In Vitro Cleavage Assay to Characterize DENV NS2B3 Antagonism of cGAS.

cGAS is a key cytosolic dsDNA receptor that senses viral infection and elicits interferon production through the cGAS-cGAMP-STING axis. cGAS is activated by dsDNA from viral and bacterial origins as well as dsDNA leaked from damaged mitochondria and nucleus. Eventually, cGAS activation launches the cell into an antiviral state to restrict the replication of both DNA and RNA viruses. Throughout the long co-evolution, viruses devise many strategies to evade cGAS detection or suppress cGAS activation. We recently reported that the Dengue virus protease NS2B3 proteolytically cleaves human cGAS in its N-terminal region, effectively reducing cGAS binding to DNA and consequent production of the second messenger cGAMP. Several other RNA viruses likely adopt the cleavage strategy. Here, we describe a protocol for the purification of recombinant human cGAS and Dengue NS2B3 protease, as well as the in vitro cleavage assay.

Telas de proteção em habitações para prevenção de doenças transmitidas por mosquitos: sinopse baseada em evidências

Contexto e objetivo: A transmissão de doenças por mosquitos afeta a população e a economia de todo o mundo. Há um número considerável de doenças que podem ser transmitidas por mosquitos, com destaque para a malária e a dengue, endêmica em regiões tropicais. Evidentemente, medidas preventivas são imprescindíveis para a redução da transmissão. Avaliar as evidências de efetividade das telas de proteção com e sem inseticida para prevenção de doenças transmitidas por mosquitos. Métodos: Trata-se de sinopse baseada em evidências. Procedeu-se à busca por estudos que associavam o uso de telas de proteção contra mosquitos à redução do contágio de doenças transmitidas por mosquitos em três bases de dados: PubMed (1966-2024), Portal BVS (1982-2024) e Epistemonikos (2024) e também no metabuscador de evidências TRIP DATABASE (2024). O desfecho de análise envolveu a efetividade das telas de proteção na redução de doenças transmitidas por mosquitos. Resultados: Foram encontradas 307 citações. Seis estudos (1 revisão sistemática e 5 ensaios clínicos) foram incluídos. Discussão: A maioria dos estudos envolveu a colocação de telas de proteção com inseticida, havendo evidência de alta certeza para redução de mortalidade por malária e redução na entrada de mosquitos nas habitações, mesmo com redes sem inseticida. Conclusões: Embora não haja robustez na evidência da efetividade das telas de proteção sem inseticidas contra mosquitos transmissores de doenças, o que demanda a necessidade de realização de novos estudos prospectivos, parece lícita e benéfica a utilização de telas de proteção em regiões endêmicas para doenças transmitidas por esses vetores.

Circulating dengue virus serotypes, demographics, and epidemiology in the 2023 dengue outbreak in Chittagong, Bangladesh.

Dengue is a serious epidemic for Bangladesh affecting thousands of lives. This study aimed to identify and determine the prevalence of the circulating variants of dengue virus (DENV) and their association with demographics and clinical manifestations among the dengue-infected patients. A total of 711 participants with NS1 antigen positivity were enrolled, followed by viral RNA extraction from the collected blood samples and a multiplex real-time reverse transcription-polymerase chain reaction (RT-PCR) assay to determine the dengue virus serotypes. Of 711 dengue-infected patients, 503 (70.7%) were male. Among different age groups, most of the patients were 21-30 years old (n = 255, 35.9%). The DENV2 (n = 483, 67.9%) serotype was more prevalent than the DENV3 (n = 144, 20.3%) and DENV1 (n = 84, 11.8%). The duration of fever was highest in the DENV-1 patients (4.79 ± 1.84 days) in contrast to DENV-3 (4.48 ± 1.68 days) and DENV-2 (4.33 ± 1.45 days) (P = 0.039). Importantly, five highly populated areas were identified as dengue hotspots in Chittagong metropolitan city. Our results provide crucial insights into the patterns of dengue virus transmission and severity among southern Bangladeshi population, thereby aiding in the development of targeted public health interventions and management strategies to combat future outbreaks.

