Elisabetta Grilli

Continuous versus intermittent infusion of vancomycin for the treatment of Gram-positive infections: systematic review and meta-analysis

OBJECTIVES To summarize available evidence on the effect of continuous infusion (CoI) of vancomycin compared with intermittent infusion (InI) in adult patients with Gram-positive infections. METHODS MEDLINE, EMBASE and Cochrane databases were searched. Randomized clinical trials (RCTs) and observational studies that comparatively assessed CoI and InI of vancomycin in terms of mortality, clinical cure, toxicity rates and serum drug exposure [trough concentration (C(min)) for InI and steady-state concentration (C(ss)) for CoI; area under the curve at 24 h (AUC(24)) for both] were included. Meta-analysis was conducted combining and analysing the relative risk (RR) and computing a summary RR of the effects with 95% confidence interval (CI). The standardized mean difference was calculated for continuous outcomes. The I(2) test was calculated to assess heterogeneity across studies. RESULTS One RCT and five observational studies were included in the analysis. Compared with InI, CoI of vancomycin was associated with a significantly lower risk of nephrotoxicity (RR 0.6, 95% CI 0.4-0.9, P = 0.02; I(2)= 0). Overall mortality was not different between the two groups (RR 1.03, 95% CI 0.7-1.6, P = 0.9; I(2)= 0). CONCLUSIONS Our meta-analysis suggests that administration of vancomycin for the treatment of Gram-positive infections by CoI is associated with a significantly lower risk of nephrotoxicity when compared with InI of the drug. RCTs are needed to define the impact on mortality rate and on the pharmacodynamic activity in terms of AUC/MIC ratio.

Clinical Experience of Colistin-Glycopeptide Combination in Critically Ill Patients Infected with Gram-Negative Bacteria

ABSTRACT A colistin-glycopeptide combination (CGC) has been shown in vitro to be synergistic against multidrug-resistant Gram-negative bacteria (MDR GNB), especially Acinetobacter baumannii, and to prevent further resistance. However, clinical data are lacking. We carried out a retrospective multicenter study of patients hospitalized in intensive care units (ICUs) who received colistin for GNB infection over a 1-year period, to assess the rates of nephrotoxicity and 30-day mortality after treatment onset among patients treated with and without CGC for ≥48 h. Of the 184 patients treated with colistin, GNB infection was documented for 166. The main causative agents were MDR A. baumannii (59.6%), MDR Pseudomonas aeruginosa (18.7%), and carbapenem-resistant Klebsiella pneumoniae (14.5%); in 16.9% of patients, a Gram-positive bacterium (GPB) coinfection was documented. Overall, 68 patients (40.9%) received CGC. Comparison of patients treated with and without CGC showed significant differences for respiratory failure (39.7% versus 58.2%), ventilator-associated pneumonia (54.4% versus 71.4%), MDR A. baumannii infection (70.6% versus 52%), and GPB coinfection (41.2% versus 0%); there were no differences for nephrotoxicity (11.8% versus 13.3%) and 30-day mortality (33.8% versus 29.6%). Cox analysis performed on patients who survived for ≥5 days after treatment onset showed that the Charlson index (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.01 to 1.44; P = 0.001) and MDR A. baumannii infection (HR, 2.51; 95% CI, 1.23 to 5.12; P = 0.01) were independent predictors of 30-day mortality, whereas receiving CGC for ≥5 days was a protective factor (HR, 0.42; 95% CI, 0.19 to 0.93; P = 0.03). We found that CGC was not associated with higher nephrotoxicity and was a protective factor for mortality if administered for ≥5 days.

Rhodococcus equi infection in HIV-infected individuals: case reports and review of the literature.

