred exclusively in the control group, yielding an IR of 0.5 (0.2-1.2)/100 person-years. Concomitant steroid-pulse treatment and baseline lymphopenia were the most significant risk factors for PCP. Treatment episodes with at least one of these factors (n = 173, high-risk subgroup) showed higher 1-year PCP IR (3.4 (1.1-8.0)/100 person-years), while no PCP occurred in other treatment episodes. TMP-SMX numerically reduced the risk (adjusted HR = 0.2 (0.001-2.3)) in the high-risk subgroup. The IR of adverse drug reactions (ADRs) related to TMP-SMX was 41.5 (22.3-71.6)/100 person-years, including one serious ADR. The number needed to treat with TMP-SMX to prevent one PCP in the high-risk subgroup (31 (17-226)) was lower than the number needed to harm by serious ADR (45 (15-∞)).

CONCLUSION

Incidence of PCP in patients with rheumatic diseases receiving prolonged, medium-dose steroids depends on the presence of risk factors. Prophylactic TMP-SMX may have greater benefit than potential risk in the high-risk subgroup.

Transcriptomic and Proteomic Approaches to Finding Novel Diagnostic and Immunogenic Candidates in Pneumocystis

Pneumocystis pneumonia is the most common serious opportunistic infection in patients with HIV/AIDS. Furthermore, Pneumocystis pneumonia is a feared complication of the immunosuppressive drug regimens used to treat autoimmunity, malignancy, and posttransplantation rejection. With an increasing at-risk population, there is a strong need for novel approaches to discover diagnostic and vaccine targets. There are multiple challenges to finding these targets, however. First, Pneumocystis has a largely unannotated genome. To address this, we evaluated each protein encoded within the Pneumocystis genome by comparisons to proteins encoded within the genomes of other fungi using NCBI BLAST. Second, Pneumocystis relies on a multiphasic life cycle, as both the transmissible form (the ascus) and the replicative form (the trophozoite [troph]) reside within the alveolar space of the host. To that end, we purified asci and trophs from Pneumocystis murina and utilized transcriptomics to identify differentially regulated genes. Two such genes, Arp9 and Sp, are differentially regulated in the ascus and the troph, respectively, and can be utilized to characterize the state of the Pneumocystis life cycle in vivo Gsc1, encoding a β-1,3-glucan synthase with a large extracellular domain previously identified using surface proteomics, was more highly expressed on the ascus form of Pneumocystis GSC-1 ectodomain immunization generated a strong antibody response that demonstrated the ability to recognize the surface of the Pneumocystis asci. GSC-1 ectodomain immunization was also capable of reducing ascus burden following primary challenge with Pneumocystis murina Finally, mice immunized with the GSC-1 ectodomain had limited fungal burden following natural transmission of Pneumocystis using a cohousing model.IMPORTANCE The current report enhances our understanding of Pneumocystis biology in a number of ways. First, the current study provided a preliminary annotation of the Pneumocystis murina genome, addressing a long-standing issue in the field. Second, this study validated two novel transcripts enriched in the two predominant life forms of Pneumocystis These findings allow better characterization of the Pneumocystis life cycle in vivo and could be valuable diagnostic tools. Furthermore, this study outlined a novel pipeline of -omics techniques capable of revealing novel antigens (e.g., GSC-1) for the development of vaccines against Pneumocystis.

IL-4 polymorphism influences susceptibility to Pneumocystis jirovecii pneumonia in HIV-positive patients

OBJECTIVES

Pneumocystis jirovecii pneumonia (PJP) is an important cause of morbidity and mortality in HIV-positive patients. Polymorphisms in immune genes are increasingly reported to influence susceptibility to fungal infections. We analysed the role of 21 single nucleotide polymorphisms from 19 candidate genes on PJP development in patients from the Swiss HIV Cohort Study.

DESIGN AND METHODS

The analysis included patients with a nadir CD4 T-cell count less than 200 cells/μl, divided into a discovery (N = 1645) and a replication (N = 1861) cohort. The associations were analysed by using cumulative incidence curves as well as competing risk regression over 18 years, starting from the estimated date of HIV infection, considering death a competing risk, with censoring at lost follow-up, and assuming the dominant mode of inheritance.

RESULTS

The minor allele of rs2243250 in IL-4 was associated with the risk of PJP in the discovery cohort (cumulative incidence 0.18 versus 0.12, P = 0.002). This association was replicated in the validation cohort (0.16 versus 0.12, P = 0.02). It was still significant in multivariate models, adjusted for HIV transmission mode, viral load, CD4 T cells slope, age, antiretroviral therapy, tobacco smoking, hepatitis C virus coinfection, year of cohort entry and PJP prophylaxis (global subhazard ratio 1.42, 95% confidence interval 1.17-1.73, P = 0.0004).

CONCLUSION

Our data suggest rs2243250, a single nucleotide polymorphism known to influence IL-4 production, is associated with susceptibility to PJP in HIV-positive patients.

