Viral hemorrhagic fever

Dengue viruses (DENV) are positive-stranded RNA viruses belonging to the Flaviviridae family. DENV is the causative agent of dengue, the most rapidly spreading viral disease transmitted by mosquitoes. Each year, millions of people contract the virus through bites from infected female mosquitoes of the Aedes species. In the majority of individuals, the infection is asymptomatic, and the immune system successfully manages to control virus replication within a few days. Symptomatic individuals may present with a mild fever (Dengue fever or DF) that may or may not progress to a more critical disease termed Dengue hemorrhagic fever (DHF) or the fatal Dengue shock syndrome (DSS)...

BACKGROUND OBJECTIVES: Kyasanur Forest Disease (KFD) is a tick-borne, zoonotic viral hemorrhagic fever, previously known to be endemic to the state of Karnataka, India. The first outbreak of KFD in Goa state was reported in the Sattari taluka, in North Goa in 2015. This study aimed to investigate the outbreak and report the clinical manifestations and risk factors in people diagnosed with KFD. METHODS: A mixed methods approach was used, which included a case series report and 19 in-depth interviews (IDIs) conducted with people diagnosed with KFD...

Assay validation is an essential component of disease surveillance testing, but can be problematic in settings where access to positive control material is limited and a safety risk for handlers. Here we describe a single non-infectious synthetic control that can help develop and validate the PCR based detection of the viral causes of Crimean-Congo hemorrhagic fever, Ebola virus disease, Lassa fever, Marburg virus disease and Rift Valley fever. We designed non-infectious synthetic DNA oligonucleotide sequences incorporating primer binding sites suitable for five assays, and a T7 promotor site which was used to transcribe the sequence...

Dengue virus (DENV) represents a significant global health burden, with 50% of the world's population at risk of infection, and there is an urgent need for next-generation vaccines. Virus-like particle (VLP)-based vaccines, which mimic the antigenic structure of the virus but lack the viral genome, are an attractive approach. Here, we describe a dengue VLP (DENVLP) vaccine which generates a neutralizing antibody response against all four DENV serotypes in 100% of immunized non-human primates for up to 1 year...

BACKGROUND: The human population in Guyana, located on the South American continent, is vulnerable to zoonotic diseases due to an appreciable reliance on Neotropical wildlife as a food source and for trade. An existing suboptimal health surveillance system may affect the effective monitoring of important zoonotic diseases. To effectively address this deficit, a One Health zoonotic disease prioritization workshop was conducted to identify nationally significant zoonoses. METHODS: Prioritization of zoonotic diseases was conducted for the first time in Guyana & Caribbean region using literature review, prioritization criteria and a risk prioritization tool in combination with a consultative One Health workshop...

African swine fever (ASF) is a highly contagious and lethal viral disease that causes severe hemorrhagic fever in pigs. It keeps spreading around the world, posing a severe socioeconomic risk and endangering biodiversity and domestic food security. ASF first outbroke in China in 2018, and has spread to most provinces nationwide. Genotypes I and II ASF virus (ASFV) as the etiological pathogens have been found in China. In this study, three pairs of specific primers and probes targeting the ASFV B646L gene, F1055L gene, and E183L gene were designed to detect universal, genotype I, and genotype II strains, respectively...

Purpose: To report patients who first presented with various ocular manifestations and eventually ascertained to have underlying dengue. Methods: A prospective study was conducted at multiple tertiary eye-care centers in India from 2012 to 2022. Cases reporting initially with ocular features along with fever/past history of fever over the last two weeks or with clinical features of dengue were selected. After an ophthalmological examination, patients underwent complete serological and biochemical analysis and those with reduced platelet counts were evaluated for dengue...

BACKGROUND: Dengue fever is the most common cause of viral hemorrhagic fever, with more than 400 million cases being reported annually, worldwide. Even though hepatic involvement is common, acute liver failure (ALF) is a rare complication of dengue fever. AIM: To analyze the demographic profile, symptomology, hospital course and outcomes of patients presenting with ALF secondary to dengue infection by reviewing the published case reports. METHODS: A systematic search was performed from multiple databases including PubMed, Reference Citation Analysis , Science Direct, and Google Scholar...

Intermolecular interactions of protein-protein complexes play a principal role in the process of discovering new substances used in the diagnosis and treatment of many diseases. Among such complexes of proteins, we have to mention antibodies; they interact with specific antigens of two genera of single-stranded RNA viruses belonging to the family Filoviridae-Ebolavirus and Marburgvirus; both cause rare but fatal viral hemorrhagic fever in Africa, with pandemic potential. In this research, we conduct studies aimed at the design and evaluation of antibodies targeting the filovirus glycoprotein precursor GP-1,2 to develop potential targets for the pan-filovirus easy-to-use rapid diagnostic tests...

Monoclonal antibodies (mAbs) are an important class of antiviral therapeutics. MAbs are highly selective, well tolerated, and have long in vivo half-life as well as the capacity to induce immune-mediated virus clearance. Their activities can be further enhanced by integration of their variable fragments (Fvs) into bispecific antibodies (bsAbs), affording simultaneous targeting of multiple epitopes to improve potency and breadth and/or to mitigate against viral escape by a single mutation. Here, we explore a bsAb strategy for generation of pan-ebolavirus and pan-filovirus immunotherapeutics...

