Search Results (216)

Enteric diseases represent one of the main causes of morbidity and mortality in poultry production, especially in turkeys (Meleagris gallopavo), significantly affecting the profitability of the sector. Turkey enteric complex (PEC) is a multifactorial syndrome characterized by diarrhea, stunting, poor feed conversion, and increased mortality in young turkeys. Its aetiologia includes multiple avian enteric viruses, including astrovirus, rotavirus, reovirus, parvovirus, adenovirus, and coronavirus, which can act singly or in co-infection, increasing clinical severity. This study performs a systematic review of the literature on these viruses and a meta-analysis of their prevalence in different regions of the world. Phylogenetic analyses were used to assess the genetic diversity of the main viruses and their geographical distribution. The results show a wide regional and genetic variability, which underlines the need for continuous epidemiological surveillance. Health and production implications are discussed, proposing control strategies based on biosecurity, targeted vaccination, and optimized nutrition. These findings highlight the importance of integrated management to mitigate the impact of CSF in poultry. Full article

Background: Parvovirus B19 (B19V) can cause severe relapsing episodes of pure red cell aplasia in immunocompromised individuals, which are commonly treated with intravenous immunoglobulins (IVIGs). Few data are available on B19V intra-host evolution and the role of humoral immune selection. Here, we report the dynamics of genomic mutations and subsequent protein changes during relapsing infection. Methods: Longitudinal plasma samples from immunocompromised patients with relapsing B19V infection in the period 2011–2019 were analyzed using whole-genome sequencing to evaluate intra-host evolution. The impact of mutations on the 3D viral protein structure was predicted by deep neural network modeling. Results: Of the three immunocompromised patients with relapsing infections for 3 to 9 months, one patient developed two consecutive nonsynonymous mutations in the VP1/2 region: T372S/T145S and Q422L/Q195L. The first mutation was detected in multiple B19V IgG-seropositive follow-up samples and resolved after IgG seroreversion. Computational prediction of the VP1 3D structure of this mutant showed a conformational change in the proximity of the antibody binding domain. No conformational changes were predicted for the other mutations detected. Discussion: Analysis of relapsing B19V infections showed mutational changes occurring over time. Resulting amino acid changes were predicted to lead to a conformational capsid protein change in an IgG-seropositive patient. The impact of humoral response and IVIG treatment on B19V infections should be further investigated to understand viral evolution and potential immune escape. Full article

The whitefly Bemisia tabaci (Hemiptera: Aleyrodoidea) causes direct feeding damage to crop plants and transmits pathogenic plant viruses, thereby threatening global food security. Although whitefly-infecting RNA viruses are known and proposed as biocontrol agents, no insect DNA virus has been found in any member of Aleyrodoidea. Using rolling circle amplification (RCA) of viral DNA from whiteflies collected from crop fields in Morocco, followed by Illumina sequencing of the RCA products, we found a novel insect single-stranded (ss) DNA parvovirus (family Parvoviridae) in addition to plant ssDNA geminiviruses transmitted by whiteflies. Based on its genome organization with inverted terminal repeats and evolutionarily conserved proteins mediating viral DNA replication (NS1/Rep) and encapsidation (VP), encoded on the forward and reverse strands, respectively, we named this virus Bemisia tabaci ambidensovirus (BtaDV) and classified it as a founding member of a new genus within the subfamily Densovirinae. This subfamily also contains three distinct genera of ambisense densoviruses of other hemipteran insects (Aphidoidea, Coccoidea, and Psylloidea). Furthermore, we provide evidence for the genetic variants of BtaDV circulating in whitefly populations and for its partial sequences integrated into the B. tabaci genome, with one integrant locus potentially expressing a fusion protein composed of viral Rep endonuclease and host DNA-binding domains. This suggests a long-term virus-host interaction and neofunctionalization of BtaDV-derived endogenous viral elements. Full article

Wild boars are recognized reservoirs of numerous viral pathogens, posing a significant risk to domestic pig populations, particularly in areas with poor biosecurity. This study assessed the prevalence and co-infection patterns of porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine cytomegalovirus (PCMV), African swine fever virus (ASFV), classical swine fever virus (CSFV), and pseudorabies virus (PRV) in wild boars from western Serbia and the Republic of Srpska (Bosnia and Herzegovina). Sixty-six spleen samples from legally hunted wild boars were analyzed by qPCR. All animals were negative for ASFV, CSFV, and PRV. The cumulative prevalence of infection with at least one of the other three viruses was 86.4% (95% CI: 76.2–92.8%). PCMV was detected in 74.2% of samples, PCV2 in 50%, and PPV in 28.8%. Co-infections were common: 42.4% of animals were positive for two viruses, and 12.1% for all three. A statistically significant association was observed between triple co-infection and sex, with higher rates in males. Subadult wild boars showed the highest PCV2 + PCMV co-infection rate (p = 0.0547). These findings highlight the need to expand molecular surveillance, particularly for PCMV, in both wild and domestic pigs, especially in regions reliant on low-biosecurity backyard farming. Full article

