Human seroprevalence of Toscana virus and Sicilian phlebovirus in the southwest of Portugal.

Toscana virus (TOSV) is emergent in the Mediterranean region and responsible for outbreaks of encephalitis or meningoencephalitis. Sicilian phlebovirus (SFSV) cause epidemics of febrile illness during the summer. The aim of this study was to evaluate the presence of antibodies against TOSV and SFSV in humans in the southwest of Portugal. Neutralizing antibodies to TOSV and SFSV were respectively detected in 5.3% and 4.3% out of 400 human sera tested highlighting the need to increase public health awareness regarding phleboviruses and to include them in the differential diagnosis in patients presenting with fever of short duration and neurological manifestations.

Severe fever with thrombocytopenia syndrome: a systematic review and meta-analysis of epidemiology, clinical signs, routine laboratory diagnosis, risk factors, and outcomes.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease with the high case-fatality rate, and lack of vaccines. We aimed to systematically analysed the epidemiological characteristics, clinical signs, routine laboratory diagnosis, risk factors, and outcomes. METHODS: Documents on SFTS were collected by searching the Chinese National Knowledge Infrastructure, Wan Fang Data, PubMed, Embase, and Web of Science databases from 2011 to 2018. Meta-analysis was performed by using Review Manager and Stata software. RESULTS: Twenty-five articles involving 4143 cases were included. Diarrhea (odds ratio (OR) =1.60, 95% confidence interval (CI): 1.06 to 2.42, P = 0.02), and vomiting (OR = 1.56, 95% CI: 1.01 to 2.39, P = 0.04) on admission were associated with the fatal outcomes of SFTS. Compared to patients with mild symptoms, patients with severe symptoms had significantly elevated levels of lactic acid dehydrogenase (standard mean difference (SMD) =1.27, 95% CI: 0.59 to 1.94), alanine aminotransferase (SMD = 0.55, 95% CI: 0.24 to 0.85), aspirate aminotransferase (SMD = 1.01, 95% CI: 0.69 to 1.32), and creatine kinase (SMD = 1.04, 95% CI: 0.74 to 1.33) but had reduced platelet counts (SMD = -0.87, 95% CI: - 1.16 to - 0.58) and albumin levels (SMD = -1.00, 95% CI: - 1.32 to - 0.68). The risk factors for poor prognosis included age (mean difference (MD) =6.88, 95% CI: 5.41 to 8.35) and farming (OR = 2.01, 95% CI: 1.06 to 3.80). For the risk factors of contracting SFTS, the incidence of SFTS related to tick bites was 24% [95% CI: 0.18 to 0.31]. The pooled case-fatality rate of SFTS patients was 18% [95% CI: 0.16 to 0.21]. CONCLUSIONS: China is the country with the highest incidence of SFTS. May to July was the peak of the epidemic, and farmers were a high-risk group. The risk factor for SFTS included age (poor prognosis) and tick bites (contracting SFTS). Patients with severe diarrhea and vomiting symptoms on admission should be noted. Clinicians could use routine laboratory parameters and clinical symptoms as references for clinically suspected cases, classification of SFTS, and timely treatment, especially in basic hospitals.

