Respiratory syncytial virus (RSV) is a significant cause of respiratory infections in adults, particularly among older adults and individuals with chronic diseases. While traditionally linked to pediatric populations, RSV’s impact on adults, especially the elderly, is increasingly recognized but remains understudied in many regions. This retrospective study, conducted at the University Hospital Center Zagreb from October 2022 to April 2024, is the first to analyze RSV-positive adults in Croatia. Using RT-PCR testing, we evaluated clinical and epidemiological characteristics in both hospitalized and outpatient populations, focusing on those aged > 65 years. Among 2631 tested individuals, the RSV prevalence was 5.25%, with older adults experiencing the most severe outcomes, including pneumonia, COPD exacerbation, and intensive care admissions. Seasonal analysis confirmed a winter peak in RSV cases, while chronic conditions such as cardiovascular and respiratory diseases were strongly associated with higher complication rates. These findings demonstrate that older adults with comorbidities bear the greatest burden of RSV infection, highlighting the need for the early identification of high-risk patients. By providing detailed insights into RSV-related outcomes in this population, this study supports the development of targeted prevention and management strategies to reduce the burden of RSV in vulnerable groups.

There has been a substantial increase in the number of cases of invasive fungal infections worldwide, which is associated with a growing number of immunosuppressed patients and a rise in antifungal resistance. Some fungi that were previously considered harmless to humans have become emerging pathogens. One of them is Purpureocillium lilacinum, a ubiquitous filamentous fungus commonly found in the environment, especially in the air and soil. P. lilacinum belongs to a bigger group of hyaline fungi that cause hyalohyphomycosis, a fungal infection caused by fungi with colorless hyphae. Although this is a heterogeneous group of fungi, there are similarities regarding their ubiquity, ways of transmission, affected patients, and difficulties in diagnostics and treatment. In hyalohyphomycosis, the skin is one of the most affected organs, which is why the involvement of dermatologists is crucial for the initial assessment, since the timely recognition and early diagnosis of this condition can prevent life-threatening infections and death. In this review, we covered cutaneous hyalohyphomycosis caused by P. lilacinum and other fungi in the same group, including Fusarium, Penicilium, Scedosporium, Scopulariopsis, Acremonium, and Trichoderma genera.

Campylobacter jejuni is a leading cause of bacterial gastroenteritis worldwide which usually presents as mild, and self-limiting disease in immunocompetent individuals. However, in immunocompromised patients, such as those with common variable immunodeficiency, C. jejuni can cause severe recurrent infections requiring antibiotic treatment. Our study reports a case of a 37-year-old male patient with CVID, who had multiple episodes of C. jejuni intestinal infections over a 3.5-year period. A total of 27 stool samples were collected and analyzed between December 2020 and July 2024 during acute febrile diarrheal episodes, with C. jejuni isolated in 15 samples. Antimicrobial susceptibility testing (AST) during the course of the disease revealed three different antimicrobial resistance profiles including multi-drug-resistant phenotype. Whole genome sequencing was performed on three representative isolates, all identified as MLST type 367, ST-257 complex, with minimal genetic divergence, indicating a clonal origin. Genes and point mutations conferring resistance to macrolides, fluoroquinolones, beta-lactams, and tetracycline were identified in different C. jejuni isolates, along with key virulence factors linked to adherence, invasion, motility, and immune evasion. The genetic analysis of macrolide phenotypic resistance revealed different resistance mechanisms. Genotypic and phenotypic analyses of the same C. jejuni clone from single patient, and identified multidrug resistance pattern, present the first documented case of in vivo resistance development of C. jejuni in Croatia. This case highlights the role of prolonged antibiotic pressure in driving resistance evolution and underscores the need for careful antimicrobial stewardship and genomic monitoring in immunocompromised patients. Further research is needed to correlate phenotypic resistance with genetic determinants in Campylobacter spp.