To genetically characterise an epidemic isolate of feline panleukopenia virus (FPLV) harbouring the Ala91Ser mutation in China, a clinical strain (accession number: OR921195.1), named FPLV-CC19-02, was isolated from a PCR-positive faecal swab sample. Phylogenetic analysis revealed that it is far removed from all current commercial vaccine strains and differs from the FPLV prototype strain Cu-4 (M38246.1), specifically the vaccine strain of Fel-O-Vax^® PCT, at positions 91 (Ala91Ser) and 101 (Ile101Thr) within the VP2 protein. This virus can induce the typical cytopathic effect seen in parvovirus infection in feline kidney cells, resulting in severe clinical symptoms in cats, including haematochezia and hyperthermia. Furthermore, infected cats died of virus infection within 5–10 days post-infection (dpi) (100% morbidity and 83% mortality), indicating that FPLV-CC19-02 is a strain with increased virulence. Additionally, it demonstrated good immunogenicity in cats. Overall, these findings may help us to better understand the molecular prevalence of feline panleukopenia virus in cats and provide valuable basic data for the development of effective, locally adapted feline panleukopenia virus vaccines in China. Full article

Parvoviruses have compact genomic organizations with overlapping open reading frames and thus utilize alternative RNA processing strategies, alternative splicing, alternative polyadenylation, and alternative translation mechanisms to generate a range of diverse proteins encoded within their genome. This comprehensive review provides an update on recent insights into the diverse mRNA processing mechanisms utilized by members of the Parvoviridae family, with emphasis on Bocaparvoviruses and Dependoparvoviruses to expand their protein repertoire and maintain their replicative advantage in infected host cells. It highlights the role of Bocaparvovirus ancillary nonstructural protein NP1; the first parvovirus protein involved in mRNA processing, specifically alternative splicing and alternative polyadenylation. Full article

The novel goose parvovirus (NGPV) and the novel duck reovirus (NDRV) are pathogens that can substantially affect the growth and development of ducklings, causing considerable economic losses to duck farms. Therefore, a timely, rapid, accurate, and high-throughput diagnosis and identification of viral infections are critical for preventing the spread of epidemics. In this study, a TaqMan probe-based duplex one-step RT-qPCR was established for the simultaneous detection and qualitative and quantitative identification of the two viruses. It demonstrated greater sensitivity than conventional PCR, detecting as low as 2.42 copies/μL of NGPV genome and 70.1 copies/μL of NDRV genome. Additionally, it exhibited remarkable specificity, responding exclusively to the nucleic acids of target pathogens. It also demonstrated excellent reproducibility and availability, particularly in clinical settings, with a coinfection detection rate of 13.3%, contributing to the development of NGPV- and NDRV-testing technologies. Full article

Many viruses mutate rapidly to adapt to host defenses, and for some of these viruses, the result is long-term infection in individual hosts. The work described here examines the infection and long-term maintenance of a newly identified virus, equine parvovirus-hepatitis (EqPV-H), in an individual horse. This description is possible because of a hypervariable region in the capsid gene; sequence variants were tracked by high-throughput sequencing of serum samples taken over a 16-year period. The data support the hypothesis that EqPV-H infection resulted in a sequence variant bottleneck. The continuing infection evolved into a complex viral population showing a pattern of emergence, dominance, and recession with replacement. This is the first temporal description of the capsid gene evolution of EqPV-H in a single animal. Full article

Feline parvovirus (FPV) causes feline panleukopenia, a highly contagious disease in cats, marked by severe leukopenia, biphasic fever, diarrhea, vomiting, and hemorrhagic enteritis. Recently, FPV infection in giant pandas has increased, causing diarrhea and ultimately fatal outcomes, thereby threatening their survival and reproduction. Here, we investigated the transmission of FPV in giant pandas and its interaction with cellular receptors using an FPV strain (pFPV-sc) isolated from giant panda feces. Recombinant feline transferrin receptor 1 (fTfR1) and the giant panda ortholog (gpTfR1) were expressed in non-susceptible HEK293T and HeLa cells, while viral infection levels were measured to determine the effect of gpTfR1 on pFPV-sc replication. The findings indicated that gpTfR1 overexpression in non-susceptible cells significantly enhanced pFPV-sc replication, particularly influencing the viral attachment and internalization stages. Our data further revealed early-stage colocalization between gpTfR1 expression and virus infection, suggesting that gpTfR1 facilitates early viral infection and replication. Taken together, our study provides the first evidence on the mechanism of FPV cross-species infection in giant pandas and elucidates the interaction between gpTfR1 and FPV, which establishes a theoretical basis for the development of preventive and therapeutic strategies, thereby safeguarding the health and survival of giant panda populations from FPV. Full article