Predictive risk score model for severe fever with thrombocytopenia syndrome mortality based on qSOFA and SIRS scoring system.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is a severe systemic virus infectious disease usually having multi-organ dysfunction which resembles sepsis. METHODS: Data of 321 patients with laboratory-confirmed SFTS from May 2013 to July 2017 were retrospectively analyzed. Demographic and clinical characteristics, calculated quick sequential organ failure assessment (qSOFA) score and systemic inflammatory response syndrome (SIRS) criteria for survivors and nonsurvivors were compared. Independent risk factors associated with in-hospital mortality were obtained using multivariable logistic regression analysis. Risk score models containing different risk factors for mortality in stratified patients were established whose predictive values were evaluated using the area under ROC curve (AUC). RESULTS: Of 321 patients, 87 died (27.1%). Age (p < 0.001) and percentage numbers of patients with qSOFA≥2 and SIRS≥2 (p < 0.0001) were profoundly greater in nonsurvivors than in survivors. Age, qSOFA score, SIRS score and aspartate aminotransferase (AST) were independent risk factors for mortality for all patients. qSOFA score was the only common risk factor in all patients, those age ≥ 60 years and those enrolled in the intensive care unit (ICU). A risk score model containing all these risk factors (Model1) has high predictive value for in-hospital mortality in these three groups with AUCs (95% CI): 0.919 (0.883-0.946), 0.929 (0.862-0.944) and 0.815 (0.710-0.894), respectively. A model only including age and qSOFA also has high predictive value for mortality in these groups with AUCs (95% CI): 0.872 (0.830-0.906), 0.885(0.801-0.900) and 0.865 (0.767-0.932), respectively. CONCLUSIONS: Risk models containing qSOFA have high predictive validity for SFTS mortality.

Serial analysis of cytokine and chemokine profiles and viral load in severe fever with thrombocytopenia syndrome: Case report and review of literature.

RATIONALE: Severe fever with thrombocytopenia syndrome (SFTS) is a recently recognized fatal infectious disease caused by the SFTS virus, and severe cases are complicated by the presence of hemophagocytic lymphohistiocytosis (HLH) associated with a cytokine storm. Herein, we report on serial changes of serum cytokine levels and viral load in a severe case of SFTS. PATIENT CONCERNS: A 63-year-old Japanese woman presented with high-grade fever, abdominal pain, diarrhea, impaired consciousness, leukocytopenia, and thrombocytopenia. DIAGNOSIS: SFTS was diagnosed based on a positive serum test for SFTS virus RNA and electroencephalogram (EEG) findings of encephalopathy. INTERVENTIONS: The patient was treated with supportive therapy, including steroid pulse therapy (intravenous methylprednisolone 1 g/d for 3 days) for HLH and intravenous recombinant thrombomodulin 19200 U/d for 7 days for disseminated intravascular coagulation. OUTCOMES: Treatment for 7 days improved both symptoms and abnormal EEG findings, and SFTS virus RNA disappeared from the serum at day 10 from the onset of symptoms. The serum cytokines and chemokines analysis during the clinical course revealed 2 distinct phases: the acute phase and the recovery phase. The cytokines and chemokines elevated in the acute phase included interleukin (IL)-6, IL-10, interferon (IFN)-α2, IFN-γ, tumor necrosis factor-α, interferon-γ-induced protein-10, and fractalkine, while the IL-1ß, IL-12p40, IL-17, and vascular endothelial growth factor levels were higher in the recovery phase. CONCLUSION: These observations suggest that the cytokines and chemokines elevated in the acute phase may reflect the disease severity resulted in a cytokine storm, while those in the recovery phase may be attributed to T-cell activation and differentiation.

Cutaneous histopathology of the tick-bite region in severe fever with thrombocytopenia syndrome.

A case of severe fever with thrombocytopenia syndrome (SFTS) in which a skin biopsy from the tick-bite region was analyzed is reported. The patient was a 72-year-old woman who developed fever and thrombocytopenia after a tick bite. SFTS was diagnosed from polymerase chain reaction (PCR) analysis of a blood sample. Histopathological analysis of a skin biopsy specimen from the tick-bite region showed CD20-positive perivascular and interstitial immunoblastic cells, which were positive to anti-SFTS virus (SFTSV) nucleoprotein antibody. In addition, SFTSV RNA was detected by real-time PCR from this biopsy specimen. Moreover, hemophagocytosis was also found in the tick-bite region. To the best of our knowledge, this is the first report to analyze the details of the tick-bite region of skin in SFTS, and the first to detect virus-infected cells in the skin. The present findings may help elucidate the mechanisms of entry of SFTSV.

