Serum and bal beta-D-glucan for the diagnosis of Pneumocystis pneumonia in HIV positive patients.

BACKGROUND/PURPOSE: The diagnosis of patients with pulmonary infiltrates and human immunodeficiency virus (HIV) infection remains a challenge. In current clinical practice the gold standard for Pneumocystis jirovecii pneumonia (PCP) diagnosis remains the identification of the organism in bronco alveolar lavage (BAL) using microscopy (e.g., silver stain). (1->3)-ß -d-glucan (BG) is a polysaccharide that is present within the cell wall of Pneumocystis and other fungi. METHODS: We analyzed serum and BAL lavage fluid from a cohort of 119 patients that did have HIV, a diagnosis of pneumonia and underwent bronchoscopy (FOB) for diagnosis of PCP. RESULTS: The discriminative power of serum BG for the diagnosis of PCP in this group of patients was very high. Using a cutoff of 300 pg/mL, the sensitivity, specificity, positive predictive value(PPV) and negative predictive value (NPV) were 91%, 92%, 89% and 93% respectively. A model for ROC with just serum BG (N = 108) had an AUC of 0.95. Serum procalcitonin (PCT) and BAL BG were not as accurate for the diagnosis of PCP. For BAL BG using a cutoff of 783 pg/mL, the sensitivity,specificity, positive predictive value (PPV) and negative predictive value (NPV) were 72%, 79%,72% and 79% respectively. The differences between the medians for serum PCT between the group with a without PCP did not reach statistical significance (p = 0.6137). CONCLUSION: The measurement of serum BG should be incorporated in the diagnostic work up of HIV positive patients with dyspnea and infiltrates on chest X X-ray. Our study confirms the diagnostic value of serum BG previously reported by others but we add a cutoff value that we believe is more accurate for patients with AIDS and suspicion of PCP.

Endovascular Mycobacterium abscessus infection in a heart transplant recipient: a case report and review of the literature.

Nontuberculous mycobacteria are ubiquitous in the environment. Although rarely a cause of infection in immunocompetent individuals, increased risk and severity of infection are seen in patients who are immunocompromised, such as those with solid organ transplants. In this report, we describe the first case of disseminated endovascular Mycobacterium abscessus in a heart transplant recipient. A review of the literature regarding this infection in heart transplant recipients and its therapeutic options and concerns are summarized.

Non- epidermidis coagulase-negative staphylococcal bacteremia: clinical predictors of true bacteremia.

In order to explore the clinical significance and risk factors for true bacteremia caused by coagulase-negative staphylococci (CNS) other than Staphylococcus epidermidis, a retrospective cohort study of 160 patients with at least one blood culture positive for non- epidermidis CNS was performed. True bacteremia was diagnosed in 32 (20%) of the patients. On multivariate analysis the following factors were associated with true bacteremia: (i) more than one positive blood culture, (ii) presence of a central venous catheter, and (iii) methicillin resistance. The results of this study indicate that non- epidermidis CNS can cause significant bloodstream infections.

Infected total knee arthroplasty due to Actinomyces naeslundii.

A case of a total knee arthroplasty infection with Actinomyces naeslundii is described. The difficulties of therapeutic decision-making are emphasized.

Tolerance and pharmacokinetic interactions of rifabutin and azithromycin.

This multicenter study evaluated the tolerance and potential pharmacokinetic interactions between azithromycin and rifabutin in volunteers with or without human immunodeficiency virus infection. Daily dosing with the combination of azithromycin and rifabutin was poorly tolerated, primarily because of gastrointestinal symptoms and neutropenia. No significant pharmacokinetic interactions were found between these drugs.

Advances in antimicrobial therapy for respiratory tract infections.

Even at the turn of the millennium, respiratory infections exact a heavy toll on the American public. Pneumonia is the leading infectious disease cause of death, and influenza costs Medicare more than $1 billion each year. This article highlights some of the advances this past year in antimicrobial therapy for respiratory tract infections. Efforts are targeted at shortening the length of treatment and reducing costs for pneumonia. A promising new class of antivirals has been introduced for the treatment of influenza, and alternative medicine continues to receive more scientific scrutiny. Antimicrobials alone are not the answer, and preliminary work on immunomodulatory therapies may usher in a new era of multifaceted treatment approaches.

