Vana Sypsa

Carbapenemase-Producing Klebsiella pneumoniae Bloodstream Infections: Lowering Mortality by Antibiotic Combination Schemes and the Role of Carbapenems

ABSTRACT Carbapenemase-producing Klebsiella pneumoniae strains (CP-Kps) are currently among the most important nosocomial pathogens. An observational study was conducted during 2009 to 2010 in two hospitals located in a high-prevalence area (Athens, Greece). The aims were (i) to evaluate the clinical outcome of patients with CP-Kp bloodstream infections (BSIs), (ii) to identify predictors of mortality, and (iii) to evaluate the various antibiotic schemes employed. A total of 205 patients with CP-Kp BSIs were identified: 163 (79.5%) were infected with KPC or KPC and VIM, and 42 were infected with VIM producers. For definitive treatment, 103 patients received combination therapy (two or more active drugs), 72 received monotherapy (one active drug), and 12 received therapy with no active drug. The remaining 18 patients died within 48 h after the onset of bacteremia. The all-cause 28-day mortality was 40%. A significantly higher mortality rate was observed in patients treated with monotherapy than in those treated with combination therapy (44.4% versus 27.2%; P = 0.018). The lowest mortality rate (19.3%) was observed in patients treated with carbapenem-containing combinations. In the Cox proportion hazards model, ultimately fatal disease (hazards ratio [HR], 3.25; 95% confidence interval [CI], 1.51 to 7.03; P = 0.003), the presence of rapidly fatal underlying diseases (HR, 4.20; 95% CI, 2.19 to 8.08; P < 0.001), and septic shock (HR, 2.15; 95% CI, 1.16 to 3.96; P = 0.015) were independent predictors of death. Combination therapy was strongly associated with survival (HR of death for monotherapy versus combination, 2.08; 95% CI, 1.23 to 3.51; P = 0.006), mostly due to the effectiveness of the carbapenem-containing regimens.

The Effectiveness of a 9-Month Regimen of Isoniazid Alone versus 3- and 4-Month Regimens of Isoniazid plus Rifampin for Treatment of Latent Tuberculosis Infection in Children: Results of an 11-Year Randomized Study

BACKGROUND A 9-month course of isoniazid monotherapy is currently recommended for the treatment of latent tuberculosis infection (LTBI) and has been shown to be effective in both children and adults. Reduced compliance with this regimen has forced physicians to explore shorter regimens. The aim of this study was to compare 3- and 4-month combination regimens of isoniazid plus rifampin with a 9-month regimen of isoniazid monotherapy for the treatment of LTBI in children. METHODS This prospective, randomized, controlled study was conducted over an 11-year period (1995-2005). In period 1 (1995-1998), 232 patients received isoniazid therapy for 9 months (group A), and 238 patients received isoniazid and rifampin for 4 months (group B). In period 2 (1999-2002), 236 patients were treated with isoniazid and rifampin for 4 months (group C), and 220 patients received the same regimen for 3 months (group D). All patients were observed for > or = 3 years. RESULTS Overall compliance with treatment was good, but patients who received isoniazid monotherapy were less compliant than were those who received short-course combination therapy (P=.011, for group A vs. group B; P=.510, for group C vs. group D). No patient in any group developed clinical disease during the follow-up period. New radiographic findings suggestive of possible active disease were more common in patients who received isoniazid monotherapy (24%) than in those treated with shorter regimens (11.8%, 13.6%, and 11% for groups B, C, and D, respectively; P=.001 for group A vs. group B; P=.418 for group C vs. group D). Serious drug-related adverse effects were not detected. CONCLUSIONS Short-course treatment with isoniazid and rifampin for 3-4 months is safe and seems to be superior to a 9-month course of isoniazid monotherapy.