Rhodococcus equi is a gram-positive, coryneform bacterium that causes zoonotic infection mainly in horses and foals. It sometimes affects humans presenting as cavitary pneumonia. Immunocompromised patients, including HIV-infected patients, are more susceptible to R. equi infection. We present 10 cases of R. equi infection in HIV-positive patients admitted to our institute from 1991 to June 2008. Moreover, we have reviewed 272 cases of R. equi infection in HIV-infected persons, published from 1986 through 2008. With respect to the literature data, the R. equi strains isolated in our case series showed lower sensitivity to ceftriaxone, amoxicillin/clavulanic acid, and cotrimoxazole. Prompt diagnosis, early initiation of antiretroviral treatment and combined antimicrobial treatment seem to be effective to eradicate the infection and to improve the outcome.

Pulmonary hypertension and human immunodeficiency virus infection: epidemiology, pathogenesis, and clinical approach

In recent years, the pathogenic role of human immunodeficiency virus (HIV) and the clinical manifestations of HIV-associated pulmonary arterial hypertension (HIV-PAH), which currently represents one of the most severe complications of HIV infection, have received more attention HIV-PAH occurs at all stages of the disease, and does not seem to be related to the degree of immune deficiency. Many of the symptoms in HIV-PAH result from right ventricular dysfunction: the first clinical manifestation is effort intolerance and exertional dyspnoea that will progress to the point of breathlessness at rest. Echocardiography is an extremely useful tool for the diagnosis of HIV-PAH, and Doppler echocardiography can be used to estimate systolic pulmonary artery pressure. Assessment of haemodynamic measures by catheterization remains, however, the best test for evaluating the response to therapy. Cardiac catheterization is mandatory to definitively diagnose the disease and exclude any underlying cardiac shunt as the aetiology. Recently, effective therapies for pulmonary arterial hypertension (PAH) have been available, including prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors, allowing amelioration of symptoms and a better prognosis. However, HIV-PAH remains a progressive disease for which treatment is often unsatisfactory and there is no cure. As new efficient antiretroviral treatment is introduced, clinicians should expect to encounter an increasing number of cases of PAH in HIV-infected patients in the future.

Cytomegalovirus pneumonia in immunocompetent host: Case report and literature review

CMV infection is highly prevalent in general population and its clinical picture generally ranges from asymptomatic disease to mononucleosis-like syndrome. While severe life-threatening CMV disease is well documented in certain immunocompromised risk groups, severe infection with symptomatic pneumonia in immunocompetent hosts has been rarely documented. In this paper we describe a case of primary CMV infection, complicated by severe CMV pneumonia in an immunocompetent host, successfully treated with oral valganciclovir. Moreover, we reviewed CMV pneumonia cases in immunocompetent adults reported in the literature.

The novel influenza A (H1N1) virus pandemic: An update.

In the 4 months since it was first recognized, the pandemic strain of a novel influenza A (H1N1) virus has spread to all continents and, after documentation of human-to-human transmission of the virus in at least three countries in two separate World Health Organization (WHO) regions, the pandemic alert was raised to level 6. The agent responsible for this pandemic, a swine-origin influenza A (H1N1) virus (S-OIV), is characterized by a unique combination of gene segments that has not previously been identified among human or swine influenza A viruses. As of 31th July 2009, 168 countries and overseas territories/communities have each reported at least one laboratory-confirmed case of pandemic H1N1 infection. There have been a total of 162,380 reported cases and 1154 associated deaths. Influenza epidemics usually take off in autumn, and it is important to prepare for an earlier start this season. Estimates from Europe indicate that 230 millions Europe inhabitants will have clinical signs and symptoms of S-OIV this autumn, and 7–35% of the clinical cases will have a fatal outcome, which means that there will be 160,000–750,000 H1N1-related deaths. A vaccine against H1N1 is expected to be the most effective tool for controlling influenza A (H1N1) infection in terms of reducing morbidity and mortality and limiting diffusion. However, there are several issues with regard to vaccine manufacture and approval, as well as production capacity, that remain unsettled. We searched the literature indexed in PubMed as well as the websites of major international health agencies to obtain the material presented in this update on the current S-OIV pandemic.