Dual DNA Barcoding for the Molecular Identification of the Agents of Invasive Fungal Infections

Invasive fungal infections, such as aspergillosis, candidiasis, and cryptococcosis, have significantly increased among immunocompromised people. To tackle these infections the first and most decisive step is the accurate identification of the causal pathogen. Routine identification of invasive fungal infections has progressed away from culture-dependent methods toward molecular techniques, including DNA barcoding, a highly efficient and widely used diagnostic technique. Fungal DNA barcoding previously relied on a single barcoding region, the internal transcribed spacer (ITS) region. However, this allowed only for 75% of all fungi to be correctly identified. As such, the translational elongation factor 1α (TEF1α) was recently introduced as the secondary barcode region to close the gap. Both loci together form the dual fungal DNA barcoding scheme. As a result, the ISHAM Barcoding Database has been expanded to include sequences for both barcoding regions to enable practical implementation of the dual barcoding scheme into clinical practice. The present study investigates the impact of the secondary barcode on the identification of clinically important fungal taxa, that have been demonstrated to cause severe invasive disease. Analysis of the barcoding regions was performed using barcoding gap analysis based on the genetic distances generated with the Kimura 2-parameter model. The secondary barcode demonstrated an improvement in identification for all taxa that were unidentifiable with the primary barcode, and when combined with the primary barcode ensured accurate identification for all taxa analyzed, making DNA barcoding an important, efficient and reliable addition to the diagnostic toolset of invasive fungal infections.

Airborne acquisition of Pneumocystis in bronchoscopy units: a hidden danger to healthcare workers

The possible presence of Pneumocystis in a bronchoscopy unit of a tertiary-hospital was examined by detecting Pneumocystis-specific DNA by polymerase chain reaction in prospectively obtained samples of oropharyngeal wash from seven healthcare workers (HCWs) and air from three areas of the unit at different time points (baseline, days +15,+30,+60,+90 after initiation of the study). Positive samples were genotyped at two genetic loci: the mitochondrial large subunit ribosomal RNA (mtLSUrRNA) fragment by direct sequencing and the gene for dihydropteroate synthase (DHPS) by restriction fragment-length polymorphism. Pneumocystis DNA was identified in 13/24 samples from HCWs, in 4/14 air samples and also in two patients with Pneumocystis pneumonia (PcP) and another with a Pneumocystis-associated disease subjected to bronchoscopy on days +15 and +60 after initiation of the study. The HCWs harbored a high rate of mtLSU-rRNA genotypes 1 and 3 and samples from air and patients with only genotype 3. DHPS mutations related to sulpha resistance were detected in three samples from HCWs and in one from air; 65% of the positive samples showed genotypic concordance. The study demonstrates that HCWs of bronchoscopy units represent a new dynamic reservoir and a possible source of infection for human Pneumocystis species, including DHPS genotypes related to sulpha resistance that could be transmitted within hospitals to immunosuppressed hosts in whom a PcP can develop. The results provide the first evidence of the risk of Pneumocystis transmission in the bronchoscopy units and arguments to improve prevention and control of this infection in nosocomial setting.

Pneumocystis jiroveci pneumonia in Taiwan from 2014 to 2017: Clinical manifestations and outcomes between pediatric and adult patients

BACKGROUND

Pneumocystis jiroveci pneumonia (PJP) is a severe and lethal opportunistic infection in the immunocompromised patients. As the increasing usage of immunosuppressants, the incidence of non-HIV related PJP has increased in recent years. Still, there is little research regarding children with PJP. The aim of this study is to understand PJP more among pediatric population.

METHODS

We reviewed the medical records of the patients with PJP in National Taiwan University Hospital from 2014 to 2017. Diagnosis was made if the patient met all of the criteria: presence of relevant pulmonary symptoms and signs, pulmonary infiltrates on images, detection of Pneumocystis jiroveci from respiratory specimens via polymerase chain reaction (PCR), and received antibiotics for PJP.

RESULTS

Twenty children and 132 adults were enrolled in this study. The most common underlying diseases among children included malignancy (40%), post-transplantation (30%), and primary immunodeficiency (20%). The major underlying diseases in adults included malignancy (36%), HIV with acquired immunodeficiency syndrome (AIDS) (31%), and autoimmune diseases (24%). There is no significant difference in the clinical manifestations, mortality, and complication between children and adults, but children tended to have less chance of using alternative antibiotics, methylprednisolone and inhaled nitric oxide (NO). The chance of concomitant cytomegalovirus disease was also significantly lower in pediatric patients.

CONCLUSION

No significant difference was found in the clinical manifestations, mortality, and complication between children and adults, but children tended to have lesser chance of using alternative antibiotics, methylprednisolone and inhaled NO. The chance of associated cytomegalovirus (CMV) disease was also significantly lower in children.

Epidemiologic Trends and Clinical Features of Pneumocystis jirovecii Pneumonia in Non-HIV Patients in a Tertiary-Care Hospital in Korea over a 15-Year-Period

Subsequent to the increasing use of immunosuppressant therapy, Pneumocystis jirovecii pneumonia (PcP) has emerged as a life-threatening condition in human immunodeficiency virus (HIV)-negative patients. We investigated changes in epidemiological and clinical characteristics among PcP cases with and without HIV infections. Data of 424 patients diagnosed with PcP in a 2,700-bed Korean tertiary care hospital between February 2003 and April 2017 were retrospectively analyzed. The study included patients with compatible clinical findings in whom PcP was confirmed via direct immunofluorescence assay. The annual average number of cases increased from 12.2 (initial 5-year period) to 42.2 (recent 5-year period). In HIV-negative patients, hematologic malignancy (34.8%) and solid organ transplantation (32.9%) were the most frequent major underlying conditions, and immunosuppressive therapies including corticosteroids (342/362, 94.5%) and chemotherapy (122/362, 33.7%) were significantly associated with PcP infection (p ＜ 0.001 for both). The incidence of PcP has continued to increase among non-HIV-infected immunocompromised patients in recent years.