Effectiveness and safety of the tetravalent TAK-003 dengue vaccine: a systematic review.

In Argentina, the dengue virus has experienced an increase in recent years. This study aims to conduct a systematic review to evaluate the effectiveness and safety of the TAK-003 tetravalent dengue vaccine in this context. A systematic review of randomized controlled trials comparing the effectiveness and safety of the vaccine with placebo in the general population was conducted. The search was carried out in Epistemonikos, and two researchers independently assessed the studies. Risk of bias was evaluated using the Cochrane Rob 2 tool. A meta-analysis of the results was performed, and the certainty of evidence was assessed using the GRADE methodology. We concluded, with high certainty of evidence, that the tetravalent dengue vaccine reduces severe infections (RR 0.17, 95% CI 0.12 to 0.24) and infections by the dengue virus (RR 0.40, 95% CI 0.36 to 0.45) in a population ≤17 years. The vaccine may not increase the risk of serious adverse events, although it is important to note the low certainty of evidence (RR 1.04, 95% CI: 0.69-1.55). The use of the tetravalent dengue vaccine decreases the risk of severe and non-severe dengue infections in this population. However, there is low certainty of evidence regarding the vaccine's safety. The decision to vaccinate should consider the magnitude of benefits relative to the risk of infection.

En Argentina, el virus del dengue ha experimentado un aumento en los últimos años. Este estudio se propone realizar una revisión sistemática para evaluar la efectividad y seguridad de la vacuna TAK-003 tetravalente contra el dengue en este contexto. Se llevó a cabo una revisión sistemática de ensayos clínicos controlados aleatorizados que comparaban la efectividad y seguridad de la vacuna con placebo en la población general. La búsqueda se efectuó en Epistemonikos y dos investigadores evaluaron los estudios de manera independiente. El riesgo de sesgo se evaluó con la herramienta Rob 2 de Cochrane. Se realizó un metaanálisis de los resultados y la certeza en la evidencia se evaluó mediante la metodología GRADE. Concluimos, con alta certeza de evidencia, que la vacuna tetravalente contra el dengue reduce las infecciones graves (RR 0.17, IC 95% 0.12 a 0.24) e infecciones por el virus del dengue (RR 0.40, IC 95% 0.36 a 0.45) en una población de ≤17 años. La vacuna podría no incrementar el riesgo de eventos adversos serios, aunque es importante destacar la baja certeza de evidencia (RR 1.04, IC 95%: 0.69-1.55). La aplicación de la vacuna tetravalente contra el dengue disminuye el riesgo de infecciones graves y no graves por el dengue en esta población. No obstante, existe baja certeza en la evidencia en relación a la seguridad de la vacuna. La decisión de la vacunación debe considerar la magnitud de los beneficios en función del riesgo de infección.

[Considerations for the acute management of stroke during the dengue epidemic]. / Consideraciones para el manejo agudo del accidente cerebrovascular durante la epidemia de dengue.

Stroke is the leading cause of disability and the third leading cause of mortality in our country. Argentina and the Region of the Americas are going through the worst epidemic outbreak of dengue on record with significant demand on the health system. Dengue could increase the risk of stroke and given the time-dependent nature of the management of this disease to reduce morbidity and mortality and the potential considerations to be taken into account in patients with dengue, we present a focused review of the literature with points of uncertainty and aspects to be considered in the stroke code considering the clinical characteristics and high demand of the health system caused by the dengue fever. A call is also made to generate evidence on the management of stroke in patients with dengue.

El accidente cerebrovascular (ACV) es la principal causa de discapacidad y la tercera causa de mortalidad en nuestro país. Argentina y la región de las Américas se encuentran atravesando el peor brote epidémico de dengue del que se tenga registro, con una importante demanda en el sistema de salud. El dengue podría aumentar el riesgo de ACV y dada la naturaleza tiempo dependiente del manejo de esta enfermedad para reducir la morbilidad y mortalidad, y las potenciales consideraciones a tener en cuenta en los pacientes con dengue, se presenta una revisión breve de la literatura con puntos de incertidumbre y aspectos a considerar en el protocolo o código de ACV, considerando las características clínicas y alta demanda del sistema de salud provocada por el dengue. Se realiza también un llamado a generar evidencia sobre el manejo del ACV en pacientes con dengue.

