BackgroundHBsAg immune-escape mutations can favor HBV-transmission also in vaccinated individuals, promote immunosuppression-driven HBV-reactivation, and increase fitness of drug-resistant strains. Stop-codons can enhance HBV oncogenic-properties. Furthermore, as a consequence of the overlapping structure of HBV genome, some immune-escape mutations or stop-codons in HBsAg can derive from drug-resistance mutations in RT. This study is aimed at gaining insight in prevalence and characteristics of immune-associated escape mutations, and stop-codons in HBsAg in chronically HBV-infected patients experiencing nucleos(t)ide analogues (NA) in Europe.MethodsThis study analyzed 828 chronically HBV-infected European patients exposed to ≥ 1 NA, with detectable HBV-DNA and with an available HBsAg-sequence.The immune-associated escape mutations and the NA-induced immune-escape mutations sI195M, sI196S, and sE164D (resulting from drug-resistance mutation rtM204 V, rtM204I, and rtV173L) were retrieved from literature and examined. Mutations were defined as an aminoacid substitution with respect to a genotype A or D reference sequence.ResultsAt least one immune-associated escape mutation was detected in 22.1% of patients with rising temporal-trend. By multivariable-analysis, genotype-D correlated with higher selection of ≥ 1 immune-associated escape mutation (OR[95%CI]:2.20[1.32–3.67], P = 0.002). In genotype-D, the presence of ≥ 1 immune-associated escape mutations was significantly higher in drug-exposed patients with drug-resistant strains than with wild-type virus (29.5% vs 20.3% P = 0.012). Result confirmed by analysing drug-naïve patients (29.5% vs 21.2%, P = 0.032). Strong correlation was observed between sP120T and rtM204I/V (P < 0.001), and their co-presence determined an increased HBV-DNA.At least one NA-induced immune-escape mutation occurred in 28.6% of patients, and their selection correlated with genotype-A (OR[95%CI]:2.03[1.32–3.10],P = 0.001).Finally, stop-codons are present in 8.4% of patients also at HBsAg-positions 172 and 182, described to enhance viral oncogenic-properties.ConclusionsImmune-escape mutations and stop-codons develop in a large fraction of NA-exposed patients from Europe. This may represent a potential threat for horizontal and vertical HBV transmission also to vaccinated persons, and fuel drug-resistance emergence.Electronic supplementary materialThe online version of this article (10.1186/s12879-018-3161-2) contains supplementary material, which is available to authorized users.

Introduction:Intensive care units (ICUs) are associated with a greater risk of developing nosocomial infections (NIs) than other departments.Aim:The aim of this study was to determine the rate, the site and causative organisms of NIs in the surgical ICU at University Clinical Center Tuzla.Methods:All patients admitted to the surgical ICU were followed prospectively, for the development of NIs (January-December 2010). Determination of NIs was performed using standardized the Centers for Disease Control and Prevention (CDC) criteria.Results:94 out of 834 patients (11.27%) developed NIs. Respiratory tract infections were seen in 56 (60%), urinary tract infections in 15 (16%) and gastrointestinal tract infections in 8 (9%) patients. Other infections identified were surgical site, bloodstream and skin infections. Gram-negative organisms were reported in approximately 75% of cases (78.7% extended-spectrum beta-lactamase (ESBL)-producers). Klebsiella pneumoniae was the commonest (51.0%), followed by Proteus mirabilis (21.3%) and Pseudomonas aeruginosa (10.6%). Methicillin-resistant Staphylococcus aureus (MRSA) (16%), and Clostridium difficile (9.6%) were the commonest among gram-positive bacteria.Conclusion:Respiratory and urinary tract infections made up the great majority of NIs. ICU patients are more susceptible to NIs, emphasizing the importance of continuous surveillance and enforcement of specific infection control measures.

Introduction:Acinetobacter baumannii is a frequent cause of infections in hospitals around the world, which is very difficult to control and treat. It is particularly prevalent in intensive care wards.Aim:The main objective of the research was to establish the application of epidemiological monitoring of nosocomial infections (NIs) caused by A. baumannii in order to determine: the type and distribution of NIs, and to investigate antimicrobial drug resistance of A. baumannii.Material and Methods:855 patients treated at the Clinic of Anesthesiology and Reanimation, University Clinical Center Tuzla during 2013 were followed prospectively for the development of NIs. Infections caused by A. baumannii were characterized by the anatomical site and antibiotics resistance profile.Results:NIs were registered in 105 patients (12.3%; 855/105). The predominant cause of infection was A. baumannii with an incidence of 51.4% (54/105), followed by ESBL-producing Klebsiella pneumoniae with 15.2% (16/105) of cases, methicillin-resistant Staphylococcus aureus with 8.6% (9/105), and ESBL-producing Proteus mirabilis with 7.6% (8/105). According to the anatomical site, and type of NIs caused by A. baumannii, the most frequent were respiratory infections (74.1%; 40/54). Infections of surgical sites were registered in 11.1% (6/54) of cases, while bloodstream infections in 9.2% (5/54). A. baumannii isolates tested resistant against most antibiotics examined, but showed a high degree of susceptibility to tobramycin (87%; 47/54) and colistin (100%; 54/54).Conclusion:The increasing incidence of multi- and extensively drug-resistant Acinetobacter spp. emphasizes the importance of administration of an adequate antibiotic strategy and the implementation of strict monitoring of the measures for controlling nosocomial infections.

These findings support resistance testing in cases of apparent NA therapy failure. This survey highlights the impact of exposure to lamivudine and adefovir on development of drug resistance and cross-resistance. Continued use of these NAs needs to be reconsidered at a pan-European level.

Hepatitis C infection is important global health problem with wide spectrum of health, social and economic consequences. The goal of this research was to estimate prevalence of hepatitis C virus infection in risk groups, and to determine association hepatitis C virus (HCV) infection and risk factors. Research included 4627 subjects divided in two groups. Test group included 2627 subjects divided in 4 subgroups with risk for HCV infection: those who received blood transfusion without screening on HCV (it was introduced in 1995) (700); intravenous drug users (60); patients on hemodialysis (168) and health care workers (1699). Control group included 2000 healthy volunteer blood donors. In all subjects anti-HCV antibodies were tested with third generation ELISA test. Positive serum samples were tested for presence of HCVRNA, using reaction of reverse transcription and polymerase chain reaction. In all anti-HCV positive subjects further epidemiological and clinical workup was performed. Prevalence of HCV infection in risk groups was: 4.6% in subjects who have received blood transfusions without HCV blood screening, 35% in intravenous drug users, 58.9% in patients on chronic dialysis, and 0.4% in health care workers. In control group prevalence was low (0.2%). In the group of 158 anti-HCV positive subjects, 73.4% had HCVRNA. The largest number of subjects with HCV infection was in the age group of 30-49 years (45.8%). This study showed that multiple blood transfusions before introducing the blood screening for HCV, longer duration of intravenous drug abuse, longer duration of hemodialysis treatment, larger number of accidental injuries in health care workers are independent and statistically significant risk factors for those groups examined. Results of this study confirm that general screening for HCV infection is recommended in risk groups for HCV infection in order to identify to prevent and to treat it.