Community-acquired bacterial pneumonia in human immunodeficiency virus-infected patients: validation of severity criteria. The Grupo Andaluz para el Estudio de las Enfermedades Infecciosas

Predictors of Mortality Among Hospitalized Patients With Lower Respiratory Tract Infections in a High HIV Burden Setting

INTRODUCTION

Lower respiratory tract infections (LRTIs) are a leading cause of mortality in sub-Saharan Africa. Triaging identifies patients at high risk of death, but laboratory tests proposed for use in severity-of-illness scores are not readily available, limiting their clinical use. Our objective was to determine whether baseline characteristics in hospitalized participants with LRTI predicted increased risk of death.

METHODS

This was a secondary analysis from the Mulago Inpatient Non-invasive Diagnosis-International HIV-associated Opportunistic Pneumonias (MIND-IHOP) cohort of adults hospitalized with LRTI who underwent standardized investigations and treatment. The primary outcome was all-cause mortality at 2 months. Predictors of mortality were determined using multiple logistic regression.

RESULTS

Of 1887 hospitalized participants with LRTI, 372 (19.7%) died. The median participant age was 34.3 years (interquartile range, 28.0-43.3 years), 978 (51.8%) were men, and 1192 (63.2%) were HIV-positive with median CD4 counts of 81 cells/µL (interquartile range, 21-226 cells/µL). Seven hundred eleven (37.7%) participants had a microbiologically confirmed diagnosis. Temperature <35.5°C [adjusted odds ratio (aOR) = 1.77, 95% confidence intervals (CI): 1.20 to 2.60; P = 0.004], heart rate >120/min (aOR = 1.82, 95% CI: 1.37 to 2.43; P < 0.0001), oxygen saturation <90% (aOR = 2.74, 95% CI: 1.97 to 3.81; P < 0.0001), being bed-bound (aOR = 1.88, 95% CI: 1.47 to 2.41; P < 0.0001), and being HIV-positive (aOR = 1.49, 95% CI: 1.14 to 1.94; P = 0.003) were independently associated with mortality at 2 months.

CONCLUSIONS

Having temperature <35.5°C, heart rate >120/min, hypoxia, being HIV-positive, and bed-bound independently predicts mortality in participants hospitalized with LRTI. These readily available characteristics could be used to triage patients with LRTI in low-income settings. Providing adequate oxygen, adequate intravenous fluids, and early antiretroviral therapy (in people living with HIV/AIDS) may be life-saving in hospitalized patients with LRTI.

Prevalence and clinical impact of Streptococcus pneumoniae nasopharyngeal carriage in solid organ transplant recipients

Background

S. pneumoniae is the leading cause of community-acquired pneumonia in the solid organ transplant recipient (SOTR); nevertheless, the prevalence of colonization and of the colonizing/infecting serotypes has not been studied in this population. In this context, the aim of the present study was to describe the rate, characteristics, and clinical impact of S. pneumoniae nasopharyngeal carriage.

Methods

A prospective observational cohort of Solid Organ Transplant recipients (SOTR) was held at the University Hospital Virgen del Rocío, Seville, Spain with the aim to evaluate the S. pneumoniae colonization and the serotype prevalence in SOTR. Two different pharyngeal swabs samples from 500 patients were included in two different seasonal periods winter and spring/summer. Optochin and bile solubility tests were performed for the isolation of thew strains. Antimicrobial susceptibility studies (MICs, mg/l) of levofloxacin, trimethoprim-sulfamethoxazole, penicillin, amoxicillin, cefotaxime, ceftriaxone, erythromycin, azithromycin and vancomycin for each isolate were determined by E-test strips. Capsular typing was done by sequential multiplex PCR reactions. A multivariate logistic regression analysis of factors potentially associated with pneumococcal nasopharyngeal carriage and disease was performed.

Results

Twenty-six (5.6%) and fifteen (3.2%) patients were colonized in winter and spring/summer periods, respectively. Colonized SOT recipients compared to non-colonized patients were more frequently men (79.5% vs. 63.1%, P < 0.05) and cohabitated regularly with children (59% vs. 32.2%, P < 0.001). The most prevalent serotype in both studied periods was 35B. Forty-five percent of total isolates were included in the pneumococcal vaccine PPV23. Trimethoprim-sulfamethoxazole and macrolides were the less active antibiotics. Three patients had non-bacteremic pneumococcal pneumonia, and two of them died.

Conclusions

Pneumococcal colonization in SOTR is low with the most colonizing serotypes not included in the pneumococcal vaccines.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4321-8) contains supplementary material, which is available to authorized users.

Prognostic indicators in the World Health Organization's algorithm for seriously ill HIV-infected inpatients with suspected tuberculosis

BACKGROUND

Criteria for the 2007 WHO algorithm for diagnosing tuberculosis among HIV-infected seriously ill patients are the presence of one or more danger signs (respiratory rate > 30/min, heart rate > 120/min, temperature > 39 °C, and being unable to walk unaided) and cough ≥ 14 days. Determining predictors of poor outcomes among HIV-infected inpatients presenting with WHO danger signs could result in improved treatment and diagnostic algorithms.

