Search Results (156)

Objectives: COVID-19, caused by the SARS-CoV-2 virus, has infected over 777 million individuals and led to approximately 7 million deaths worldwide. Despite significant efforts to develop effective therapies, treatment remains largely supportive, especially for severe complications like acute respiratory distress syndrome (ARDS). Numerous compounds from diverse pharmacological classes are currently undergoing preclinical and clinical evaluation, targeting both the virus and the host immune response. Methods: Despite the large number of articles published and after a preliminary attempt was published, we discarded the option of a systematic review. Instead, we have done a description of therapies with these results and a tentative mechanism of action. Results: Preliminary studies and early-phase clinical trials have demonstrated the potential of Mesenchymal Stem Cells (MSCs) in mitigating severe lung damage in COVID-19 patients. Previous research has shown MSCs to be effective in treating various pulmonary conditions, including acute lung injury, idiopathic pulmonary fibrosis, ARDS, asthma, chronic obstructive pulmonary disease, and lung cancer. Their ability to reduce inflammation and promote tissue repair supports their potential role in managing COVID-19-related complications. This review demonstrates the utility of MSCs in the acute phase of COVID-19 and postulates the etiopathogenic role of mitochondria in Long-COVID. Even more, their combination with other therapies is also analyzed. Conclusions: While the therapeutic application of MSCs in COVID-19 is still in early stages, emerging evidence suggests promising outcomes. As research advances, MSCs may become an integral part of treatment strategies for severe COVID-19, particularly in addressing immune-related lung injury and promoting recovery. However, a full pathogenic mechanism may explain or unify the complexity of signs and symptoms of Long COVID and Post-Acute Sequelae (PASC). Full article

Equine influenza is a highly contagious disease caused by the equine influenza virus (EIV). The occurrence of EIV outbreaks in America is associated with low levels of vaccination coverage. In Colombia, no seroprevalence evaluation has been carried out to estimate the distribution of the virus within the country. Our aim was to perform a sero-epidemiological survey of equine influenza infections and to identify associated risk factors in horses from four departments of Colombia. Serological testing was carried out by using an ELISA for the detection of IgG antibodies against the influenza A virus. The evaluation of epidemiological variables, clinical manifestations, and vaccination history was carried out through the application of a data collection instrument. Among the 385 horses analyzed, 27% of the samples tested positive, with a higher prevalence in Study 1 from horses with respiratory symptoms (40.4%) than in Study 2 from horses without clinical signs (16.1%). Only horses housed in stables had higher odds of testing positive. The study also revealed that unvaccinated horses were 68% less likely to test positive than vaccinated horses were. This research highlights a significant gap in vaccination coverage and the presence of antibodies even in asymptomatic horses. Management factors such as activity type and housing should be considered when strategies for EIV prevention are developed. Full article

Background: Marburg virus disease (MVD) is a highly lethal filoviral infection, yet its long-term health consequences remain poorly understood. We present one of the most temporally distant evaluations of MVD survivors, conducted 13 years post-outbreak in Uganda, offering novel insights into chronic physiological, biochemical, haematological, and psychosocial outcomes. Methods: A cross-sectional, community-based study compared ten MVD survivors with nineteen age- and sex-matched unexposed controls. Clinical evaluations included vital signs, anthropometry, mental health screening, and symptom reporting. Laboratory analyses covered electrolytes, inflammatory markers, renal and liver function tests, haematology, and urinalysis. Standardised psychological assessments measured anxiety, depression, perceived stigma, and social support. Findings: Survivors exhibited an elevated body mass index (BMI), higher systolic and diastolic blood pressure, and lower respiratory rates compared to controls, indicating ongoing cardiometabolic and autonomic changes. These trends may reflect persistent cardiometabolic stress and potential alterations in autonomic regulation, warranting further investigation. Biochemically, survivors exhibited disruptions in serum chloride, bilirubin, and total protein levels, suggesting subclinical hepatic and renal stress. Haematological analysis revealed persistent reticulocytosis despite normal haemoglobin levels, indicating long-term erythropoietic modulation. Despite these physiological changes, survivors reported minimal psychological morbidity, sharply contrasting with the post-recovery profiles of other viral haemorrhagic fevers. Stigma was prevalent during the outbreak; however, strong family support alleviated long-term psychosocial distress. Interpretation: Thirteen years post-infection, MVD survivors demonstrate multisystem physiological perturbations without marked psychological sequelae. These findings challenge assumptions of universal post-viral trauma and highlight the necessity for tailored survivor care models. Future longitudinal studies should investigate the mechanistic pathways underlying cardiometabolic and haematological reprogramming to inform intervention strategies in resource-limited settings. Full article