The ART of Antiretroviral Therapy in Critically Ill Patients With HIV

The management of patients with human immunodeficiency virus (HIV) can be a complicated specialty within itself, made even more complex when there are so many unanswered questions regarding the care of critically ill patients with HIV. The lack of consensus on the use of antiretroviral medications in the critically ill patient population has contributed to an ongoing clinical debate among intensivists. This review focuses on the pharmacological complications of antiretroviral therapy (ART) in the intensive care setting, specifically the initiation of ART in patients newly diagnosed with HIV, immune reconstitution inflammatory syndrome (IRIS), continuation of ART in those who were on a complete regimen prior to intensive care unit admission, barriers of drug delivery alternatives, and drug-drug interactions.

Intrinsic Programming of Alveolar Macrophages for Protective Antifungal Innate Immunity Against Pneumocystis Infection

Invasive fungal infections, including Pneumocystis Pneumonia (PcP), remain frequent life-threatening conditions of patients with adaptive immune defects. While innate immunity helps control pathogen growth early during infection, it is typically not sufficient for complete protection against Pneumocystis and other human fungal pathogens. Alveolar macrophages (AM) possess pattern recognition molecules capable of recognizing antigenic and structural determinants of Pneumocystis. However, this pathogen effectively evades innate immunity to infect both immunocompetent and immunosuppressed hosts, albeit with differing outcomes. During our studies of mouse models of PcP, the FVB/N strain was identified as unique because of its ability to mount a protective innate immune response against Pneumocystis infection. In contrast to other immunocompetent strains, which become transiently infected prior to the onset of adaptive immunity, FVB/N mice rapidly eradicated Pneumocystis before an adaptive immune response was triggered. Furthermore, FVB/N mice remained highly resistant to infection even in the absence of functional T cells. The effector mechanism of innate protection required the action of functional alveolar macrophages, and the adoptive transfer of resistant FVB/N AMs, but not susceptible CB.17 AMs, conferred protection to immunodeficient mice. Macrophage IFNγ receptor signaling was not required for innate resistance, and FVB/N macrophages were found to display markers of alternative activation. IFNγ reprogrammed resistant FVB/N macrophages to a permissive M1 biased phenotype through a mechanism that required direct activation of the macrophage IFNγR. These results demonstrate that appropriately programmed macrophages provide protective innate immunity against this opportunistic fungal pathogen, and suggest that modulating macrophage function may represent a feasible therapeutic strategy to enhance antifungal host defense. The identification of resistant and susceptible macrophages provides a novel platform to study not only the mechanisms of macrophage-mediated antifungal defense, but also the mechanisms by which Pneumocystis evades innate immunity.

Healthcare related transmission of Pneumocystis pneumonia: From key insights toward comprehensive prevention

In at risk populations, Pneumocystis pneumonia (PCP) may occur as a solitary event as well as in a cluster- or outbreak setting due to interpatient transmission of Pneumocystis jirovecii. Despite the data and insights obtained from studies of outbreaks of PCP, the development and implementation of comprehensive recommendations for the prevention of healthcare related transmission of P. jirovecii have been delayed. Both optimization of chemoprophylaxis strategies as well as combination with prudent use of isolation precautions are warranted to achieve this goal. The rationale of the available measures for the prevention of PCP should be viewed in the context of what is currently known about the complex biology and epidemiology of P. jirovecii. From there, phased but practical prevention strategies can be deducted to balance the efforts, costs and negative consequences of chemoprophylaxis and isolation precautions with the beneficial effect of preventing healthcare related transmission of P. jirovecii and development of PCP.

Murine models of Pneumocystis infection recapitulate human primary immune disorders

Despite the discovery of key pattern recognition receptors and CD4+ T cell subsets in laboratory mice, there is ongoing discussion of the value of murine models to reflect human disease. Pneumocystis is an AIDS-defining illness, in which risk of infection is inversely correlated with peripheral CD4+ T cell counts. Due to medical advances in the control of HIV, the current epidemiology of Pneumocystis infection is predominantly due to primary human immunodeficiencies and immunosuppressive therapies. To this end, we found that every human genetic immunodeficiency associated with Pneumocystis infection that has been tested in mice recapitulated susceptibility. For example, humans with a loss-of-function IL21R mutation are severely immunocompromised. We found that IL-21R, in addition to CD4+ T cell intrinsic STAT3 signaling, were required for generating protective antifungal class-switched antibody responses, as well as effector T cell-mediated protection. Furthermore, CD4+ T cell intrinsic IL-21R/STAT3 signaling was required for CD4+ T cell effector responses, including IL-22 production. Recombinant IL-22 administration to Il21r-/- mice induced the expression of a fungicidal peptide, cathelicidin antimicrobial peptide, which showed in vitro fungicidal activity. In conclusion, SPF laboratory mice faithfully replicate many aspects of human primary immunodeficiency and provide useful tools to understand the generation and nature of effector CD4+ T cell immunity.