[Observations on the dengue vaccination strategy in Argentina]. / Observaciones sobre la estrategia de vacunación contra el dengue en Argentina.

A new dengue vaccine has recently been licensed in Argentina, with the Argentine government planning to acquire it in order to develop a vaccination strategy. As the disease is gradually following a path to endemicity in some regions of the country, the incorporation of these vaccines will have the potential to tackle the growing incidence of the disease and to reduce the disease burden. However, the establishment of the vaccination programme may also be susceptible of threats related to the epidemiological shift of the disease. Selecting a specific age group for the vaccine may result in a change in the peak incidence to other age groups more susceptible to severe forms of the disease, such as children or the elderly. Furthermore, the perception of protection following vaccine introduction in one jurisdiction may reduce adherence to vector control activities, increasing the risk of virus introduction and transmission in other areas not prioritised by the vaccination strategy, and the risk of other arboviral diseases such as Zika and chikungunya fever. These and other potential limitations to be considered prior to the implementation of vaccination programmes are discussed in this article, with a series of recommendations on how to address these concerns. These recommendations can help decision makers and public health practitioners at this early stage of the vaccination programme development.

Una nueva vacuna contra el dengue ha sido recientemente aprobada en Argentina, y el gobierno argentino se encuentra planificando su adquisición para desarrollar una estrategia de vacunación. Mientras la enfermedad se está dirigiendo gradualmente hacia la endemicidad en algunas regiones del país, la incorporación de estas vacunas tendrá el potencial de atacar la creciente incidencia de la enfermedad y de reducir su carga. Sin embargo, el establecimiento de un programa de vacunación puede también ser susceptible de amenazas relacionadas con el cambio epidemiológico de la enfermedad. La selección de un grupo de edad específico para la vacunación puede resultar en un cambio en el pico de la incidencia hacia otros grupos de edad más vulnerables a las formas graves de la enfermedad, como los niños o los ancianos. Además, la percepción de protección luego de la introducción de la vacuna en una jurisdicción puede reducir la adherencia a las actividades de control del vector, incrementando el riesgo de introducción y transmisión del virus en otras áreas no priorizadas por la estrategia de vacunación, y aumentando el riesgo de otras arbovirosis como las fiebres Zika y chikungunya. Estas y otras potenciales limitaciones para ser consideradas antes de la implementación de los programas de vacunación son discutidas en este artículo, en conjunto con una serie de recomendaciones sobre cómo abordar estas preocupaciones. Estas recomendaciones pueden resultar de utilidad para los tomadores de decisión y actores sanitarios, en esta etapa temprana del desarrollo de un programa de vacunación.

[Dengue encephalitis in Argentina]. / Encefalitis por dengue en Argentina.

Dengue virus is an endemic virus in Argentina that, although it was initially considered to be non-neurotropic, it is currently recognized to be neuroinvasive; thus conditioning a prevalence of neurological manifestations of up to 15% among patients. Even being considered severe symptoms, there is underdiagnoses of dengue encephalitis due to its varied clinical presentation. Neurological manifestations of dengue encephalitis can range from fever and headache to altered levels of consciousness and seizures. Although the cerebrospinal fluid may be normal in up to a third of cases, it usually presents increased protein concentration and pleocytosis. Regarding neuroimaging methods, the findings are usually varied and nonspecific, and can even be normal in up to 40-50% of cases. We present three cases of dengue encephalitis diagnosed in a university hospital in Buenos Aires, Argentina, where the clinical presentation varied from temporal-spatial disorientation to refractory convulsive status with different presentations in the cerebrospinal fluid but all with positive PCR for dengue in it and with normal neuroimaging.