Impact of Hepatitis B Virus Infection on the Progression of AIDS and Mortality in HIV-Infected Individuals: A Cohort Study and Meta-Analysis

BACKGROUND The effect of hepatitis B virus (HBV) infection on the natural history of human immunodeficiency virus (HIV) disease remains uncertain. Therefore, a retrospective cohort study was conducted to examine the influence of HIV-HBV coinfection on AIDS development and overall mortality. Moreover, our results were added to those of previous studies in a literature-based meta-analysis. METHODS Serum samples obtained from HIV-seropositive patients from 1984 through 2003 were retrospectively tested for hepatitis B surface antigen. Multivariable analyses were performed using Poisson and logistic regression models. For meta-analytic purposes, eligible articles were identified and relevant data were abstracted. Pooled estimates of effect were calculated applying fixed and random effects models. RESULTS The prevalence of chronic HBV infection (documented hepatitis B surface antigen seropositivity for >6 months) among 1729 HIV-positive patients was approximately 6%. The multivariable analyses in our primary study revealed no significant impact of concomitant HIV-HBV infection on progression to AIDS and all-cause mortality. However, a meta-analysis performed on data from 12,382 patients enrolled in 11 studies revealed a significant effect of HIV-HBV coinfection on overall mortality (pooled effect estimate, 1.36; 95% confidence interval, 1.12-1.64). The increased rate of death among coinfected individuals was observed in the meta-analyses of studies conducted both before (pooled effect estimate, 1.60; 95% confidence interval, 1.07-2.39) and after (pooled effect estimate, 1.28; 95% confidence interval, 1.03-1.60) commencement of highly active antiretroviral therapy. CONCLUSIONS HIV-HBV coinfection seems to affect all-cause mortality, and strategies to reduce liver damage in patients coinfected with HIV and HBV are justified.

Molecular epidemiology of hepatitis C virus (HCV) in Greece: temporal trends in HCV genotype-specific incidence and molecular characterization of genotype 4 isolates

Summary.  This study aimed to estimate the overall HCV genotype distribution and to reconstruct the HCV genotype‐specific incidence in Greece during the recent decades. It also focused at the identification of genotype 4 subtype variability in Greek isolates. A total of 1686 chronically infected HCV patients with detectable serum HCV RNA by RT‐PCR, belonging to different risk groups were studied. Amplified products from the 5′‐noncoding region were typed using a commercially available assay based on the reverse hybridization principle. The HCV genotype‐specific incidence was estimated using a previously described back calculation method. HCV genotype 1 was the most prevalent (46.9%) followed by genotype 3 (28.1%), 4 (13.2%), 2 (6.9%) and 5 (0.4%). A high prevalence of genotype 1 (66.3%) in haemophilia patients was recorded whereas HCV genotype 3 was found mainly among patients infected by I.V. drug use (58.2%). Data on the temporal patterns of HCV genotype‐specific incidence in Greece revealed a moderate increase (1.3–1.6 times) for genotypes 1 and 4, and a decrease (1.5 times) for genotype 2 from 1970 to 1990, whereas there was a sharp (13‐fold) increase for genotype 3. The molecular characterization of 41 genotype 4 HCV isolates belonging to various risk groups revealed that, subtype 4a was the most frequently detected (78%). Phylogenetic comparison of the Greek 4a isolates with all HCV‐4a isolates reported worldwide so far revealed a topology which does not discriminate Greek isolates from the others. HCV‐4 does not represent a recent introduction in Greece.

Incidence and predictors of hepatocellular carcinoma in Caucasian chronic hepatitis B patients receiving entecavir or tenofovir

BACKGROUND & AIMS The risk of hepatocellular carcinoma (HCC) in Caucasian patients with chronic hepatitis B (CHB), treated with entecavir (ETV) or tenofovir (TDF), is unclear. We evaluated the incidence and predictors of HCC and the accuracy of existing HCC risk scores in Caucasian CHB patients receiving ETV/TDF. METHODS This large, multicentre, retrospective cohort study included 1666 adult Caucasian CHB patients under ETV/TDF for 39 months. CHB without cirrhosis, compensated and decompensated cirrhosis were present in 67%, 39%, and 3% of patients, respectively. The predictability of baseline parameters and three risk scores (GAG-HCC, CU-HCC, and REACH-B), developed in Asian patients, was assessed. RESULTS The cumulative probability of HCC was 1.3%, 3.4%, and 8.7% at year-1, year-3, and year-5 after ETV/TDF onset. Older age and lower platelets were strong independent HCC predictors in the total population and in the subgroups of cirrhotic and non-cirrhotic patients, while liver disease severity was an independent HCC predictor in the total population and in the cirrhotics. GAG-HCC, CU-HCC, and REACH-B risk scores were associated with HCC development only in the univariable but not in the multivariable analyses and offered poor to modest predictability. CONCLUSIONS HCC can still develop in Caucasian CHB patients treated with ETV/TDF. Besides the well-known predictors of HCC, such as older age, male gender and more advanced liver disease, lower platelets represent an independent factor of higher HCC risk. The applicability and predictability of HCC risk scores developed in Asian patients are poor or modest in Caucasian CHB patients, for whom different risk scores are required.