The proportion, origin and pro-inflammation roles of low density neutrophils in SFTS disease.

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is a novel emerging viral infectious disease. We explored the percentage, origins and functional roles of low density neutrophils (LDNs), one of the neutrophils subsets, in SFTS. METHODS: The LDNs and normal density neutrophils (NDNs) from blood of SFTS and normal volunteers which were collected separately. The percentage, origins and the phagocytic capability of SFTS viral (SFTSV) of LDNs were investigated by flow cytometry and real time PCR. The capacity of LDNs to secrete cytokines and to damage endothelial cells was assessed by ELISA and flow cytometry. RESULTS: We observed that the proportion of LDNs increased dramatically compared with the healthy donors and became the dominant circulating neutrophil population in SFTS patients. Interestingly, the NDNs from the normal donors could switch to LDNs under the SFTS environment. Moreover, SFTSV load in LDNs was significantly higher than that of NDNs in the severe SFTS patients. In addition, the LDNs secreted much higher levels of pro-inflammatory cytokines than NDNs in SFTS and could induce endothelial cell injury. CONCLUSION: The NDNs can be converted to LDNs. This conversion mechanism could become the source of LDNs. The LDNs in severe SFTS patient could engulf more SFTSV and exhibit pro-inflammation functions. TRIAL REGISTRATION: The Ethics Committee of Tongji Medical College, Huazhong University of Science and Technology (IORG No: IORG0003571) gave a final APPROVAL for the study.

Neutralizing antibodies to Severe Fever with Thrombocytopenia Syndrome Virus in general population, Shandong Province, China.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS virus (SFTSV) in East Asia. The research on seroprevalence of SFTSV in healthy people and risk factors had been detailed. However, the levels of neutralizing antibodies against SFTSV in general population were currently unclear. In the present study, we tested 1375 healthy persons from Penglai County, eastern China, for SFTSV neutralizing antibodies; 0.58% (8/1,375) was positive and the positive rates were not significantly different among people at different age groups, occupations and genders. Besides, a follow-up study was conducted and the titer of neutralizing antibodies decreased over time in all eight people but one, and the neutralizing antibodies of five lasted for the entire study period of seven years. Our results suggesting that subclinical infection or a relatively mild form of SFTS illness is occurring in this population, but a small percentage of sera have neutralizing capacity to SFTSV. Hence, most people are just susceptible to SFTSV infection.

Analysis of clinical features and early warning indicators of death from severe fever with thrombocytopenia syndrome.

OBJECTIVE: To determine the clinical features of confirmed cases of severe fever with thrombocytopenia syndrome (SFTS) and to explore the early warning indicators of death from SFTS. METHODS: A retrospective case-control study was performed at a single medical institution in Yantai. A total of 20 SFTS patients who died (death group) during January 2014 to December 2015 and another 40 age- and sex-matched SFTS patients who survived (survivor group) were identified from the case records. The differences in demographic characteristics, clinical signs and symptoms, and laboratory parameters in the early stage of disease were compared between the two groups. Conditional logistic regression was used to identify the independent risk factors for mortality in SFTS patients. RESULTS: Univariate logistic regression analysis showed that a disturbance of consciousness, pulse-temperature deficit, neurological signs, hemorrhagic manifestations, pulmonary infection, decreased lymphocyte percentage, high lactate dehydrogenase and creatine kinase levels, increased serum creatinine, blood urea nitrogen, and C-reactive protein (CRP), hyponatremia, and prolonged activated partial thromboplastin time (APPT) and prothrombin time were associated with mortality. On multivariate logistic regression analysis, the independent predictors of death were neurological signs (odds ratio (OR) 31.247, 95% confidence interval (CI) 4.813-202.853), hemorrhagic manifestations (OR 20.251, 95% CI 2.056-199.443), disturbance of consciousness (OR 15.359, 95% CI 2.139-110.268), hyponatremia (OR 5.280, 95% CI 1.235-22.575), increased CRP (OR 2.641, 95% CI 1.090-6.396), increased serum creatinine (OR 6.776, 95% CI 1.047-43.840), and prolonged APTT (OR 6.018, 95% CI 1.450-24.975). CONCLUSIONS: Neurological signs, hemorrhagic manifestations, disturbance of consciousness, hyponatremia, prolonged APTT, and increased CRP and serum creatinine are risk factors for death in SFTS.

