Search Results (16)

Eight sandfly-borne phleboviruses were found to circulate in North Africa. Phleboviruses detected in sandflies were Toscana (TOSV), Sandfly Fever Sicilian (SFSV), Sandfly Fever Naples (SFNV), Cyprus (CYPV), Punique (PUNV), Utique, Saddaguia, and Medjerda Valley (MVV) viruses, yielding an overall infection rate of 0.02–0.6%. Phlebotomus perniciosus and Phlebotomus longicuspis were the most common vector species in the region. TOSV seroprevalence in dogs from Algeria (4.56%) and Tunisia (7.5%) was low and close, unlike SFSV (38.1%) and PUNV (43.5%), which were restricted to Tunisia. SFSV (1.3–21%) and TOSV (3.8–50%) were the most prevalent among humans. TOSV was frequently detected and symptomatically confirmed in both Algeria (3.8%) and Tunisia (12.86%). Other sandfly-borne phleboviruses have also been detected but less importantly, such as SFNV in Morocco (2.9%) and Tunisia (1.1%) and PUNV (8.72%), CYPV (2.9%), and MVV (1.35%) in Tunisia. Their distribution was mainly northern. Overall, 15.9% of the healthy population were seropositive for sandfly-borne phleboviruses, with evidenced cocirculation. Noticeably, studies conducted in Morocco were mostly interested in TOSV in sandflies. Available data from Libya and Egypt were scant or historical. Further elaboration is required to check the sporadic detection of less-prevalent phleboviruses and fully elucidate the epidemiological situation. Full article

The aim of this study was to determine the prevalence of six viruses, from two families of the order Bunyavirales, in the general population of central Tunisia. Sera collected from 377 asymptomatic blood donors were serologically assayed for Rift Valley fever virus (RVFV), Crimean–Congo hemorrhagic fever virus (CCHFV), and four sandfly-borne phleboviruses: Toscana virus (TOSV), sandfly fever Naples virus (SFNV), sandfly fever Sicilian virus (SFSV), and sandfly fever Cyprus virus (SFCV). Of the 377 subjects enrolled in this study, 17.3% were IgG positive for at least one of the viruses tested. The most frequently detected antibodies were against TOSV (13.3%), followed by SFCV (2.9%), RVFV (1.9%), SFSV (1.3%), and SFNV (1.1%). Only one sample was IgG positive for CCHFV. Dual reactivity was observed in nine cases: SFSV + SFCV in three cases (0.8%) and TOSV + SFNV, TOSV + SFCV, and TOSV + RVFV in two cases (0.5%) each. 15.9% of donors were IgG positive against sandfly-borne phleboviruses. Among the 65 donors IgG positive for phleboviruses, 50.8% were from rural areas compared to 12.3% from urban areas (p < 0.001); 92.3% had animals in their living quarters (p = 0.009); and 70.8% lived in the vicinity of stagnant water (p = 0.062). Seroprevalence was significantly higher among donors living with chronic diseases (p = 0.039). Furthermore, the seroprevalence of phleboviruses was higher in Kairouan, the central governorate, than in the two coastal governorates: Monastir and Sousse, with 33.4%, 24.2%, and 14.9%, respectively. The presence of antibodies in the general population needs further investigation to better assess the extent of these viruses. Only TOSV was known to have an extensive circulation in Tunisia and in North Africa. Continued surveillance and interventions are necessary to detect the emergence of all arboviruses and to prevent further transmission. Full article

Vector-borne viral diseases (VBVDs) continue to pose a considerable public health risk to animals and humans globally. Vectors have integral roles in autochthonous circulation and dissemination of VBVDs worldwide. The interplay of agricultural activities, population expansion, urbanization, host/pathogen evolution, and climate change, all contribute to the continual flux in shaping the epidemiology of VBVDs. In recent decades, VBVDs, once endemic to particular countries, have expanded into new regions such as Iran and its neighbors, increasing the risk of outbreaks and other public health concerns. Both Iran and its neighboring countries are known to host a number of VBVDs that are endemic to these countries or newly circulating. The proximity of Iran to countries hosting regional diseases, along with increased global socioeconomic activities, e.g., international trade and travel, potentially increases the risk for introduction of new VBVDs into Iran. In this review, we examined the epidemiology of numerous VBVDs circulating in Iran, such as Chikungunya virus, Dengue virus, Sindbis virus, West Nile virus, Crimean–Congo hemorrhagic fever virus, Sandfly-borne phleboviruses, and Hantavirus, in relation to their vectors, specifically mosquitoes, ticks, sandflies, and rodents. In addition, we discussed the interplay of factors, e.g., urbanization and climate change on VBVD dissemination patterns and the consequent public health risks in Iran, highlighting the importance of a One Health approach to further surveil and to evolve mitigation strategies. Full article