Economic Recession and Emergence of an HIV-1 Outbreak among Drug Injectors in Athens Metropolitan Area: A Longitudinal Study

Background During 2011, a dramatic increase (1600%) of reported HIV-1 infections among injecting drug users (IDUs) was noted in Athens, Greece. We herein assess the potential causal pathways associated with this outbreak. Methods Our study employed high resolution HIV-1 phylogenetic and phylogeographic analyses. We examined also longitudinal data of ecological variables such as the annual growth of gross domestic product (GDP) of Greece in association with HIV-1 and HCV sentinel prevalence in IDUs, unemployment and homelessness rates and HIV transmission networks in Athens IDUs before and during economic recession (2008–2012). Results IDU isolates sampled in 2011 and 2012 suggested transmission networks in 94.6% and 92.7% of the cases in striking contrast with the sporadic networking (5%) during 1998–2009. The geographic origin of most HIV-1 isolates was consistent with the recently documented migratory waves in Greece. The decline in GDP was inversely correlated with annual prevalence rates of HIV and HCV and with unemployment and homelessness rates in IDUs (all p<0.001). The slope of anti-HCV prevalence in the sentinel populations of IDUs and in “new” drug injectors was found 120 and 1.9-fold (p = 0.007, p = 0.08 respectively) higher in 2008–2012 (economic recession) compared with 2002–2006. The median (25th, 75th) size of transmission networks were 34 (12, 58) and 2 (2, 2) (p = 0.057) in 2008–2012 and 1998–2007, respectively. The coverage of harm reduction services was low throughout the study period. Conclusions Scaling-up harm reduction services and addressing social and structural factors related to the current economic crisis should be urgently considered in environments where HIV-1 outbreaks may occur.

Increasing Prevalence of HIV-1 Subtype A in Greece: Estimating Epidemic History and Origin

BACKGROUND In North America and Europe, human immunodeficiency virus (HIV)-1 infection has typically been dominated by subtype B transmission. More recently, however, non-B subtypes have been increasingly reported in Europe. METHODS We analyzed 1158 HIV-1-infected individuals in Greece by DNA sequencing and phylogenetic analyses of protease and partial reverse-transcriptase regions. RESULTS We found that the prevalence of non-B subtypes has increased over time and that this significant trend can be mainly attributed to subtype A, which eventually surpassed subtype B in prevalence in 2004 (42% and 33%, respectively). Multivariate analysis revealed that the year of HIV diagnosis was independently associated with subtype A infection (odds ratio for being infected with subtype A for a 10-year increase in the time period of diagnosis, 2.09 [95% confidence interval, 1.36-3.24]; P<.001). Phylogenetic analysis revealed that the subtype A epidemic in Greece is the result of a single founder event. The date of the most recent common ancestor of the subtype A in Greece was estimated to be 1977.9 (95% highest posterior density interval, 1973.7-1981.9). CONCLUSIONS Subtype A circulates among the long-term residents of Greece. This is in contrast to the situation in most European countries, in which infection with non-B genetic forms is associated either with being an immigrant or heterosexual or with intravenous drug use.

The impact of the heptavalent pneumococcal conjugate vaccine on the epidemiology of acute otitis media complicated by otorrhea.