METHODS

We conducted a prospective cohort study of inpatients presenting with any duration of cough and WHO danger signs to two regional hospitals in Cape Town, South Africa. The primary outcome was all-cause mortality up to 56 days post-discharge, and the secondary outcome a composite of any one of: hospital admission for > 7 days, died in hospital, transfer to a tertiary level or tuberculosis hospital. We first assessed the WHO danger signs as predictors of poor outcomes, then assessed the added value of other variables selected a priori for their ability to predict mortality in common respiratory opportunistic infections (CD4 count, body mass index (BMI), being on antiretroviral therapy (ART), hypotension, and confusion) by comparing the receiver operating characteristic (ROC) area under the curve (AUC) of the two multivariate models.

RESULTS

484 participants were enrolled, median age 36, 66% women, 53% had tuberculosis confirmed on culture. The 56-day mortality was 13.2%. Inability to walk unaided, low BMI, low CD4 count, and being on ART were independently associated with poor outcomes. The multivariate model of the WHO danger signs showed a ROC AUC of 0.649 (95% CI 0.582-0.717) for predicting 56-day mortality, which improved to ROC AUC of 0.740 (95% CI 0.681-0.800; p = 0.004 for comparison between the two ROC AUCs) with the multivariate model including the a priori selected variables. Findings were similar in sub-analyses of participants with culture-positive tuberculosis and with cough duration ≥ 14 days.

CONCLUSION

The study design prevented a rigorous evaluation of the prognostic value of the WHO danger signs. Our prognostic model could result in improved algorithms, but needs to be validated.

Atypical bacterial pneumonia in the HIV-infected population

Human immunodeficiency virus (HIV)-infected individuals are more susceptible to respiratory tract infections by other infectious agents (viruses, bacteria, parasites, and fungi) as their disease progresses to acquired immunodeficiency syndrome. Despite effective antiretroviral therapy, bacterial pneumonia (the most frequently occurring HIV-associated pulmonary illness) remains a common cause of morbidity and mortality in the HIV-infected population. Over the last few decades, studies have looked at the role of atypical bacterial pneumonia (i.e. pneumonia that causes an atypical clinical presentation or responds differently to typical therapeutics) in association with HIV infection. Due to the lack of available diagnostic strategies, the lack of consideration, and the declining immunity of the patient, HIV co-infections with atypical bacteria are currently believed to be underreported. Thus, following an extensive database search, this review aimed to highlight the current knowledge and gaps regarding atypical bacterial pneumonia in HIV. The authors discuss the prevalence of Chlamydophila pneumoniae, Mycoplasma pneumoniae, Coxiella burnetii, Legionella species and others in the HIV-infected population as well as their clinical presentation, methods of detection, and treatment. Further studies looking at the role of these microbes in association with HIV are required. Increased knowledge of these atypical bacteria will lead to a more rapid diagnosis of these infections, resulting in an improved quality of life for the HIV-infected population.

Characteristics of hospital admissions for pneumonia in HIV-positive individuals in Winnipeg, Manitoba: a cross-sectional retrospective analysis

Lung infection in human immunodeficiency virus (HIV)-positive individuals remains an important cause of morbidity and mortality, even in the current antiretroviral therapy era. Pneumonia is the most common cause of admission in HIV-positive individuals in our centre as reported in a previously published study. The objective of this retrospective observational study was to further characterize these admissions, with respect to index of disease severity at presentation, organisms identified, and investigations pursued including bronchoalveolar lavage (BAL). There were 123 unique patients accounting for a total of 209 admissions from 2005 to 2015. An organism was isolated in only 33% of all admissions (68/209). The most common organism was Pneumocystis jirovecii with a frequency of 29% of all admissions. Eighty-seven percent of presentations were mild, and 13% were moderate by CURB-65 criteria. A total of 39 BALs were performed, of which 27 yielded an organism (69%). Considering the burden of disease, low diagnostic yield of the current diagnostic strategy and increased morbidity and mortality caused by pneumonia in HIV-positive individuals, further methods are needed to more accurately target therapy. The preponderance of mild disease in this study suggests that better diagnostic tests may identify individuals that can be candidates for outpatient therapy.

Impact of HIV on the severity of influenza

Despite current antiretroviral therapy, HIV/AIDS is one of the most prelevant problems in healthcare worldwide. Similarly, influenza viruses are causes of epidemics outbreaks. HIV-infected patients are considered a high risk group for severe influenza infection, although several recent observational studies suggest that not all HIV-infected patients are equally susceptible to complications and that these patients should be stratified by their immunodeficiency status and other factors (such as smoking or comorbidities). Here, we have compiled the most recent data on the impact that HIV has on influenza infection.

