Clinical and laboratory findings of a sandfly fever Turkey Virus outbreak in Ankara

Comprehensive Cross-Sectional Evaluation of Human Sandfly-Borne Phlebovirus Exposure in an Endemic Region

Sandfly-borne phleboviruses are endemic in countries around the Mediterranean Basin and pose a significant health threat for populations, with symptoms spanning from febrile diseases to central nervous system involvement. We carried out a comprehensive cross-sectional screening via microneutralization (MN) assays for a quantitative assessment of neutralizing antibodies (NAs) to seven phleboviruses representing three distinct serocomplexes, using samples previously screened via immunofluorescence assays (IFAs) in Turkey, an endemic region with various phleboviruses in circulation. We detected NAs to three phleboviruses: Toscana virus (TOSV), sandfly fever Naples virus (SFNV), and sandfly fever Sicilian virus (SFSV), while assays utilizing Adana virus, Punique virus, Massilia virus, and Zerdali virus remained negative. The most frequently observed virus exposure was due to TOSV, with a total prevalence of 22.6%, followed by SFNV (15.3%) and SFSV (12.1%). For each virus, IFA reactivity was significantly associated with NA detection, and further correlated with NA titers. TOSV and SFSV seroreactivities were co-detected, suggesting exposure to multiple pathogenic viruses presumably due to shared sandfly vectors. In 9.6% of the samples, multiple virus exposure was documented. In conclusion, our findings demonstrate widespread exposure to distinct pathogenic phleboviruses, for which diagnostic testing and serological screening efforts should be directed.

Sandfly Fever Viruses Attenuate the Type I Interferon Response by Targeting the Phosphorylation of JAK-STAT Components

Sandfly fever viruses are emerging Phleboviruses typically causing mild febrile illness. Some strains, however, can cause severe and occasionally fatal neuro-invasive disease. Like most viruses, Phleboviruses have devised various strategies to inhibit the type I interferon (IFN) response to support a productive infection. Still, most of the strategies identified so far focus on inhibiting the sensing arm of the IFN response. In contrast, the effect of sandfly virus infection on signaling from the IFN receptor is less characterized. Therefore, we tested the effect of sandfly fever virus Naples (SFNV) and Sicily (SFSV) infection on IFN signaling. We found that infection with either of these viruses inhibits signaling from the IFN receptor by inhibiting STAT1 phosphorylation and nuclear localization. We show that the viral nonstructural protein NSs mediates these effects, but only NSs from SFNV was found to interact with STAT1 directly. Thus, we tested the upstream IFN signaling components and found that Janus kinase 1 (Jak1) phosphorylation is also impaired by infection.

Furthermore, the NSs proteins from both viruses directly interacted with Jak1. Last, we show that IFN inhibition by SFNV and SFSV is most likely downstream of the IFN receptor at the Jak1 level. Overall, our results reveal the multiple strategies used by these related viruses to overcome host defenses.

[Virus-induced exanthems in returning travellers]

Dermatological diseases are among the most common travel-associated diseases. In particular, viral infections not only with tropical and subtropical pathogens, but also with viruses common in Germany, which are often accompanied by skin rashes and general symptoms, are of great importance. In addition to an accurate travel history and possible risk exposures, epidemiological information on country-specific risks in combination with molecular and serological analyses is helpful in making the correct diagnosis. This article provides an overview of important virus-induced exanthems in returned travellers.

An Insight into Nanomedicinal Approaches to Combat Viral Zoonoses

BACKGROUND

Emerging viral zoonotic diseases are one of the major obstacles to secure the "One Health" concept under the current scenario. Current prophylactic, diagnostic and therapeutic approaches often associated with certain limitations and thus proved to be insufficient for customizing rapid and efficient combating strategy against the highly transmissible pathogenic infectious agents leading to the disastrous socio-economic outcome. Moreover, most of the viral zoonoses originate from the wildlife and poor knowledge about the global virome database renders it difficult to predict future outbreaks. Thus, alternative management strategy in terms of improved prophylactic vaccines and their delivery systems; rapid and efficient diagnostics and effective targeted therapeutics are the need of the hour.