Background: Human cytomegalovirus (HCMV) is the leading cause of congenital and acquired viral infections in newborns. While acquired infections are often asymptomatic, premature infants—especially those born before 30 weeks of gestation or with a very low birth weight (<1500 g)—are at an increased risk for severe infections. These can manifest as thrombocytopenia, liver failure, sepsis-like symptoms, and, in rare cases, death. HCMV is transmitted through various human secretions, including breast milk, which is the optimal feeding method for premature infants. Methods: We present five premature neonates, born between 23 and 26 weeks of gestation, each with a distinct clinical presentation of acquired HCMV infection. Results: All infants tested negative for congenital CMV infection via molecular urine testing within the first three weeks of life. Acquired infection was diagnosed between the second and third month of life, with symptoms such as septic shock, persistent thrombocytopenia, and signs of liver failure. Each infant received antiviral treatment along with regular viral load monitoring. Unfortunately, one patient died due to complications of prematurity. The remaining infants were discharged and continue to receive follow-up care in an outpatient clinic. Conclusions: These cases of postnatally acquired CMV infection aim to increase awareness of its highly heterogeneous and nonspecific clinical presentation, which may result in an incorrect, delayed, or concealed diagnosis. Currently, there are no clear guidelines on how to manage the presence of the virus in maternal breast milk, particularly for premature infants. It should be recommended to perform a molecular CMV test in all breast-fed preterm infants who present with sepsis-like symptoms, thrombocytopenia, liver failure, or other organ involvement. In case of a confirmed aCMV diagnosis, appropriate treatment should be introduced. Full article

Arthropod-borne viral infections, ranging from asymptomatic to fatal diseases, are expanding from endemic to nonendemic areas. Climate change, deforestation, and globalization favor their spread. Although arboviral manifestations mainly determine the onset of generalized symptoms, distinct clinical signs have been assessed, depending on the particular arthropod-borne virus (arbovirus) involved in the infectious process. A number of arboviruses cause neuroinvasive diseases in vertebrate hosts, with acute to chronic outcomes. Long-term neurological sequelae can include cognitive dysfunction and Parkinsonism. To increase knowledge of host interactions with arboviruses, in-depth investigations are needed to highlight how arboviruses exploit a host cell for efficient infection and clarify the molecular alterations underlying human brain diseases. This review focuses on the involvement of host cytoskeletal networks and associated signalling pathways in modulating the neurotropism of emerging arboviruses. A better understanding at the molecular level of the potential for emerging infectious diseases is fundamental for prevention and outbreak control. Full article

Trichomonas vaginalis, a prevalent sexually transmitted protozoan parasite, is associated with adverse birth outcomes, increased risk of HIV and other sexually transmitted infections, infertility, and cervical cancer. Despite its widespread impact, trichomoniasis remains underdiagnosed and underreported globally. Trichomonas vaginalis virus (TVV), a double-stranded RNA (dsRNA) virus infecting T. vaginalis, could impact T. vaginalis pathogenicity. We provide an overview of TVV, including its genomic structure, transmission, impact on protein expression, role in 5-nitroimidazole drug susceptibility, and clinical significance. TVV is a ~5 kbp dsRNA virus enclosed within a viral capsid closely associated with the Golgi complex and plasma membrane of infected parasites. Hypothetical mechanisms of TVV transmission have been proposed. TVV affects protein expression in T. vaginalis, including cysteine proteases and surface antigens, thus impacting its virulence and ability to evade the immune system. Additionally, TVV may influence the sensitivity of T. vaginalis to treatment; clinical isolates of T. vaginalis not harboring TVV are more likely to be resistant to metronidazole. Clinically, TVV-positive T. vaginalis infections have been associated with a range in severity of genital signs and symptoms. Further research into interactions between T. vaginalis and TVV is essential in improving diagnosis, treatment, and the development of targeted interventions. Full article