While the pathogenic role of donor-specific anti-HLA antibodies (DSAs) in long-term immune-mediated injury after kidney transplantation is well established, the clinical relevance of non-donor-specific antibodies (nDSAs), also detected in transplant recipients, remains a subject of debate. This retrospective study evaluated the prognostic value of nDSAs in 92 pediatric kidney transplant recipients (89.1%, 9.8%, and 1.1% for first, second, and third transplants, respectively) at the University Hospital of Padua between January 2015 and December 2022, investigating the association between antibody development and clinical outcomes, including graft function, rejection episodes, and viral infections. Clinical, immunological, virological, and histopathological data were collected at 6, 12, and 24 months post-transplant. Antibody prevalence increased over time, with nDSAs being more frequent than DSAs at all timepoints. The combined presence of DSAs and nDSAs significantly increased the risk of ABMR (HR = 45.10; p < 0.001). Isolated nDSAs and DSAs were also associated with an increased risk of ABMR (HR = 6.43 and 12.10, respectively), suggesting a synergistic alloimmune effect. Viral infections also emerged as relevant cofactors in humoral alloimmunity. EBV viremia and intrarenal Parvovirus B19 (PVB19) infection were significantly associated with ABMR, with PVB19 also correlating with nDSA formation. In conclusion, integrated immunological and virological monitoring may support risk stratification and guide individualized post-transplant management. Larger multicenter studies are warranted to define the long-term impact of nDSAs in pediatric kidney transplantation. Full article

Background: Parvovirus B19 is the major cause of transient aplastic crisis in children with hereditary spherocytosis (HS) inhibiting erythropoiesis and leading to a severe drop in hemoglobin levels, requiring hospitalization and transfusional support. During the COVID-19 pandemic, the circulation of non-COVID respiratory viruses, such as parvovirus B19, initially declined but subsequently increased abruptly following the relaxation of containment strategies. Moreover, it remains unclear whether this has resulted in a rise in parvovirus B19-induced aplastic crises among individuals with HS. Methods: This retrospective, single-center study conducted at the Pediatric University Hospital of Bari (Italy) aims to describe the clinical characteristics and frequency of parvovirus B19-induced aplastic crises in pediatric patients with HS before and after the COVID-19 Public Health Emergency of International Concern (PHEIC, 30 January 2020–5 May 2023). The study was divided into four distinct periods: Period A: from 1 December 2018 to 31 December 2019, representing one year before the declaration of the PHEIC; Period B: from 1 June 2023 to 30 June 2024, representing one year after the cessation of the PHEIC; Period C: before 1 December 2018; Period D: from 1 January 2020 to 31 May 2023, which refers to the pandemic period. Results: A total of 30 patients (55% of the study population, n = 55) experienced a parvovirus B19-induced aplastic crisis. The frequency of these crises in Period B was significantly higher than in Period A (p < 0.0001). Conclusions: This study suggests a substantial increase in parvovirus B19-induced aplastic crises among children with HS following the COVID-19 outbreak indicating a potential impact of public health containment strategies on parvovirus B19 infection rates. Full article

Macrophage activation syndrome (MAS) is a complex, life-threatening, hyperinflammatory condition occurring as a form of hemophagocytic lymphohistiocytosis (HLH), commonly associated with several autoimmune and autoinflammatory diseases, and certain infections such as Parvovirus B19 (P19V). The onset of systemic lupus erythematosus (SLE) presenting as MAS during pregnancy is uncommon, posing significant diagnostic and therapeutic challenges. We present a case of a 30-year-old woman at the 12th gestational week with fever, arthralgia, rash, cervical lymphadenopathy, cytopenia, and elevated liver enzyme. Bone marrow biopsy revealing hemophagocytosis, elevated ferritin and triglycerides, high interleukin-2, fever and cytopenia, confirmed the diagnosis of HLH. Further evaluation revealed the diagnosis of SLE. Treatment was initiated with intravenous immunoglobulin and corticosteroids. Given the deterioration in the patient’s clinical condition, a decision was made to terminate the pregnancy. She continued in the following months to receive SLE treatment with corticosteroids, cyclophosphamide, hydroxychloroquine, and later with mycophenolate mofetil due to the development of Class IV of lupus nephritis. P19V IgM antibodies were initially positive, later seroconverted to IgG, indicating that infection may have acted as a trigger for the onset of SLE and MAS development during pregnancy. The overlapping clinical features of P19V infection, SLE, and MAS pose significant diagnostic and therapeutic challenges. Early recognition and comprehensive diagnostic evaluation are crucial for the management of these conditions, especially during pregnancy, where both maternal outcomes are at risk. Full article

