Alexandra Mangili

Transmission of infectious diseases during commercial air travel

Summary Because of the increasing ease and affordability of air travel and mobility of people, airborne, food-borne, vector-borne, and zoonotic infectious diseases transmitted during commercial air travel are an important public health issue. Heightened fear of bioterrorism agents has caused health officials to re-examine the potential of these agents to be spread by air travel. The severe acute respiratory syndrome outbreak of 2002 showed how air travel can have an important role in the rapid spread of newly emerging infections and could potentially even start pandemics. In addition to the flight crew, public health officials and health care professionals have an important role in the management of infectious diseases transmitted on airlines and should be familiar with guidelines provided by local and international authorities.

Daptomycin-Resistant, Methicillin-Resistant Staphylococcus aureus Bacteremia

We describe a patient who developed daptomycin-resistant, methicillin-resistant Staphylococcus aureus (MRSA) during an episode of presumed septic thrombophlebitis of the portal vein. Although daptomycin is an alternative agent for treatment of drug-resistant gram-positive bacterial infections, development of resistance during prolonged use may occur with MRSA bacteremia from a persistent focus.

Nutrition and HIV Infection: Review of Weight Loss and Wasting in the Era of Highly Active Antiretroviral Therapy from the Nutrition for Healthy Living Cohort

Despite major advances in the treatment and survival of patients infected with human immunodeficiency virus (HIV), weight loss and wasting remain common problems. In the HIV-infected population, weight loss is associated with lower CD4+ cell counts and is an independent predictor of mortality. The etiology of weight loss and wasting is complex and multifactorial. We discuss, on the basis of a large longitudinal cohort that examined nutritional status in HIV infection, data on weight loss and wasting from the present clinical era. The definition, prevalence, and significance of HIV-associated weight loss and wasting are summarized. The etiology of weight loss is discussed for 2 main categories: inadequate nutrient intake and altered metabolism. Finally, studies of interventions to treat HIV-associated weight loss and wasting are discussed. This information is intended to raise awareness among health care providers of HIV-infected patients that weight loss and wasting remain important acquired immunodeficiency syndrome-defining conditions, despite the advent of HAART.

Risk of Cardiovascular Disease in a Cohort of HIV-Infected Adults: A Study Using Carotid Intima-Media Thickness and Coronary Artery Calcium Score

BACKGROUND There is concern that human immunodeficiency virus (HIV) infection and the use of highly active antiretroviral therapy lead to accelerated atherosclerosis and increased risk of cardiovascular disease. We measured 2 surrogate markers of subclinical atherosclerosis, carotid intima-media thickness (c-IMT) and coronary artery calcium (CAC) scores, in HIV-infected adults. METHODS A cross-sectional analysis of 242 men and 85 women with HIV infection was used. Carotid ultrasonography and coronary computed tomography were performed, and their associations with cardiovascular risk factors were examined. RESULTS Among men, the mean (+/- standard deviation [SD]) common c-IMT was 0.62+/-0.2 mm, the mean (+/-SD) internal c-IMT was 0.76+/-0.5 mm, and 136 patients (56.1%) had detectable CAC. Among women, the mean (+/-SD) common c-IMT was 0.59+/-0.2 mm, the mean (+/-SD) internal c-IMT was 0.66+/-0.4 mm, and 40 patients (47.1%) had detectable CAC. Neither the c-IMT nor the CAC score differed by antiretroviral therapy class or individual medications for either sex. For men, age and waist circumference independently predicted common c-IMT; age, systolic blood pressure, and high-sensitivity C-reactive protein level independently predicted internal c-IMT; and age, apolipoprotein B level, and high-sensitivity C-reactive protein level independently predicted CAC score. For women, age and body mass index independently predicted common c-IMT; age independently predicted internal c-IMT; and age and glucose level independently predicted CAC score. CONCLUSIONS Our participants had more abnormal surrogate markers than expected at a relatively young age, but those were not associated with use of highly active antiretroviral therapy or protease inhibitors. At present, the positive associations were primarily with traditional and novel cardiovascular risk factors. Some HIV-specific (not treatment-specific) factors were observed; they may become more evident with prolonged HIV infection and treatment.