Background: The heptavalent pneumococcal conjugate vaccine (PCV7) has a considerable effect on the epidemiology of pneumococcal disease. The aim of this observational hospital-based study was to examine the effect of the PCV7 (introduced in our settings in 2004) on the epidemiology of spontaneously draining acute otitis media. Methods: Results of all middle ear fluid cultures (n = 3446) obtained from children with acute otitis media complicated with otorrhea before the introduction of immunization (between 2000 and 2003) were compared with those (n = 2134) obtained during a similar post-PCV7 period (between 2005 and 2008). Results of cultures obtained between 2006 and 2008 were examined prospectively, whereas those obtained in previous years were retrospectively reviewed. Results: Following PCV7 immunization, the rates of otorrhea visits per 10,000 emergency department visits decreased by 38% from 133 to 83 (95% confidence interval of the difference, 42–53; P < 0.001), mainly as a result of the decrease in the incidence of pneumococcal disease (48% decrease—25 vs. 13 per 10,000 emergency department visits; P < 0.001). Otorrhea due to Haemophilus influenzae decreased by 20% (20–16 per 10,000 visits; P < 0.001). Serotype 19A accounted for 1 of 47 (2%) pneumococcal strains in 2006, for 5 of 34 (15%) in 2007, and for 13 of 53 (25%) in 2008 (P for trend: 0.001). In the postvaccine years, penicillin-resistant pneumococcal strains (minimum inhibitory concentration ≥2 &mgr;g/mL) increased from 4% to 13% (P < 0.001). However, the proportion of pneumococci resistant to macrolides decreased (44% vs. 35%; P = 0.01). Conclusions: After the introduction of immunization, otorrhea incidents decreased considerably, mainly because of the decrease in pneumococcal disease. H. influenzae is now the predominant organism. Serotype 19A has increased significantly and is the most common nonvaccine pneumococcal serotype. Penicillin resistance has increased in recent years.

Low-Dose IFN-α Monotherapy in Treatment-Naive Individuals with HIV-1 Infection: Evidence of Potent Suppression of Viral Replication

To evaluate the safety and antiviral action of interferon-alpha (IFN-alpha) in HIV-1 infection, we undertook a proof of concept study in 27 treatment-naive patients. Eligible patients comprised two groups: the IFN-alphaT group (n = 17), which received 5 MIU IFN-alpha s.c. daily for 32 consecutive days, and the IFN-alphaNT group (n = 10), which did not receive IFN-alpha prior to highly active antiretroviral therapy (HAART), which was commenced on day 28 in both groups. IFN-alphaTreatment was well tolerated in 14 of the 17 patients of the IFN-alphaT group who completed the study. The mean HIV RNA reduction in the IFN-alphaT group on day 14 was 1.1 log(10). Viral load suppression was inversely associated with baseline viral load (p = 0.031). Four weeks after initiation of HAART, IFN-alphaT and IFN-alphaNT group patients had 2.40 and 1.82 log(10) HIV RNA reduction from baseline, respectively (p < 0.001). There was no evidence of cross-resistance with existing antiretrovirals in patients with HIV-RNA rebound after initial plasma viral load decline > or = 1 log(10) during IFN-alpha monotherapy. Thus, low daily IFN-alpha exhibits potent anti-HIV-1 activity in vivo without serious adverse effects. These properties render IFN-alpha an attractive candidate for further assessment as a constituent of HAART.

Reconstructing and predicting the hepatitis C virus epidemic in Greece: increasing trends of cirrhosis and hepatocellular carcinoma despite the decline in incidence of HCV infection

Summary.  In this study, a comprehensive methodology for modelling the hepatitis C virus (HCV) epidemic is proposed to predict the future disease burden and assess whether the recent decline in the incidence of HCV may affect the future occurrence of cirrhosis and hepatocellular carcinoma (HCC) cases. Using the prevalence of HCV, the distribution of chronic hepatitis C (CHC) patients within the various transmission groups and their infection‐onset times, it was possible to reconstruct the incident infections per year in the past that progressed to CHC in Greece. The natural history of the disease was simulated in subcohorts of newly infected subjects using transition probabilities derived either empirically between fibrosis stages 0–4 or from literature review. Annual estimates of the incidence and prevalence of CHC by fibrosis stage, HCC and mortality in Greece were obtained up to 2030. HCV incidence peaked in the late 1980s at five new infections/10 000 person‐years. Under the assumption of 20–100% decline in HCV incidence after 1990, the cumulative number of incident cirrhosis and HCC cases from 2002–2030 was projected to be lower by 9.6–48.2% and 5.9–29.5%, respectively, than that estimated under the assumption of no decline. However, the prevalent cirrhotic/HCC cases and HCV‐related deaths are predicted to decline in the next 30 years only under the assumption of complete elimination of new HCV infections after 1990. Despite the progress in the reduction of HCV transmission, primary prevention does not seem adequate to reverse the rise in the incidence of cirrhosis and HCC.