El virus dengue es un virus endémico en Argentina que, si bien inicialmente se consideró que no era neurotrópico, actualmente se reconoce que tiene neuroinvasión, condicionando así una prevalencia de manifestaciones neurológicas de hasta el 15% entre los enfermos. Aun siendo considerados síntomas de gravedad, existe subdiagnóstico de encefalitis por dengue debido a su variada forma de presentación clínica. Las manifestaciones neurológicas de la encefalitis por dengue pueden abarcar desde fiebre y cefalea hasta alteraciones del nivel de conciencia y convulsiones. Si bien el líquido cefalorraquídeo (LCR) puede hallarse normal en hasta un tercio de los casos, lo habitual es que presente aumento de concentración de proteínas y pleocitosis. En cuanto a los métodos de neuroimagen, los hallazgos suelen ser variados e inespecíficos, e incluso pueden ser normales hasta en 40-50% de los casos. Se presentan 3 casos de encefalitis por dengue diagnosticados en un hospital universitario de Buenos Aires, Argentina, en donde la presentación clínica varió desde desorientación témporo-espacial hasta estatus convulsivo refractario con diferentes presentaciones en el LCR pero todos con PCR positivo para dengue y con neuroimágenes sin alteraciones.

Zika virus capsid protein closed structure modulates binding to host lipid systems.

Zika virus (ZIKV), a mosquito-borne Flavivirus of international concern, causes congenital microcephaly in newborns and Guillain-Barré syndrome in adults. ZIKV capsid (C) protein, one of three key structural proteins, is essential for viral assembly and encapsidation. In dengue virus, a closely related flavivirus, the homologous C protein interacts with host lipid systems, namely intracellular lipid droplets, for successful viral replication. Here, we investigate ZIKV C interaction with host lipid systems, showing that it binds host lipid droplets but, contrary to expected, in an unspecific manner. Contrasting with other flaviviruses, ZIKV C also does not bind very-low density-lipoproteins. Comparing with other Flavivirus, capsid proteins show that ZIKV C structure is particularly thermostable and seems to be locked into an auto-inhibitory conformation due to a disordered N-terminal, hence blocking specific interactions and supporting the experimental differences observed. Such distinct structural features must be considered when targeting capsid proteins in drug development.

Regional molecular epidemiology of dengue and the potential optimization of its control through the use of vaccines. Report of the Arbovirus Committee of the Latin American Society of Pediatric Infectious Diseases, SLIPE.

INTRODUCTION: Dengue disease represents a large and growing global threat to public health, accounting for a significant burden to health systems of endemic countries. The World Health Organization's (WHO) Strategic Advisory Group of Experts (SAGE) and the European Medicines Agency (EMA) currently recommend the use of TAK-003 dengue vaccine in high dengue burden and transmission settings for countries considering vaccination as part of their integrated management strategy for prevention and control of Dengue. AREAS COVERED: This paper describes the main conclusions of a workshop held by the Arbovirus Committee of the Latin American Society of Pediatric Infectious Diseases (SLIPE) in November 2023, to generate consensus recommendations on the introduction of this new vaccine in the region. Considerations were made regarding the molecular epidemiology of dengue infection in the Americas and the need for more precise phylogenetic classification and correlation with clinical outcome and disease severity. EXPERT OPINION: Introduction of dengue vaccine should be considered as an strategy for health entities in the region, with participation of social sectors, scientific societies, and ministries of health that could be able to create a successful vaccination program.

Global risk of dengue outbreaks and the impact of El Niño events.

BACKGROUND: Dengue fever is an arboviral disease caused by the dengue virus (DENV). Its geographical distribution and health burden have been steadily increasing through tropical and subtropical climates in recent decades. METHODS: We developed a temperature- and precipitation-dependent mechanistic model for the global risk of dengue fever outbreaks using the basic reproduction number (R0) as the metric of disease transmission risk. We used our model to evaluate the global risk of dengue outbreaks from 1950 to 2020 and to investigate the impact of annual seasons and El Niño events. RESULTS: We showed that the global annual risk of dengue outbreaks has steadily increased during the last four decades. Highest R0 values were observed in South America, Southeast Asia, and the Equatorial region of Africa year-round with large seasonal variations occurring in other regions. El Niño was shown to be positively correlated with the global risk of dengue outbreaks with a correlation of 0.52. However, the impact of El Niño on dengue R0 was shown to vary across geographical regions and between El Niño events. CONCLUSIONS: Strong El Niño events may increase the risk of dengue outbreaks across the globe. The onset of these events may trigger a surge of control efforts to minimize risk of dengue outbreaks.