A Clinical Predictor Score for 30-Day Mortality among HIV-Infected Adults Hospitalized with Pneumonia in Uganda

Background

Pneumonia is a major cause of mortality among HIV-infected patients. Pneumonia severity scores are promising tools to assist clinicians in predicting patients’ 30-day mortality, but existing scores were developed in populations infected with neither HIV nor tuberculosis (TB) and include laboratory data that may not be available in resource-limited settings. The objective of this study was to develop a score to predict mortality in HIV-infected adults with pneumonia in TB-endemic, resource-limited settings.

Methods

We conducted a secondary analysis of data from a prospective study enrolling HIV-infected adults with cough ≥2 weeks and <6 months and clinically suspected pneumonia admitted to Mulago Hospital in Kampala, Uganda from September 2008 to March 2011. Patients provided two sputum specimens for mycobacteria, and those with Ziehl-Neelsen sputum smears that were negative for mycobacteria underwent bronchoscopy with inspection for Kaposi sarcoma and testing for mycobacteria and fungi, including Pneumocystis jirovecii. A multivariable best subsets regression model was developed, and one point was assigned to each variable in the model to develop a clinical predictor score for 30-day mortality.

Results

Overall, 835 patients were studied (mean age 34 years, 53.4% female, 30-day mortality 18.2%). A four-point clinical predictor score was identified and included heart rate >120 beats/minute, respiratory rate >30 breaths/minute, oxygen saturation <90%, and CD4 cell count <50 cells/mm³. Patients’ 30-day mortality, stratified by score, was: score 0 or 1, 12.6%, score 2 or 3, 23.4%, score 4, 53.9%. For each 1 point change in clinical predictor score, the odds of 30-day mortality increased by 65% (OR 1.65, 95% CI 1.39-1.96, p <0.001).

Conclusions

A simple, four-point scoring system can stratify patients by levels of risk for mortality. Rapid identification of higher risk patients combined with provision of timely and appropriate treatment may improve clinical outcomes. This predictor score should be validated in other resource-limited settings.

[Comparative diagnosis of bacterial pneumonia and pulmonary tuberculosis in HIV positive patients]

INTRODUCTION

Immunodepression induced by the human immunodeficiency virus (HIV) modifies the clinical, radiological and microbiological manifestations of pulmonary tuberculosis; leading to similarities between pulmonary tuberculosis and acute community-acquired bacterial pneumonia. A consequence is the high proportion of discordant pre- and post-mortem diagnoses of pneumonia. The aim of our study was to contribute to the improvement in the diagnosis of acute bacterial pneumonia in HIV positive patients in areas where tuberculosis is endemic.

METHODS

This retrospective study in HIV positive patients has compared 94 cases of positive smear cases pulmonary tuberculosis and 78 cases of acute community-acquired bacterial pneumonia.

RESULTS

Using logistic regression, the following features were positively associated with bacterial pneumonia: the sudden onset of signs (OR=8.48 [CI 95% 2.50-28.74]), a delay in the evolution of symptoms of less than 15 days (OR=3.70 [CI 95% 1.11-12.35]), chest pain (OR=2.81 [CI 95% 1.10-7.18]), radiological alveolar shadowing (OR=12.98 [CI 95% 4.66-36.12) and high leukocytosis (OR=3.52 [CI 95% 1.19-10.44]). These five variables allowed us to establish a diagnostic score for bacterial pneumonia ranging from 0 to 5. The area under the ROC curve was 0.886 [CI 95% 0.84-0.94, P<0.001]). Its specificity was >96.8% for a score of greater than or equal to 4.

CONCLUSION

The diagnostic score for acute community-acquired pneumonia may improve the management of bacterial pneumonia in areas where tuberculosis is endemic.

Pneumococcal disease in adult solid organ transplantation recipients

In solid organ transplant (SOT) recipients, Streptococcus pneumoniae can cause substantial morbidity and mortality ranging from non-invasive to invasive diseases, including pneumonia, bacteremia, and meningitis, with a risk of invasive pneumococcal disease 12 times higher than that observed in non-immunocompromised patients. Moreover, pneumococcal infection has been related to graft dysfunction. Several factors have been involved in the risk of pneumococcal disease in SOT recipients, such as type of transplant, time since transplantation, influenza activity, and nasopharyngeal colonization. Pneumococcal vaccination is recommended for all SOT recipients with 23-valent pneumococcal polysaccharides vaccine. Although immunological rate response is appropriate, it is lower than in the rest of the population, decreases with time, and its clinical efficacy is variable. Booster strategy with 7-valent pneumococcal conjugate vaccine has not shown benefit in this population. Despite its relevance, there are few studies focused on invasive pneumococcal disease in SOT recipients. Further studies addressing clinical, microbiological, and epidemiological data of pneumococcal disease in the transplant setting as well as new strategies for improving the protection of SOT recipients are warranted.