METHODS

Structured literature search has been performed with specific keywords in bibliographic databases for the accumulation of information regarding current nanomedicine interventions along with standard books for basic virology inputs.

RESULTS

Multi-arrayed applications of nanomedicine have proved to be an effective alternative in all the aspects regarding the prevention, diagnosis, and control of zoonotic viral diseases. The current review is focused to outline the applications of nanomaterials as anti-viral vaccines or vaccine/drug delivery systems, diagnostics and directly acting therapeutic agents in combating the important zoonotic viral diseases in the recent scenario along with their potential benefits, challenges and prospects to design successful control strategies.

CONCLUSION

This review provides significant introspection towards the multi-arrayed applications of nanomedicine to combat several important zoonotic viral diseases.

Vector-borne viruses in Turkey: A systematic review and bibliography

Turkey serves as a natural hub for the dissemination of vector-borne viruses and provides many suitable habitats with diverse ecologies for introduction and establishment of new pathogens. This manuscript provides an updated systematic review and meta-analysis of the vector-borne viruses documented in Turkey. Following web-based identification, screening and eligibility evaluation, 291 published reports were reviewed. The publications were categorized and listed as a supplementary bibliography accompanying the manuscript. In brief, Crimean-Congo hemorrhagic fever virus (CCHFV) and West Nile virus (WNV) are currently documented as prominent tick and mosquito-borne viral pathogens in Turkey. CCHFV produces a significant number of infections annually, with severe outcome or death in a portion of cases. WNV gained attention following the clustering of cases in 2010. Exposure and infections with sandfly-borne phleboviruses, such as Toscana virus, are indigenous and widespread. Epidemiology, risk factors, symptomatic infections in susceptible hosts, vectors and reservoirs for these pathogens have been explored in detail. Detection of novel viruses in mosquitoes, sandflies and ticks from several regions is of particular interest, despite scarce information on their epidemiology and pathogenicity in vertebrates. Introduction and emergence of viruses transmitted by invasive Aedes mosquitoes constitute a threat, albeit only imported infections have so far been documented. Detection of Rift valley fever virus exposure is also of concern, due to its detrimental effects on livestock and spillover infections in humans. Vigilance to identify and diagnose probable cases as well as vector surveillance for established and potential pathogens is therefore, imperative.

Viral Febrile Illnesses and Emerging Pathogens

Emerging or emerged diseases and viral pathogens are responsible historically and currently for large epidemics, global pandemics, and significant morbidity and mortality. Our civilization will continue to face the emergence of new pathogens and viruses: viruses will continue to evolve and adapt to new environments at a high rate; our population continues to grow through birth rate, land development, and migration; climate change will continue to increase the vector burden and spread and change the migratory pattern of animals; and our societal mobility will continue to increase through rapid transportation. The clinical evaluation of the febrile patient with a potential emerging viral pathogen involves documenting the likelihood for an infection by a detailed travel history, calculation of an incubation time by exposure, and an understanding of the disease progression though the clinical illness, which drives the differential diagnosis and the type of diagnostics ordered. Ultimately, the proper identification and diagnosis of a patient with a viral febrile illness due to an emerging pathogen will elicit the appropriate precautions to protect health care providers and communities, deliver appropriate therapeutic interventions, and initiate a targeted public health response.

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The majority of emerging diseases are caused by viruses, with many that are transmitted by insect vectors or are zoonotic.

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RNA viruses in particular have high mutation rates and can evolve rapidly in new and changing environments. This, in combination with societal factors, climate change, and rapid travel, has increased the number of epidemics from emerging pathogens in the last several decades.

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Understanding the travel history, incubation time of potential viruses, and the clinical presentation by illness day is essential in making the right diagnosis and identifying the infecting virus.