Tolerance and pharmacokinetic interactions of rifabutin and clarithromycin in human immunodeficiency virus-infected volunteers.

This study evaluated the tolerance and potential pharmacokinetic interactions between clarithromycin (500 mg every 12 h) and rifabutin (300 mg daily) in clinically stable human immunodeficiency virus-infected volunteers with CD4 counts of <200 cells/mm3. Thirty-four subjects were randomized equally to either regimen A or regimen B. On days 1 to 14, subjects assigned to regimen A received clarithromycin and subjects assigned to regimen B received rifabutin, and then both groups received both drugs on days 15 to 42. Of the 14 regimen A and the 15 regimen B subjects who started combination therapy, 1 subject in each group prematurely discontinued therapy due to toxicity, but 19 of 29 subjects reported nausea, vomiting, and/or diarrhea. Pharmacokinetic analysis included data for 11 regimen A and 14 regimen B subjects. Steady-state pharmacokinetic parameters for single-agent therapy (day 14) and combination therapy (day 42) were compared. Regimen A resulted in a mean decrease of 44% (P = 0.003) in the clarithromycin area under the plasma concentration-time curve (AUC), while there was a mean increase of 57% (P = 0.004) in the AUC of the clarithromycin metabolite 14-OH-clarithromycin. Regimen B resulted in a mean increase of 99% (P = 0.001) in the rifabutin AUC and a mean increase of 375% (P < 0.001) in the AUC of the rifabutin metabolite 25-O-desacetyl-rifabutin. The usefulness of this combination for prophylaxis of Mycobacterium avium infections is limited by frequent gastrointestinal adverse events. Coadministration of clarithromycin and rifabutin results in significant bidirectional pharmacokinetic interactions. The resulting increase in rifabutin levels may explain the increased frequency of uveitis observed with concomitant use of these drugs.

Clinical manifestations and implications of coinfection with Mycobacterium kansasii and human immunodeficiency virus type 1.

We conducted a retrospective study to further elucidate the clinical presentations and prognosis of disease due to Mycobacterium kansasii in patients infected with human immunodeficiency virus (HIV). Forty-nine HIV-infected patients first had M. kansasii isolated at a mean CD4 cell count of 62/mm3 and at a mean interval of 17 months after the diagnosis of AIDS. Seventeen of the 49 patients had disseminated disease caused by M. kansasii. Twenty-nine patients had a positive acid-fast smear of sputum, and 35 were known to be cigarette smokers. At the time of initial isolation of M. kansasii, 13 patients had other concurrent pulmonary isolates and 15 had another mycobacterial species concurrently isolated (the Mycobacterium avium complex in 13 instances). Patients who received antimycobacterial treatment survived longer than those who did not. Only one of the 49 patients was definitively determined to be colonized with M. kansasii without disease; therefore, it appears that pulmonary isolates of M. kansasii in HIV-infected patients are almost always associated with disease. The increase in rates of M. kansasii disease among HIV-infected patients has paralleled the rise of AIDS in Louisiana. So far, this state has recorded more coinfections with M. kansasii and HIV than any other.

Case report: Chlamydia pneumoniae pneumonia in an HIV-infected man.

We report a case of an HIV-infected adult with Chlamydia pneumoniae. Our patient presented with a clinical picture suggestive of Pneumocystis carinii pneumonia (PCP), but did not respond to empiric anti-PCP therapy. The diagnosis was eventually confirmed by bronchoscopy and serology. C. pneumoniae pneumonia should be considered in the differential of pathogens that cause interstitial infiltrates in HIV-infected persons.

Neurologic aspects of North American zoonoses.

Neurologic dysfunction is a frequent presentation or complication of zoonotic infections. The differential diagnosis is broad and will include nonzoonotic diseases as well. Patterns of neurologic findings, systemic signs of infection, and epidemiologic risk factors are useful in the approach to diagnosis and initial empiric treatment of the patient with suspected zoonotic infection. Associations between these patterns and specific organisms are emphasized by means of tables and algorithms.