Influence of HIV infection on the clinical presentation and outcome of adults with acute community-acquired pneumonia in Yaounde, Cameroon: a retrospective hospital-based study

Background

The impact of HIV infection on the evolution of acute community-acquired pneumonia (CAP) is still controversial. The aim of this study was to investigate possible differences in the clinical presentation and in-hospital outcomes of patients with CAP with and without HIV infection in a specialised service in Yaounde.

Methods

Medical files of 106 patients (51 men) aged 15 years and above, admitted to the Pneumology service of the Yaounde Jamot Hospital between January 2008 and May 2012, were retrospectively studied.

Results

Sixty-two (58.5%) patients were HIV infected. The median age of all patients was 40 years (interquartile range: 31.75-53) and there was no difference in the clinical and radiological profile of patients with and without HIV infection. The median leukocyte count (interquartile range) was 14,600/mm³ (10,900-20,600) and 10,450/mm³ (6,400-16,850) respectively in HIV negative and HIV positive patients (p = 0.002). Median haemoglobin level (interquartile range) was 10.8 g/dl (8.9-12) in HIV negative and 9.7 g/dl (8–11.6) in HIV positive patients (p = 0.025). In-hospital treatment failure on third day (39.5% vs. 25.5.1%, p = 0.137) and mortality rates (9% vs. 14.5%, p = 0.401) were similar between HIV negative and HIV positive patients.

Conclusion

Clinical and radiological features as well as response to treatment and in hospital fatal outcomes are similar in adult patients hospitalised with acute community-acquired pneumonia in Yaounde. In contrast, HIV infected patients tend to be more anaemic and have lower white cell counts than HIV negative patients. Larger prospective studies are needed to consolidate these findings.

Community-acquired pneumonia due to Panton-Valentine leukocidin-producing Staphylococcus aureus in an HIV-2-infected patient

Pneumonia caused by Panton-Valentine leukocidin-producing Staphylococcus aureus is associated with a high fatality rate. There have been few reported cases in HIV-1-co-infected patients. Here we report a fatal case of severe community-acquired pneumonia caused by Panton-Valentine leukocidin-producing S. aureus in a 45-year-old woman with HIV-2 infection.

Defining severe pneumonia

Pneumonia is an important clinical and public health problem. Identification and prediction of severe pneumonia are significant concerns. Attempts to define severe pneumonia should recognize that different purposes are served by different definitions; no single definition meets all needs. At present, several prediction models have been proposed or validated. Biomarkers are not yet ready for routine use. The authors recommend careful consideration of the implications of any given definition of pneumonia severity. Outcome studies are needed to integrate human and health care system factors with the application of pneumonia severity definitions.

Predictors of pneumonia severity in HIV-infected adults admitted to an Urban public hospital

Data on outcomes of community-acquired pneumonia (CAP) in the HIV-infected population are mixed and the perception of worse outcomes in HIV may lead to excess hospitalization. We retrospectively evaluated the utility of the Pneumonia Severity Index, or PORT score, as a prediction rule for mortality in 102 HIV-infected adults hospitalized at an urban public hospital with CAP. Primary outcome was survival at 30 days. Secondary outcomes included survival on discharge, intensive care unit (ICU) admission, length of stay, and readmission within 30 days. The cohort was predominantly male (70%) with a mean age of 45.4 years (standard deviation [SD] ± 7.4). Mean CD4 cell count was 318 cells per microliter; 40 (39%) had CD4 less than 200 cells per microliter. Forty-three percent were on antiretroviral therapy at the time of admission and 31% on prophylactic antibiotics. Twelve patients had bacteremia on admission, predominantly with Streptococcus pneumoniae. Of the 46 patients with admission sputum cultures, 20 yielded an organism, most commonly Haemophilus influenzae and S. pneumoniae. Overall survival in the cohort was high, 96%. Most patients (81%) had a low PORT risk score (class I-III). PORT score predicted 30-day survival (p=0.01) and ICU admission (p=0.03), but antiretroviral use did not. In contrast to a prior study, we did not find that CD4 cell count predicted CAP outcome. Lack of stable housing was not associated with worse outcomes. The PORT score may be a valid tool to predict mortality and need for hospital admission in HIV-infected patients with CAP.

Changing needs of community-acquired pneumonia

Community-acquired pneumonia (CAP) is a serious condition associated with significant morbidity and potential long-term mortality. Although the majority of patients with CAP are treated as outpatients, the greatest proportion of pneumonia-related mortality and healthcare expenditure occurs among the patients who are hospitalized. There has been considerable interest in determining risk factors and severity criteria assessments to assist with site-of-care decisions. For both inpatients and outpatients, the most common pathogens associated with CAP include Streptococcus pneumoniae, Haemophilus influenzae, group A streptococci and Moraxella catarrhalis. Atypical pathogens, Gram-negative bacilli, methicillin-resistant Staphylococcus aureus (MRSA) and viruses are also recognized aetiological agents of CAP. Despite the availability of antimicrobial therapies, the recent emergence of drug-resistant pneumococcal and staphylococcal isolates has limited the effectiveness of currently available agents. Because early and rapid initiation of empirical antimicrobial treatment is critical for achieving a favourable outcome in CAP, newer agents with activity against drug-resistant strains of S. pneumoniae and MRSA are needed for the management of patients with CAP.

