Trends in hospitalizations for AIDS-associated Pneumocystis jirovecii Pneumonia in the United States (1986 to 2005)

Global prevalence, mortality, and main characteristics of HIV-associated pneumocystosis: A systematic review and meta-analysis

The epidemiology of Human Immunodeficiency Virus (HIV)-associated pneumocystosis (HAP) is poorly described on a worldwide scale. We searched related databases between January 2000 and December 2022 for studies reporting HAP. Meta-analysis was performed using StatsDirect (version 2.7.9) and STATA (version 17) according to the random-effects model for DerSimonian and Laird method and metan and metaprop commands, respectively. Twenty-nine studies with 38554 HIV-positive, 79893 HIV-negative, and 4044 HAP populations were included. The pooled prevalence of HAP was 35.4% (95% CI 23.8 to 47.9). In contrast, the pooled prevalence of PCP among HIV-negative patients was 10.16% (95% CI 2 to 25.3). HIV-positive patients are almost 12 times more susceptible to PCP than the HIV-negative population (OR: 11.710; 95% CI: 5.420 to 25.297). The mortality among HAP patients was 52% higher than non-PCP patients (OR 1.522; 95% CI 0.959 to 2.416). HIV-positive men had a 7% higher chance rate for PCP than women (OR 1.073; 95% CI 0.674 to 1.706). Prophylactic (OR: 6.191; 95% CI: 0.945 to 40.545) and antiretroviral therapy (OR 3.356; 95% CI 0.785 to 14.349) were used in HAP patients six and three times more than HIV-positive PCP-negatives, respectively. The control and management strategies should revise and updated by health policy-makers on a worldwide scale. Finally, for better management and understanding of the epidemiology and characteristics of this coinfection, designing further studies is recommended.

SAR study of N'-(Salicylidene)heteroarenecarbohydrazides as promising antifungal agents

Clinically available antifungal drugs have therapeutic limitations due to toxicity, narrow spectrum of activity, and intrinsic or acquired drug resistance. Thus, there is an urgent need for new broad-spectrum antifungal agents with low toxicity and a novel mechanism of action. In this context, we have successfully identified several highly promising lead compounds, i.e., aromatic N'-(salicylidene)carbohydrazides, exhibiting excellent antifungal activities against Cryptococcus neoformans, Candida albicans, Aspergillus fumigatus and several other fungi both in vitro and in vivo. Building upon these highly promising results, 71 novel N'-(salicylidene)heteroarenecarbohydrazides 5 were designed, synthesized and their antifungal activities examined against fungi. Based on the SAR study, four highly promising lead compounds, i.e., 5.6a, 5.6b, 5.7b and 5.13a were identified, which exhibited excellent potency against C. neoformans, C. albicans and A. fumigatus, and displayed impressive time-kill profiles against C. neoformans with exceptionally high selectivity indices (SI ≥ 500). These four lead compounds also showed synergy with clinical antifungal drugs, fluconazole, caspofungin (CS) and amphotericin B against C. neoformans. For the SAR study, we also employed quantitative structure-activity relationship (QSAR) analysis by taking advantage of the accumulated data on a large number of aromatic and heteroaromatic N'-(salicylidene)carbohydrazides, which successfully led to rational design and selection of promising compounds for chemical synthesis and biological evaluation.

Clinical characteristics and risk factors of in-hospital mortality in patients coinfected with Pneumocystis jirovecii and Aspergillus

OBJECTIVE

To analyze clinical characteristics and risk factors for in-hospital mortality in patients coinfected with P. jirovecii and Aspergillus.

METHODS

This study included 53 patients with coinfection of P. jirovecii pneumonia (PJP) and invasive pulmonary aspergillosis (IPA) in our center from January 2011 to December 2021. All cases were divided into survivor (n=27) and non-survivor groups (n=26). Medical records, laboratory and radiology data were collected. Risk factors for in-hospital mortality were identified by multivariable analyses.

RESULTS

HIV-positive patients accounted for 3.8%. Fever (77.4%), dyspnea (69.8%) and wet cough (24.5%) were common symptoms. Ground-glass opacity (83.0%), consolidation (71.7%), septal thickening (66.0%), and nodules (54.7%) were the most common radiological signs. CD4+ T cell count and serum albumin (ALB) level were significantly lower in non-survival group than in the survival group. Conversely, serum lactate dehydrogenase (LDH) and procalcitonin (PCT) levels were higher in non-survival group than in survival group. Lactic acidosis [odds ratio (OR): 33.999,95% confidential interval (CI): 3.112-371.409; p=0.004], low CD4+ T cell count (<114 cell/µL) [OR: 19.343, 95% CI: 1.533-259.380; p=0.022] and high level of LDH (> 519 U/L) [OR: 11.422, 95% CI: 1.271-102.669; p=0.030] were independent risk factors for mortality.

CONCLUSION

PJP coinfected with IPA incurs high mortality with nonspecific clinical characteristics and is more likely to involve HIV-negative patients. Lactic acidosis, low CD4+ T cell count and high LDH level are independent risk factors for mortality, close monitoring of these parameters is necessary to help distinguish high-risk patients and make appropriate clinical decisions.

Pulmonary Infections and Outcomes in AIDS Patients with Respiratory Failure: A 10-Year Retrospective Review

Background

Respiratory failure in acquired immunodeficiency syndrome (AIDS) patients was the leading cause of intensive care unit (ICU) admission in our center. We aimed to describe the pulmonary infections and outcomes for respiratory failure in AIDS patients.

Methods

A retrospective study was conducted on AIDS adult patients with respiratory failure who were admitted to the ICU in Beijing Ditan hospital, China, from January 2012 to December 2021. We investigated pulmonary infections complicated by respiratory failure in AIDS patients. The primary outcome was ICU mortality, and a comparison between survivors and nonsurvivors was performed. Multiple logistic regression analysis was used to identify predictors of ICU mortality. The Kaplan-Meier curve and Log rank test were used for survival analysis.

Results

A total of 231 AIDS patients were admitted to ICU with respiratory failure over a 10-year period with a male predominance (95.7%). Pneumocystis jirovecii pneumonia was the main etiology of pulmonary infections (80.1%). The ICU mortality was 32.9%. In multivariate analysis, ICU mortality was independently associated with invasive mechanical ventilation (IMV) [odds ratio (OR), 27.910; 95% confidence interval (CI, 8.392-92.818; p = 0.000) and the time before ICU admission (OR, 0.959; 95% CI, 0.920-0.999; p = 0.046). In the survival analysis, patients with IMV and later admission to ICU had a higher probability of mortality.