Commercial Enzyme-Linked Immunosorbent Assay Kit Is Useful for Detection of Recombinant and Secretory Nonstructural-1 Protein Antigen of Dengue Virus.

Background: Dengue is a mosquito-borne tropical disease, caused by the Dengue virus (DENV). It has become a severe problem and is a rising threat to public health. In this study, we have evaluated commercial Merilisa i Dengue NS1 Antigen kit (Meril LifeSciences India Pvt. Ltd.) to detect recombinant dengue virus 2 NS1 antigen (rDNS1Ag) and secreted forms of NS1 antigen (sDNS1Ag). Methods: To determine the detection limit of the kit, 100 nanogram (ng) to 0.001 ng rDNS1Ag was tested. The sensitivity and specificity of the kit was determined using recombinant NS1 antigens of all serotypes of DENV and other flaviviruses. For testing sDNS1Ag, the culture supernatant of the Vero cell lines infected with DENV-2 was tested. Further, a spiking experiment was carried out to check the sensitivity of the kit to detect rDNS1Ag in the pools of Aedes aegypti mosquitoes. Results: It was observed that the kit can detect the rDNS1Ag at 1 ng concentration. The kit was sensitive to detect NS1 antigen of DENV-1, DENV-2 and DENV-3 serotypes and specific for detection of only DNS1Ag as it did not cross-react with NS1 antigen of flaviviruses. The kit was sensitive to detect rDNS1Ag in the mosquito pools as well. In addition, the kit was able to detect the sDNS1Ag in Vero cell culture supernatant. Conclusions: Overall, we observed that the Merilisa i Dengue NS1 Ag kit is sensitive and specific for the detection of DNS1Ag both in recombinant and secretory forms.

Post-dengue mucormycosis- a novel entity or COVID-19 associated in disguise?

Dengue is a disease endemic to tropical countries such as India. In the past two years, cases of COVID-19 associated Mucormycosis have become a commonly encountered phenomenon. However, cases of dengue associated Mucormycosis have not found a significant mention in the literature yet. We, therefore, report two such cases in which Mucormycosis developed after recovery from Dengue fever and try to dig into the possible mechanism behind such an occurrence.

Cytokine Storm Syndrome Associated with Hemorrhagic Fever and Other Viruses.

A wide variety of infections can trigger cytokine storm syndromes including those caused by bacteria, viruses, fungi and parasites. The most frequent viral trigger is Epstein-.Barr virus which is covered in Chapter 16. CSS associated with COVID-19 is also discussed separately (Chapter 22). This chapter will focus on other viruses including the hemorrhagic fever viruses, influenza, parainfluenza, adenovirus, parvovirus, hepatitis viruses, measles, mumps, rubella, enterovirus, parechovirus, rotavirus, human metapneumovirus and human T-lymphotropic virus. The published literature consists of many single case reports and moderate-sized case series reporting CSS, in most circumstances meeting the 2004 diagnostic criteria for hemophagocytic lymphohistiocytosis (HLH). There is no published clinical trial evidence specifically for management of HLH associated with these viruses. In some situations, patients received supportive therapy and blood product transfusions only but in most cases, they were treated with one or more of intravenous corticosteroids, intravenous immunoglobulin and/or etoposide. These were successful in many patients although in significant numbers progression of infection to CSS was associated with mortality.

Rare Instances of Culture-Positive Dengue-Related Panophthalmitis: A Case Series.

Panophthalmitis is an exceptionally rare but severe ocular complication of dengue fever, which is currently a significant health concern in parts of India. It is a purulent inflammation encompassing all structures of the globe (choroid, retina, vitreous fluid, aqueous fluid, cornea, sclera, and conjunctiva) along with surrounding orbital and periorbital structures. This case series highlights the occurrence of panophthalmitis in three patients diagnosed with dengue, who were aged 35, 50, and 75 years. Despite aggressive medical management, including intravenous antibiotics, the patients were ultimately scheduled for evisceration surgery due to the extreme severity of the condition. Healthcare providers must be aware of the potential ocular complications in dengue cases and diagnose them promptly. While ocular involvement in dengue is rare, this case series emphasizes the importance of recognizing ocular manifestations in dengue patients, as early diagnosis and prompt intervention can prevent severe complications.