AIDS Patients in the ICU

At the beginning of the AIDS epidemic, there were higher mortality rates in patients requiring admission to an intensive care unit (ICU) most likely due to acute respiratory failure. Whereas the use of prophylaxis and corticosteroids for Pneumocystisjiroveci pneumonia and highly active antiretroviral therapy has changed this outcome and has improved survival rate. However, respiratory failure has remained the most common indication for an ICU admission. When HIV-infected patients are admitted to the ICU, intensivists need to be knowledgeable about the manifestations of common diseases and the new manifestations related to antiretroviral therapy. Much HIV mortality has been linked directly to late diagnosis and late initiation of appropriate antiviral therapy. This l, the most important cause of ICU admission for AIDS patients. We analyzed the characteristics of P.jiroveci pneumonia, bacterial pneumonia, cytomegalovirus pneumonia, mycobacterial infections, pulmonary invasive fungal infections, Kaposi’s sarcoma, and the immune reconstitution inflammatory syndrome.

[Characteristics of supposedly bacterial community acute pneumonia among HIV-positive patients: prospective preliminary study]

INTRODUCTION

Community-acquired pneumonia (CAP) is the second leading cause of hospitalization in the respirology department in Abidjan after tuberculosis. Frequently associated with HIV infection, it has a high mortality rate of about 20% to 30%. The aim of this study is to identify the specificities and severity factors associated with bacterial CAP (BCAP) outcome in HIV-positive patients.

METHODS

The authors conducted a prospective and comparative preliminary study on two groups of patients: 29 HIV-positive patients with BCAP and 21 HIV-negative patients with BCAP. All of the patients were hospitalized for BCAP with symptoms of severity according to the usual score of severity.

RESULTS

The sociodemographic, clinical and paraclinical characteristics were similar in both groups. Failures and deaths were more frequent in the group with HIV infection. In particular, HIV infected patients with a body mass index under 18.5 and a rate of T CD4 lymphocytes lower than 200/mm(3) presented the least favourable evolution.

CONCLUSIONS

A more extensive study should help define the appropriate severity criteria for BCAP associated with HIV infection.

Review: Novel targets in the management of pneumonia

Community-acquired pneumonia (CAP) is the leading cause of death from infectious diseases in the US. It accounts each year for 500,000 hospitalizations and 45,000 deaths and represents one of the most common causes of intensive care unit (ICU) admission. The mortality rate due to severe CAP has shown little improvement in the past three decades, remaining between 21% and 58% in patients admitted to the intensive care unit. Antimicrobial agents are the cornerstone of therapy against CAP, but there are some novel antibiotic and nonantibiotic therapies that have been recently tested that may potentially impact outcomes of patients with severe CAP. We will review the most recent data regarding novel therapies in patients with the highest risk of death such as those with severe CAP.

Pneumonia in HIV-infected persons: increased risk with cigarette smoking and treatment interruption

RATIONALE

Bacterial pneumonia is a major cause of morbidity for HIV-infected persons and contributes to excess mortality in this population.

OBJECTIVES

To evaluate the frequency and risk factors for occurrence of bacterial pneumonia in the present era of potent antiretroviral therapy.

METHODS

We evaluated data from a randomized trial of episodic antiretroviral therapy. The study, Strategies for Management of Antiretroviral Therapy, enrolled 5,472 participants at 318 sites in 33 countries. Study patients had more than 350 CD4 cells at baseline. Diagnosis of bacterial pneumonia was confirmed by a blinded clinical-events committee.

MEASUREMENTS AND MAIN RESULTS

During a mean follow-up of 16 months, 116 participants (2.2%) developed at least one episode of bacterial pneumonia. Patients randomized to receive episodic antiretroviral therapy were significantly more likely to develop pneumonia than patients randomized to receive continuous antiretroviral therapy (hazard ratio, 1.55; 95% confidence interval, 1.07-2.25; P = 0.02). Cigarette smoking was a major risk factor: Current-smokers had more than an 80% higher risk of pneumonia compared with never-smokers (hazard ratio, 1.82; 95% confidence interval, 1.09-3.04; P = 0.02). Participants who were on continuous HIV treatment and were current smokers were three times more likely to develop bacterial pneumonia than nonsmokers. Current smoking status was significant, but a past history of smoking was not.

CONCLUSIONS

Bacterial pneumonia is a major source of morbidity, even for persons on potent antiretroviral therapy, including those with high CD4 cells. Efforts to reduce this illness should stress the importance of uninterrupted antiretroviral therapy and attainment and/or maintenance of nonsmoking status.

