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Objective: The aim of this study was to estimate the prevalence of ankylosing spondylitis (AS) in Spain.Method: This is a cross-sectional, population-based study of people aged 20 years or older in Spain. Randomly selected individuals were contacted by telephone and rheumatic disease screening was performed. If the first screening was positive, medical records were then reviewed and/or a telephone questionnaire was conducted by a rheumatologist, followed by an appointment if necessary. Cases had to fulfil the modified New York (mNY) criteria.Results: In total, 4916 individuals were included, of whom 355 had a positive screening result for AS. Of these, 11 were classified as AS. An additional individual who reported a prior diagnosis of rheumatoid arthritis had a diagnosis of AS confirmed on review of the medical records. Estimated prevalence was 0.26% (95% CI 0.14-0.49).Conclusion: EPISER2016 is the first population-based study to estimate the prevalence of AS in Spain, which has been estimated as being similar to that in other European countries. [ABSTRACT FROM AUTHOR]

Abstract Background Early interaction of dengue virus and monocyte/macrophages could be an important feature for virus dissemination after its initial entry via the mosquito vector. Since ultrastructural analysis of this interaction has not been reported, dengue type 2 (DEN2) virus-infected human monocyte cultures were studied at 1, 2, 4 and 6 hours after infection. Results Typical dengue particles and fuzzy coated viral particles were 35 to 42 nm and 74 to 85 nm respectively. Viruses were engulfed by phagocytosis and macropicnocytosis leading to huge vacuoles and phagosomes inside the monocytes. Interaction of monocytes with DEN2 virus induced apoptosis, characterized by nuclear condensation and fragmentation, cellular shrinkage, blebbing and budding phenomena and phagocytosis of apoptotic cells by neighboring monocytes. This finding was confirmed by TUNEL. Ultrastructural features associated to DEN2 virus replication were not observed. Conclusion These data suggest that clearance of the virus by monocytes and cellular death are the main features during the initial interaction of DEN2 virus and monocytes and this could be important in the rapid elimination of the virus after infection by mosquito vector.

Introduction: Some studies have noted that scores relying solely on clinical values to evaluate remission in rheumatoid arthritis (RA) may miss subclinical inflammation, which can lead to exacerbations when therapy is reduced. This opens the possibility of supporting clinical evaluation with imaging studies, one of which is ultrasound (US) evaluation, since it is an accessible tool. Therefore, we have decided to design a study to try to demonstrate the usefulness of US as a complementary measure for the decision-making process in determining the optimization of therapy in patients with RA., Materials and Methods: A multicenter, blinded, randomized, prospective study was conducted in RA patients meeting 2010 ACR/EULAR criteria for sustained remission by DAS28-ESR, with concomitant CDAI/SDAI evaluation. Patients were classified into clinical and ultrasound groups, with treatment remission based on DAS28 or grayscale synovitis/Doppler values. Ultrasound assessments included grayscale (GS) and power Doppler (PD) for joints (A) and tendons (T). A 12 months follow-up was performed, with a subset analyzed at both 18 and 24 months. Exacerbation criteria: DAS28-ESR rise > 1.2 or CDAI/SDAI > 16., Results: Across all centers, 78 patients were initially recruited, but only 46 completed the 12-month follow-up, with 28 undergoing further evaluation at 24 months. The average baseline DAS28 scores were 1.85 for the clinical group and 1.80 for the ultrasound group. During the study, 18 patients experienced disease exacerbation based on DAS28 score elevation, with 10 in the clinical group and 8 in the ultrasound group. Seven patients experienced disease exacerbation based on CDAI score elevation, all of whom were included in the clinical group. Eight patients showed disease exacerbation based on SDAI score elevation, all in the clinical group., Conclusion: We have demonstrated the utility of ultrasound when optimizing management of rheumatoid arthritis patients. In our patient cohort, ultrasound helps to reduce the number of exacerbations using the SDAI/CDAI index. We highlight the limitations of current assessment methods that rely solely on clinical evaluation, underscore the potential significance of evaluating subclinical synovitis, and emphasize the role of ultrasound as an objective tool in guiding therapy decisions. Our study offers valuable insights for optimizing treatment strategies in RA patients and improving their long-term outcomes., (© 2024. Società Italiana di Ultrasonologia in Medicina e Biologia (SIUMB).)