Metabolic Syndrome and Subclinical Atherosclerosis in Patients Infected with HIV

BACKGROUND The present study examines the association between carotid and coronary atherosclerosis and metabolic syndrome in human immunodeficiency virus (HIV)-infected adults. METHODS We measured the common and internal carotid intima-media thickness (c-IMT) using B-mode ultrasonography, and we measured coronary artery calcium (CAC) using high-resolution, electrocardiographic, synchronized, computed tomography, for 314 HIV-infected men and women. Metabolic syndrome was defined by National Cholesterol Education Program/Adult Treatment Panel III criteria. We compared the c-IMT measurements and CAC scores of patients with metabolic syndrome with the scores of those without metabolic syndrome using a Wilcoxon test for continuous variables and a chi2 test for categorical variables. To examine the association between surrogate markers and metabolic syndrome, we used logistic regression analysis. RESULTS Participants with metabolic syndrome were more likely to have a common c-IMT measurement >0.8 mm than were those without metabolic syndrome (17% vs.7%; P=.009), but both groups were equally likely to have an internal c-IMT measurement >1.0 mm (20% vs. 13%; P=.15). Any positive CAC score was more likely to occur for participants with metabolic syndrome (80.3% vs. 46.7%; P<.0001). In a multivariate model adjusted for sex, age, ethnicity, and smoking status, participants with metabolic syndrome were more likely than those without metabolic syndrome to have an abnormal common c-IMT measurement (odds ratio [OR], 2.9; P=.020) and detectable CAC scores (OR, 4.9; P<.0001) but not a higher internal c-IMT measurement (OR, 1.6; P=.255). CONCLUSION Our study demonstrates that HIV-infected individuals with metabolic syndrome may be at increased risk for subclinical atherosclerosis and supports screening for metabolic syndrome among HIV-infected patients at risk for cardiovascular disease.

Markers of Atherosclerosis and Inflammation and Mortality in Patients with HIV Infection

OBJECTIVE HIV-infected patients are at increased risk for cardiovascular disease, which may be mediated in part by inflammation. Surrogate marker studies suggest an increased prevalence of vascular abnormalities in HIV infection. We examined the association of all-cause mortality in HIV-infected patients with carotid artery intima-media thickness (cIMT) and high-sensitivity C-reactive protein (hsCRP). DESIGN AND METHODS Baseline risk factors, cIMT and hsCRP were prospectively measured in 327 HIV-infected participants. Follow-up time with median of 3.1 years was calculated from baseline to death or censored dated 7/31/07. Cox Proportional Hazards models were used to study risk factors associated with mortality. RESULTS Thirty-eight (11.6%) of participants have died since study enrollment. cIMT was significantly higher in those who died and decedents were significantly more likely to have cIMT above the 75th percentile. Those who died had higher hsCRP than those alive and more had hsCRP values above 3mg/L. CD4 count was lower and log(10) viral load was higher in decedents, but antiretroviral regimens were similar in both groups. cIMT and hsCRP levels were significantly associated with mortality (HR = 2.74, 95% CI 1.26-5.97, p = 0.01; HR = 2.38, 95% CI 1.15-4.9, p = 0.02). CONCLUSIONS Our study demonstrated a strong association of carotid IMT and hsCRP with all-cause death in this HIV-infected population despite being similar with respect to exposure to antiretroviral medications. Together these surrogate markers may be indices of chronic inflammation and unfavorable outcomes in HIV-positive patients.

Contribution of Genetic Background, Traditional Risk Factors, and HIV-Related Factors to Coronary Artery Disease Events in HIV-Positive Persons

BACKGROUND Persons infected with human immunodeficiency virus (HIV) have increased rates of coronary artery disease (CAD). The relative contribution of genetic background, HIV-related factors, antiretroviral medications, and traditional risk factors to CAD has not been fully evaluated in the setting of HIV infection. METHODS In the general population, 23 common single-nucleotide polymorphisms (SNPs) were shown to be associated with CAD through genome-wide association analysis. Using the Metabochip, we genotyped 1875 HIV-positive, white individuals enrolled in 24 HIV observational studies, including 571 participants with a first CAD event during the 9-year study period and 1304 controls matched on sex and cohort. RESULTS A genetic risk score built from 23 CAD-associated SNPs contributed significantly to CAD (P = 2.9 × 10(-4)). In the final multivariable model, participants with an unfavorable genetic background (top genetic score quartile) had a CAD odds ratio (OR) of 1.47 (95% confidence interval [CI], 1.05-2.04). This effect was similar to hypertension (OR = 1.36; 95% CI, 1.06-1.73), hypercholesterolemia (OR = 1.51; 95% CI, 1.16-1.96), diabetes (OR = 1.66; 95% CI, 1.10-2.49), ≥ 1 year lopinavir exposure (OR = 1.36; 95% CI, 1.06-1.73), and current abacavir treatment (OR = 1.56; 95% CI, 1.17-2.07). The effect of the genetic risk score was additive to the effect of nongenetic CAD risk factors, and did not change after adjustment for family history of CAD. CONCLUSIONS In the setting of HIV infection, the effect of an unfavorable genetic background was similar to traditional CAD risk factors and certain adverse antiretroviral exposures. Genetic testing may provide prognostic information complementary to family history of CAD.

Progression of carotid intima-media thickness and coronary artery calcium over 6 years in an HIV-infected cohort.