Community-acquired pneumonia: what is relevant and what is not?

PURPOSE OF REVIEW

Community-acquired pneumonia is associated with significant morbidity and mortality and is the most common cause of death from infectious diseases in North America. The purpose of this review is to highlight recent advances in epidemiology, risk factors, severity criteria and antibiotic therapeutic regimens used for community-acquired pneumonia management.

RECENT FINDINGS

All guidelines recommend early and appropriate empiric therapy directed against common typical organisms, such as Streptococcus pneumoniae, and other atypical organisms, but clinicians should be aware of newer emerging pathogens such as community-acquired methicillin-resistant Staphylococcus aureus and Gram-negative pathogens.

SUMMARY

The optimum outcome in community-acquired pneumonia can be achieved by careful risk stratification using prediction rules together with appropriate antibiotic regimens. The mainstay of community-acquired pneumonia prevention is influenza and pneumococcal immunization. Promotion of smoking cessation will also help curtail the incidence of pneumococcal disease.

Community-Acquired Respiratory Complications in the Intensive Care Unit: Pneumonia and Acute Exacerbations of COPD

This chapter will review the two most common lower respiratory tract infections in the intensive care unit (ICU), community-acquired pneumonia (CAP) and acute exacerbations of chronic obstructive pulmonary disease (AECOPD). In addition we will provide an overview of the topics including recommendations for the diagnosis and treatment.

The role of new therapies for severe community-acquired pneumonia

PURPOSE OF REVIEW

Community-acquired pneumonia (CAP) is associated with significant morbidity and mortality and is the most common cause of death from infectious diseases. CAP patients requiring intensive care unit (ICU) admission carry the highest mortality rates. This paper aims to review the current literature regarding epidemiology, risk factors, severity criteria and reasons for admitting the hospitalized patient to the ICU, and the empiric and specific antibiotic therapeutic regimens employed.

RECENT FINDINGS

Multiple sets of clinical practice guidelines have been published in the past few years addressing the treatment of CAP. The guidelines all agree that CAP patients admitted to the hospital represent a major concern, and appropriate empiric therapy should be instituted to improve clinical outcomes.

SUMMARY

The cost, morbidity and mortality of CAP patients requiring ICU admission remain unacceptably high. These are heterogeneous groups of patients, so it is important to use risk-stratification based on clinical parameters and prediction tools. Appropriate antibiotic therapy is an important component in the management of both groups of patients. In particular, it is essential to administer an appropriate antimicrobial agent from the initiation of therapy, so that the risks of treatment failure and the morbidity of CAP may be minimized.

Pneumonia severity index in the immunocompromised

BACKGROUND

The pneumonia severity index (PSI) accounts for many comorbidities, but not immunosuppression.

OBJECTIVES

To document the utility of the PSI to predict mortality in immunocompromised patients (IP) with community-acquired pneumonia (CAP).

METHODS

Charts of 284 patients with immunosuppression and CAP were reviewed, and these patients were compared with a contemporary sample of non-IP with CAP. The ability of the PSI to predict mortality was assessed by using multiple logistic regression. Discrimination of the PSI was studied by using the concordance index.

RESULTS

Thirty-nine of 284 IP died. Mortality varied according to the etiology of the immunosuppression. Patients with HIV, solid organ transplantation or treatment with immunosuppressive drugs (n=118) had a low in-hospital mortality (4.3%) and were classified as low risk. IP with hematological malignancies, chemotherapy, chest radiation or marrow transplantation (n=166) had a high mortality (20%) and were classified as high risk. Compared with non-IP, low-risk IP had similar PSI-controlled mortality (OR=0.9, P=0.80), whereas high-risk IP had significantly greater mortality (OR=2.8, P<0.0001). The concordance index revealed similar discrimination for the PSI in low-risk IP (0.77) and in non-IP (0.7), but inferior discrimination in high-risk patients (0.6).

CONCLUSIONS

Patients with CAP and immunosuppression can be divided into low-risk and high-risk groups. The low-risk IP have mortality similar to non-IP and can be risk stratified by using the PSI.