Vitamin Biosynthesis as an Antifungal Target

The large increase in the population of immunosuppressed patients, coupled with the limited efficacy of existing antifungals and rising resistance toward them, have dramatically highlighted the need to develop novel drugs for the treatment of invasive fungal infections. An attractive possibility is the identification of possible drug targets within essential fungal metabolic pathways not shared with humans. Here, we review the vitamin biosynthetic pathways (vitamins A⁻E, K) as candidates for the development of antifungals. We present a set of ranking criteria that identify the vitamin B2 (riboflavin), B5 (pantothenic acid), and B9 (folate) biosynthesis pathways as being particularly rich in new antifungal targets. We propose that recent scientific advances in the fields of drug design and fungal genomics have developed sufficiently to merit a renewed look at these pathways as promising sources for the development of novel classes of antifungals.

Prophylactic effect of trimethoprim-sulfamethoxazole for pneumocystis pneumonia in patients with rheumatic diseases exposed to prolonged high-dose glucocorticoids

OBJECTIVES

To investigate the efficacy and safety of trimethoprim/sulfamethoxazole (TMP-SMX) as primary prophylaxis for pneumocystis pneumonia (PCP) in patients with rheumatic diseases receiving high-dose steroids.

METHODS

The study included 1522 treatment episodes with prolonged (≥4 weeks) high-dose (≥30 mg/day prednisone) steroids in 1092 patients over a 12-year period. Of these, 262 treatment episodes involved TMP-SMX (prophylaxis group) while other episodes involved no prophylaxis (control group). Differences in 1-year PCP incidence and its mortality between the two groups were estimated using Cox regression. To minimise baseline imbalance, propensity score matching was performed and efficacy outcome was mainly assessed in the postmatched population (n=235 in both groups).

RESULTS

During a total of 1474.4 person-years, 30 PCP cases occurred with a mortality rate of 36.7%. One non-fatal case occurred in the prophylaxis group. TMP-SMX significantly reduced the 1-year PCP incidence (adjusted HR=0.07(95% CI 0.01 to 0.53)) and related mortality (adjusted HR=0.08 (95% CI 0.0006 to 0.71)) in the postmatched population. The result of the same analysis performed in the whole population was consistent with that of the primary analysis. Incidence rate of adverse drug reactions (ADR) related to TMP-SMX was 21.2 (14.8-29.3)/100 person-years. Only two serious ADRs (including one Stevens-Johnson syndrome case) occurred. The number needed to treat for preventing one PCP (52 (33-124)) was lower than the number needed to harm for serious ADR (131 (55-∞)).

CONCLUSION

TMP-SMX prophylaxis significantly reduces the PCP incidence with a favourable safety profile in patients with rheumatic disease receiving prolonged, high-dose steroids.

Burden of Serious Fungal Infections in Argentina

The number of fungal infections at any given time in Argentina is not known. Here we estimate the burden of serious fungal infections in Argentina for the first time. Specific population statistics were searched from multiple sources, local literature was identified, and estimates made. Some additional data were sourced from the Ministry of Health, the Global Initiative for Asthma (GINA) program, and national haematology and transplant societies. Argentina has a population of 43.8 million, with 25% of this total being children under 15 years. The predicted candidemia annual incidence is 2193 cases, with 50% occurring in the ICU. At a 6% prevalence rate, an estimated 593,695 women suffer from recurrent vulvovaginal candidiasis. Invasive aspergillosis is relatively common because of high smoking and chronic obstructive pulmonary disease (COPD) rates, with 268 cases in immunocompromised patients and another 1938 in the 168,000 COPD patients admitted to hospital. Asthma is also common, affecting 14% of adults, and so allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS) are major problems. An estimated 432 cases of cryptococcal meningitis (CM)—90% of them in AIDS patients—and 1177 cases of Pneumocystis pneumonia (PCP) occur each year. The estimated annual case number of disseminated histoplasmosis is 404 in AIDS patients, almost as frequent as CM. Paracoccidioidomycosis annual incidence is estimated at 219, and coccidioidomycosis at 16 cases. At least 881,023 people (>2.01%) in Argentina are affected by a serious fungal disease annually, with considerable morbidity and mortality.

Clinical, Diagnostic, and Treatment Disparities between HIV-Infected and Non-HIV-Infected Immunocompromised Patients with Pneumocystis jirovecii Pneumonia

The substantial decline in the Pneumocystis jirovecii pneumonia (PCP) incidence in HIV-infected patients after the introduction of antiretroviral therapy (ART) in resource-rich settings and the growing number of non-HIV-infected immunocompromised patients at risk leads to considerable epidemiologic changes with clinical, diagnostic, and treatment consequences for physicians. HIV-infected patients usually develop a subacute course of disease, while non-HIV-infected immunocompromised patients are characterized by a rapid disease progression with higher risk of respiratory failure and higher mortality. The main symptoms usually include exertional dyspnea, dry cough, and subfebrile temperature or fever. Lactate dehydrogenase may be elevated. Typical findings on computed tomography scans of the chest are bilateral ground-glass opacities with or without cystic lesions, which are usually associated with the presence of AIDS. Empiric treatment should be initiated as soon as PCP is suspected. Bronchoalveolar lavage has a higher diagnostic yield compared to induced sputum. Immunofluorescence is superior to conventional staining. A combination of different diagnostic tests such as microscopy, polymerase chain reaction, and (1,3)-β-D-glucan is recommended. Trimeth-oprim/sulfamethoxazole for 21 days is the treatment of choice in adults and children. Alternative treatment regimens include dapsone with trimethoprim, clindamycin with primaquine, atovaquone, or pentamidine. Patients with moderate to severe disease should receive adjunctive corticosteroids. In newly diagnosed HIV-infected patients with PCP, ART should be initiated as soon as possible. In non-HIV-infected immunocompromised patients, improvement of the immune status should be discussed (e.g., temporary reduction of immunosuppressive agents). PCP prophylaxis is effective and depends on the immune status of the patient and the underlying immunocompromising disease.

