Does pre-existing immunity determine the course of SARS-CoV-2 infection in health-care workers? Single-center experience.

OBJECTIVES: To assess the severity of symptoms, duration of infection and viral loads of health-care workers (HCWs) who tested positive for Coronavirus disease 2019 (COVID-19) during Omicron's prevalence, in regard to vaccination and previous infection. METHODS: During 2 weeks of highest rate of COVID-19 cases in Bosnia and Herzegovina, the positive nasopharyngeal swabs were analysed in 141 HCWs by reverse transcription quantitative PCR, targeting four different genes: RdRp, E, N and nsp14. Uniformed questionnaire was used to collect relevant sociodemographic and epidemiological data from HCWs divided into four groups: unvaccinated/not previously infected (group 1); unvaccinated/previously infected (group 2); vaccinated/not previously infected (group 3); and vaccinated/previously infected (group 4). RESULTS: We observed that occurrence of fever and smell or taste loss were more frequent in group 1 (86.4% and 25%) and group 3 (76.9% and 19.2%), in comparison to group 2 (64.4% and 6.7%) and group 4 (69.2% and 3.8%), (p = 0.023 and p = 0.003). Although statistically not significant, group 2 (61.9%), group 3 (65.4%), and group 4 (70.8%) experienced negativization within 7 days of positive RT-qPCR test, whereas 51.2% of HCWs from group 1 tested negative later on. There is no significant difference between all four groups regarding Ct values of analysed genes. CONCLUSION: During Omicron's prevalence, the vaccination had less substantial effect on symptomatic disease among HCWs, while fever and loss of smell or taste were considerably less likely to occur upon reinfection. Since viral loads and negativization periods do not seem to significantly vary, irrespective of pre-existing immunity, systemic vaccination and mask-wearing should still be considered among HCWs.

Molecular Characterization and Survival of Carbapenem-Resistant Acinetobacter baumannii Isolated from Hospitalized Patients in Mostar, Bosnia and Herzegovina.

Increasingly difficult treatment of multidrug-resistant (MDR) bacteria has become a global problem of the 21st century. Within a group of multiresistant bacteria, the Acinetobacter baumannii convincingly occupies the position at the top of the group designated as ESKAPE pathogens. In this study, 61 isolates of A. baumannii were recovered from different samples originating from various departments of the University Clinical Hospital Mostar during 2018. All of the isolates were identified using conventional phenotypic methods and the VITEK® 2 Compact System, and were confirmed by MALDI-TOF mass spectrometry. The minimum inhibitory concentrations (MICs) were determined by the microbroth dilution method using MICRONAUT-S MDR MRGN-Screening and VITEK 2 Compact System. All strains were resistant to carbapenems and classified in eight different resistotypes according to their antibiotic resistance and macrorestriction pulsed-field gel electrophoresis profiles, with all belonging to IC II. One isolate displayed resistance to colistin (MIC ≥16 mg/L). The presence of blaOXA genes encoding OXA-type carbapenemases was investigated by multiplex PCR and the Eazyplex® SuperBugAcineto system and showed 100% compatibility with the detection of acquired oxacillinases. Molecular characterization of the isolates tested in this study revealed the OXA-23- and OXA-40-like groups of acquired oxacillinases. Sequencing of two PCR products of the OXA-40-like group confirmed the presence of OXA-72. Survival assays with two selected isolates of A. baumannii encoding different mechanisms of carbapenem resistance revealed that one isolate was able to survive on a fragment of white laboratory coat during 90 days of monitoring. To the best of our knowledge, this is the first article to present the results of a comprehensive phenotypic, genotypic, and molecular analysis of A. baumannii isolates from the leading clinical hospital center in the southwestern part of Bosnia and Herzegovina, including data for the survival of this pathogen on the white laboratory coats used as compulsory medical clothing.

Cytomegalovirus Seroprevalence and Birth Prevalence of Congenital CMV Infection in Bosnia and Herzegovina: A Single-Center Experience.

BACKGROUND: Congenital cytomegalovirus infection (cCMV) is a leading cause of sensorineural hearing loss (SNHL) and neurodevelopmental disabilities in developed countries. Although high cCMV rates have been reported in populations with high seroprevalence, the cCMV prevalence in low/middle-income countries in Europe has not been defined. OBJECTIVE: To determine cytomegalovirus (CMV) seroprevalence and the cCMV prevalence in Bosnia and Herzegovina. METHODS: Between March 2010 and February 2019, 5222 sera samples from patients seen at the University Clinical Hospital Mostar were tested for CMV IgG. The cord blood samples collected from 2091 infants between July 2011 and January 2013 were analyzed for CMV IgG and CMV DNA. The cCMV prevalence was determined by testing saliva swabs from 1293 infants between November 2015 and October 2016. RESULTS: The overall CMV IgG prevalence was 81.4% (95% confidence interval: 0.8-0.82). Significantly higher prevalence was observed among females (84.9%) than in males (77.0%), and the rate increased from 50.8% in the 1 to 5 years group to 97.7% in the group > 65 years old. Most cord blood samples (2091/1925, 92.1%) were CMV IgG positive, and 2 (0.1%) were CMV DNA positive. Of the 1293 saliva swabs, 8 (0.62%; 95% confidence interval: 0.3-1.2) were CMV positive. All 8 infected infants had asymptomatic cCMV, and none had SNHL at 18 months of age. CONCLUSIONS: In a highly CMV seropositive population, the prevalence of cCMV was lower compared with that reported from other low/middle-income countries populations. None of the infected infants had symptomatic infection or SNHL at 18 months.

Characteristics of Vancomycin-Resistant Enterococcus Strains in the West Balkans: A First Report.

Vancomycin-resistant enterococci are among the major causes of nosocomial infections and represent a growing problem in many European countries. Among the most common enterococcal isolates, Enterococcus faecium is considered to be the reservoir of VanA and VanB-mediated resistance to glycopeptides. Enterococci with VanA-mediated resistance can transfer resistance genes to other enterococci and gram-positive bacteria. Hence, monitoring and surveillance of vancomycin-resistant enterococci (VREs) are crucial for the prevention of the spread of glycopeptide resistance. No reports have yet been published that document the resistance rates and typization of VREs in the region of Bosnia and Herzegovina as well as Croatia. In this study, 64 clinical enterococcal strains that were isolated in clinical centers, Mostar, Sarajevo, and Zagreb, were studied and findings regarding characteristics of vancomycin-resistant strains found in the West Balkan region are reported for the first time. All of the strains were identified using conventional phenotypic methods, and the resistance to glycopeptides was determined using the disk diffusion method, Vitek 2, and genotypic Enterococcus assay. The results of genotyping showed that 40 strains were identified as VREs (30% Enterococcus faecalis and 70% E. faecium), while the sensitivity of the phenotypic methods was 87.5%. Furthermore, VanA and VanB resistance types were found in Bosnia and Herzegovina and Croatia, with slightly higher prevalence of the latter (72.5%) over the former (27.5%).