Conclusion

Pneumocystis jirovecii pneumonia was the primary etiology for respiratory failure in AIDS patients admitted to the ICU. Respiratory failure remains a severe illness with high mortality, and ICU mortality was negatively associated with IMV and later admission to ICU.

Low-dose trimethoprim-sulfamethoxazole for the treatment of Pneumocystis jirovecii pneumonia (LOW-TMP): protocol for a phase III randomised, placebo-controlled, dose-comparison trial

INTRODUCTION

Pneumocystis jirovecii pneumonia (PJP) is an opportunistic infection of immunocompromised hosts with significant morbidity and mortality. The current standard of care, trimethoprim-sulfamethoxazole (TMP-SMX) at a dose of 15-20 mg/kg/day, is associated with serious adverse drug events (ADE) in 20%-60% of patients. ADEs include hypersensitivity reactions, drug-induced liver injury, cytopenias and renal failure, all of which can be treatment limiting. In a recent meta-analysis of observational studies, reduced dose TMP-SMX for the treatment of PJP was associated with fewer ADEs, without increased mortality.

METHODS AND ANALYSIS

A phase III randomised, placebo-controlled, trial to directly compare the efficacy and safety of low-dose TMP-SMX (10 mg/kg/day of TMP) with the standard of care (15 mg/kg/day of TMP) among patients with PJP, for a composite primary outcome of change of treatment, new mechanical ventilation, or death. The trial will be undertaken at 16 Canadian hospitals. Data will be analysed as intention to treat. Primary and secondary outcomes will be compared using logistic regression adjusting for stratification and presented with 95% CI.

ETHICS AND DISSEMINATION

This study has been conditionally approved by the McGill University Health Centre; Ethics approval will be obtained from all participating centres. Results will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04851015.

On the Treatment of Pneumocystis jirovecii Pneumonia: Current Practice Based on Outdated Evidence

Pneumocystis jirovecii pneumonia (PCP) is a common opportunistic infection causing more than 400000 cases annually worldwide. Although antiretroviral therapy has reduced the burden of PCP in persons with human immunodeficiency virus (HIV), an increasing proportion of cases occur in other immunocompromised populations. In this review, we synthesize the available randomized controlled trial (RCT) evidence base for PCP treatment. We identified 14 RCTs that were conducted 25-35 years ago, principally in 40-year-old men with HIV. Trimethoprim-sulfamethoxazole, at a dose of 15-20 mg/kg per day, is the treatment of choice based on historical practice rather than on quality comparative, dose-finding studies. Treatment duration is similarly based on historical practice and is not evidence based. Corticosteroids have a demonstrated role in hypoxemic patients with HIV but have yet to be studied in RCTs as an adjunctive therapy in non-HIV populations. The echinocandins are potential synergistic treatments in need of further investigation.

Recent Trends in the Epidemiology of Fungal Infections

The breadth of fungi causing human disease and the spectrum of clinical presentations associated with these infections has widened. Epidemiologic trends display dramatic shifts with expanding geographic ranges, identification of new at-risk groups, increasing prevalence of resistant infections, and emergence of novel multidrug-resistant pathogenic fungi. Certain fungi have been transmitted between patients in clinical settings. Major health events not typically associated with mycoses resulted in larger proportions of the population susceptible to secondary fungal infections. Many health care-related, environmental, and socioeconomic factors have influenced these epidemiologic shifts. This review summarizes updates to clinically significant fungal pathogens in North America.

Glucose - The X factor for the survival of human fungal pathogens and disease progression in the host

The incidence of human fungal infections is increasing due to the expansion of the immunocompromised patient population. The continuous use of different antifungal agents has eventually resulted in the establishment of resistant fungal species. The fungal pathogens unfold multiple resistance strategies to successfully tackle the effect of different antifungal agents. For the successful colonization and establishment of infection inside the host, the pathogenic fungi switch to the process of metabolic flexibility to regulate distinct nutrient uptake systems as well as to modulate their metabolism accordingly. Glucose the most favourable carbon source helps carry out the important survival and niche colonization processes. Adopting glucose as the center, this review has been put forward to provide an outline of the important processes like growth, the progression of infection, and the metabolism regulated by glucose, affecting the pathogenicity and virulence traits in the human pathogenic fungi. This could help in the identification of better treatment options and appropriate target-oriented antifungal drugs based on the glucose-regulated pathways and processes. In the article, we have also presented a summary of the novel studies and findings pointing to glucose-based potential therapeutic avenues to be explored to tackle the problem of globally increasing multidrug-resistant human fungal infections.

Blood urea nitrogen-to-serum albumin ratio and A-DROP are useful in assessing the severity of Pneumocystis pneumonia in patients without human immunodeficiency virus infection

INTRODUCTION

There is an increasing incidence of Pneumocystis pneumonia (PcP) among individuals without human immunodeficiency virus (HIV) infection (non-HIV PcP). However, prognostic factors for patients with non-HIV PcP have not been identified. Moreover, A-DROP (for classifying the severity of community-acquired pneumonia) or the blood urea nitrogen-to-serum albumin ratio (BUN/Alb), which is reported to be a predictor of mortality of community-acquired pneumonia, has not been established as an efficient prognostic factor in patients with non-HIV PcP. In this study, we analyzed the prognostic factors for non-HIV PcP and evaluated the prognostic ability of A-DROP and the BUN/Alb ratio.

METHODS

This retrospective study involved a chart review of the medical records of 102 patients diagnosed with non-HIV PcP between January 2003 and May 2019 at five medical facilities.

RESULTS

Overall, 102 patients were involved in this study. The 30-day mortality rate for non-HIV PcP was 20.5% in this study population. Compared with survivors, non-survivors had significantly lower serum albumin levels and significantly higher age, corticosteroid dosage at the PcP onset, alveolar-arterial oxygen gradient, A-DROP score, lactate dehydrogenase levels, blood urea nitrogen levels, and BUN/Alb ratio. Multivariate analysis showed that a high BUN/Alb ratio at treatment initiation was significantly associated with 30-day mortality risk. The receiver operating characteristic curves showed that A-DROP score had the highest prognostic ability in estimating 30-day mortality.

CONCLUSIONS

In patients with non-HIV PcP, a high BUN/Alb ratio is an independent prognostic predictor of mortality risk, and A-DROP is useful for classifying the severity.

Metagenomic Next-Generation Sequencing in Diagnosis of a Case of Pneumocystis jirovecii Pneumonia in a Kidney Transplant Recipient and Literature Review

BACKGROUND

Despite the increasing incidences of Pneumocystis jirovecii pneumonia (PCP) in renal transplant recipients, diagnosis of PCP remains challenging due to its nonspecific clinical presentation and the inadequate performance of conventional diagnostic methods. There is a need for novel diagnostic methods.