Background/Objectives: Feline panleukopenia, caused by FPV, is a highly contagious disease in cats. Current vaccines face challenges including complex production, high cost, and safety risks. Developing safer, more efficient alternatives is crucial. This study aimed to produce FPV virus-like particles (VLPs) using a recombinant baculovirus system expressing the VP2 gene and evaluate their immunogenicity and protective efficacy in cats. Methods: Sf9 insect cells were infected with recombinant baculovirus to express VP2 protein. The VP2 protein was purified using ultrafiltration and size-exclusion chromatography (SEC). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) confirmed the assembly of VLPs. Twenty healthy cats were randomly divided into four groups; three groups received different doses (5 μg, 15 μg, and 45 μg) of FPV VLP vaccine, while the fourth group served as the control group immunized with PBS. Blood samples were collected on day 21 to measure hemagglutination inhibition (HI) and virus-neutralizing (VN) antibody responses. Cats in the 15 μg dose group were challenged with virulent FPV strain 708 on day 21, and clinical signs and white blood cell counts were monitored for 10 days. Results: Immunized cats exhibited significantly higher HI and VN antibody titers compared to controls. After challenge, vaccinated cats showed no clinical signs of disease, and their white blood cell counts remained stable. In contrast, control cats developed severe symptoms and experienced significant leukopenia. Conclusions: The FPV VLP vaccine generated in this study are highly immunogenic and provide effective protection against virulent FPV challenge, demonstrating their potential as a safer vaccine candidate for feline panleukopenia. Full article

Human T-lymphotropic virus 1 (HTLV-1) infection has been associated with inflammatory, autoimmune, and lymphoproliferative diseases with a wide spectrum of clinical manifestations. Among patients with inflammatory rheumatological disease manifestations, cases of rheumatoid arthritis, Sjögren’s syndrome, polymyositis, and fibromyalgia, among others, have been reported. Another common feature of rheumatological diseases is the presence of joint manifestations, such as arthralgia and arthritis. In the present study, we sought to determine the laboratory profile and clinical rheumatological manifestations of people living with HTLV-1/2 residing in a metropolitan area in the Brazilian Amazon. A total of 957 individuals were screened for HTLV-1/2 infection by enzyme-linked immunosorbent assay (ELISA), and samples from seropositive individuals were subjected to infection confirmation by Western blotting or quantitative polymerase chain reaction (qPCR). Individuals with confirmed HTLV-1 and HTLV-2 infection were clinically evaluated for signs and symptoms of rheumatological diseases. Of the 957 individuals tested, 69 were positive for HTLV-1/2 infection, with 56 confirmed cases of HTLV-1 infection (5.9%), 12 of HTLV-2 infection (1.2%), and 1 classified as undetermined (0.1%). After clinical screening, 15 infected individuals with complaints suggestive of rheumatological disease were selected for evaluation by a rheumatologist (11 with HTLV-1 infection (1.1%) and 4 with HTLV-2 infection (0.4%)). The predominant pain pattern was symmetrical polyarthralgia, with large joints predominantly being affected. The diseases diagnosed were psoriatic arthritis, osteoarthritis, fibromyalgia, and regional pain syndromes. Antinuclear antibody (ANA) positivity was observed in two patients. Our findings confirm that HTLV-1 infection is associated with rheumatological disease manifestations and highlight the novel finding of cases of HTLV-2 infection in patients with rheumatoid arthritis symptoms. Full article

Viral infections may vary from mild to severe, manifesting with a wide range of symptoms, including skin lesions, influenza-like symptoms, or meningitis/meningoencephalitis signs. Viruses that cause both skin lesions and meningitis comprise, e.g., Enteroviruses (EVs) and Herpes viruses (HV). EVs are responsible for approximately 90% of viral meningitis cases. They occur frequently among children under 3 years of age and are characterized by various types of rash. HV infections are responsible for up to 18% of viral meningitis, mostly among adults or older children. Most patients with viral meningitis recover entirely. However, the rates of serious complications and mortality may be as high as 74% and 10%, respectively, for particularly vulnerable neonatal or immunocompromised patients. Patients that present signs of encephalitis and/or are suspected to have HSV/VZV infection require immediate implementation of empiric acyclovir therapy before receiving the polymerase chain reaction (PCR) test results. The clinical picture of viral meningitis may differ depending on the virus, including the presence of both meningeal signs and skin lesions. Therefore, early identification of the etiological factor is necessary for early and proper treatment implementation. It is crucial to accurately differentiate between the causative agents, and this work focuses on answering the question of how skin lesions can assist in achieving a better and faster diagnosis. The aim of this review was to analyze the characteristics of skin lesions in the course of meningitis caused by various viral species. This can be helpful for physicians in the diagnostic process and subsequent treatment. Full article