A mini-review of Bunyaviruses recorded in India

Newly emerging and re-emerging viral infections are of major public health concern. Bunyaviridae family of viruses comprises a large group of animal viruses. Clinical symptoms exhibited by persons infected by viruses belonging to this family vary from mild-to-severe diseases i.e., febrile illness, encephalitis, haemorrhagic fever and acute respiratory illness. Several arthropods-borne viruses have been discovered and classified at serological level in India in the past. Some of these are highly pathogenic as the recent emergence and spread of Crimean-Congo haemorrhagic fever virus and presence of antibodies against Hantavirus in humans in India have provided evidences that it may become one of the emerging diseases in this country. For many of the discovered viruses, we still need to study their relevance to human and animal health. Chittoor virus, a variant of Batai virus; Ganjam virus, an Asian variant of Nairobi sheep disease virus; tick-borne viruses such as Bhanja, Palma and mosquito-borne viruses such as Sathuperi, Thimiri, Umbre and Ingwavuma viruses have been identified as the members of this family. As Bunyaviruses are three segmented RNA viruses, they can reassort the segments into genetically distinct viruses in target cells. This ability is believed to play a major role in evolution, pathogenesis and epidemiology of the viruses. Here, we provide a comprehensive overview of discovery, emergence and distribution of Bunyaviruses in India.

Modeling the climatic suitability of leishmaniasis vector species in Europe

Climate change will affect the geographical distribution of many species in the future. Phlebotomine sandflies are vector species for leishmaniasis, a tropical neglected disease. We applied an ensemble forecasting niche modeling approach to project future changes in climatic suitability for ten vector competent sandfly species in Europe. Whereas the main area of sandfly distribution currently lies in the Mediterranean region, models generally projected a northwards expansion of areas with suitable climatic conditions for most species (P. alexandri, P. neglectus, P. papatasi, P. perfiliewi, P. tobbi) in the future. The range of distribution for only two species (P. ariasi, P. mascittii) was projected to decline in the future. According to our results, a higher number of vector competent species in Central Europe can generally be expected, assuming no limitations to dispersal. We recommend monitoring for the establishment of vector species, especially in areas with projected climatic suitability for multiple vector species, as a precautious strategy. An increased number of vector species, or a higher abundance of a single species, might result in a higher transmission risk of leishmaniasis, provided that the pathogens follow the projected range shifts.

Novel and emergent sandfly-borne phleboviruses in Asia Minor: a systematic review

Sandfly-transmitted phleboviruses are globally spread agents causing febrile diseases and central nervous system infections. The activity of pathogenic phleboviruses, as well as several novel strains, has been reported from Turkey, a transboundary country connecting Asia, Europe, and Africa with suitable habitats for sandflies. This study overviews all published data on phleboviruses from Turkey and evaluates the impact from the virological, epidemiological, and public health perspectives. A systematic review of Web-based global and local resources was performed. Comparison and phylogenetic analyses of particular phlebovirus sequences were also undertaken. Through the evaluation of 1693 international and regional entries, 31 manuscripts providing data on case reports or outbreaks, serological surveillance, animal infections and exposure, virus characterization, vector surveillance, and/or diagnostics were accessed. Detailed information on 5 novel phleboviruses completely or partially characterized during 2008-2015 as well as on clinical and epidemiological features of major phleboviruses established as human pathogens such as Toscana virus and sandfly fever Sicilian virus has been compiled. The ongoing activity of these agents, as indicated by consistently reported symptomatic cases and confirmed exposure in vertebrates including humans, was noted. The circulation in the Anatolian peninsula of phleboviruses with surprising diversity as well as distinct virus species is documented. Specific phlebovirus strains constitute a public health threat for local populations and travelers and must be considered in the diagnostic workup of clinically compatible cases. Human health impact and epidemiological aspects of certain viruses require further investigation via intensive surveillance.

Phleboviruses and the Type I Interferon Response

The genus Phlebovirus of the family Bunyaviridae contains a number of emerging virus species which pose a threat to both human and animal health. Most prominent members include Rift Valley fever virus (RVFV), sandfly fever Naples virus (SFNV), sandfly fever Sicilian virus (SFSV), Toscana virus (TOSV), Punta Toro virus (PTV), and the two new members severe fever with thrombocytopenia syndrome virus (SFTSV) and Heartland virus (HRTV). The nonstructural protein NSs is well established as the main phleboviral virulence factor in the mammalian host. NSs acts as antagonist of the antiviral type I interferon (IFN) system. Recent progress in the elucidation of the molecular functions of a growing list of NSs proteins highlights the astonishing variety of strategies employed by phleboviruses to evade the IFN system.