CASE PRESENTATION

A 27-year-old woman developed acute pneumonia 4 months after renal transplantation. Blood tests revealed a low CD4 count, a normal 1,3-beta-D-glucan level and other changes typical of inflammatory responses. Chest imaging showed bilateral diffuse infiltrates. Microscopic examination of stained sputum and bronchoalveolar lavage fluid (BALF) smear specimens did not find Pneumocystis organisms. There was also no evidence for other pathogens known to cause pneumonia in various antibody and culture tests. Direct metagenomic next-generation sequencing (mNGS) analysis of a BALF specimen identified a large number of P. jirovecii reads, allowing to confirm the diagnosis of PCP. Following treatment with trimethoprim-sulfamethoxazole for two weeks, the patient was cured and discharged.

CONCLUSION

This case report supports the value of mNGS in diagnosing PCP, highlights the inadequate sensitivity of conventional diagnostic methods for PCP, and calls for the need to add PCP prophylaxis to the current Diagnosis and Treatment Guideline of Invasive Fungal Infections in Solid Organ Transplant Recipients in China.

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.

Prognostic impact of pre-existing interstitial lung disease in non-HIV patients with Pneumocystis pneumonia

BACKGROUND

The increasing incidence of life-threatening Pneumocystis pneumonia (PCP) in non-HIV immunocompromised patients is a global concern. Yet, no reports have examined the prognostic significance of pre-existing interstitial lung disease (ILD) in non-HIV PCP.

METHODS

We retrospectively reviewed the medical records of non-HIV PCP patients with (ILD group) or without (non-ILD group) pre-existing ILD. The clinical features and outcomes of the ILD group were compared with those of the non-ILD group. Cox regression models were constructed to identify prognostic factors.

RESULTS

74 patients were enrolled in this study. The 90-day mortality was significantly higher in the ILD group than in the non-ILD group (62.5% versus 19.0%, p<0.001). In the ILD group, patients with a higher percentage of bronchoalveolar lavage fluid neutrophils had worse outcomes compared to those having a lower percentage (p=0.026). Multivariate analyses revealed that pre-existing ILD (p=0.002) and low levels of serum albumin (p=0.009) were independent risk factors for 90-day mortality. Serum levels of β-d-glucan were significantly reduced after treatment of PCP in both groups, whereas levels of Krebs von den Lungen-6 (KL-6) significantly increased in the ILD group. In the ILD group, the 90-day mortality of patients with increasing KL-6 levels after treatment was significantly higher than those with decreasing levels (78.9% versus 0%, p=0.019).

CONCLUSION

In non-HIV PCP patients, pre-existing ILD is associated with a poorer prognosis. Prophylaxis for PCP is needed in patients with pre-existing ILD under immunosuppression.

The Contribution of Host Cells to Pneumocystis Immunity: An Update

Pneumocystis is a ubiquitous atypical fungus that is distributed globally. The genus comprises morphologically similar but genetically heterogeneous species that have co-evolved with specific mammalian hosts as obligate intra-pulmonary pathogens. In humans, Pneumocystis jirovecii is the causative organism of Pneumocystis pneumonia (PCP) in immunocompromised individuals, a serious illness frequently leading to life-threatening respiratory failure. Initially observed in acquired immunodeficiency syndrome (AIDS) patients, PCP is increasingly observed in immunocompromised non-AIDS patients. The evolving epidemiology and persistently poor outcomes of this common infection will require new strategies for diagnosis and treatment. A deeper understanding of host immune responses and of the cells that mediate them will improve the chance of developing new treatment strategies. This brief review provides an update on recent studies on the role of host immunity against Pneumocystis.

Drug-likeness of linear pentamidine analogues and their impact on the hERG K+channel – correlation with structural features

The pentamidines with S atoms or sulfanilide groups in the linker have favorable drug-likeness parameters and low toxicity.

Pneumocystis jirovecii pneumonia (PCP) PCR-negative conversion predicts prognosis of HIV-negative patients with PCP and acute respiratory failure

Background

Pneumocystis jirovecii pneumonia (PCP) is often fatal in human immunodeficiency (HIV)-negative patients and typically presents with respiratory insufficiency. Predicting treatment failure is challenging. This study aimed to identify prognostic factors and examine PCP polymerase chain reaction (PCR)-negative conversion in non-HIV PCP patients with respiratory failure.

Method

We retrospectively enrolled 81 non-HIV patients diagnosed with and treated for PCP with respiratory failure in the intensive care unit at a tertiary hospital over a 3-year period. PCP was diagnosed via nested PCR-mediated detection of Pneumocystis jirovecii in induced sputum samples, endotracheal aspirates, and bronchoalveolar lavage fluids. PCP PCR was performed weekly to check for negative conversion.

Results

The overall survival rate was 35.8%. Seventy-four patients (91.3%) required mechanical ventilation, and 6 (7.4%) required high-flow nasal oxygen treatment. The PCP PCR-negative conversion rate was 70.5% (survivors, 97%; non-survivors, 63.5%); the median time to conversion was 10 (7.0–14.0) days. On univariate analysis, the APACHE II score (p < 0.001), renal failure requiring renal replacement therapy (p = 0.04), PCP PCR-negative conversion (p = 0.003), and the PaO₂/FiO₂ ratio (first 24 hours) (p < 0.001) significantly correlated with mortality. On multivariate analysis, PCP PCR-negative conversion (hazard ratio, 0.433; 95% confidence interval, 0.203–0.928; p = 0.031) and the PaO₂/FiO₂ ratio (first 24 hours) (hazard ratio, 0.988; 95% confidence interval, 0.983–0.993; p < 0.001) independently predicted prognosis.

Conclusions

Determination of PCP PCR-negative conversion and PaO₂/FiO₂ ratios may help physicians predict treatment failure and mortality in non-HIV PCP patients with respiratory failure.