Background: Dengue is the most important reemerging mosquito-borne viral disease worldwide. Caused by dengue virus (DENV), a member of the genus Flavivirus in the Flaviviridae family, dengue can be asymptomatic (approx. 80% of cases) or symptomatic, ranging from a flu-like illness known as dengue fever, to a life-threatening form called severe dengue. DENV is primarily transmitted from human to human through the bite of mosquitoes of the genus Aedes; however, it is also transmissible by transfusion of blood and blood components and by solid organ transplant. Nucleic acid test (NAT) assays are considered the most appropriate approach for blood donor screening for recent DENV infections, but there is no Food and Drug Administration-approved assay for the screening of blood for DENV., Study Design and Methods: An international collaborative study was conducted to assess the suitability of reference reagent (RR) candidates for DENV Types 1 to 4 RNA for use in NAT-based assays., Results: Two sets of RR candidates were prepared for each DENV type, one liquid frozen (Set 1) and one lyophilized (Set 2). A total of 28 laboratories from 20 countries agreed to participate in the study, of which 21 submitted the results for qualitative and/or quantitative assessments., Conclusion: The World Health Organization has established the lyophilized materials as international RRs for DENV RNA with a unitage of 13,500, 69,200, 23,400, and 33,900 units/mL for DENV-1 to -4, respectively., (© 2017 AABB.)

Molecular diagnostics are increasingly used in the blood bank industry. A device that can combine simultaneous detection of multiple targets with the flexibility of inclusion of emerging pathogens is desirable for testing blood products. A highly multiplexed blood-borne pathogen panel (BBPP) using dual-label probe chemistry (TaqMan assays) was developed for simultaneous detection and discrimination of 17 viral pathogens in human plasma samples and 13 bacterial and protozoan pathogens in human blood samples on the OpenArray platform. The custom BBPP OpenArray plate was tested for specificity and analytical sensitivity with purified nucleic acids from each pathogen and with pathogen-spiked human blood and plasma samples. The results of analytical validation of known samples yielded decision trees for identification of coded samples: pathogens spiked in human plasma or whole blood. Results from coded samples demonstrated no false positives among the plasma or whole blood specimens. Samples not detected were at the lower limit of the detectible range or qualified for retesting as indeterminate. Further demonstration of the performance of the BBPP OpenArray was achieved with clinical samples from a blood donor testing organization. Ninety-five percent of virus-positive samples were correctly identified. These results show that a high-throughput OpenArray PCR platform can be expanded and adapted for higher discrimination and newly emerging agents, enabling consideration for development as a next-generation device for testing blood products., (Copyright © 2017 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.)

West Nile virus (WNV) is an arbovirus maintained in nature in a bird-mosquito enzootic cycle which can also infect other vertebrates including humans. WNV is now endemic in the United States (U.S.), causing yearly outbreaks that have resulted in an estimated total of 4-5 million human infections. Over 41,700 cases of West Nile disease, including 18,810 neuroinvasive cases and 1,765 deaths, were reported to the CDC between 1999 and 2014. In 2012, the second largest West Nile outbreak in the U.S. was reported, which caused 5,674 cases and 286 deaths. WNV continues to evolve, and three major WNV lineage I genotypes (NY99, WN02, and SW/WN03) have been described in the U.S. since introduction of the virus in 1999. We report here the WNV sequences obtained from 19 human samples acquired during the 2012 U.S. outbreak and our examination of the evolutionary dynamics in WNV isolates sequenced from 1999-2012. Maximum-likelihood and Bayesian methods were used to perform the phylogenetic analyses. Selection pressure analyses were performed with the HyPhy package using the Datamonkey web-server. Using different codon-based and branch-site selection models, we detected a number of codons subjected to positive pressure in WNV genes. Thirteen of the 19 completely sequenced isolates from 10 U.S. states were genetically similar, sharing up to 55 nucleotide mutations and 4 amino acid substitutions when compared with the prototype isolate WN-NY99. Overall, these analyses showed that following a brief contraction in 2008-2009, WNV genetic divergence in the U.S. continued to increase in 2012, and that closely related variants were found across a broad geographic range of the U.S., coincident with the second-largest WNV outbreak in U.S.