Contribution of imaging in the diagnosis of three neglected diseases in the Southern Cone: Leishmaniasis, Dengue, and Chikungunya.

Neglected diseases such as leishmaniasis, dengue, and chikungunya pose significant challenges to public health due to their high prevalence and wide geographic distribution in the Southern Cone region. These diseases are transmitted through insect bites, which serve as natural reservoirs. While their imaging findings are not always conclusive, they can play a crucial role in the diagnosis and monitoring. This review provides a concise overview of the clinical manifestations, epidemiological context, and imaging findings associated with these diseases. The primary purpose of this article is to share our experience and offer valuable insights into the use of imaging for the diagnosis and monitoring of patients suspected to have these diseases.

Differential Proteomic Profiling at Different Phases of Dengue Infection: An Intricate Insight from Proteins to Pathogenesis.

Dengue fever is a rapidly emerging tropical disease and an important cause of morbidity in its severe form worldwide. A wide spectrum of the pathophysiology is associated with the transition of dengue fever to severe dengue, which is driven by the host immune response and might reflect in patients' proteome profile. This study aims to analyze the plasma from different phases of dengue-infected patients at two time points. A mass-spectrometry-based proteomic approach was utilized to understand the involvement of probable candidate proteins toward developing a more severe, hemorrhagic form of dengue fever. Dengue-infected hospital-admitted patients with <5 days of fever were included in this study. Patient samples from the acute phase were screened for the presence of NS1 antigen using ELISA and subjected to molecular serotyping. Dengue molecular serotype-confirmed patient samples, pairwise from acute and critical phases with healthy control were subjected to qualitative and quantitative proteomic analysis, and then pathway analysis was performed. The protein-protein interaction network between the dengue virus and host proteins was depicted in the search for proteins associated with severe dengue pathophysiology. An array of apolipoprotein, cytokines, and endothelial proteins in association with virus replication and endothelial dysfunction were validated as biomolecules involved in severe dengue pathophysiology.

Beyond the norm: a rare presentation of dengue fever resulting in combined rhabdomyolysis and TMA-induced AKI-a case report.

Dengue is the most prevalent arthropod-transmitted infection worldwide. Its clinical presentation ranges from subclinical illness to multi-organ failure. Acute kidney injury (AKI) is one of its complications, having a number of different pathogeneses. The patient herein described presented with thrombotic microangiopathy (TMA) and rhabdomyolysis, a combination never previously reported in the literature. He was diagnosed with dengue at a primary care hospital, after which he was referred to us with fever and oliguria. His blood workup and kidney biopsy revealed a picture of combined TMA and rhabdomyolysis-induced AKI. He developed sepsis after his first session of plasmapheresis, that had to be discontinued and he was further managed with dialysis and supportive care. The patient showed remarkable recovery, regaining kidney function after one month.

Dengue virus type 3 infection in a traveler returning from Costa Rica to Japan in 2023.

The number of dengue cases has increased dramatically in recent years. In Latin America, the number of cases and deaths in 2023 was the highest ever recorded. We report on a patient who had been infected with dengue virus during his stay in Costa Rica in September 2023, and developed the disease after returning to Japan. Plasma obtained from the patient was used for diagnosis and dengue virus serotyping by real-time PCR. The nucleotide sequence of the envelope region of dengue virus was then determined by the direct sequencing method, and this sequence was used for phylogenetic analyses. The patient was found to be infected with dengue virus type 3 genotype III. The sequence from the present case was more homologous with sequences registered in Florida, USA, associated with travel to Cuba in 2022 than with sequences registered in Costa Rica 10 years ago. The Pan American Health Organization reported that only dengue virus type 1 and 2 cases were reported in Costa Rica in 2019-2021, whereas dengue virus type 3 and 4 cases started being reported in 2022. In 2023, the reported numbers of cases with dengue virus types 3 and 4 exceeded those of dengue virus types 1 and 2. In addition, regional differences in endemic strains have been observed in Costa Rica. Our findings suggest that the dengue virus type 3 that infected the patient was more likely an influx of a strain that had been circulating in Caribbean countries such as Cuba in recent years, rather than a re-emergence of an indigenous virus in Costa Rica. The serotypes of dengue virus prevalent in Costa Rica have been changing since 2022. All four serotypes were prevalent in 2023, with a particularly sharp increase in the number of cases of dengue virus types 3 and 4. Future monitoring and surveillance are essential because changes in endemic serotypes can cause antibody-dependent enhancement, which can lead to severe dengue disease presentations.