Outcomes of HIV-associated pneumocystis pneumonia at a South African referral hospital

HIV-associated pneumocystis pneumonia (PCP) is increasingly recognized as an important cause of severe respiratory illness in sub-Saharan Africa. Outcomes of HIV-infected patients with PCP, especially those requiring intensive care unit (ICU) admission, have not been adequately studied in sub-Saharan Africa. The aim of this study was to describe the clinical phenotype and outcomes of HIV-associated PCP in a group of hospitalized South African patients, and to identify predictors of mortality. We conducted a retrospective record review at an academic referral center in Cape Town. HIV-infected patients over the age of 18 years with definite (any positive laboratory test) or probable PCP (defined according to the WHO/CDC clinical case definition) were included. The primary outcome measure was 90-day mortality. Logistic regression and Cox proportional hazards models were constructed to identify factors associated with mortality. We screened 562 test requests between 1 May 2004 and 31 April 2015; 124 PCP cases (68 confirmed and 56 probable) were included in the analysis. Median age was 34 years (interquartile range, IQR, 29 to 41), 89 (72%) were female, and median CD4 cell count was 26 cells/mm3 (IQR 12 to 70). Patients admitted to the ICU (n = 42) had more severe impairment of gas exchange (median ratio of arterial to inspired oxygen (PaO2:FiO2) 158 mmHg vs. 243 mmHg, p < 0.0001), and increased markers of systemic inflammation compared to those admitted to the ward (n = 82). Twenty-nine (23.6%) patients were newly-diagnosed with tuberculosis during their admission. Twenty-six (61.9%) patients admitted to ICU and 21 (25.9%) admitted to the ward had died at 90-days post-admission. Significant predictors of 90-day mortality included PaO2:FiO2 ratio (aOR 3.7; 95% CI, 1.1 to 12.9 for every 50 mgHg decrease), serum LDH (aOR 2.1; 95% CI, 1.1 to 4.1 for every 500 U/L increase), and concomitant antituberculosis therapy (aOR 82; 95% CI, 1.9 to 3525.4; P = 0.021). PaO2:FiO2 < 100 mmHg was significantly associated with inpatient death (aHR 3.8; 95% CI, 1.6 to 8.9; P = 0.003). HIV-associated PCP was associated with a severe clinical phenotype and high rates of tuberculosis co-infection. Mortality was high, particularly in patients admitted to the ICU, but was comparable to other settings. Prognostic indictors could be used to inform ICU admission policy for patients with this condition.

Acylhydrazones as Antifungal Agents Targeting the Synthesis of Fungal Sphingolipids

The incidence of invasive fungal infections has risen dramatically in recent decades. Current antifungal drugs are either toxic, likely to interact with other drugs, have a narrow spectrum of activity, or induce fungal resistance. Hence, there is a great need for new antifungals, possibly with novel mechanisms of action. Previously our group reported an acylhydrazone called BHBM that targeted the sphingolipid pathway and showed strong antifungal activity against several fungi. In this study, we screened 19 derivatives of BHBM. Three out of 19 derivatives were highly active against Cryptococcus neoformansin vitro and had low toxicity in mammalian cells. In particular, one of them, called D13, had a high selectivity index and showed better activity in an animal model of cryptococcosis, candidiasis, and pulmonary aspergillosis. D13 also displayed suitable pharmacokinetic properties and was able to pass through the blood-brain barrier. These results suggest that acylhydrazones are promising molecules for the research and development of new antifungal agents.

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.

Risk factors for mortality from pneumocystis carinii pneumonia (PCP) in non-HIV patients: a meta-analysis

The number of patients with non-human immunodeficiency virus (HIV) related pneumocystis carinii pneumonia (PCP) is increasing with widespread immunosuppressive treatment. We performed a meta-analysis to describe the clinical characteristics and factors associated with outcomes of PCP in HIV-negative patients. A total of 13 studies including 867 patients with non-HIV related PCP was included. The overall mortality for non-HIV patients with PCP was 30.6%. The most common underlying disorder for the development of PCP is hematological malignancies (29.1%), followed by autoimmune disease (20.1%), organ or bone marrow transplantation (14.0%), and solid tumors (6.0%). Risk factors associated with increased mortality rate including old age, female sex, longer time from onset of symptoms to diagnosis, respiratory failure, solid tumors, high lactate dehydrogenase, low serum albumin, bacterial, and aspergillus co-infection, etc (P < 0.05). Adjunctive corticosteroid and PCP prophylaxis was not shown to improve the outcome of PCP in non-HIV patients (P > 0.05). Our findings indicate that mortality in non-HIV patients with PCP is high. Improved knowledge about the prognostic factors may guide the early treatment.

Pulmonary co-infections by Pneumocystis jirovecii and Aspergillus fumigatus in non-HIV patients: A report of two cases and literature review

Pneumocystis jirovecii is the causative agent of Pneumocystis pneumonia (PcP), a common and often life-threatening opportunistic infection in HIV-infected patients. However, non-HIV, immunocompromised patients are at risk of PcP as well, whereas the mortality appears to be higher among these patients. Pneumocystis co-infections with other microorganisms are less frequent and only sparse reports of combined PcP and invasive pulmonary fungal infections exist in the literature, especially in the non-HIV patients. Two cases of pulmonary co-infections by P. jirovecii and Aspergillus fumigatus are presented. Both patients were non-HIV infected, the first one was suffering from crescentic IgA nephropathy under immunosuppressive treatment and the second from resistant non-Hodgkin lymphoma under chemotherapy. Both patients were treated with intravenous trimethoprim/sulphamethoxazole (TMP/SMX) combined with voriconazole. The first patient showed gradual clinical improvement while the outcome for the second patient was unfavourable. In addition, a literature review of the previous published cases of co-infection by P. jirovecii and other fungi in non-HIV patients was performed. Our target was to provide comprehensive information on this kind of infections, highlighting the importance of clinical suspicion.

The Changing Epidemiology of Invasive Fungal Infections

Invasive fungal infections (IFI) are an emerging problem worldwide with invasive candidiasis and candidemia responsible for the majority of cases. This is predominantly driven by the widespread adoption of aggressive immunosuppressive therapy among certain patient populations (e.g., chemotherapy, transplants) and the increasing use of invasive devices such as central venous catheters (CVCs). The use of new immune modifying drugs has also opened up an entirely new spectrum of patients at risk of IFIs. While the epidemiology of candida infections has changed in the last decade, with a gradual shift from C. albicans to non-albicans candida (NAC) strains which may be less susceptible to azoles, these changes vary between hospitals and regions depending on the type of population risk factors and antifungal use. In certain parts of the world, the incidence of IFI is strongly linked to the prevalence of other disease conditions and the ecological niche for the organism; for instance cryptococcal and pneumocystis infections are particularly common in areas with a high prevalence of HIV disease. Poorly controlled diabetes is a major risk factor for invasive mould infections. Environmental factors and trauma also play a unique role in the epidemiology of mould infections, with well-described hospital outbreaks linked to the use of contaminated instruments and devices. Blastomycosis is associated with occupational exposure (e.g., forest rangers) and recreational activities (e.g., camping and fishing).The true burden of IFI is probably an underestimate because of the absence of reliable diagnostics and lack of universal application. For example, the sensitivity of most blood culture systems for detecting candida is typically 50 %. The advent of new technology including molecular techniques such as 18S ribosomal RNA PCR and genome sequencing is leading to an improved understanding of the epidemiology of the less common mould and dimorphic fungal infections. Molecular techniques are also providing a platform for improved diagnosis and management of IFI.Many factors affect mortality in IFI, not least the underlying medical condition, choice of therapy, and the ability to achieve early source control. For instance, mortality due to pneumocystis pneumonia in HIV-seronegative individuals is now higher than in seropositive patients. Of significant concern is the progressive increase in resistance to azoles and echinocandins among candida isolates, which appears to worsen the already significant mortality associated with invasive candidiasis. Mortality with mould infections approaches 50 % in most studies and varies depending on the site, underlying disease and the use of antifungal agents such as echinocandins and voriconazole. Nevertheless, mortality for most IFIs has generally fallen with advances in medical technology, improved care of CVCs, improved diagnostics, and more effective preemptive therapy and prophylaxis.