Background: Dengue is a mosquito-borne viral disease caused by the four dengue viruses (DENV-1 to 4) that can also be transmitted by blood transfusion and organ transplantation. The distribution of DENV in the components of blood from infected donors is poorly understood., Methods: We used an in-house TaqMan qRT-PCR assay to test residual samples of plasma, cellular components of whole blood (CCWB), serum and clot specimens from the same collection from blood donors who were DENV-RNA-reactive in a parallel blood safety study. To assess whether DENV RNA detected by TaqMan was associated with infectious virus, DENV infectivity in available samples was determined by culture in mosquito cells., Results: DENV RNA was detected by TaqMan in all tested blood components, albeit more consistently in the cellular components; 78.8% of CCWB, 73.3% of clots, 86.7% of sera and 41.8% of plasma samples. DENV-1 was detected in 48 plasma and 97 CCWB samples while DENV-4 was detected in 21 plasma and 31 CCWB samples. In mosquito cell cultures, 29/111 (26.1%) plasma and 32/97 (32.7%) CCWB samples were infectious. A subset of samples from 29 donors was separately analyzed to compare DENV viral loads in the available blood components. DENV viral loads did not differ significantly between components and ranged from 3-8 log10 PCR-detectable units/ml., Conclusions: DENV was present in all tested components from most donors, and viral RNA was not preferentially distributed in any of the tested components. Infectious DENV was also present in similar proportions in cultured plasma, clot and CCWB samples, indicating that these components may serve as a resource when sample sizes are limited. However, these results suggest that the sensitivity of the nucleic acid tests (NAT) for these viruses would not be improved by testing whole blood or components other than plasma.

Dengue virus (DENV), a member of the Flaviviridae family, is the most common and clinically significant arbovirus in the world and is endemic in more than 100 countries. Here, we report the complete sequences of four DENV serotypes used in the development of the CBER/FDA RNA reference reagents and WHO International Standard candidates for nucleic acid testing., (Copyright © 2016 Añez et al.)

Dengue is the most important reemerging mosquito-borne viral disease worldwide. It is caused by any of four Dengue virus types or serotypes (DENV-1 to DENV-4) and is transmitted by mosquitoes from the genus Aedes. Ecological changes have favored the geographic expansion of the vector and, since the dengue pandemic in the Asian and Pacific regions, the infection became widely distributed worldwide, reaching Brazil in 1845. The incidence of dengue in Brazil has been frequently high, and the number of cases in the country has at some point in time represented up to 60% of the dengue reported cases worldwide. This review addresses vector distribution, dengue outbreaks, circulating serotypes and genotypes, and prevention approaches being utilized in Brazil.

We report the complete sequences of two West Nile virus strains (FDA-Hu02 and NY99) used for the formulation of CBER/FDA RNA reference reagents and lot release panels for use with nucleic acid technology testing., (Copyright © 2014 Grinev et al.)

We have sequenced the complete coding region of a chikungunya virus isolate (R91064) used in the formulation of CBER/FDA RNA reference reagents for nucleic acid technology testing., (Copyright © 2014 Añez et al.)

Immunosuppressive status against infections in monocytes from neonates and elderly subjects has been reported. The interaction between dengue virus and monocytes/macrophages plays an important role during dengue disease. The aim of this study was to determine the cytokine response of monocytes from individuals with different ages after infection with dengue virus. Monocyte/macrophage cultures from neonatal, adult, and elderly subjects (n=10 each group) were incubated with all four dengue virus types (DENV-1 to -4). After 1 and 3 days of culture, cytokine concentrations (TNF-α, IL-6, and IL-1β) were determined in culture supernatants by enzyme-linked immunosorbant assay. Increased production of all studied cytokines was induced by the different viral types in monocyte/macrophage cultures regardless of their source. However, lower cytokine concentrations were found in neonatal and elderly monocytes. The relative monocyte/macrophage immunosuppressive status observed in neonates and the elderly could be relevant during dengue infection in those age groups and important in innate and adaptive immunity responses against this virus.

