Orally administered compounds represent the great majority of all pharmaceutical compounds produced for human use and are the most popular among patients since they are practical and easy to self-administer. Following ingestion, orally administered drugs begin a “perilous” journey down the gastrointestinal tract and their bioavailability is modulated by numerous factors. The gastrointestinal (GI) tract anatomy can modulate drug bioavailability and accounts for interpatient drug response heterogeneity. Furthermore, host genetics is a contributor to drug bioavailability modulation. Importantly, a component of the GI tract that has been gaining notoriety with regard to drug treatment interactions is the gut microbiota, which shares a two-way interaction with pharmaceutical compounds in that they can be influenced by and are able to influence administered drugs. Overall, orally administered drugs are a patient-friendly treatment option. However, during their journey down the GI tract, there are numerous host factors that can modulate drug bioavailability in a patient-specific manner.

Erythema infectiosum is the most common clinical manifestation of Parvovirus B19 infection although it has also been associated with rheumatologic diseases and various types of systemic vasculitides. Acute hepatitis and benign myositis however are rarely reported in association with Parvovirus B19 infection.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has hit its second year and continues to damage lives and livelihoods across the globe. There continues to be a global effort to present serological data on SARS-CoV-2 antibodies in different individuals. As such, this study aimed to characterize the seroprevalence of SARS-CoV-2 antibodies in the Cypriot population for the first time since the pandemic started. Our results show that a majority of people infected with SARS-CoV-2 developed IgG antibodies against the virus, whether anti-NP, anti-S1RBD, or both, at least 20 days after their infection. Additionally, the percentage of people with at least one antibody against SARS-CoV-2 in the group of volunteers deemed SARS-CoV-2 negative via RT-PCR or who remain untested/undetermined (14.43%) is comparable to other reported percentages worldwide, ranging anywhere from 0.2% to 24%. We postulate that these percentages reflect the underreporting of true infections in the population, and also show the steady increase of herd immunity. Additionally, we showed a significantly marked decrease in anti-NP IgG antibodies in contrast to relatively stable levels of anti-S1RBD IgG antibodies in previously infected individuals across time.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system characterized by immune-mediated demyelination and neurodegeneration. Although the exact cause of MS remains unclear, accumulating epidemiological and immunological evidence strongly implicates Epstein–Barr virus (EBV) infection as a major environmental factor associated with disease development. Nearly all individuals with MS are EBV seropositive, and longitudinal studies have demonstrated that EBV infection precedes MS onset, supporting a causal relationship. EBV establishes lifelong latency in B cells and can profoundly influence host immune responses, providing several potential mechanisms through which it may contribute to autoimmunity. In this review, we summarize current knowledge of EBV biology and discuss epidemiological findings linking EBV infection with MS risk. We then examine alterations in EBV-specific immune responses observed in MS, including dysregulated humoral and cellular immunity. Particular attention is given to molecular mimicry involving the Epstein–Barr nuclear antigen 1 (EBNA1) and central nervous system proteins, which may promote cross-reactive autoimmune responses. Finally, we discuss evidence for the presence and potential role of EBV-infected immune cells within the MS brain and highlight key unanswered questions that remain critical for understanding EBV-driven neuroinflammation.

The COVID-19 pandemic has had a profound impact on healthcare systems worldwide, with severe consequences on the global economy and society. The clinical presentation of SARS-CoV-2 infection varies widely, ranging from asymptomatic cases to severe disease and death. Coinfection with other respiratory pathogens in SARS-CoV-2-positive individuals may exacerbate symptom severity and lead to poorer clinical outcomes. Background/Objectives: This study is the first to investigate the prevalence of viral and bacterial co-infections in SARS-CoV-2-positive individuals in Cyprus. Methods: A total of 1111 SARS-CoV-2-positive nasopharyngeal swab samples collected from non-hospitalized patients were analyzed for the presence of 18 viral and 3 bacterial respiratory pathogens. Results: Of these, 51 samples (4.6%) were found to have at least one additional respiratory pathogen. The most frequently detected viruses were rhinovirus/enterovirus (n = 28; 2.5%) and adenovirus (n = 8; 0.7%), while the bacterial pathogens identified were Legionella pneumophila (n = 1; 0.1%) and Bordetella pertussis (n = 1; 0.1%). The highest proportion of co-infections was observed in the youngest age group (<10 years), where 52.9% of co-infections were identified, followed by the 30–39 age group, which accounted for 15.7% of cases. Among single respiratory virus co-infections, rhinovirus/enterovirus (27.5%) and adenovirus (13.7%) were the most frequently detected in the <10 age group, followed by RSV (3.9%), bocavirus, influenza B, HMPV A + B, and coronavirus NL63 (each at 2%). Conclusions: The current study underscores the importance of simultaneous testing for SARS-CoV-2 and other respiratory pathogens, as this may have significant implications for both individual patient care and healthcare services.

West Nile virus (WNV) causes human disease with variable severity. Toll-like receptor 3 (TLR3) is essential for innate immune responses to viral infections, including WNV. The non-synonymous single-nucleotide polymorphism (SNP) rs3775291 (C/T), which alters TLR3 function, has been linked to susceptibility to several viral pathogens, but its role in WNV infection is unclear. This study investigates the association between rs3775291 and WNV infection in hospitalized patients. A case–control study was conducted in Cyprus, including 20 hospitalized WNV patients and 22 healthy controls (HCs). Genotyping was performed using a TaqMan allelic discrimination assay. The C/T genotype was significantly more frequent in WNV patients (65%) than in HCs (27.3%) (p = 0.0217; OR = 0.1648, 95% CI: 0.04073–0.6731). C/T and T/T genotypes combined were more common in patients (75%) versus HCs (36.4%) (p = 0.0157; OR = 0.1905, 95% CI: 0.05017–0.7232). The T allele was more frequent in patients, but not statistically significant (p = 0.0640). The results indicate that the C/T genotype is associated with increased susceptibility to WNV infection and the likelihood of hospitalization. Further studies in larger, independent cohorts and across diverse populations and age groups are warranted to validate these findings.