A patient with severe fever with thrombocytopenia syndrome and hemophagocytic lymphohistiocytosis-associated involvement of the central nervous system.

Severe fever with thrombocytopenia syndrome (SFTS), a severe infectious disease caused by novel bunyavirus, SFTS virus (SFTSV), is endemic to China, Korea, and Japan. Most SFTS patients show abnormalities in consciousness. Pathological findings in the central nervous system (CNS) of SFTS patients are not reported. A 53-year-old Japanese man was admitted to Uwajima City Hospital with an 8-day history of fever and diarrhea. Laboratory tests revealed leukopenia, thrombocytopenia, and liver enzyme elevation. He was diagnosed as having severe fever with thrombocytopenia syndrome (SFTS) following detection of the SFTSV genome in his blood. Bone marrow aspiration revealed hemophagocytic lymphohistiocytosis. He suffered progressive CNS disturbance and died on day 13 from onset of first symptoms. The SFTSV genome load in blood and levels of certain cytokines increased over the disease course. Necrotizing lymphadenitis with systemic lymphoid tissues positive for nucleocapsid protein (NP) of SFTSV was revealed by immunohistochemical (IHC) analysis. SFTSV-NP-positive immunoblasts were detected in all organs examined, including the CNS, and in the vascular lumina of each organ. Parenchymal cells of all organs examined were negative for SFTSV-NP on IHC analysis. Microscopic examination of the pons showed focal neuronal cell degeneration with hemosiderin-laden macrophages around extended microvessels with perivascular inflammatory cell infiltration and intravascular fibrin deposition. Autopsy confirmed this patient with SFTS was positive for systemic hemophagocytic lymphohistiocytosis including in the CNS. This patient's neurological abnormalities may have been caused by both functional and organic abnormalities. These novel findings provide important insights into the pathophysiology of SFTS.

High Rates of Neutralizing Antibodies to Toscana and Sandfly Fever Sicilian Viruses in Livestock, Kosovo.

Toscana and sandfly fever Sicilian viruses (TOSV and SFSV, respectively), both transmitted by sand flies, are prominent human pathogens in the Old World. Of 1,086 serum samples collected from cattle and sheep during 2013 in various regions of Kosovo (Balkan Peninsula), 4.7% and 53.4% had neutralizing antibodies against TOSV and SFSV, respectively.

Hyperferritinemia as a Diagnostic Marker for Severe Fever with Thrombocytopenia Syndrome.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging viral disease in East Asia with high mortality. Few studies have examined markers that suggest SFTS in febrile patients. To determine useful biochemical markers for SFTS, patients aged 18 years or older with SFTS or microbiologically confirmed community-onset bacteremia with thrombocytopenia (BT) at presentation between June 2013 and December 2015 were included from two tertiary university hospitals in Republic of Korea retrospectively. Eleven patients with SFTS and 62 patients with bacteremia and thrombocytopenia were identified in the study period. Age and sex did not show significant difference among two groups. Fever was more commonly observed but comorbidities were less common in SFTS than in BT (P < 0.05, each). The areas under the curves of serum ferritin, C-reactive protein, white blood cell count, serum procalcitonin, and fibrinogen were above 0.9, indicating the discriminative power of these biomarkers (1.000, 0.991, 0.963, 0.931, and 0.934, resp., all P < 0.05). The optimal cutoff value of serum ferritin was 3,822 ng/mL in this study. These results suggest that hyperferritinemia is a typical laboratory feature of SFTS, and the serum ferritin level can be used as a marker for clinicians suspecting SFTS.