West Nile virus (WNV) appeared in the U.S. in 1999 and has since become endemic, with yearly summer epidemics causing tens of thousands of cases of serious disease over the past 14 years. Analysis of WNV strains isolated during the 2006-2007 epidemic seasons demonstrates that a new genetic variant had emerged coincidentally with an intense outbreak in Idaho during 2006. The isolates belonging to the new variant carry a 13 nt deletion, termed ID-Δ13, located at the variable region of the 3'UTR, and are genetically related. The analysis of deletions and insertions in the 3'UTR of two major lineages of WNV revealed the presence of conserved repeats and two indel motifs in the variable region of the 3'UTR. One human and two bird isolates from the Idaho 2006-2007 outbreaks were sequenced using Illumina technology and within-host variability was analyzed. Continued monitoring of new genetic variants is important for public health as WNV continues to evolve.

Changes in immune response during lifespan of man are well known. These changes involve decreased neonatal and elderly immune response. In addition, it has been shown a relationship between immune and oxidative mechanisms, suggesting that altered immune response could be associated to altered oxidative response. Increased expression of nitric oxide (NO) has been documented in dengue and in monocyte cultures infected with different types of dengue virus. However, there is no information about the age-dependent NO oxidative response in humans infected by dengue virus. In this study, monocyte cultures from neonatal, elderly and adult individuals (n = 10 each group) were infected with different dengue virus types (DENV- 1 to 4) and oxidative/antioxidative responses and apoptosis were measured at days 1 and 3 of culture. Increased production of NO, lipid peroxidation and enzymatic and nonenzymatic anti-oxidative responses in dengue infected monocyte cultures were observed. However, neonatal and elderly monocytes had lower values of studied parameters when compared to those in adult-derived cultures. Apoptosis was present in infected monocytes with higher values at day 3 of culture. This reduced oxidant/antioxidant response of neonatal and elderly monocytes could be relevant in the pathogenesis of dengue disease.

West Nile virus (WNV), an arbovirus maintained in a bird-mosquito enzootic cycle, can infect other vertebrates including humans. WNV was first reported in the US in 1999 where, to date, three genotypes belonging to WNV lineage I have been described (NY99, WN02, SW/WN03). We report here the WNV sequences obtained from two birds, one mosquito, and 29 selected human samples acquired during the US epidemics from 2006-2011 and our examination of the evolutionary dynamics in the open-reading frame of WNV isolates reported from 1999-2011. Maximum-likelihood and Bayesian methods were used to perform the phylogenetic analyses and selection pressure analyses were conducted with the HyPhy package. Phylogenetic analysis identified human WNV isolates within the main WNV genotypes that have circulated in the US. Within genotype SW/WN03, we have identified a cluster with strains derived from blood donors and birds from Idaho and North Dakota collected during 2006-2007, termed here MW/WN06. Using different codon-based and branch-site selection models, we detected a number of codons subjected to positive pressure in WNV genes. The mean nucleotide substitution rate for WNV isolates obtained from humans was calculated to be 5.06×10(-4) substitutions/site/year (s/s/y). The Bayesian skyline plot shows that after a period of high genetic variability following the introduction of WNV into the US, the WNV population appears to have reached genetic stability. The establishment of WNV in the US represents a unique opportunity to understand how an arbovirus adapts and evolves in a naïve environment. We describe a novel, well-supported cluster of WNV formed by strains collected from humans and birds from Idaho and North Dakota. Adequate genetic surveillance is essential to public health since new mutants could potentially affect viral pathogenesis, decrease performance of diagnostic assays, and negatively impact the efficacy of vaccines and the development of specific therapies.