Special Issue: Novel Antifungal Drug Discovery

This Special Issue is designed to highlight the latest research and development on new antifungal compounds with mechanisms of action different from the ones of polyenes, azoles, and echinocandins. The papers presented here highlight new pathways and targets that could be exploited for the future development of new antifungal agents to be used alone or in combination with existing antifungals. A computational model for better predicting antifungal drug resistance is also presented.

Burden of pneumocystis pneumonia in HIV-infected adults in sub-Saharan Africa: a systematic review and meta-analysis

Background

Seroprevalence data and clinical studies in children suggest that the burden of pneumocystis pneumonia (PCP) in Africa may be underestimated. We performed a systematic review to determine the prevalence and attributable mortality of PCP amongst HIV-infected adults in sub-Saharan Africa.

Methods

We searched Pubmed, Web of Science, Africa-Wide: NiPAD and CINAHL, from Jan 1 1995 to June 1 2015, for studies that reported the prevalence, mortality or case fatality of PCP in HIV-infected adults living in sub-Saharan African countries. Prevalence data from individual studies were combined by random-effects meta-analysis according to the Mantel-Haenszel method. Data were stratified by clinical setting, diagnostic method, and study year.

Results

We included 48 unique study populations comprising 6884 individuals from 18 countries in sub-Saharan Africa. The pooled prevalence of PCP among 6018 patients from all clinical settings was 15 · 4 % (95 % CI 12 · 9–18 · 0), and was highest amongst inpatients, 22 · 4 % (95 % CI 17 · 2–27 · 7). More cases were identified by bronchoalveolar lavage, 21 · 0 % (15 · 0–27 · 0), compared with expectorated, 7 · 7 % (4 · 4–11 · 1), or induced sputum, 11 · 7 % (4 · 9–18 · 4). Polymerase chain reaction (PCR) was used in 14 studies (n = 1686). There was a trend of decreasing PCP prevalence amongst inpatients over time, from 28 % (21–34) in the 1990s to 9 % (8–10) after 2005. The case fatality rate was 18 · 8 % (11 · 0–26 · 5), and PCP accounted for 6 · 5 % (3 · 7–9 · 3) of study deaths.

Conclusions

PCP is an important opportunistic infection amongst HIV-infected adults in sub-Saharan Africa, particularly amongst patients admitted to hospital. Although prevalence appears to be decreasing, improved access to antiretroviral therapy and non-invasive diagnostics, such as PCR, are needed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1809-3) contains supplementary material, which is available to authorized users.

Pneumocystis jiroveci pneumonia in patients treated with systemic immunosuppressive agents for dermatologic conditions: a systematic review with recommendations for prophylaxis

Pneumocystis jiroveci pneumonia is an opportunistic infection associated with substantial rates of mortality in immunosuppressed patients. Prophylaxis recommendations are mostly targeted toward patients with non-dermatologic diagnoses. This study was conducted to determine when dermatology patients treated with immunosuppressive medications should be offered P. jiroveci pneumonia prophylaxis. We searched the literature from January 1, 1993, to December 31, 2013, using terms relating to P. jiroveci pneumonia and dermatologic diagnoses to analyze the clinical characteristics of previously affected patients. Guidelines for P. jiroveci pneumonia prophylaxis from other medical fields were also analyzed. Of 17 dermatology patients reported to have contracted P. jiroveci pneumonia, eight (47.1%) died of the pneumonia. Risk factors included lack of prophylaxis, systemic corticosteroid therapy, lymphopenia, hypoalbuminemia, low serum CD4 counts, comorbid pulmonary or renal disease, malignancy, and prior organ transplantation. The present conclusions are limited by heterogeneity among the selected studies and limitations in their identification and selection. However, P. jiroveci pneumonia in dermatology patients is associated with a high mortality rate. Based on our analysis, we propose that prophylaxis be considered in dermatology patients in whom treatment with systemic corticosteroids at doses exceeding 20 mg/day or treatment with corticosteroid-sparing immunosuppressive agents is anticipated for at least 4 weeks, and in patients with additional risk factors for P. jiroveci pneumonia.

Development and validation of a Pneumocystis jirovecii real-time polymerase chain reaction assay for diagnosis of Pneumocystis pneumonia

BACKGROUND

Pneumocystis jirovecii (PJ), a pathogenic fungus, causes severe interstitial Pneumocystis pneumonia (PCP) among immunocompromised patients. A laboratory-developed real-time polyermase chain reaction (PCR) assay was validated for PJ detection to improve diagnosis of PCP.

METHODS

Forty stored bronchoalveolar lavage (BAL) samples (20 known PJ positive [PJ+] and 20 known PJ negative [PJ-]) were initially tested using the molecular assay. Ninety-two sequentially collected BAL samples were then analyzed using an immunofluorescence assay (IFA) and secondarily tested using the PJ real-time PCR assay. Discrepant results were resolved by retesting BAL samples using another real-time PCR assay with a different target. PJ real-time PCR assay performance was compared with the existing gold standard (ie, IFA) and a modified gold standard, in which a true positive was defined as a sample that tested positive in two of three methods in a patient suspected to have PCP.

RESULTS

Ninety of 132 (68%) BAL fluid samples were collected from immunocompromised patients. Thirteen of 92 (14%) BALs collected were PJ+ when tested using IFA. A total of 40 BAL samples were PJ+ in the present study including: all IFA positive samples (n=13); all referred PJ+ BAL samples (n=20); and seven additional BAL samples that were IFA negative, but positive using the modified gold standard. Compared with IFA, the PJ real-time PCR had sensitivity, specificity, and positive and negative predictive values of 100%, 91%, 65% and 100%, respectively. Compared with the modified gold standard, PJ real-time PCR had a sensitivity, specificity, and positive and negative predictive values of 100%.