Seroprevalence of Sandfly-Borne Phleboviruses Belonging to Three Serocomplexes (Sandfly fever Naples, Sandfly fever Sicilian and Salehabad) in Dogs from Greece and Cyprus Using Neutralization Test.

Phleboviruses transmitted by sandflies are endemic in the Mediterranean area. The last decade has witnessed the description of an accumulating number of novel viruses. Although, the risk of exposure of vertebrates is globally assessed, detailed geographic knowledge is poor even in Greece and Cyprus where sandfly fever has been recognized for a long time and repeatedly. A total of 1,250 dogs from mainland Greece and Greek archipelago on one hand and 422 dogs from Cyprus on the other hand have been sampled and tested for neutralising antibodies against Toscana virus (TOSV), Sandfly fever Sicilian virus (SFSV), Arbia virus, and Adana virus i.e. four viruses belonging to the 3 sandfly-borne serocomplexes known to circulate actively in the Mediterranean area. Our results showed that (i) SFSV is highly prevalent with 71.9% (50.7-84.9% depending on the region) in Greece and 60.2% (40.0-72.6%) in Cyprus; (ii) TOSV ranked second with 4.4% (0-15.4%) in Greece and 8.4% (0-11.4%) in Cyprus; (iii) Salehabad viruses (Arbia and Adana) displayed also substantial prevalence rates in both countries with values ranging from 0-22.6% depending on the region and on the virus strain used in the test. These results demonstrate that circulation of viruses transmitted by sand flies can be estimated qualitatively using dog sera. As reported in other regions of the Mediterranean, these results indicate that it is time to shift these viruses from the "neglected" status to the "priority" status in order to stimulate studies aiming at defining and quantifying their medical and veterinary importance and possible public health impact. Specifically, viruses belonging to the Sandfly fever Sicilian complex should be given careful consideration. This calls for implementation of direct and indirect diagnosis in National reference centers and in hospital microbiology laboratories and systematic testing of unelucidated febrile illness and central and peripheral nervous system febrile manifestations.

Neutralization-based seroprevalence of Toscana virus and sandfly fever Sicilian virus in dogs and cats from Portugal.

Sandfly-borne phleboviruses are endemic in the Mediterranean basin. However, levels of exposure of human and animal populations are inadequately researched. Toscana virus (TOSV) is present in Portugal where it causes human infection and disease; in contrast there are few data for sandfly fever Sicilian virus (SFSV) which has neither been isolated nor detected by molecular tests and for which there are only limited serological data. The sera collected from 1160 dogs and 189 cats in southern Portugal were tested for the presence of neutralizing antibodies against TOSV and SFSV, two viruses recognized as distinct serocomplexes in the Mediterranean region. Our data showed (i) seropositivity to TOSV and SFSV in dogs at a rate of 6.8 and 50.8 %, respectively, and (ii) that 3.7 % of cats were seropositive for TOSV. TOSV findings are in line with previous results obtained with less stringent serological assays. Our results for SFSV in dogs clearly indicate that the virus is circulating widely and that humans may be exposed to infection via the dogs. Although the presence of SFSV was suggested by haemagglutination inhibition in 4/1690 human sera in 1974, this is the first time, as far as we know, that SFSV has been shown to circulate so widely in dogs in Portugal. Future studies should be directed at isolating strains of SFSV in Portugal from dogs, humans and sandflies collected in high prevalence regions. As dogs appear to be good sentinels for SFSV, their role as a possible reservoir in the natural cycle should also be considered.

Severe fever with thrombocytopenia syndrome bunyavirus-related human encephalitis.