Treatment and outcome of pulmonary arterial hypertension in HIV-infected patients: a review of the literature.

Pulmonary arterial hypertension (PAH) is a life-threatening complication of HIV infection. The prevalence of HIV-associated PAH (HIV-PAH) seems not to be changed over time, regardless of the introduction of highly active antiretroviral therapy (HAART). HIV-PAH treatment is similar to that for all PAH conditions and includes lifestyle modifications, general treatments, and disease-specific treatments. We reviewed the cases of HIV-PAH reported in the Literature in order to evaluate the role of HAART and specific PAH therapy in the prognosis and outcome of HIV-PAH. The research was performed through the PubMed database, by using the following key words: human immunodeficiency virus, AIDS, pulmonary hypertension, antiretroviral, and treatment. The outcome was reported as survival at the end of the observation period of each study. We found 509 patients with HIV-PAH described in the literature to date. At the end of follow-up period, survival rates were 55% and 22% among patients treated or not with antiretroviral therapy (ART), respectively (p = 0.02). Moreover, survival rates at the end of follow-up were 76% and 32% among patients treated or not with specific therapy for PAH (PAH-ST), respectively (p<0.0000001). Survival rates were 69% and 38% among patients treated or not with ART and PAH-ST, respectively (p = 0.02). Specific therapy for PAH should be strongly recommended in patients with HIV-PAH. The role of the HAART in influencing the outcome of HIV-PAH is controversial, even if some evidences seem to indicate a beneficial effect in the clinical course of the disease.

Selenium Deficiency and HIV Infection

Selenium is a non-metallic chemical element of great important to human health. Low selenium levels in humans are associated with several pathological conditions and are a common finding in HIV infected individuals. We conducted a review of the literature to assess if selenium deficiency or selenium supplementation could play a role in modifying the clinical course of HIV disease. Several studies investigated the role of selenium in disease progression, morbidity and mortality in HIV infected individuals. Larger studies were conducted in countries with poor economic resources and limited access to HAART. According to the majority of published studies low selenium levels appear to have an association with mortality, and selenium supplementation appears to play a beneficial role on survival or on slowing disease progression among HIV infected individuals. The role of selenium supplementation on preventing hospital admission among HIV outpatients was also noticed. The literature suggests an association between selenium deficiency and development of HIV associated cardiomyopathy and furthermore, selenium supplementation appears to improve the cardiac function in HIV infected individuals with cardiomyopathy. However, there is conflicting evidence regarding the role selenium in modifying HIV viral load and immune status in HIV infection.

Hemolytic anemia due to acute cytomegalovirus infection in an immunocompetent adult: a case report and review of the literature

IntroductionCytomegalovirus is a common virus responsible for a wide range of clinical manifestations. Hemolysis is a rare but potentially life-threatening complication of cytomegalovirus infection, described mostly in immunocompromised patients, the pathogenesis of which is still unclear.We performed a review of the literature regarding cases of hemolytic anemia during acute cytomegalovirus infection in apparently immunocompetent individuals. We searched for relevant articles in PubMed for the period of 1980 through 2008.Case presentationWe describe a case of Coombs-negative hemolytic anemia in a 44-year-old Caucasian immunocompetent man with acute cytomegalovirus infection.ConclusionClinicians should consider cytomegalovirus infection in the differential diagnosis of hemolytic anemia in immunocompetent adults. Possible therapeutic options include antiviral therapy and steroids, although the best treatment strategy is still controversial.

Fulminant VZV infection in an adult AIDS patient treated with steroids: A case report

Varicella zoster virus (VZV) typically causes a benign disease in childhood. However, VZV can lead to severe complication in immunocompromised patients, involving skin and nearly every organ system, with significant morbidity and mortality. VZV infection occurs more frequently in patients treated with steroids. Herein, we describe a case of rapidly fatal disseminated VZV infection with cutaneous and visceral involvement in an adult AIDS patient treated with steroids.