CONCLUSION

PJ real-time PCR improved detection of PJ in immunocompromised patients.

Opportunistic yeast pathogens: reservoirs, virulence mechanisms, and therapeutic strategies

Life-threatening invasive fungal infections are becoming increasingly common, at least in part due to the prevalence of medical interventions resulting in immunosuppression. Opportunistic fungal pathogens of humans exploit hosts that are immunocompromised, whether by immunosuppression or genetic predisposition, with infections originating from either commensal or environmental sources. Fungal pathogens are armed with an arsenal of traits that promote pathogenesis, including the ability to survive host physiological conditions and to switch between different morphological states. Despite the profound impact of fungal pathogens on human health worldwide, diagnostic strategies remain crude and treatment options are limited, with resistance to antifungal drugs on the rise. This review will focus on the global burden of fungal infections, the reservoirs of these pathogens, the traits of opportunistic yeast that lead to pathogenesis, host genetic susceptibilities, and the challenges that must be overcome to combat antifungal drug resistance and improve clinical outcome.

Population-based analysis of invasive fungal infections, France, 2001-2010

These infections are underrecognized as a cause of death in the general population and high-risk groups.

To determine the epidemiology and trends of invasive fungal infections (IFIs) in France, we analyzed incidence, risk factors, and in-hospital death rates related to the most frequent IFIs registered in the national hospital discharge database during 2001–2010. The identified 35,876 IFI cases included candidemia (43.4%), Pneumocystis jirovecii pneumonia (26.1%), invasive aspergillosis (IA, 23.9%), cryptococcosis (5.2%), and mucormycosis (1.5%). The overall incidence was 5.9/100,000 cases/year and the mortality rate was 27.6%; both increased over the period (+1.5%, +2.9%/year, respectively). Incidences substantially increased for candidemia, IA, and mucormycosis. Pneumocystis jirovecii pneumonia incidence decreased among AIDS patients (−14.3%/year) but increased in non-HIV–infected patients (+13.3%/year). Candidemia and IA incidence was increased among patients with hematologic malignancies (>+4%/year) and those with chronic renal failure (>+10%/year). In-hospital deaths substantially increased in some groups, e.g., in those with hematologic malignancies. IFIs occur among a broad spectrum of non–HIV-infected patients and should be a major public health priority.

Epidemiology and long-term survival in HIV-infected patients with Pneumocystis jirovecii pneumonia in the HAART era: experience in a university hospital and review of the literature

As highly active antiretroviral treatment (HAART) is widely available, the incidence of Pneumocystis jirovecii pneumonia (PJP) has decreased significantly but still represents a significant cause of morbidity and mortality in developed countries. We analyzed all the cases with PJP in human immunodeficiency virus (HIV)-infected patients from 2000 to 2013 in a university hospital in Barcelona, Spain, and conducted a systematic literature review to evaluate data regarding incidence, mortality, and long-term survival after PJP in developed settings. One hundred thirty-six episodes of PJP were analyzed. During the study period, the incidence decreased significantly (from 13.4 cases/1000 patients-year to 3.3 cases/1000 patients-year, P < 0.001). Oppositely, median age of the patients increased from 34 years in 2000 to 45 in 2013 (P = 0.024). PJP preceded HIV diagnosis in nearly 50% of the cases. Fifteen (11%) patients died during the PJP episode. The main risk factor for in-hospital mortality in our cohort was age >50 years (odds ratio 4.96, 95% confidence interval [CI] 1.45-15.14). Patients who survived were followed-up during a mean time of 44 months. Overall 5-year survival of patients after hospital discharge was 73%. Survival likelihood was 54% higher (88% [95% CI 81-96]) among HAART-adherent patients. Mean age and the proportion of patients with unknown HIV infection at the time of PJP diagnosis have increased in developed countries in the HAART era. Although the incidence has decreased, in-hospital mortality remains stable in this setting. Long-term survival is very high among HAART-adherent patients.

Prevalence of Pneumocystis jirovecii pneumonia (2010-2013): the first Croatian report

Pneumocystis jirovecii is an important cause of interstitial pneumonia particularly among immunocompromised hosts. We analysed the prevalence of P. jirovecii pneumonia (PCP) among HIV-infected and HIV-uninfected patients presented with interstitial pneumonia or acute respiratory syndrome hospitalized in six Croatian tertiary care hospitals. Over four-year period (2010-2013), a total of 328 lower respiratory tract samples: 253 (77.1%) bronchoalveolar lavage fluid, 43 (13.1%) tracheal aspirates and 32 (9.8%) bronchial aspirates from 290 patients were examined by real-time polymerase chain reaction (PCR). PCP was detected in 23 (7.9%) patients. The prevalence of PCP differed significantly among tested groups (χ2 = 95.03; d.f. = 3; p < 0.001). HIV-infected patients were more often positive (56.6%, 95%CI = 37.3-72.4) compared to other groups (patients with malignant disease 7.7%, 95%CI = 2.6-20.3; transplant patients 7.7%, 95%CI = 2.2-24.1; patients with other diagnosis 1.5%, 95%CI = 0.5-4.4). Majority of HIV-positive patients (80%) were newly diagnosed cases. Our results indicate that HIV-infected patients still represents the main risk group for P. jirovecii infection. PCP is responsible for pneumonia in 56.6% HIV-positive patients in Croatia, primarily those who do not know that they are HIV infected.

Burden of pneumocystis pneumonia in HIV-infected adults in sub-Saharan Africa: protocol for a systematic review

BACKGROUND

Reports from Africa have suggested that pneumocystis pneumonia (PCP) is a less important cause of morbidity than in the developed world. However, more recent studies have shown high seroprevalence rates of P. jirovecii in healthy individuals with HIV as well as high rates of clinical disease in African children. This suggests that PCP may be more common in Africa than was previously recognised. Understanding the contribution of PCP to disease in HIV-infected individuals in sub-Saharan Africa (SSA) has important implications for diagnosis, management and resource allocation. We therefore propose to conduct a systematic review and meta-analysis in order to investigate the burden of PCP in this population.

METHODS AND DESIGN

We plan to search electronic databases and reference lists of relevant articles published from 1995 to May 2013 using broad terms for pneumocystis, HIV/AIDS and sub-Saharan Africa. Studies will be included if they provide clear diagnostic criteria for PCP and well-defined study populations or mortality data (denominator). A novel quality score assessment tool has been developed to ensure fidelity to inclusion criteria, minimise risk of selection bias between reviewers and to assess quality of outcome ascertainment. This will be applied to eligible full-text articles. We will extract data using a standardised form and perform descriptive and quantitative analysis to assess PCP prevalence, mortality and case fatality, as well as the quality of included studies. This review protocol has been published in the PROSPERO International Prospective Register of systematic reviews, registration number CRD42013005530.