BACKGROUND: Severe Fever with Thrombocytopenia Syndrome (SFTS) is an emerging infectious disease caused by a novel bunyavirus. Until recently, SFTSV-associated encephalitis remained largely uninvestigated. METHODS: We made clinical investigation on SFTS patients who experienced encephalitis in one reference hospital in Henan Province from 2011 to 2013 to identify the risk factors for encephalitis occurrence and their fatal outcome development. RESULTS: Altogether 538 SFTS patients were included and 19.1% of them developed encephalitis. Fatal outcome occurred in 44.7% of the encephalitis patients. The risk factors associated with encephalitis occurrence and death included older age, longer delay between disease onset and hospital admission, pre-existing diabetes and myalgias, as well as the laboratory evaluations of higher virus load on admission, decreased WBC, PLT count, lymphocyte percentage and ALB, elevated neutrophils percentage, AST, ALT, LDH, CK, ALP, GGT, BUN and CREA. These parameters could be used as potential predictors referring to severe SFTS cases. One SFTSV strain was isolated from cerebrospinal fluid sample. Cytokine/chemokine assay revealed that blood EOTAXIN, IFN-γ, IL-15, IL-6, IP-10, TNF-α were remarkably elevated before clinical deterioration in the confirmed encephalitis patient. CONCLUSIONS: SFTSV is capable of infecting the central nervous system and screening for SFTSV in encephalitis of unknown reason should be performed in SFTS endemic regions. The encephalitis occurrence and fatal outcome could be potentially predicted by clinical and laboratory evaluations.

Neuroinvasive phlebovirus infection in Greece: a case report.

OBJECTIVE: Sandfly fever phleboviruses are endemic in Mediterranean countries. We report a febrile phlebovirus case in a Greek patient who presented signs of neuroinvasive infection. METHODS: In summer 2010, a 20-year-old male was admitted to hospital with fever and lethargy; he was a resident of central Macedonia, northern Greece, where a large outbreak of West Nile virus (WNV) infections occurred at that time. Since there was no laboratory evidence of WNV infection, the patient's serum and cerebrospinal fluid were tested for a probable phlebovirus infection. RESULTS: High titers of IgM and IgG antibodies against Toscana virus were detected in serum and cerebrospinal fluid, while the titers against sandfly fever Naples virus were lower; no reactivity was detected against sandfly Sicilian and Cyprus viruses. Since neutralization assays were not performed and PCR resulted in being negative, it was concluded that the causative agent was a phlebovirus of the sandfly fever Naples serocomplex. CONCLUSION: The present case confirms results from previous seroprevalence studies showing that phleboviruses of the sandfly fever Naples serocomplex are present in Greece and provides evidence that they cause febrile neuroinvasive disease in humans, prompting for inclusion of phleboviral infections in the differential diagnosis of acute febrile cases during the time when sandflies are active.

Person-to-person transmission of severe fever with thrombocytopenia syndrome bunyavirus through blood contact.

Severe fever with thrombocytopenia syndrome bunyavirus is a newly discovered bunyavirus with high pathogenicity to human. The transmission model has been largely uncharacterized. Investigation on a cluster of severe fever with thrombocytopenia syndrome cases provided evidence of person-to-person transmission through blood contact to the index patient with high serum virus load.

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

Sandfly fever (SF) is an arthropod-borne disease, which has not yet been reported from Ankara. In the summer of 2007, the disease started to be seen in our region, surprisingly causing severe clinical presentations. This report reviews the clinical and laboratory findings of patients with sandfly virus infection of disease outbreaks in 2008 and 2009. A retrospective single-centre descriptive study was performed. Clinically suspected cases were defined on the basis of epidemiologic history and clinical and laboratory findings. The sera samples of the suspected patients were sent to Germany for diagnostic assistance. 50 patients were included in the study. Fever, headache, photophobia, conjunctivitis, myalgia, arthralgia, nausea, abdominal pain and anorexia were common symptoms. Although the fever lasted only 3-6 days, complete recovery required up to 30 days. Leukopenia, thrombocytopenia and elevated serum aspartate-aminotransferase and alanine-aminotransferase levels were remarkable findings. The viral-load of Sandfly fever Turkey Virus (SFTV) was detected in the serum of acute patients ranged from 3.19×10(6) to 2.79×10(9) viral RNA molecules/ml. As a result we want to underline that the new type of sandfly virus causes a severe clinical picture with elevated liver enzymes and thrombocytopenia, to an extent not described before in the literature, which might be due to the elevated viral-load observed.