This study investigates the virulence properties and pathogenetic characteristics of the Kazakhstani strain of LSDV (LSDV KZ-Kostanay-2018) in indigenous cattle under controlled conditions. Twelve non-breed cattle were inoculated intradermally and monitored for clinical, pathological, and immunological responses. Clinical signs, including fever, skin nodules, and lymphadenopathy, emerged as early as day 5 post-infection (pi), with peak severity observed between days 11 and 14. Rapid seroconversion was observed, with 100% of animals showing virus-neutralizing antibodies by day 13. Pathological findings revealed extensive necrosis, thrombosis, and edema, with pronounced damage in the spleen, lungs, and lymph nodes. Histological analyses identified widespread destructive changes in the dermis and systemic tissues, consistent with highly aggressive disease progression. Viral genome and replication were confirmed in blood, skin nodules, and lymph nodes, with peak viral loads between days 11 and 14 pi. These results align with findings in Russian cattle infected with the Saratov/2017 strain but demonstrate more rapid symptom onset and severe pathology, suggesting strain-specific virulence. These findings contribute to a deeper understanding of LSDV pathogenesis and underscore the importance of regional adaptations in disease management. Full article

Due to its high genomic variability, the epidemiological landscape of porcine reproductive and respiratory syndrome virus (PRRSV) has become increasingly complex in recent years. From 2022 to 2023, we collected a total of 1044 clinical samples from pigs suspected of PRRSV infection in China and discovered a PRRSV-positive rate of 29.8% (311/1044) using RT-PCR targeting the nsp2 gene. Among these positive samples, NADC30/34-like PRRSV, highly pathogenic PRRSV (HP-PRRSV), and classical PRRSV strains accounted for 60.1%, 37.9%, and 4.5%, respectively. These results indicate that the most prevalent PRRSV strains in China are NADC30/34-like PRRSV, followed by HP-PRRSV. Two PRRSV strains, JX03 and HN08, were isolated, and TCID₅₀ assays were performed to determine their titers at different time points post-infection, revealing differences in their proliferation kinetics. Phylogenetic, amino acid sequence, and recombination analyses demonstrated that the JX03 and HN08 strains cluster within lineage 8 (HP-PRRSV) and sublineage 1.5 (NADC34-like PRRSV), respectively. Notably, the HN08 strain was identified as a recombinant between the NADC30-like and NADC34-like strains, while no recombination event was detected in the JX03 strain. Pathogenicity assessments showed that the JX03 strain exhibited higher pathogenicity than the CHN-HB-2018 strain (a NADC30-like PRRSV strain was previously isolated by our lab), as evidenced by differences in clinical signs and mortality rates in piglets. In contrast, HN08 displayed no obvious clinical symptoms or mortality, revealing lower pathogenicity than the CHN-HB-2018 strain. These findings provide valuable information on the epidemiological and genetic characteristics of PRRSV strains in China, laying a foundation for the development of effective strategies against PRRSV. Full article

Parainfluenza virus (PIV) infections contribute to the overall childhood morbidity from acute respiratory illness, yet virus-specific epidemiologic data are lacking across many regions globally. Here, we describe the clinical manifestations, seasonality, and meteorologic associations with PIV infections in Ecuadorian children. Between July 2018 and July 2023, we documented demographic and clinical information from children younger than 5 years seen in a single public health clinic with signs and symptoms consistent with an acute respiratory infection. Nasopharyngeal swabs collected at study enrollment underwent multiplex polymerase chain reaction-based diagnostic testing (Biofire FilmArray v. 1.7™). Regional meteorological data from the same period were provided by Ecuador’s Instituto Nacional de Meteorologia e Hidrologia. Parainfluenza viruses were detected in 9% of the 1251 enrolled subjects. PIVs were most frequently detected between March and July, with no change in seasonality following SARS-CoV-2 pandemic onset. Clinical manifestations of PIV infections included non-specific upper respiratory illness (82%), laryngotracheitis (3%), and bronchiolitis (11%). Events of PIV detection were negatively associated with ambient temperature and rainfall. Our findings highlight the contribution that PIVs play in the morbidity associated with pediatric medically attended outpatient respiratory tract infection and provide new insights into the seasonal epidemiology of PIV infections in coastal Ecuador. Full article