Mutual potentiation drives synergy between trimethoprim and sulfamethoxazole

Trimethoprim (TMP)-sulfamethoxazole (SMX) is a widely used synergistic antimicrobial combination to treat a variety of bacterial and certain fungal infections. These drugs act by targeting sequential steps in the biosynthetic pathway for tetrahydrofolate (THF), where SMX inhibits production of the THF precursor dihydropteroate, and TMP inhibits conversion of dihydrofolate (DHF) to THF. Consequently, SMX potentiates TMP by limiting de novo DHF production and this mono-potentiation mechanism is the current explanation for their synergistic action. Here, we demonstrate that this model is insufficient to explain the potent synergy of TMP-SMX. Using genetic and biochemical approaches, we characterize a metabolic feedback loop in which THF is critical for production of the folate precursor dihydropterin pyrophosphate (DHPPP). We reveal that TMP potentiates SMX activity through inhibition of DHPPP synthesis. Our study demonstrates that the TMP-SMX synergy is driven by mutual potentiation of the action of each drug on the other.

Rare cause of pulmonary cavitation in a 75-year-old man

A 75-year-old man of Asian descent presented to the acute medical unit with signs and symptoms suggestive of a community-acquired pneumonia. He had multiple comorbidities and was relatively immunocompromised as a result. Initial investigations supported the diagnosis of community-acquired pneumonia complicated by a cavitating lung lesion, and the patient was treated as per hospital guidelines. He continued to deteriorate despite appropriate therapy and developed a hydropneumothorax, requiring the insertion of a chest drain. A diagnosis of pulmonary mucormycosis (Rhizopus microsporus) was made based on microbiology results from pleural aspirate, and patient was treated with intravenous antifungals. The patient was referred to the thoracic team for consideration of surgical intervention but was not suitable due to his multiple comorbidities. This case highlighted the importance of early consideration of fungal infection in patients with multiple risk factors and the need for aggressive therapy to ensure the best outcome.

LOW CD4 LYMPHOCYTE COUNT RELATED RISK TO Pneumocystis jiroveci PNEUMONIA IN HIV/AIDS PATIENTS FROM BRONCHOALVEOLAR LAVAGE SPECIMENS USING REAL TIME PCR DETECTION

HIV and opportunistic infections remain a big problem especially in developing country. Pneumocystis jiroveci pneumonia is a prevalent infection  in HIV infected patient with high mortality rate. Diagnosis of Pneumocystis jiroveci pneumonia is mainly based on clinical evidence. Microbiological diagnosis is quite challenging since this microorganism cannot be cultured and is mainly based on microscopic examination. Microscopic examination with special staining is still a gold standard diagnosis for P. jiroveci infection.The objectives of this study was to describe CD4 lymphocyte profile and establish microbiological diagnosis with recent molecular method in PJP suspected HIV positive patients. Fiberoptic bronchoscopy of HIV infected patients with lower respiratory tract infection in Dr. Soetomo general hospital Surabaya were performed to collect bronchoalveolar lavage specimens  from December 2016 to April 2017 for identification of Pneumocystis jiroveci using real time PCR assay. Positive samples were then evaluated for  microscopic examination with Gommori Methenamine Silver staining for comparison. Patient’s CD4 lymphocyte count were gathered prior of admission. CD4 lymphocyte count from this study were very low with 61% of the patients were below 50 cells/ µL. There were five of  total thirteen patients (38,5%) with positive real time PCR assay (MSG gene)  and one patient was also positive with GMS staining showing characteristic cysts shape with dark centered area of P. jiroveci. Patient with positive microscopic examination showed no history of prophylactic therapy. Low CD4 lymphocyte count remains a strong risk factor of P. jiroveci pneumonia in HIV/AIDS patients. Real time PCR assay shows high value in detection of P. jiroveci regarding patient’s prophylactic status.

Pneumocystis-Driven Inducible Bronchus-Associated Lymphoid Tissue Formation Requires Th2 and Th17 Immunity

Inducible bronchus-associated lymphoid tissue (iBALT) is an ectopic lymphoid structure composed of highly organized T cell and B cell zones that forms in the lung in response to infectious or inflammatory stimuli. Here, we develop a model for fungal-mediated iBALT formation, using infection with Pneumocystis that induces development of pulmonary lymphoid follicles. Pneumocystis-dependent iBALT structure formation and organization required CXCL13 signaling. Cxcl13 expression was regulated by interleukin (IL)-17 family members, as Il17ra^-/-, Il17rb^-/-, and Il17rc^-/- mice failed to develop iBALT. Interestingly, Il17rb^-/- mice have intact Th17 responses, but failed to generate an anti-Pneumocystis Th2 response. Given a role for Th2 and Th17 immunity in iBALT formation, we demonstrated that primary pulmonary fibroblasts synergistically upregulated Cxcl13 transcription following dual stimulation with IL-13 and IL-17A in a STAT3/GATA3-dependent manner. Together, these findings uncover a role for Th2/Th17 cells in regulating Cxcl13 expression and provide an experimental model for fungal-driven iBALT formation.