[Seroprevalence survey of Toscana virus infection in Oporto region]. / Estudo de seroprevalência da infecção por vírus Toscânia na região do Porto.

UNLABELLED: Toscana virus (TOSV) endemic in central Italy, has been documented in several European countries of the Mediterranean region. It is a neurotropic virus and in some of these countries studies to investigate seroprevalence have been done. In a recent etiologic study of meningitis we chose 106 of 308 samples to be tested for TOSV using a nested RT-PCR assay, and found six (5.6%) cases of meningitis by Toscana virus. AIM: To investigate the seroprevalence of antibodies against TOSV in a cohort of a population attended in our Hospital. MATERIAL AND METHODS: In serum samples collected for routine study we have investigated the presence of antibodies for TOSV. The study included samples of patients hospitalized and others observed in ambulatory and includes children and adults. Immunocompromised patients were excluded. The test was based on the-ELISA technique ((ENZYWELL), according to the manufacture instructions, being positive for a cut-off>1.2, negative if the cut-off <0.8 and doubtful if the cut-off >0.8 e <1.2. RESULTS: 334 serum samples arbitrarily were used for seroprevalence study of antibodies to TOSV, 304 adults and 30 children. Positive results for anti-TOSV were obtained in 13 (3.9%) samples; in other 21 the result was doubtful and in those cases it was not possible to repeat because we have only one pair of serum and in the remaining 300 the result was negative. The positive samples were all from adults, 8 females and 5 males, 8 (62%) of them were older than 60 years. All children' samples were negative for TOSV antibodies. CONCLUSION: We documented a seroprevalence of 3.9% to TOSV, namely in adults older than 60 years. Our prevalence is lower when compared to other European countries, namely Spain (5-22%).

[Toscana virus in the Portuguese population: serosurvey and clinical cases]. / Vírus Toscana na população Portuguesa: vigilância sero-epidemiológica e casos clínicos.

Toscana virus (Phlebovirus genus, Bunyaviridae family) is a neurotropic virus which circulates in the Mediterranean Basin. Although Portugal has been the second country where its presence was reported, the existence of this virus in our country has been referred only sporadically, and there is a lack of knowledge regarding the prevalence of antibodies in the population. Thus, the objective of this study was to analyse the prevalence of antibodies anti-Toscana virus in the human population in our country. Sero-epidemiological investigations were performed with indirect immunofluorescence assay (IFA) and enzyme linked immunosorbent assay (ELISA) tests. The study population consisted of a control population (blood donors, n=150), a population considered at risk (n=236) and a population of individuals with symptoms and laboratory diagnostic request for vector-borne viruses. The latter population was divided into two groups: those individuals with neurological symptoms (n=165) and those without neurological symptoms (n=373). We tested sera from a total of 924 individuals. The seroprevalence of IgG antibodies in the control population was 2%. In the population considered at risk, the prevalence was 3.4%. In the population with central nervous system disease, we detected a seroprevalence of 4.2%. For the same type of antibodies and in subjects without central nervous system disease, the prevalence was 1.3%. Five cases of recent infection (3%) were detected in the population with neurological signs. Those infections have been acquired in the districts of Faro, Coimbra, Aveiro and Lisbon. The associated clinical diagnoses were meningitis, meningoencephalitis and rash. The observed seroprevalences were, in general, lower than reported in other endemic countries. Only 5 of the 29 sera which gave positive results by IFA and ELISA were confirmed by plaque reduction neutralization tests with the Italian strain ISS.Phl.3. This can indicate the presence of more than one Toscana virus serotype circulating in Portugal and emphasizes the need for more research about this etiological agent in our country.