The chicken infectious anemia virus (CIAV) and fowl adenovirus serotype E8b (FAdV E8b) are pathogens that cause aplastic anemia and inclusion body hepatitis (IBH) in chickens, respectively. The co-infection of CIAV and FAdV E8b poses a significant threat to poultry health, potentially worsening clinical symptoms and increasing mortality rates. This study aimed to explore the combined pathogenic effects of FAdV E8b and CIAV co-infection on one-day-old specific pathogen-free (SPF) chickens. The results showed that co-infection led to significantly higher clinical scores and mortality rates compared to FAdV E8b infection alone. Additionally, there were different tissue distribution patterns for FAdV E8b between the single infection and co-infection groups, indicating potential changes in viral tropism. Biochemical analysis revealed elevated markers of liver and/or muscle damage in both the FAdV E8b infection group and the co-infection group, consistent with the viral infection process. These findings suggest that co-infection with FAdV E8b and CIAV can intensify clinical signs and mortality, and may potentially alter viral replication and tissue tropism in chickens. This study establishes a foundation for future investigations into the underlying mechanisms governing the interaction between CIAV and FAdV E8b during co-infection. Full article

Background: The coronavirus–caused disease (COVID-19), first identified in China in December 2019, has spread worldwide becoming a global pandemic. Although people infected with the SARS-CoV-2 virus presented mainly respiratory and gastrointestinal symptoms, an increase in cardiovascular incidents was observed in several scientific studies. SARS-CoV-2 virus has been shown to disrupt the normal immune response leading to a dysregulation of immune system function and massive production of inflammatory cytokines commonly known as “cytokine storm”. Methods: 57 patients eventually participated in the study, assigned to non–COVID (24 patients) and COVID (33 patients) groups. After signing consent to participate in the study, each patient was given a self–administered questionnaire to fill out prior to specimen collection, anthropometric measurements were taken and venous blood was collected for the following determinations: pro- and anti–inflammatory cytokines using a Bio–Plex 200 system, oxidative stress markers and basic hematological blood parameters. Results: showed statistically significant higher values of IL–1Ra and IL–1β in the COVID-19 group. Of the oxidative stress markers, only MDA levels were higher in the COVID-19 group. Conclusions: the results of our study provide evidence and support the occurrence of elevated levels of IL–1Ra, IL–1β and MDA in the COVID-19 group of patients, which are associated with a worse course and prognosis of COVID-19. A better understanding of the pathophysiology and dysregulation of the immune system associated with the cytokine storm is essential to select patients at risk and develop effective drugs and vaccines. Full article

The trigeminal nerve is the primary gateway through which the rabies virus enters the brain. Viral infection-related trigeminal neuritis is associated with certain clinical signs. This study investigated trigeminal ganglion histopathology in 92 rabid dogs. Trigeminal ganglionitis was classified into three pathological grades: mild, moderate, and severe. Immunostaining of selected sections was performed using antibodies against lymphocytes (CD3, CD20), stellate cells (glial fibrillary acidic protein, GFAP), macrophages (Iba-1, HLA-DR), ganglion cells (neurofilament, NF), and Schwann cells (S-100) to identify lesion cell types. In moderate and severe cases, double-immunofluorescence staining was performed to determine neuronophagia and Nageotte nodule cell types. Mild (13.0%) cases had minimal morphological changes in ganglion cells; moderate (56.5%) and severe (30.4%) cases showed infected ganglion cells and axons with degenerative necrosis, which were replaced by inflammatory cells. Immunohistochemically, viral antigens were detected in most ganglion cells in mild cases and were significantly reduced in severe cases. The number of CD3-, CD20-, GFAP-, and Iba-1-positive cells increased as the severity progressed, and neuronophagia and Nageotte nodules primarily comprised HLA-DR-positive cells. These findings suggest that the rabies virus reaches the trigeminal ganglion via ascending or descending routes and induces trigeminal neuropathological changes, contributing to neurological symptoms in rabid dogs. Full article