Bacillus anthracis is a well-known zoonotic pathogen that can cause disease in both animals and humans. Moreover, it has a high bioterrorism potential as its lethal spores are resistant to inactivation, are easy to produce in large quantities, and are easily spread over large areas. Anthrax cases occur in different parts of the world, including most European countries. Specific areas of Croatia are long known as anthrax districts, but with sporadically reported cases over the years. Here, we present a major outbreak of animal and human anthrax in the region of Lonjsko Polje in Croatia, a region not known to have anthrax cases in the past. The outbreak started in July 2022 and lasted several months, but most human and animal cases were reported in the first month. During the outbreak, there were 17 reported human cases of cutaneous anthrax and 29 laboratory-confirmed animal cases. However, due to issues in reporting in animals and the late finding of the carcasses, which made laboratory diagnostics challenging, the actual number of animal cases was probably significantly higher.

Background: Surgical site infections (SSIs) are among the most frequent healthcare-associated infections (HCAIs) worldwide. Changes in the functioning of healthcare systems may affect the implementation of SSIs prevention practices, with consequent alterations in the occurrence of HCAIs. The main aims of our study were to analyze specific SSIs prevalence and proportions together with overall HCAIs prevalence in acute care hospitals (ACHs) before and after the COVID-19 pandemic. Additional aims were to identify bacterial causative agents, the use of perioperative antibiotic prophylaxis (PAP), related structural and process quality indicators, and to determine trends between two periods. Methods: The National Reference Centre for HCAIs (University Hospital Centre Zagreb) conducted point prevalence surveys in May 2017 and May 2023 in ACHs throughout Croatia, using the technical protocol developed by the European Centre for Disease Prevention and Control (ECDC). Results: The prevalence of HCAIs in ACHs in Croatia rose from 5.3% (95% CI 4.8–5.7) in 2017 to 7.2% (95% CI 6.6–7.8) in 2023 (p = 9.93 × 10⁻¹⁴). This trend was paralleled with the rising of the HCAIs prevalence in surgical departments from 5.1% to 6.7% (p = 0.0099). The prevalence of overall SSIs across ACHs increased from 0.9% (95% CI 0.7–1.1) in 2017 to 1.2% (95% CI 1.0–1.5) in 2023 (OR 1.36 (1.03–1.80), p = 0.032. While the prevalence of superficial incisional SSIs significantly decreased (OR 0.53 (0.30–0.95), p = 0.028), the share of deep-seated SSIs (deep incisional and organ/space SSIs) among classified SSIs shifted from 48/92 to 77/96; odds ratio (OR) 2.09 (95% CI 1.45–3.01). In 2017, Gram-positive cocci were the most frequently isolated bacterial causative agents (44.6%). By 2023, this shifted, with Enterobacterales species comprising most isolates (42.2%). In 2023, significantly a higher proportion of patients received PAP (χ² = 25.419, df = 1, p < 0.5). An increase in the positive trend of alcohol-based hand rub antiseptics use in surgical departments (+15.7 L/patient-days, p < 0.001) contrasted with a decrease in infection prevention and control (IPC) nurses and medical doctors per hospital (−0.5, p = 0.041/−0.5, p = 0.003). Conclusions: Findings of the two point prevalence surveys over time indicate the changes in trends in surgical site infections burden, and highlight the need for the implementation and strengthening of preventive measures with the focus on targeted prevention of deep-seated infections.

Salmonella Mikawasima is a rare, mainly environmental serovar. In 2020, an outbreak was observed in neonatal and maternal wards of the University Hospital of Split and was established as an endemic until the end of 2024. Using whole-genome sequencing, this study aimed to analyse the phenotypic and genotypic characteristics of S. Mikawasima isolates and to elaborate whether the spread of the same clone occurred. Sequenced isolates were classified as ST2030, with the presence of aminoglycoside and extended spectrum beta-lactam resistance genes. Ten percent of the sequenced isolates exhibit multi-drug resistance. Identified virulence factors that include biofilm formation genes suggest the potential persistence of S. Mikawasima in the hospital environment, while spatial and temporal analysis reveal clonal expansion and possible horizontal transmission between different hospital wards. This study provides a deep understanding of the genomic composition of S. Mikawasima and emphasises the need for more stringent infection prevention measures, especially in vulnerable neonatal and postpartum settings, to mitigate the risk of healthcare-associated infections, and it should be followed by further microbiological and epidemiological investigations to identify the source of infection.