In 2024, Europe experienced a significant upsurge in cases of Parvovirus B19 (B19V), the etiological agent of erythema infectiosum, also known as fifth disease. The prevalence of B19V in pregnant women, a particularly vulnerable population, holds critical clinical significance. Typically, B19V follows a well-documented seasonal pattern, with annual epidemics peaking in the spring and larger outbreaks occurring approximately every four years. B19V exhibits a tropism for erythroid precursor cells, potentially resulting in fetal anemia and, in the most severe scenarios, intrauterine demise. Severe in utero infections necessitate intrauterine erythrocyte transfusion (IUT), a highly specialized and technically demanding procedure that is exclusively performed in tertiary-level prenatal care units. This study delineates how the notable increase in B19V infections is also reflected in our prenatal diagnosis unit at Fondazione Policlinico Agostino Gemelli (FPG) IRCCS, Rome, Italy. According to our case series, since 2018, B19V has been identified as the second most common cause of fetal anemia during the study period (29%, 6 patients), yet it accounted for the majority of IUT procedures performed in 2024 (16 out of 19 cases, 84.2%). Given the rising incidence of severe intrauterine infections in recent epidemic cycles, healthcare professionals should maintain a high index of suspicion regarding the clinical manifestations of maternal B19V infection and its potential obstetric complications. Further research is imperative to evaluate the cost-effectiveness of routine screening for B19V immunity in pregnant women and to investigate the long-term neurodevelopmental and clinical outcomes of neonates affected by intrauterine B19V infection. Full article

Duck enteritis virus (DEV), goose parvovirus (GPV), and muscovy duck parvovirus (MDPV) all have similar symptoms after infection, such as severe diarrhea, which seriously affects the healthy development of the waterfowl industry. Hence, it is important to devise a rapid and precise assay for the detection of these three viruses. In this study, a TaqMan probe-based multi-quantitative polymerase chain reaction (qPCR) assay was developed and optimized. Three specific primers and probes were designed according to the conserved regions of UL6 of DEV, REP of GPV, and VP1 of MDPV, respectively. DEV demonstrated a detection limit of 11.6 copies, GPV detected a limit of 95 copies, and MDPV showcased a detection limit of 14.8 copies. The correlation coefficient is greater than 0.99, and the amplification efficiency is 89% to 93%. These results indicate that the multiplex qPCR assay has high sensitivity, specificity, and stability. Of the 215 clinical samples used in this study, 33 tested DEV positive, 25 tested GPV positive, and 24 tested MDPV positive. Overall, the assay established in the current study presents a rapid, efficient, specific, and sensitive tool for of detecting DEV, GPV, and MDPV. Full article

Parvovirus B19 (B19V) infection in healthy individuals is commonly asymptomatic or has non-specific symptoms, such as fever, headache, chills, myalgia, rash, and arthralgia. However, some groups of individuals, such as pregnant women, patients with hemolytic disorders, and immunocompromised individuals, may present severe forms of the infection, which may even lead to a negative outcome. To better understand what leads to this divergence of outcomes in different populational groups, this study sought to analyze the role of miRNAs in the pathogenesis of B19V infection. The miRNAs that potentially bind to the B19V transcripts were identified using complete genomic sequences retrieved from Genbank and miRNAs cataloged in miRbase. The results of this alignment between the seed region of the miRNAs with the B19V complete genome identified 1517 miRNAs that showed 100% identity, of which 412 are bound to NS1, VP1, and VP2 transcripts. Based on the number of total binds to the genome, these miRNAs were ranked, and the top five, miR-4799-5p, miR-5690, miR-335-3p, miR-193b-5p, and miR-6771-3p, were selected to evaluate the target genes and signaling pathways in which they act. We identified 214 common genes among the top five miRNAs, and five of these genes bind to at least two of these miRNAs. Based on WikiPathways and KEGG, these 214 genes act on 29 statistically significant pathways, and the three main pathways were selected. Our results revealed some miRNAs that may be involved in regulating B19V replication and that can act as potential biomarkers for the prognosis of infection. Full article