Sadfly fever: two case reports

Sandfly fever, also known as 'three-day fever' or 'pappataci fever' or 'Phlebotomus fever' is a viral infection that causes self-limited influenza-like symptoms and characterized by a rapid onset. The disease occurs commonly in endemic areas in summer months and especially in August during which sandflies are active. In this article, two siblings who presented with high fever, redness in the eyes, headache, weakness, malaise and inability to walk, who were found to have increased liver function tests and creatine kinase levels and who were diagnosed with sadfly fever with positive sadfly IgM and IgG antibodies are reported because of the rarity of this disease.

Experimental evaluation of sand fly collection and storage methods for the isolation and molecular detection of Phlebotomus-borne viruses

BACKGROUND

Several viruses have been recently isolated from Mediterranean phlebotomine sand flies; some are known to cause human disease while some are new to science. To monitor the Phlebotomus-borne viruses spreading, field studies are in progress using different sand fly collection and storage methods. Two main sampling techniques consist of CDC light traps, an attraction method allowing collection of live insects in which the virus is presumed to be fairly preserved, and sticky traps, an interception method suitable to collect dead specimens in high numbers, with a risk for virus viability or integrity. Sand flies storage requires a "deep cold chain" or specimen preservation in ethanol. In the present study the influence of sand fly collection and storage methods on viral isolation and RNA detection performances was evaluated experimentally.

METHODS

Specimens of laboratory-reared Phlebotomus perniciosus were artificially fed with blood containing Toscana virus (family Bunyaviridae, genus Phlebovirus). Various collection and storage conditions of blood-fed females were evaluated to mimic field procedures using single and pool samples. Isolation on VERO cell cultures, quantitative Real time-Retro-transcriptase (RT)-PCR and Nested-RT-PCR were performed according to techniques commonly used in surveillance studies.

RESULTS

Live engorged sand flies stored immediately at -80 °C were the most suitable sample for phlebovirus identification by both virus isolation and RNA detection. The viral isolation rate remained very high (26/28) for single dead engorged females frozen after 1 day, while it was moderate (10/30) for specimens collected by sticky traps maintained up to 3 days at room temperature and then stored frozen without ethanol. Opposed to viral isolation, molecular RNA detection kept very high on dead sand flies collected by sticky traps when left at room temperature up to 6 days post blood meal and then stored frozen in presence (88/95) or absence (87/88) of ethanol. Data were confirmed using sand fly pools.

CONCLUSIONS

While the collection and storage methods investigated had not much impact on the ability to detect viral RNA by molecular methods, they affected the capacity to recover viable viruses. Consequently, sand fly collection and handling procedures should be established in advance depending on the goal of the surveillance studies.

Clinical features and factors associated with severity and fatality among patients with severe fever with thrombocytopenia syndrome Bunyavirus infection in Northeast China

BACKGROUND

In 2009, severe fever with thrombocytopenia syndrome virus (SFTSV) was identified as a novel member of the genus phlebovirus in the Bunyaviridae family in China. The detailed clinical features of cases with SFTSV infection have not been well described, and the risk factors for severity among patients and fatality among severe patients remain to be determined.