HIV Impairs TNF-α Release in Response to Toll-Like Receptor 4 Stimulation in Human MacrophagesIn Vitro

The molecular mechanisms for increased risk of bacterial pneumonia in HIV+ persons remain incompletely understood. Recognizing the critical role of Toll-like receptor (TLR) signaling in host defense, this study showed that human U937 macrophage stimulation by the TLR4-specific ligand, lipid A (biologically active component of bacterial LPS), promoted TNF-alpha release through extracellular regulated kinase (ERK)1/2 mitogen-activated protein (MAP) kinase phosphorylation. In contrast, HIV+ U1 macrophages had significantly reduced TNF-alpha release (despite preserved TLR4 expression) and reduced ERK1/2 phosphorylation, whereas TNF-alpha release was intact via a TLR4-independent pathway. In HIV+ U1 cells, reduced ERK1/2 phosphorylation was not due to reduced upstream MEK1/2 activation, but was associated with a reciprocal induction of MAP kinase phosphatase-1 (MKP-1). HIV nef protein was sufficient to reduce TNF-alpha release and induce MKP-1 in healthy macrophages. Pharmacologic inhibition of endogenous cellular phosphatases increased ERK1/2 phosphorylation and partially restored TLR4-mediated TNF-alpha release in HIV+ macrophages. Furthermore, targeted gene silencing of MKP-1 partially restored lipid A-mediated TNF-alpha release in HIV+ U1 cells. Similar results were observed using clinically relevant human alveolar macrophages, comparing healthy to asymptomatic HIV+ persons at clinical risk for bacterial pneumonia. Thus, reduced TLR4-mediated TNF-alpha release through altered ERK1/2 regulation by HIV may impair an effective innate immune response to bacterial challenge. Inhibition of cellular phosphatases may serve as a potential therapeutic target in the management of bacterial pneumonia in HIV+ persons.

Etiology of community-acquired pneumonia

Community-acquired pneumonia (CAP) is a serious lower respiratory tract infection associated with significant morbidity and mortality that is characterized by disputes over diagnostic evaluations and therapeutic decisions. With the widespread use of broad-spectrum antimicrobial agents and the increasing number of immunocompromised hosts, the etiology and the drug resistance patterns of pathogens responsible for CAP have changed. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis remain the leading causes of CAP in immunocompetent patients. Opportunistic infections with organisms such as Pneumocystis jiroveci and Mycobacterium tuberculosis and other opportunistic fungal pneumonias should also be considered in the differential diagnosis of CAP in immunocompromised patients. This article examines the current peer-reviewed literature on etiology, risk factors, and outcomes of patients with CAP.

Antimicrobial treatment of community-acquired pneumonia

Community-acquired pneumonia (CAP) is a clinical diagnosis that has a significant impact on health care management around the world. Early clinical suspicion and prompt empiric antimicrobial therapies are mandatory in patients with CAP. This article provides a review of recent studies and guidelines addressing antimicrobial therapy for hospitalized patients with CAP.

[The radiology of opportunistic pneumonias. I: Epidemiological, laboratory and clinical background]

In the guidelines of the German Society of Pneumology on diagnosis and therapy of opportunistic pneumonias, chest x-ray is listed as the basic diagnostic method in congenital and acquired immunodepression. In case of discrepancy between radiographic and the clinical findings or in cases of bilateral infiltrates, infection refractory to therapy or a difficult course in patients requiring artificial ventilation, a CT, or if necessary, ultrasound or MRI should be carried out. Cross-sectional imaging allows more precise assessment of the radiological pattern, estimation of the degree of severity (number of infiltrated segments) and detection of complications (pleural effusion, empyema, thorax wall infiltration). Clinical and laboratory parameters, bacteriological and serological examinations as well as information on the underlying immunocompromising factors must be taken into account in the differential diagnosis. The radiographic finding is an important diagnostic parameter which is used in the determination of the degree of severity of the pneumonia. The pattern of findings is one of rationales for the use of antibiotic therapy. In the first part of this contribution the epidemiological, laboratory and clinical background of the diagnosis of opportunistic pneumonias is discussed.

Two cases of acute respiratory failure due to carcinomatous lymphangitis in HIV patients

In HIV-infected patients, acute respiratory failure is usually due to infectious pneumonia. In this report, we describe two cases of acute respiratory failure in HIV patients with clinical presentation suggesting infectious pneumonia. In both cases, the clinical condition deteriorated and death occurred after several days despite therapy. In both cases bronchial biopsies confirmedbronchogenic carcinoma responsible for carcinomatous lymphangitis.

Importance of severity of illness assessment in management of lower respiratory infections

PURPOSE OF REVIEW

Patients with lower respiratory infections display a wide spectrum of disease severity. Management decisions regarding site of care, extent of investigations and level of treatment are mainly based on disease severity. Several severity assessment tools are still undergoing evaluation. This review highlights recent relevant studies.

RECENT FINDINGS

Severity prediction rules such as the Pneumonia Severity Index cannot be relied upon as the sole means of identifying patients with lower respiratory infections who do not need hospital admission. Up to 40% of patients assigned to low-risk groups may require hospitalization. The most common medical reason for hospitalization in these circumstances is the presence of unstable comorbid illness. Social factors are equally important in the decision to admit. A new prediction rule based on the British Thoracic Society prediction rule has been proposed. This divides patients with community acquired pneumonia into three management groups based on risk of mortality. A prediction rule for use in patients with HIV-associated community acquired pneumonia has also been proposed. An IL-10 polymorphism has been identified as a prognostic factor in community acquired pneumonia. Audits examining the impact of adherence to severity-based guidelines on the outcome of community acquired pneumonia have revealed conflicting results. Differences in outcome may only be significant for patients with the most severe illness.