DISCUSSION

Our planned review will contribute to the diagnosis and management of community-acquired pneumonia in HIV-infected individuals in SSA by systematically assessing the burden of PCP in this population. We also describe a novel quality assessment tool that may be applied to other prevalence reviews.

Pneumocystis jirovecii (Pj) quantitative PCR to differentiate Pj pneumonia from Pj colonization in immunocompromised patients

Conventional polymerase chain reaction (PCR) in respiratory samples does not differentiate between Pneumocystis pneumonia (PCP) and Pneumocystis jirovecii (Pj) colonization. We used Pj real-time quantitative PCR (qPCR) with the objective to discriminate PCP from Pj colonization in immunocompromised patients. All positive Pj qPCR [targeting the major surface glycoprotein (MSG) gene] obtained in respiratory samples from immunocompromised patients presenting pneumonia at the Grenoble University Hospital, France, were collected between August 2009 and April 2011. Diagnoses were retrospectively determined by a multidisciplinary group of experts blinded to the Pj qPCR results. Thirty-one bronchoalveolar lavages and four broncho aspirations positive for the Pj qPCR were obtained from 35 immunocompromised patients. Diagnoses of definite, probable, and possible PCP, and pneumonia from another etiology were retrospectively made for 7, 4, 5, and 19 patients, respectively. Copy numbers were significantly higher in the “definite group” (median 465,000 copies/ml) than in the “probable group” (median 38,600 copies/ml), the “possible group” (median 1,032 copies/ml), and the “other diagnosis group” (median 390 copies/ml). With the value of 3,160 copies/ml, the sensitivity and specificity of qPCR for the diagnosis of PCP were 100 % and 70 %, respectively. With the value of 31,600 copies/ml, the sensitivity and specificity were 80 % and 100 %, respectively. The positive predictive value was 100 % for results with more than 31,600 copies/ml and the negative predictive value was 100 % for results with fewer than 3,160 copies/ml. qPCR targeting the MSG gene can be helpful to discriminate PCP from Pj colonization in immunocompromised patients, using two cut-off values, with a gray zone between them.

Dectin immunoadhesins and pneumocystis pneumonia

The opportunistic pathogen Pneumocystis jirovecii is a significant cause of disease in HIV-infected patients and others with immunosuppressive conditions. Pneumocystis can also cause complications in treatment following antiretroviral therapy or reversal of immunosuppressive therapy, as the newly reconstituted immune system can develop a pathological inflammatory response to remaining antigens or a previously undetected infection. To target β-(1,3)-glucan, a structural component of the Pneumocystis cell wall with immune-stimulating properties, we have developed immunoadhesins consisting of the carbohydrate binding domain of Dectin-1 fused to the Fc regions of the 4 subtypes of murine IgG (mIgG). These immunoadhesins bind β-glucan with high affinity, and precoating the surface of zymosan with Dectin-1:Fc can reduce cytokine production by macrophages in an in vitro stimulation assay. All Dectin-1:Fc variants showed specificity of binding to the asci of Pneumocystis murina, but effector activity of the fusion molecules varied depending on Fc subtype. Dectin-1:mIgG2a Fc was able to reduce the viability of P. murina in culture through a complement-dependent mechanism, whereas previous studies have shown the mIgG1 Fc fusion to increase macrophage-dependent killing. In an in vivo challenge model, systemic expression of Dectin-1:mIgG1 Fc significantly reduced ascus burden in the lung. When administered postinfection in a model of immune reconstitution inflammatory syndrome (IRIS), both Dectin-1:mIgG1 and Dectin-1:mIgG2a Fc reduced hypoxemia despite minimal effects on fungal burden in the lung. Taken together, these data indicate that molecules targeting β-glucan may provide a mechanism for treatment of fungal infection and for modulation of the inflammatory response to Pneumocystis and other pathogens.

Specific detection of Pneumocystis jirovecii in clinical samples by flow cytometry

Pneumocystis jirovecii is an opportunistic pathogen responsible for severe pneumonia in immunocompromised patients. Flow cytometry (FC) is a method widely used in different areas of clinical diagnosis like hematology and immunology. Recently it has started to be used in microbiology with a great potential for diagnosis of emergent microorganisms in clinical samples, especially when present in low numbers. The detection of Pneumocystis jirovecii in respiratory samples can be performed by FC, using specific monoclonal antibodies. Considering clinical diagnosis as a reference method, we previously showed FC to be 100% sensitive and specific when compared to immunofluorescence. Being an automated method, it is faster and less subject to human error than microscopic evaluation.

Lower incidence of Pneumocystis jirovecii pneumonia among Africans in the Netherlands host or environmental factors?

BACKGROUND AND OBJECTIVE

HIV-associated Pneumocystis jirovecii pneumonia (PJP) remains one of the commonest opportunistic infections in Western countries. Although it has been suggested that racial differences in PJP incidence exist, early studies report conflicting results. This study aimed to investigate differences in PJP incidence in a developed country among patients originating from sub-Saharan Africa compared with other regions of origin.

DESIGN AND METHODS

A retrospective observational cohort study was performed among 13,844 HIV-infected patients from the Dutch ATHENA cohort. The main outcome measure was occurrence of PJP.

RESULTS

A total number of 1055 PJP infections were diagnosed. Patients originating from sub-Saharan Africa had a significantly lower risk of having PJP at the time of HIV diagnosis after adjustment of confounders compared with patients from Western origin [Western Europe, Australia and New Zealand; adjusted odds ratio (aOR) 0.21 (95% confidence interval (CI) 0.15-0.29)]. Other factors associated with higher PJP risk were increasing age [aOR 1.01 per year (95% CI 1.00-1.02)], a low CD4 count at HIV diagnosis [CD4 <50 versus >350 cells/μl aOR 123.3 (95% CI 77.8-195.5)] and a high plasma HIV-RNA (>100,000 copies/ml) at HIV diagnosis [aOR 1.41 (95% CI 1.19-1.66)]. Moreover, a clearly lower risk for PJP acquisition later during follow-up was observed among sub-Saharan Africans versus Western patients [adjusted hazard ratio 0.60 (95% CI 0.39-0.90)].

CONCLUSION

Among HIV-infected patients living in the Netherlands, PJP occurrence is substantially lower in patients originating from sub-Saharan Africa, as compared to Western patients. Differences in genetic susceptibility may partially explain the lower PJP incidence in these patients.