Natural Antimicrobial Peptides as Inspiration for Design of a New Generation Antifungal Compounds

Invasive fungal infections are associated with high mortality rates, despite appropriate antifungal therapy. Limited therapeutic options, resistance development and the high mortality of invasive fungal infections brought about more concern triggering the search for new compounds capable of interfering with fungal viability and virulence. In this context, peptides gained attention as promising candidates for the antimycotics development. Variety of structural and functional characteristics identified for various natural antifungal peptides makes them excellent starting points for design novel drug candidates. Current review provides a brief overview of natural and synthetic antifungal peptides.

Evaluation of quantitative FTD-Pneumocystis jirovecii kit for Pneumocystis infection diagnosis

We evaluated the Fast track Diagnostics (FTD) Pneumocystis PCR kit, targeting the mitochondrial large subunit ribosomal RNA gene (mtLSU rRNA) of Pneumocystis jirovecii (P. jirovecii). A hundred and thirty-three patients were prospectively enrolled. Respiratory specimens were examined using both microscopy and the PCR assay. Twenty-six patients led to P. jirovecii detection. Fourteen patients presented with Pneumocystis pneumonia (PCP) whereas 12 patients were considered to be colonized. The median copy numbers in bronchoalveolar lavage fluid were significantly different in the PCP and colonization groups (1.35×10⁸/ml vs. 1.45×10⁵/ml, P < 0.0001). Lower and upper cut-off values of 3.9×10⁵ copies/ml and 3.2×10⁶ copies/ml allowed differentiating PCP and colonization. The FTD P. jirovecii assay was secondarily compared to an in-house reference PCR assay targeting the mtLSUrRNA gene. A concordance rate of 97.5% was observed (Cohen's kappa coefficient κ=0.935). The FTD Pneumocystis PCR kit showed good performance and represents an alternative method to diagnose P. jirovecii infections.

The changing trends and profile of pneumocystosis mortality in the United States, 1999-2014

Pneumocystosis (PCP) mortality in the U.S. has received less attention in recent years. This study describes recent trends in mortality and the estimated burden of PCP in the U.S., using the national multiple cause of death data during 1999-2014. PCP mortality rates were calculated for age, sex, race and year. Demographic differences were presented for decedents with and without a human immunodeficiency virus (HIV) co-diagnosis. Matched odds ratios (MOR) were generated to describe associations between non-HIV conditions and PCP mortality. In total, 11 512 PCP deaths occurred during 1999-2014. Annual age-adjusted PCP mortality decreased over this time period, from 0.479 to 0.154 per 100 000 population (1999 vs 2014 respectively). Over two-thirds of decedents were male and Blacks had the highest mortality as compared to Whites. HIV co-diagnosis accounted for 48% of all PCP deaths in 2014 vs 71% in 1999. Comorbid conditions such as connective tissue disorders (MOR=12.29; 95% confidence interval=[10.26, 14.71]) were associated with a PCP diagnosis. Productivity losses amounted to >$12 billion during the study period. Although widespread use of antiretroviral therapy and PCP prophylaxis for HIV infection likely contributed to the overall decline in PCP deaths during 1999-2014, a continual need exists to prevent and treat this fungal disease in immune-compromised populations that are not infected with HIV.

Infectious disease ward admission positively influences P. jiroveci pneumonia (PjP) outcome: A retrospective analysis of 116 HIV-positive and HIV-negative immunocompromised patients

P. jiroveci (Pj) causes a potentially fatal pneumonia in immunocompromised patients and the factors associated with a bad outcome are poorly understood. A retrospective analysis on Pj pneumonia (PjP) cases occurring in Tor Vergata University Hospital, Italy, during the period 2011–2015. The patients’ demographic, clinical and radiological characteristics and the Pj genotypes were considered. The study population included 116 patients, 37.9% of whom had haematological malignancy or underwent haematological stem cell transplantation (HSCT), 22.4% had HIV infection, 16.4% had chronic lung diseases (CLD), 7.8% had a solid cancer, and 3.4% underwent a solid organ transplant (SOT). The remaining 12.1% had a miscellaneous other condition. At univariate analysis, being older than 60 years was significantly correlated with a severe PjP (OR [95%CI] 2.52 [0.10–5.76]; p = 0.031) and death (OR [95%CI] 2.44 [1.05–5.70]; p = 0.036), while a previous trimethoprim/sulfamethoxazole (TMP/SMX) prophylaxis were significantly associated with a less severe pneumonia (OR[95%CI] 0.35 [0.15–0.84], p = 0.023); moreover, death due to PjP was significantly more frequent in patients with CLD (OR[95%CI] 3.26 [1.17–9.05]; p = 0.019) while, admission to the Infectious Diseases Unit was significantly associated with fewer deaths (OR[95%CI] 0.10 [0.03–0.36], p = 0.002). At multivariate analysis, a better PjP outcome was observed in patients taking TMP/SMX prophylaxis and that were admitted to the Infectious Diseases Unit (OR[95%CI] 0.27 [0.07–1.03], p = 0.055, OR[95%CI] 0.16 [0.05–0.55]; p = 0.004, respectively).