Dengue is a febrile illness caused by any of the four dengue virus types (DENV-1 to -4, genus Flavivirus, family Flaviviridae) mainly transmitted by the mosquito Aedes aegypti. DENV can be transmitted by blood transfusion. Dengue has been historically present in the continental United States (US), in the state of Hawaii, and in the US insular territories in the Caribbean and the Pacific. During the second half of the 20th century, most of the cases reported in the US were imported cases brought to the country by travelers. Since 2009, cases of autochthonous dengue have been recognized in the state of Florida after 75 years of absence, followed by intensification of transmission in endemic places including the US territories of US Virgin Islands and Puerto Rico, which experienced a large dengue epidemic in 2010. The widespread distribution of dengue mosquito vectors, deficient mosquito control measures and increased frequency of DENV-infected visitors to the US coming from dengue-endemic locations or places experiencing epidemics appear to be jointly responsible for the emergence and reemergence of dengue in the US and its territories.

We describe sequences of six strains of dengue virus (DENV): three DENV-1 isolates and two DENV-4 isolates from Puerto Rico, and a DENV-1 strain from Key West, Florida, obtained from blood donors during 2010 epidemics. Phylogenetic analysis revealed that the Puerto Rico DENV-1 strains constitute a new lineage within genotype V different from those that circulated in Puerto Rico during the past two decades. The newer Puerto Rico DENV-1 strains associated with strains from the Caribbean and South America. The DENV-1 strain from Key West, Florida clustered with a strain isolated from mosquito pools collected in that area and with a number of strains from Nicaragua and Mexico circulating during 2006-2009. The Puerto Rico DENV-4 isolates of genotype II associated with strains that have circulated on the island throughout the 1980s and 1990s and with strains from the Caribbean region and Central America. Introduction and circulation of novel DENV lineages in dengue-endemic regions have the potential to increase the severity of dengue cases.

Dengue is caused by any of the four serotypes of dengue virus (DENV-1 to 4). Each serotype is genetically distant from the others, and each has been subdivided into different genotypes based on phylogenetic analysis. The study of dengue evolution in endemic regions is important since the diagnosis is often made by nucleic acid amplification tests, which depends upon recognition of the viral genome target, and natural occurring mutations can affect the performance of these assays. Here we report for the first time a detailed study of the phylogenetic relationships of DENV-2 from Central America, and report the first fully sequenced DENV-2 strain from Guatemala. Our analysis of the envelope (E) protein and of the open reading frame of strains from Central American countries, between 1999 and 2009, revealed that at least two lineages of the American/Asian genotype of DENV-2 have recently circulated in that region. In occasions the co-circulation of these lineages may have occurred and that has been suggested to play a role in the observed increased severity of clinical cases. Our time-scale analysis indicated that the most recent common ancestor for Central American DENV-2 of the American/Asian genotype existed about 19 years ago. Finally, we report positive selection in DENV-2 from Central America in codons of the genes encoding for C, E, NS2A, NS3, and NS5 proteins. Some of these identified codons are novel findings, described for the first time for any of the DENV-2 genotypes.

This study evaluated the levels of TNFalpha, IL-6, IL-1beta, nitric oxide (NO), CRP, C3 and apoptosis in 36 patients with dengue fever (DF), 34 patients with dengue haemorrhagic fever (DHF) and in virus-infected monocyte cultures. IL-6, TNFalpha, NO (nitrites) and CRP levels were increased and C3 diminished in patients with DF and DHF. IL-6, TNFalpha, CPR and C3 values were associated with disease severity (DHF). Nitrite content was incremented in DF patients. TNFalpha, NO and CRP levels were associated with secondary infection. IL-6 and CRP levels were associated with dengue virus type 4 (DENV-4) and DENV-2, respectively. Low levels of C3 were associated with DENV-2 and DENV-4 infections. Similarly, increased content of TNFalpha, IL-6 and nitrites were observed in supernatants from infected monocyte cultures. IL-6 was associated with DENV-4 infection. The different virus serotypes induced apoptosis in monocyte cultures. Dengue infection did not induce elevated IL-1beta production, either in patients or in infected cultures. These results suggest that TNFalpha, IL-6, NO and CRP are involved in dengue infection and that monocytes could be an important source of cytokine and NO production.