METHODOLOGY/PRINCIPAL FINDINGS

Clinical and laboratory features of 115 hospitalized patients with SFTSV infection during the period from June 2010 to December 2011 in Northeast China were retrospectively reviewed. We assessed the risk factors associated with severity in confirmed cases and fatality in severe cases by multivariate analysis. One hundred and three (89.6%) of 115 patients presented with multiple organ dysfunction, and 22 (19.1%) of 115 proceeded to the stage of life threatening multiple organ failure. Of the 115 patients, 14 fatalities (12.2%) were reported. Multivariate analysis demonstrated that the independent predictors of risk for severity were: albumin ≤ 30 g/l (OR, 8.09; 95% CI, 2.58-25.32), APTT ≥ 66 seconds (OR, 14.28; 95% CI, 3.28-62.24), sodium ≤ 130 mmol/l (OR, 5.44; 95% CI, 1.38-21.40), and presence of neurological manifestations (OR, 7.70; 95% CI, 1.91-31.12). Among patients with severe disease, presence of acute lung injury/acute respiratory distress syndrome (HR, 4.59; 95% CI, 1.48-14.19) and disseminated intravascular coagulation (HR, 4.24; 95% CI, 1.38-13.03) were independently associated with fatality.

CONCLUSIONS/SIGNIFICANCE

SFTSV infection may present with more severe symptoms and laboratory abnormalities than hitherto reported. Due to infection with a novel bunyavirus, the patients may sufferer multiple organ dysfunction and die of multiple organ failure. In the clinical assessment of any case of SFTS, independent factors relating to prognosis need to be taken into account by clinicians.

Emergence and co-infections of West Nile virus and Toscana virus in Eastern Thrace, Turkey

The objective of this study was to identify the impact of West Nile virus (WNV) and Toscana virus (TOSV) in febrile diseases of unknown aetiology in Eastern Thrace, Turkey; this study was conducted during August-October 2012, and included 18 clinical cases and 296 blood donors for local serosurveillance. Antibodies were determined via commercial assays and further tested for specificity via neutralization assays (NA). Viral RNAs were sought via specific and/or generic primers. WNV infections were diagnosed in seven patients (38.8%), detected via RNA+IgM in four, RNA in one and IgM and low avidity IgG in two cases. The most common symptom was fever (>38°C), followed by headache, malaise/fatigue, myalgia/arthralgia, muscle stiffness/lower back pain, anorexia, nausea/vomiting, diarrhoea, supraorbital/retrobulbar pain and abdominal pain. Neurological symptoms were noted in one individual. WNV strains in RNA-detectable patients were characterized as lineage 1. TOSV RNA or IgM were identified in two individuals with confirmed WNV infections and in one patient without evidence of WNV exposure. The clinical and laboratory findings in individuals with WNV/TOSV co-infection were comparable to those in WNV-induced disease. The TOSV strain in the patient with detectable viral RNA was characterized as genotype A. In local blood donors, seroreactivity for specific WNV and TOSV immunoglobulins was observed in 1.7% (5/296) and 14.4% (26/180), respectively. These findings indicate the emergence of WNV and TOSV-associated diseases in Eastern Thrace. WNV/TOSV co-infections were documented for the first time.

Phlebotomine sandflies and the spreading of leishmaniases and other diseases of public health concern

Phlebotomine sandflies transmit pathogens that affect humans and animals worldwide. We review the roles of phlebotomines in the spreading of leishmaniases, sandfly fever, summer meningitis, vesicular stomatitis, Chandipura virus encephalitis and Carrión's disease. Among over 800 species of sandfly recorded, 98 are proven or suspected vectors of human leishmaniases; these include 42 Phlebotomus species in the Old World and 56 Lutzomyia species in the New World (all: Diptera: Psychodidae). Based on incrimination criteria, we provide an updated list of proven or suspected vector species by endemic country where data are available. Increases in sandfly diffusion and density resulting from increases in breeding sites and blood sources, and the interruption of vector control activities contribute to the spreading of leishmaniasis in the settings of human migration, deforestation, urbanization and conflict. In addition, climatic changes can be expected to affect the density and dispersion of sandflies. Phlebovirus infections and diseases are present in large areas of the Old World, especially in the Mediterranean subregion, in which virus diversity has proven to be higher than initially suspected. Vesiculovirus diseases are important to livestock and humans in the southeastern U.S.A. and Latin America, and represent emerging human threats in parts of India. Carrión's disease, formerly restricted to regions of elevated altitude in Peru, Ecuador and Colombia, has shown recent expansion to non-endemic areas of the Amazon basin.