SUMMARY

Severity of illness assessment is important in guiding management options at various stages in the clinical course of lower respiratory infections. However, no prediction rule should supercede clinical judgment.

Clinical Stability in Human Immunodeficiency Virus–Infected Patients with Community‐Acquired Pneumonia

Clinical stability (CS), defined as normalization of vital signs, is often used to manage inpatients with community-acquired pneumonia (CAP). The main objective of our study was to identify a reliable definition of CS for human immunodeficiency virus (HIV)-positive patients with CAP. During an 18-month period, 437 HIV-positive Italian inpatients with CAP were enrolled in the study. We used 3 definitions of CS (from a less conservative [definition 1] to a more conservative [definition 3] definition) based on combinations of different thresholds for vital signs. Assessments were performed at admission and daily during the hospital stay. For the 3 definitions, 14.9%, 8.0%, and 4.8% of patients were stable at baseline, with deterioration after reaching CS in 7.16%, 4.76%, and 2.05%, respectively. The 8 patients whose conditions deteriorated after reaching CS definition 3 (systolic blood pressure, >90 mm Hg; pulse, <90 beats/min; respiratory rate, <20 breaths/min; oxygen saturation, >90%; temperature, <37 degrees C; ability to eat; and normal mental status) survived and were discharged from the hospital. The more conservative definition of CS appears to be reliable for the management of HIV-infected patients with CAP.

A rapid staging system for predicting mortality from HIV-associated community-acquired pneumonia

STUDY OBJECTIVE

Community-acquired pneumonia (CAP) accounts for an increasing proportion of the pulmonary infections in individuals with HIV infection. During the mid-1990s, hospital mortality rates for HIV-associated CAP ranged from 0 to 28%. While hospital differences in case mix may account for mortality rate variation, few methods to evaluate illness severity for HIV-associated CAP have been reported previously. The study objective was to develop a staging system for categorizing mortality risk of patients with HIV-associated CAP using information available prior to hospital admission.

DESIGN/SETTING/PATIENTS

Retrospective medical records review of 1,415 patients hospitalized with HIV-associated CAP from 1995 to 1997 at 86 hospitals in seven metropolitan areas.

MEASUREMENTS

In-patient mortality rate.

RESULTS

Hierarchically optimal classification tree analysis was used to develop a preadmission staging system for predicting inpatient mortality. The overall inpatient mortality rate was 9.1%. The significant predictors of mortality included the presence of neurologic symptoms, respiratory rate > or = 25 breaths/min, and creatinine > 1.2 mg/dL. The model identified a five-category staging system, with the mortality rate increasing by stage: 2.3% for stage 1, 5.8% for stage 2, 12.9% for stage 3, 22.0% for stage 4, and 40.5% for stage 5. The classification accuracy of the model was 85.2%.

CONCLUSIONS

Our staging system categorizes inpatient mortality risk for patients with HIV-associated CAP using three routinely available variables. The staging system may be useful for guiding clinical decisions about the intensity of patient care and for case-mix adjustment in future studies addressing variation in hospital mortality rates.

Severe community-acquired pneumonia: current outcomes, epidemiology, etiology, and therapy

Severe community-acquired pneumonia is a clinical diagnosis with a significant impact on healthcare management around the world, with the highest morbidity and mortality of all of the forms of community-acquired pneumonia. Patients with severe pneumonia usually require intensive care unit management, including vasopressors or mechanical ventilation. Early clinical suspicion and prompt empiric antimicrobial therapies are mandatory in patients with severe pneumonia. A number of recent studies and guidelines addressing these issues have been published, and they will be reviewed in this article.

Pleural effusions and pneumothoraces in AIDS

Pneumothorax occurs in 1 to 2% of hospitalized patients with HIV and is associated with 34% mortality. Pneumocystis carinii pneumonia and chest radiographic evidence of cysts, pneumatoceles, or bullae are risk factors for spontaneous pneumothorax. Tube thoracostomy, pleurodesis, and surgical treatment are usually needed to manage spontaneous pneumothorax in AIDS. Pleural effusion is seen in 7 to 27% of hospitalized patients with HIV infection. Its three leading causes are parapneumonic effusions, tuberculosis, and Kaposi sarcoma. Pleural effusions occur in 15 to 89% of cases of pulmonary Kaposi sarcoma and in 68% of cases of thoracic non-Hodgkin lymphoma in patients with AIDS. Primary effusion lymphoma accounts for 1 to 2% of non-Hodgkin lymphomas. Kaposi sarcoma and primary effusion lymphoma are associated with human herpesvirus 8. The prognosis of patients with pleural Kaposi sarcoma and non-Hodgkin lymphoma in AIDS is poor, and the major goal of treatment is palliation.