Three dengue virus type 4 (DENV-4) vaccine candidates containing deletions in the 3' noncoding region were prepared by passage in DBS-FRhL-2 (FRhL) cells. Unexpectedly, these vaccine candidates and parental DENV-4 similarly passaged in the same cells failed to elicit either viremia or a virus-neutralizing antibody response. Consensus sequence analysis revealed that each of the three viruses, as well as the parental DENV-4 when passaged in FRhL cells, rapidly acquired a single Glu327-Gly substitution in domain III (DIII) of the envelope protein (E). These variants appear to have accumulated in response to growth adaptation to FRhL cells as shown by growth analysis, and the mutation was not detected in the virus following passage in C6/36 cells, primary African green monkey kidney cells, or Vero cells. The Glu327-Gly substitution was predicted by molecular modeling to increase the net positive charge on the surface of E. The Glu(327)-Gly variant of the full-length DENV-4 selected after three passages in FRhL cells showed increased affinity for heparan sulfate compared to the unpassaged DENV-4, as measured by heparin binding and infectivity inhibition assays. Evidence indicates that the Glu327-Gly mutation in DIII of the DENV-4 E protein was responsible for reduced infectivity and immunogenicity in rhesus monkeys. Our results point out the importance of cell substrates for vaccine preparation since the virus may change during passages in certain cells through adaptive selection, and such mutations may affect cell tropism, virulence, and vaccine efficacy.

Clinical features of Dengue are very variable due to multiple alterations induced by the virus in the organism. Increased levels of transaminases similar to those produced by the Hepatitis virus have been reported in patients with Dengue from hiperendemic zones in Asia. The objectives of this study were to determine alterations in the liver tests in patients with Dengue and to relate them to the disease, clinically and serologically. Clinical history, hemathological tests serum transaminases (ALT y AST) and bilirubin assays were performed in 62 patients with clinical and serological diagnosis of Dengue. According to clinical features 38.7% of the patients with classical (CD) and hemorrhagic (DHF) forms of Dengue reffered abdominal pain and 2 patients with DHF had ictericia and hepatomegaly. Laboratory test findings showed leucopenia in 72.5% in both forms of Dengue and of patients with DHF severe thrombocytopenia (< 50.000 platelets x mm3), long PT and PPT in 70.9%, 23.0% and 42.3%, respectively. Transaminase values five fold higher than the normal values (p < 0.005) were observed in 36.8% and 74.4% of patients with CD and DHF respectively; AST was predominant in both groups. Our results suggest liver damage during the course of Dengue. A differential diagnosis has to be done between the hepatic involvement of Dengue cases and others viral diseases with hepatic disfunctions.

Little information is available about Flavivirus infection in amerindian populations in western Venezuela. On this account the activity and seroprevalence of these viruses were determined and the hypothesis concerning the existence of a sylvatic cycle, conditioning the infection transmission of these viruses in indigenous populations, was studied. For this, blood samples from Yukpas (n=144) and Barí (n=110) communities were collected, 35 (Yukpas=25 and Barí=10) of which were processed for viral isolation followed by RT-PCR. The anti-Flavivirus IgG antibodies were determined by ELISA. The results did not show active Dengue cases and the seroprevalence of anti-Flavivirus IgG in the Yukpa population was significantly higher (p < 0.0001) than in the Barí population (43.1% vs. 6.4%). The present study has determined the presence of Flavivirus immunity in Yukpa and Barí populations. These results show a higher prevalence at the former than in the Barí population, which suggests circulation of Flavivirus, mainly in the Yukpa communities, being scarce and sporadic in Barí villages. However, in the indigenous populations studied, the causes or factors that determine the off set of Flavivirus infections in these zones could vary. The detected prevalence between both communities may be due to differences in the structure settlements and social habits. No evidences were found to support the presence of a sylvatic cycle in the Flavivirus transmission, specially of Dengue, in this population.

Nitric oxide (NO) has been involved in several infectious diseases. Virus dengue is capable of inducing increased levels of NO when cocultured with human Kupffer and spleen cells. However, no reports describe the levels of NO in patients with dengue infection. Increased levels of NO were found in patients with the classic form of the disease; however, in the hemorrhagic form of the disease, similar levels to those of healthy controls were found. In vitro studies showed no increased levels of NO when human platelets were incubated with the virus. Increased NO in classical dengue could be important in the evolution from the nonhemorrhagic to the hemorrhagic forms of dengue.