Yellow fever (YF) is one of the most acute viral hemorrhagic diseases of the 18th and 19th centuries, which continues to cause severe morbidity and mortality in Africa. After 21 years of no reported cases of yellow fever in Nigeria, till 2017 where a case was confirmed in Kwara State, also in November 2018,WHO was informed of a cluster of suspected yellow fever cases and deaths in Edo state, Nigeria. The study was among all age group attending health centres in Benin City, Edo state. A total of 280 blood samples were collected from consented febrile patients and were screened for antibodies to Zika virus using rapid diagnostic test (RDT) kits...

The Ebola virus (EBOV) is a lipid-enveloped virus with a negative sense RNA genome that can cause severe and often fatal viral hemorrhagic fever. The assembly and budding of EBOV is regulated by the matrix protein, VP40, which is a peripheral protein that associates with anionic lipids at the inner leaflet of the plasma membrane. VP40 is sufficient to form virus-like particles (VLPs) from cells, which are nearly indistinguishable from authentic virions. Due to the restrictions of studying EBOV in BSL-4 facilities, VP40 has served as a surrogate in cellular studies to examine the EBOV assembly and budding process from the host cell plasma membrane...

Dengue fever (DF) is an endemic infectious tropical disease and is rapidly becoming a global problem. Dengue fever is caused by one of the four dengue virus (DENV) serotypes and is spread by the female Aedes mosquito. Clinical manifestations of DF may range from asymptomatic to life-threatening severe illness with conditions of hemorrhagic fever and shock. Early and precise diagnosis is vital to avoid mortality from DF. A different approach is required to combat DF because of the challenges with the vaccines currently available, which are nonspecific; each is capable of causing cross-reaction and disease-enhancing antibody responses against the residual serotypes...

African Swine Fever virus (ASFV), the causative agent of African swine fever, is a highly lethal hemorrhagic virus affecting domestic pigs and wild boars. The primary target cells for ASFV infection are porcine alveolar macrophages (PAMs), which are difficult to obtain and maintain in vitro, and less subjective to genetic editing. To overcome these issues and facilitate ASFV research, we obtained a subclonal cell line PK1-C5 by subcloning LLC-PK1 cells that support stable ASFV proliferation. This consequential cell line exhibited high ASFV infection levels and similar viral growth characteristics to PAMs, while also allowing high-efficiency genomic editing through transfection or lentivirus transduction of Cas9...

Despite repeated spillover transmission and their potential to cause significant morbidity and mortality in human hosts, the New World mammarenaviruses remain largely understudied. These viruses are endemic to South America, with animal reservoir hosts covering large geographic areas and whose transmission ecology and spillover potential are driven in part by land use change and agriculture that put humans in regular contact with zoonotic hosts.We compiled published studies about Guanarito virus, Junin virus, Machupo virus, Chapare virus, Sabia virus, and Lymphocytic Choriomeningitis virus to review the state of knowledge about the viral hemorrhagic fevers caused by New World mammarenaviruses...

Orthohantaviruses, transmitted primarily by rodents, cause hemorrhagic fever with renal syndrome (HFRS) in Eurasia and hantavirus pulmonary syndrome in the Americas. These viruses, with documented human-to-human transmission, exhibit a wide case-fatality rate, 0.5-40 %, depending on the virus species, and no vaccine or effective treatment for severe Orthohantavirus infections exists. In Europe, the Puumala virus (PUUV), carried by the bank vole Myodes glareolus, causes a milder form of HFRS. Despite the reliance on serology and PCR for diagnosis, the three genomic segments of Swedish wild-type PUUV have yet to be completely sequenced...

BACKGROUND: Epstein-Barr virus (EBV) is a widely disseminated herpesvirus for which antibodies have been demonstrated in over 90% of adults worldwide. After subclinical primary EBV infections, as well as after infectious mononucleosis, the virus can be shed in saliva for a prolonged period of time. AIM: Diseases and disorders that can induce EBV salivary shedding include mental disorders and sex, connective tissue disease, multiple sclerosis, systemic lupus erythematosus, malaria and HIV infection...

OBJECTIVE: The development and current state of hemorrhagic fever with renal syndrome (HFRS) over the past 40 years are analyzed in this study, along with explored and discovered the hotspots and frontiers in the field, which serve as the foundation for future investigation. METHODS: CiteSpace and VOSviewer analysis software were used to visually analyze the literature data on HFRS from 1980 to 2022, including the annual number of publications, countries and research institutions, authors, co-cited literature and keywords...

African swine fever (ASF) is a highly contagious acute hemorrhagic viral disease, with the mortality rate of up to 100 % in domestic pigs. In recent years, ASF outbreaks have caused huge economic losses in numerous countries and regions, especially in Asia. Therefore, there is a pressing need to develop safe and effective vaccines against infection of the causative pathogen, African swine fever virus (ASFV). ASFV contains a large genome composed of double-stranded DNA with a size of 170-194 kb, which encodes nearly 200 viral proteins...

Rift Valley fever is a vector-borne zoonotic disease caused by the Rift Valley fever virus (Phlebovirus genus) listed among the eight pathogens included in the Bluepoint list by the WHO. The transmission is mainly vehicled by Aedes and Culex mosquito species. Symptoms of the disease are varied and non-specific, making clinical diagnosis often challenging, especially in the early stages. Due to the difficulty in distinguishing Rift Valley fever from other viral hemorrhagic fevers, as well as many other diseases that cause fever, an early diagnosis of the infection is important to limit its spread and to provide appropriate care to patients...