Colonization by Pneumocystis jirovecii and its role in disease

Although the incidence of Pneumocystis pneumonia (PCP) has decreased since the introduction of combination antiretroviral therapy, it remains an important cause of disease in both HIV-infected and non-HIV-infected immunosuppressed populations. The epidemiology of PCP has shifted over the course of the HIV epidemic both from changes in HIV and PCP treatment and prevention and from changes in critical care medicine. Although less common in non-HIV-infected immunosuppressed patients, PCP is now more frequently seen due to the increasing numbers of organ transplants and development of novel immunotherapies. New diagnostic and treatment modalities are under investigation. The immune response is critical in preventing this disease but also results in lung damage, and future work may offer potential areas for vaccine development or immunomodulatory therapy. Colonization with Pneumocystis is an area of increasing clinical and research interest and may be important in development of lung diseases such as chronic obstructive pulmonary disease. In this review, we discuss current clinical and research topics in the study of Pneumocystis and highlight areas for future research.

A comparison of seriously ill patients with or without AIDS requiring prolonged mechanical ventilation

PURPOSE

The aim of this study was to compare differences in underlying diagnoses, weaning outcomes, discharge disposition, and survival in prolonged mechanical ventilator (PMV)-dependent patients with and without AIDS.

METHODS

Ninety consecutive AIDS patients requiring PMV were retrospectively matched with 90 clinically similar non-AIDS patients to form matched cohorts to determine differences in their outcomes.

RESULTS

AIDS patients had more acute diagnoses requiring PMV, whereas non-AIDS patients had more chronic diagnoses (P < .001). Weaning outcomes were alike with 31 (35%) AIDS and 37 (41%) non-AIDS patients successfully weaned. More AIDS patients went home, and fewer, to nursing facilities (P = .04). In each cohort, successfully weaned patients had significantly longer survival than their unweaned counterparts (all P < .001). Successful weaning reduced the risk of death in AIDS and non-AIDS patients (hazard ratios, 0.29 and 0.20; 95% confidence intervals, 0.17-0.50 and 0.11-0.36, respectively; all P < .001).

CONCLUSIONS

AIDS had little effect on weaning success or survival. Successful weaning increased survival regardless of a diagnosis of AIDS. The AIDS patients had more home discharges and fewer to nursing facilities, which likely resulted from the AIDS patients having more acute illnesses leading to PMV than the non-AIDS patients.

Opportunistic and fungal infections of the lung

Opportunistic infections are a major cause of morbidity and mortality in severely immunocompromised patients, such as those receiving chemotherapy or with haematological malignancy, aplastic anaemia or HIV infection, or recipients of solid-organ or stem cell transplants. In addition, the increasing use of biological therapies will result in more patients at risk of opportunistic infections, albeit to a lesser degree than classic causes of immunocompromise. The type and degree of immune defect dictates the profile of potential opportunistic pathogens; T-cell mediated defects increase the risk of viral (cytomegalovirus and respiratory viruses) and Pneumocystis jirovecii infections, whereas neutrophil defects are associated with bacterial pneumonia and invasive aspergillosis. However, patients often have combinations of immune defects and a wide range of other opportunistic infections can cause pneumonia. The radiological pattern of disease (best assessed by CT scan) and speed of onset also help identify the likely pathogen(s), which can then be supported by targeted investigation including early use of bronchoscopy in selected patients. Rapid and expert clinical assessment can identify the most likely pathogens, which can then be treated aggressively and so provide the best opportunity for a positive outcome.

The impact of comorbid [corrected] conditions on critical illness

OBJECTIVE

To review the current knowledge of common comorbidities in the intensive care unit, including diabetes mellitus, chronic obstructive pulmonary disease, cancer, end-stage renal disease, end-stage liver disease, HIV infection, and obesity, with specific attention to epidemiology, contribution to diseases and outcomes, and the impact on treatments in these patients.

DATA SOURCE

Review of the relevant medical literature for specific common comorbidities in the critically ill.

RESULTS

Critically ill patients are admitted to the intensive care unit for various reasons, and often the admission diagnosis is accompanied by a chronic comorbidity. Chronic comorbid conditions commonly seen in critically ill patients may influence the decision to provide intensive care unit care, decisions regarding types and intensity of intensive care unit treatment options, and outcomes. The presence of comorbid conditions may predispose patients to specific complications or forms of organ dysfunction. The impact of specific comorbidities varies among critically ill medical, surgical, and other populations, and outcomes associated with certain comorbidities have changed over time. Specifically, outcomes for patients with cancer and HIV have improved, likely related to advances in therapy. Overall, the negative impact of chronic comorbidity on survival in critical illness may be primarily influenced by the degree of organ dysfunction or the cumulative severity of multiple comorbidities.

CONCLUSION

Chronic comorbid conditions are common in critically ill patients. Both the acute illness and the chronic conditions influence prognosis and optimal care delivery for these patients, particularly for adverse outcomes and complications influenced by comorbidities. Further work is needed to fully determine the individual and combined impact of chronic comorbidities on intensive care unit outcomes.

Outcomes for critically ill patients with HIV and severe sepsis in the era of highly active antiretroviral therapy

RATIONALE

With the advent of highly active antiretroviral therapy (HAART), sepsis has become a more frequent ICU diagnosis for patients with HIV infections. Yet, little is known about the etiologies of acute infections in critically ill patients with HIV and the factors that affect in-hospital mortality.

METHODS

Cases of patients with HIV requiring intensive care specifically for severe sepsis were identified over 27 months. Demographic information, variables related to acute illness severity, variables related to HIV infection, and all acute infections contributing to ICU stay were recorded.

RESULTS

Of 990 patients admitted to the ICU with severe sepsis, 136 (13.7%) were HIV-infected. There were 194 acute infections among the 125 patients with full data available; 112 of the infections were nosocomial/health care-associated, 55 were AIDS-related, and 27 were community-acquired. Patients with nosocomial/health care-associated and AIDS-related infections had lower CD4 counts and were less likely to be on HAART (P < .05). The inpatient mortality was 42%. In a multivariable logistic regression model, only the APACHE II score (odds ratio, 1.12; 95% confidence interval, 1.02-1.23) was significantly associated with hospital mortality, although any HAART use (odds ratio, 0.53; 95% confidence interval, 0.22-1.33, P = .18) approached statistical significance.

CONCLUSIONS

In this large cohort study, nosocomial/health care-associated infections were common in ICU patients with HIV and severe sepsis. Hospital mortality was associated with acute illness severity, but not clearly associated with variables related to HIV infection. Interventions that aim to prevent or more effectively treat nosocomial infections in critically ill patients with HIV may favorably impact clinical outcomes.