Flaviviruses are a heterogeneous group of viruses that may induce broad antigenic cross-reactivity. We present a patient who was admitted to the infectious disease department with symptoms suggestive of aseptic meningitis. During the clinical workup, the patient reported a tick bite two weeks before the disease onset. High titers of IgM and IgG antibodies to tick-borne encephalitis virus (TBEV) were found in both serum and cerebrospinal fluid (CSF) samples, indicating acute TBEV infection. West Nile virus (WNV) and Usutu virus (USUV) IgM and/or IgG antibodies were also detected, and a virus neutralization test (VNT) was performed. A high titer of TBEV neutralizing (NT) antibodies (640) was detected, which confirmed acute TBE. However, NT antibodies to WNV and USUV were also detected (titer 80 for both viruses). After TBEV and WNV IgG avidity evaluation, previous flavivirus infection was highly suspected (avidity index 82% and 89%, respectively). Blood, CSF, and urine samples were negative for respective viruses’ RNA. The presented case highlights the challenges in flavivirus serodiagnosis. In the published literature, different degrees of cross-reactivity or cross-neutralization between TBEV and dengue, louping ill, Omsk hemorrhagic fever, Langat, and Powassan virus were also observed. Therefore, the serology results should be interpreted with caution, including the possibility of cross-reactivity. In areas where several flaviviruses co-circulate VNT is recommended for disease confirmation.

Viral hepatitis is a significant cause of morbidity and mortality worldwide. In Croatia, hepatitis B virus (HBV) and hepatitis C virus (HCV) are widely distributed, especially in some high-risk groups such as people who inject drugs (PWID), prisoners, and highly promiscuous groups. The seroprevalence of HBV ranges from 7.0% in the general population to 38.8% in PWID, depending on the region. The seroprevalence of HCV is highest among PWID (29–75.5%) as compared to 0.9% in the general population. Analyzing the distribution of HCV genotypes, no substantial changes in the molecular epidemiology of the two most frequent HCV genotypes (1 and 3) in the past 20 years were observed. However, the predominance of subtype 1b compared to subtype 1a as detected in 1996–2005 was not confirmed in 2008–2015. Hepatitis A virus (HAV) incidence was high in the past with a decreasing trend since the 2000s, except for an outbreak in 2017–2018 as part of the large European outbreak, which was mainly among men who have sex with men. Hepatitis E virus (HEV) is an emerging virus detected for the first time in Croatia in 2012. The seroprevalence of HEV is high among hemodialysis patients (27.9%) and liver transplant recipients (19.3–24.4%). In addition, higher seroprevalence rates were observed in animal-related professions (e.g., veterinarians, 15.2%; hunters, 14.9%). All detected HEV strains belonged to genotype 3.

Background: Pelvic inflammatory disease (PID) is a public health problem that demands rapid diagnosis and treatment and may severely impair female reproductive health. Objective: To analyze anamnestic information, laboratory findings, and clinical and microbiological features of patients with severe acute PID that underwent a surgical procedure. Methods: This retrospective study enrolled 97 cases that were surgically treated in the Department of Obstetrics and Gynecology, Clinical Hospital „Sveti Duh“ between 2009 and 2019. Results: Most women were within the age group 35-44 (38.14%). Lower abdominal pain was the most common symptom (92.78%). Compared to intraoperatively confirmed PID, C-reactive protein (CRP) yielded the highest sensitivity (88.10%) while cervical motion tenderness possessed the highest specificity (53.85%). The tubo-ovarian abscess was detected in 35.05% of intraoperative specimens, mainly occurring in women between 45-54 years (P=0.017) and absent between 15-24 (P=0.012) and 25-34 years (P=0.049). The length of hospital stay was influenced by the number of symptoms (ρ=0.316, P=0.002), admission CRP levels (ρ=0.620, P<0.001), and admission body temperature (ρ=0.386, P<0.001). Out of 59.30% of positive cultures, one pathogen was isolated in 70.59%, mainly Escherichia coli (41.18%). Admission CRP levels impacted the efficacy of microbiologic isolation (P=0.001). The empirical treatment was mostly based on the clindamycin/gentamicin combination (51.72%). Conclusion: Severe clinical picture that requires surgical treatment can be expected in women >35 years. Longer hospital stay was associated with more symptoms, higher CRP, and temperature values on admission. It is important to have a low threshold for diagnosis and to consider both aerobic and anaerobic pathogens when selecting antibiotic treatment.