Surveillance of Erythrovirus B19 (B19V) in patients with acute febrile illness suspected of arboviruses in Mato Grosso do Sul state, Brazil.

Introduction: Human Erythrovirus (parvovirus) B19 infection can produce symptoms similar to those produced by Dengue, Chikungunya, and Zika viruses, making clinical diagnosis difficult. The importance of erythrovirus B19 in human pathology has been increased and reported in numerous studies published globally. Methods: The B19V infection was investigated by real-time PCR in sera samples from patients with signs and symptoms related to classic arboviral symptoms. This study was conducted to provide information on the genetic diversity of Human Erythrovirus B19 (B19V) circulating in the state of Mato Grosso do Sul, Midwest region of Brazil, from 2017 to 2022. A total of 773 sera samples of patients with negative diagnostic results for Dengue, Chikungunya, and Zika, during the study period were analyzed. Results: Erythrovirus DNA was found in 10.6% (82/773) of patients, among them 10 were pregnant women. Four samples were completely sequenced, and the other five partially, to genotype by phylogenetic reconstruction. All samples belong to worldwide dispersed genotype 1, subgenotype 1a. Discussion: The findings of the study demonstrate the importance of including B19V in differential laboratory diagnosis for epidemiological purposes and appropriate patient management. The diagnosis for B19V should be performed, particularly among pregnant women, immunocompromised patients, and individuals with hemolytic diseases, given that the infection is more severe in these cases.

Effects of Recent Prior Dengue Infection on Risk and Severity of Subsequent SARS-CoV-2 Infection: A Retrospective Cohort Study.

Background and Aims: Elucidating whether prior dengue potentially confers cross-protection against COVID-19 is of public health importance in tropical countries at risk of overlapping dengue and COVID-19 epidemics. However, studies to date have yielded conflicting results. We aimed to assess effects of recent prior dengue infection on risk and severity of subsequent SARS-CoV-2 infection among adult Singaporeans. Methods: A retrospective cohort study including all adult Singaporeans aged ≥18 years was conducted from 1 July 2021 through 31 October 2022, when a dengue outbreak driven by the DENV3 serotype preceded subsequent waves of SARS-CoV-2 Delta/Omicron transmission in Singapore. SARS-CoV-2 and dengue infection status were classified using national registries. Cox regression models adjusted for demographics, COVID-19 vaccination status, comorbidity, and socioeconomic-status were used to assess risks and severity (hospitalization, severe illness) of SARS-CoV-2 infection occurring after previous recorded dengue infection. Results: A total of 3 366 399 individuals were included, contributing 1 399 696 530 person-days of observation. A total of 13 434 dengue infections and 1 253 520 subsequent SARS-CoV-2 infections were recorded; with an average of 94.7 days (standard deviation = 83.8) between dengue infection and SARS-CoV-2 infection. Preceding dengue infection was associated with a modest increase in risk of subsequent SARS-CoV-2 infection (adjusted hazards ratio [aHR] = 1.13; 95% confidence interval [CI], 1.08-1.17), and significantly elevated risk of subsequent COVID-19 hospitalization (aHR = 3.25; 95% CI, 2.78-3.82) and severe COVID-19 (aHR = 3.39; 95% CI, 2.29-5.03). Conclusions: Increased risk of SARS-CoV-2 infection and adverse COVID-19 outcomes were observed following preceding dengue infection in a national population-based cohort of adult Singaporeans. This observation is of significance in tropical countries with overlapping dengue and COVID-19 outbreaks.