Phleboviruses are classified into two main groups: the sandfly fever group (transmitted by sandflies and mosquitoes) and the Uukuniemi group (transmitted by ticks). Old World sandfly-borne viruses (SBVs) are classified into four main serocomplexes; sandfly fever Naples viruses (SFNVs), sandfly fever Sicilian viruses (SFSVs), Karimabad viruses (KARVs), and Salehabad viruses (SALVs). This study addresses current knowledge gaps on SBVs in Iran by focusing on identification and molecular epidemiology. We used PCR to examine DNA/RNA extracts to identify sandfly species and evaluate for SBV presence. We identified five specimens positive for phleboviruses: one Ph. sergenti for Tehran virus (TEHV), one Ph. papatasi for SFSV, and two Ph. papatasi and one Ph. perfiliewi for KARV. A phylogenetic tree indicated that the TEHV isolate from this study formed a cluster with previous isolates of TEHV, Zerdali virus, and Fermo virus. Meanwhile, the identified SFSV isolate fell in lineage I and was grouped with previous isolates of SFSVs and Dashli virus in Iran. Finally, the KARV isolates from this study formed a monophyletic clade in a sister relationship with other viruses in KARV lineages I and II. This comprehensive study on SBVs in Iran provided new insights into the molecular epidemiology of TEHV, SFSVs and KARVs in this country. Full article

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. Full article

The number of newly described sandfly-borne phleboviruses has been steadily growing in recent years. Some phleboviruses are human pathogens, but their health relevance is largely uncharacterized. We aimed to investigate the circulation of these viruses in the Emilia-Romagna region where several have already been described. A total of 482 sandflies were collected in a site in Reggio Emilia in 2019 and 2020. Sandflies collected in 2020 were grouped in 21 pools with a maximum of 25 sandflies per pool, submitted to real time PCR, and isolated in Vero cell culture. Complete genome sequencing showed the isolation of a strain of a Ponticelli III virus. This virus, which belongs to the species Adana phlebovirus, differed in the M segment from the Ponticelli I and Ponticelli II viruses. Analysis performed on the genomic segments of the newly isolated virus compared with other phleboviruses highlighted a strong purifying selection in the L segments, and different substitution saturation, highest in the M segments. Future research should address the ecological processes driving the occurrence of these novel phleboviruses and their possible impact on public health. Full article

According to ICTV, there are currently 66 known phlebovirus species. More than 40 of these viruses were isolated or detected in phlebotomine sandflies and some of them are known pathogens. In Portugal, information about sandfly-borne phleboviruses is scarce and scattered sandfly-borne diseases are neglected and often not considered in differential diagnoses. The main objective of this work was to gather the existing information and to raise awareness about the circulating phleboviruses in this country. To date, Massilia and Alcube phleboviruses have been isolated from sandflies in southern Portugal. Human infections with Toscana and Sicilian phleboviruses have been reported, as well as seroprevalence in cats and dogs. More studies are needed in order to understand if the viruses isolated during the entomological surveys have an impact on human health and to fully understand the real importance of the already recognized pathogens in our country. Full article

Phlebotomine sandflies are important vectors of Leishmania spp. and phleboviruses causing disease in animals and humans. Morphological identification of phlebotomine sandflies to the species level is challenging, requiring microscopical examination of the genitalia, which is demanding and time consuming. Molecular sandfly species identification can be a practical solution to save resources since it enables further molecular studies capable of generating data, such as biting preferences by blood meal analysis. In this study, resorting to a sandfly dataset collected between 2014 and 2018 across Portuguese territory under active mosquito surveillance and sandfly specific surveys, we used molecular methods to explore the genetic diversity and spatial distribution, further exploring ecological co-variants of four sandfly species—Phlebotomus ariasi, P. perniciosus, P. sergenti, and Sergentomyia minuta—all of which are of public health importance. Sandflies were collected from Spring to Autumn (May–November) following local temperature patterns. P. perniciosus was the most widespread detected species, with a nationwide distribution. All studied species clustered together with known samples from the Iberian Peninsula. Further monitoring studies of sandfly species diversity, distribution, and seasonality are essential for surveillance and control of sandfly-borne pathogens both nationally and globally. Full article