In conclusion, in our study population, TMP/SMX prophylaxis and infectious disease specialist approach were variables correlated with a better PjP outcome.

Hospitalizations of HIV patients in a major Israeli HIV/AIDS center during the years 2000 to 2012

To evaluate hospitalization rates and causes among human immunodeficiency virus (HIV) patients in the late highly active antiretroviral therapy (HAART) era. Data during the years 2000 to 2012 were obtained from hospital/clinical charts. Hospitalizations were defined as a ≥24 hours hospital admission. Obstetric admissions were excluded. Causes of hospitalizations were defined as acquired immune deficiency syndrome (AIDS)-defining illnesses, AIDS-related diseases (HAART adverse events, metabolic complications and non-AIDS-defining tumors/infections), and non-HIV-related diseases. Hospitalization rates are presented as admissions per 100 patient years. The number of HIV patients (58% males) in our center increased from 521 in 2000 to 1169 in 2012. 1676 hospital admissions (in 557 patients) were observed during the years of the study. The mean number of admissions per hospitalized patient was 3 ± 3.39. Hospitalization rates of HIV patients declined significantly (18.4/100 in 2000, 9/100 patient years in 2012; P = .0001), but it was higher than the rates reported in the Israeli general population (X8.76 in 2000, X6.04 in 2012). Furthermore, hospitalizations for AIDS-defining illness declined (from 46.9% to 16.1%) whereas non-HIV-related hospitalizations increased (from 31.3% to 60.1%). Lower cluster of differentiation 4 (CD4) cell counts and older age, at the time of HIV diagnosis, were associated with higher rates of admissions (especially for AIDS-defining illnesses) and mortality. Hospitalization rates of HIV patients, especially for AIDS-defining illness, continue to decline in the late HAART era despite the increasing age of the patients, though it is still higher than that of the general population. Low CD4 cell counts and older age, at the time of HIV diagnosis, are associated with readmissions and mortality.

Low prevalence of Pneumocystis pneumonia in hospitalized patients with systemic lupus erythematosus: review of a clinical data warehouse

Objective In the era of powerful immunosuppression, opportunistic infections are an increasing concern in systemic lupus erythematosus. One of the best-studied opportunistic infections is Pneumocystis pneumonia; however, the prevalence of Pneumocystis pneumonia in systemic lupus erythematosus is not clearly defined. This study evaluates the prevalence of Pneumocystis pneumonia in hospitalized systemic lupus erythematosus patients, with a focus on validating the Pneumocystis pneumonia and systemic lupus erythematosus diagnoses with clinical information. Methods This retrospective cohort study evaluates the prevalence of Pneumocystis pneumonia in all systemic lupus erythematosus patients treated at Columbia University Medical Center-New York Presbyterian Hospital between January 2000 and September 2014, using electronic medical record data. Patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) and patients with renal transplants (including both early and late post-transplant patients) represented immunocompromised control groups. Patients with systemic lupus erythematosus, Pneumocystis pneumonia, HIV/AIDS, or renal transplant were identified using diagnostic codes from the International Classification of Diseases, Ninth Revision (ICD-9). Results Out of 2013 hospitalized systemic lupus erythematosus patients, nine had presumed Pneumocystis pneumonia, yielding a low prevalence of Pneumocystis pneumonia in systemic lupus erythematosus of 0.45%. Three of the nine Pneumocystis pneumonia cases were patients with concomitant systemic lupus erythematosus and HIV/AIDS. Only one of these nine cases was histologically confirmed as Pneumocystis pneumonia, in a patient with concomitant systemic lupus erythematosus and HIV/AIDS and a CD4 count of 13 cells/mm³. The prevalence of Pneumocystis pneumonia in renal transplant patients and HIV/AIDS patients was 0.61% and 5.98%, respectively. Conclusion Given the reported high rate of adverse effects to trimethoprim-sulfamethoxazole in systemic lupus erythematosus and the low prevalence of Pneumocystis pneumonia in hospitalized systemic lupus erythematosus patients, our data do not substantiate the need for Pneumocystis pneumonia prophylaxis in systemic lupus erythematosus patients, except in those with concurrent HIV/AIDS.

Detection of Pneumocystis jirovecii in oral wash from immunosuppressed patients as a diagnostic tool

Background

Diagnosis of Pneumocystis jirovecii (PJ) pneumonia ordinarily requires invasive procedures that could be avoided by PCR methodologies, if these could be designed with adequate cut-off values for confounding background carriage.

Methods

We designed a novel quantitative real-time PCR assay to detect the mitochondrial large subunit rRNA gene of PJ in oral washes. To benchmark levels of PJ carriage versus infection, we tested asymptomatic immunosuppressed patients including Danish (n = 88) and West African HIV-infected (n = 142) patients, renal transplant recipients (n = 51), rheumatologic patients (n = 102), patients with inflammatory bowel diseases (n = 98), and healthy blood donors (controls, n = 50). The fungal burden in patients with PJ pneumonia (PCP, n = 7) was also investigated.

Results

Danish HIV-infected patients (with viremia/low CD4) and recent transplant recipients were at most risk of being carriers (prevalence of 23% and 16.7% respectively), whereas PJ was rarely detected among rheumatologic patients, patients with inflammatory bowel diseases, and untreated West African HIV patients. PJ was not detected among healthy controls. The fungal burden in patients with PCP fell rapidly on treatment.