Objective:To evaluate changes in cardiovascular disease risk surrogate markers in a longitudinal cohort of HIV-infected adults over 6 years. Design:Internal carotid artery (ICA) and common carotid artery (CCA) intima-media thickness (IMT), coronary artery calcium (CAC), vascular, and HIV risk factors were prospectively examined over 6 years in HIV-infected adults from 2002 to 2010. Setting:Longitudinal cohort study with participants from urban center and surrounding communities. Subjects/Participants:Three hundred forty-five HIV-infected participants were recruited from a longitudinal cohort study. Two hundred eleven participants completed the study and were included in this analysis. Main Outcome Measures:Total and yearly ICA and CCA IMT change; CAC score progression. Results:Participants were 27% female and 49% nonwhite; mean age at start was 45 ± 7 years. The median change in ICA and CCA over 6 years was 0.15 mm (0.08, 0.28) and 0.12 mm (0.09, 0.15), respectively. Age, baseline triglycerides ≥150 mg/dL, and pack-years smoking were associated with ICA IMT change; age, cholesterol, nadir CD4+ count, and protease inhibitor use were associated with CCA IMT change. Diabetes, HIV viral load, and highly active antiretroviral therapy duration were associated with CAC progression. Conclusions:Carotid IMT and CAC progressed in this HIV-infected cohort. Some HIV-specific characteristics were associated with surrogate marker changes, but the majority of risk factors continue to be traditional. Aggressive identification and management of modifiable risk factors may reduce progression of cardiovascular disease risk in this population.

Framingham risk score and early markers of atherosclerosis in a cohort of adults infected with HIV.

BACKGROUND The utility of the Framingham risk score among individuals infected with HIV is poorly understood. We examined the association of Framingham risk scores with surrogate markers of atherosclerosis in a carefully characterized cohort of adults infected with HIV. METHODS We calculated Framingham risk scores and measured carotid intima-media thickness (c-IMT) and coronary artery calcium (CAC) scores in 334 participants from the Nutrition for Healthy Living study. Cardiovascular risk factors, c-IMT and CAC scores were assessed for each Framingham risk subgroup (low versus intermediate/high risk). We used adjusted and unadjusted linear and logistic regression to examine the association between clinical factors and Framingham risk group with c-IMT and CAC scores. RESULTS Patients with intermediate/high Framingham risk scores were more likely to have internal c-IMT ≥ 1.0 mm (26% versus 12%; P=0.003) and common c-IMT ≥ 0.8 mm (22% versus 5%; P < 0.001). These patients were also more likely to have detectable CAC (78% versus 48%; P < 0.001). Intermediate/high Framingham risk scores were significantly associated with internal c-IMT ≥ 1.0 mm (odds ratio 2.65 [95% confidence interval 1.37-5.13]) and common c-IMT ≥ 0.8 mm (odds ratio 5.24 [95% confidence interval 2.39-11.50]). Intermediate/high Framingham risk scores were also significantly associated with detectable CAC (odds ratio 3.84 [95% confidence interval 2.05-7.16]). The addition of HIV-related variables did not improve the accuracy of the Framingham risk score. CONCLUSIONS Our study shows that increased Framingham risk scores are associated with abnormal early and late surrogate markers of atherosclerosis in adults infected with HIV, and might predict the risk of cardiovascular complications in this population.

Interaction of daptomycin with two recombinant thromboplastin reagents leads to falsely prolonged patient prothrombin time/International Normalized Ratio results.

A cluster of patients experiencing elevations of International Normalized Ratio without clinical bleeding in temporal association with daptomycin therapy was identified during postmarketing safety surveillance. A common element was the thromboplastin reagent used for the laboratory assay. The present study evaluated the effect of daptomycin on measured prothrombin time using commercially available thromboplastin reagent kits commonly used in the United States. Thirty reagent kits were obtained. Daptomycin was added to pooled normal human plasma samples to achieve final concentrations of 0–200 μg/ml. Quality control ranges were established for each reagent kit using normal and abnormal control plasmas. Triplicate assays of the prothrombin time were performed on the daptomycin-spiked plasma samples using each of the 30 kits. The activated partial thromboplastin time and thrombin time were also assessed. Statistical comparisons of interest were performed using analysis of variance with the Bonferroni t-test for multiple comparisons; α = 0.05 was used. Addition of daptomycin to human plasma samples dose-dependently prolonged measured prothrombin times when two recombinant thromboplastin reagents were utilized. The findings were statistically and clinically significant. No clinically meaningful effect was observed with the other reagents. The activated partial thromboplastin time and thrombin time were not affected. Prolonged International Normalized Ratio patient values were an artifact caused by the interaction of daptomycin with the in-vitro prothrombin time test reagent; an in-vivo anticoagulant effect was not observed. Healthcare providers should consider a possible drug–laboratory test interaction if prolonged prothrombin time or elevated International Normalized Ratio values are observed in patients receiving daptomycin.