Conclusions

The quantitative PCR method described could conceivably discriminate between carriage and disease, given suitable threshold values for the former, and predict treatment efficacy by measures of the fungal burden in daily oral washes.

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

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.

Burden of serious fungal infections in Guatemala

Guatemala is a developing country in Central America with a high burden of HIV and endemic fungal infections; we attempted to estimate the burden of serious fungal infections for the country. A full literature search was done to identify epidemiology papers reporting fungal infections from Guatemala. We used specific populations at risk and fungal infection frequencies in the population to estimate national rates. The population of Guatemala in 2013 was 15.4 million; 40% were younger than 15 and 6.2% older than 60. There are an estimated 53,000 adults with HIV infection, in 2015, most presenting late. The estimated cases of opportunistic fungal infections were: 705 cases of disseminated histoplasmosis, 408 cases of cryptococcal meningitis, 816 cases of Pneumocystis pneumonia, 16,695 cases of oral candidiasis, and 4,505 cases of esophageal candidiasis. In the general population, an estimated 5,568 adult asthmatics have allergic bronchopulmonary aspergillosis (ABPA) based on a 2.42% prevalence of asthma and a 2.5% ABPA proportion. Amongst 2,452 pulmonary tuberculosis patients, we estimated a prevalence of 495 for chronic pulmonary aspergillosis in this group, and 1,484 for all conditions. An estimated 232,357 cases of recurrent vulvovaginal candidiasis is likely. Overall, 1.7% of the population are affected by these conditions. The true fungal infection burden in Guatemala is unknown. Tools and training for improved diagnosis are needed. Additional research on prevalence is needed to employ public health measures towards treatment and improving the reported data of fungal diseases.

High Pneumocystis jirovecii colonization rate among haemodialysis patients

Haemodialysis patients have been found to have an increased risk of developing Pneumocystis pneumonia (PcP) compared to the control population. To the best of our knowledge, no data are available on pulmonary colonization with Pneumocystis jirovecii in haemodialysis patients; therefore, the aim of this study was to determine the prevalence of pulmonary colonization with P. jirovecii in haemodialysis patients, and to find the related risk factors. Induced sputa of 62 haemodialysis patients were investigated using quantitative polymerase chain reaction for the presence of P. jirovecii. 20.9% of the patients were colonized with P. jirovecii and 46.2% of whom had CD4 cell counts below 400/μl. There was no significant correlation between colonization and time on dialysis treatment. As haemodialysis patients seem to be at higher risk of PcP than the general population, doctors should be aware of the high rate of P. jirovecii colonization amongst them. Furthermore, colonized patients remain a potential source of transmission of P. jirovecii to other patients or to health care workers.

Characteristics and Mortality of Pneumocystis Pneumonia in Patients With Cushing's Syndrome: A Plea for Timely Initiation of Chemoprophylaxis

In patients with Cushing's syndrome, development of Pneumocystis pneumonia (PCP) is associated with extreme cortisol production levels. In this setting, immune reconstitution after abrogation of cortisol excess appears to induce development of symptomatic PCP. The high mortality rate warrants timely initiation of chemoprophylaxis or even preemptive treatment of PCP.

Commercial Molecular Tests for Fungal Diagnosis from a Practical Point of View

The increasing interest in molecular diagnostics is a result of tremendously improved knowledge on fungal infections in the past 20 years and the rapid development of new methods, in particular polymerase chain reaction. High expectations have been placed on molecular diagnostics, and the number of laboratories now using the relevant technology is rapidly increasing-resulting in an obvious need for standardization and definition of laboratory organization. In the past 10 years, multiple new molecular tools were marketed for the detection of DNA, antibodies, cell wall components, or other antigens. In contrast to classical culture methods, molecular methods do not detect a viable organisms, but only molecules which indicate its presence; this can be nucleic acids, cell components (antigens), or antibodies (Fig. 1). In this chapter, an overview is provided on commercially available detection tools, their strength and how to use them. A main focus is laid on providing tips and tricks that make daily life easier. We try to focus and mention methodical details which are not highlighted in the manufacturer's instructions of these test kits, but are based on our personal experience in the laboratory. Important to keep in mind is that molecular tools cannot replace culture, microscopy, or a critical view on patients' clinical history, signs, and symptoms, but provide a valuable add on tool. Diagnosis should not be based solely on a molecular test, but molecular tools might deliver an important piece of information that helps matching the diagnostic puzzle to a diagnosis, in particular as few tests are in vitro diagnostic tests (IVD) or only part of the whole test carries the IVD certificate (e.g., DNA extraction is often not included). Please be aware that the authors do not claim to provide a complete overview on all commercially available diagnostic assays being currently marketed for fungal detection, as those are subject to constant change. A main focus is put on commonly used panfungal assays and pathogen-specific assays, including Aspergillus-specific, Candida-specific, Cryptococcus specific, Histoplasma-specific, and Pneumocystis-specific assays. Assays are categorized according to their underlying principle in either antigen-detecting or antibody-detecting or DNA-detecting (Fig. 1). Other non-DNA-detecting nucleic acid methods such as FISH and PNA FISH are not summarized in this chapter and an overview on test performance, common false positives, and the clinical evaluation of commercial tests in studies is provided already in a previous book series by Javier Yugueros Marcos and David H. Pincus (Marcos and Pincus, Methods Mol Biol 968:25-54, 2013).