Sandfly-borne phleboviruses (phylum Negarnavaricota, realm Riboviria, kingdom Orthornavirae, genus Phlebovirus) comprise three genome segments of ribonucleic acid (RNA) and which encode an RNA-dependent RNA polymerase, which they use to transcribe the viral RNA genome into messenger RNA and to replicate the genome. At least some of these viruses cause mild 3-day fevers in humans but some also have been associated with more severe illnesses in humans. The 67 recognized phleboviruses are listed here in a table composed by the authors from International Committee on Taxonomy of Viruses reports as well as the scientific literature. Full article

We report the isolation of a newly recognized phlebovirus, Hedi virus (HEDV), from Phlebotomus chinensis sandflies collected in Shanxi Province, China. The virus’ RNA is comprised of three segments. The greatest amino acid sequence similarity of the three gene segments between this virus and previously recognized phleboviruses is 40.85–63.52%, and the RNA-dependent RNA polymerase (RdRp) amino acid sequence has the greatest similarity (63.52%) to the Rift Valley fever virus (RVFV) ZH-548 strain. Phylogenetic analysis of the amino acid sequence of the virus RdRp indicated that HEDV is close to RVFV and distinct from other phleboviruses, forming its own evolutionary branch. We conclude that it is necessary to increase the monitoring of phleboviruses carried by sandflies in China. Full article

Toscana phlebovirus (TOSV) and Sicilian phlebovirus (SFSV) are endemic in the Mediterranean area where they are transmitted to humans by infected sandflies. Vertebrates of several species have been postulated to act as reservoirs of these viruses, but convincing evidence is still awaited. Among them, bats have been suggested, however documented evidence is lacking. Here we tested a total of 329 bats belonging to eight species collected from twelve localities in southern Spain for the presence of neutralizing antibodies specific to TOSV and SFSV. Positive sera were detected in Schreiber’s long-fingered bat (Miniopterus schreibersii), mouse-eared Myotis (Myotis myotis), European free-tailed bat (Tadarida teniotis), and common serotine (Eptesicus serotinus) with the latter showing the highest prevalence rates for SFSV (22.6%) and TOSV (10%). There was no difference between females and males. Results suggest that bats are not likely to play a major role in the natural cycle of these two sandfly-borne phleboviruses. However, large breeding colonies of bats can be used as sentinels for surveillance of the presence of such viruses in a given locality. In addition, capture–recapture studies should be initiated in order to understand better the dynamics of TOSV and SFSV in bat populations. Full article

Toscana virus (TOSV) is an arthropod-borne virus, transmitted to humans by phlebotomine sandflies. Although the majority of infections are asymptomatic, neuroinvasive disease may occur. We report three cases of neuroinvasive TOSV infection detected in Croatia. Two patients aged 21 and 54 years presented with meningitis, while a 22-year old patient presented with meningoencephalitis and right-sided brachial plexitis. Cerebrospinal fluid (CSF), serum, and urine samples were collected and tested for neuroinvasive arboviruses: tick-borne encephalitis, West Nile, Usutu, TOSV, Tahyna, and Bhanja virus. In addition, CSF and serum samples were tested for the anti-viral cytokine response. High titers of TOSV IgM (1000–3200) and IgG (3200−10,000) antibodies in serum samples confirmed TOSV infection. Antibodies to other phleboviruses (sandfly fever Sicilian/Naples/Cyprus virus) were negative. CSF samples showed high concentrations of interleukin 6 (IL-6; range 162.32−2683.90 pg/mL), interferon gamma (IFN-γ; range 110.12−1568.07 pg/mL), and IL-10 (range 28.08−858.91 pg/mL), while significantly lower cytokine production was observed in serum. Two patients recovered fully. The patient with a brachial plexitis improved significantly at discharge. The presented cases highlight the need of increasing awareness of a TOSV as a possible cause of aseptic meningitis/meningoencephalitis during summer months. Association of TOSV and brachial plexitis with long-term sequelae detected in one patient indicates the possibility of more severe disease, even in young patients. Full article

Sandfly-borne phleboviruses pathogenic to humans, such as Toscana virus (TOSV) and sandfly fever Sicilian virus (SFSV), are endemic in the Mediterranean region. In France, several autochthonous cases of TOSV infection have been described which cause either meningitis or encephalitis. The aim of the present study was to estimate the seroprevalence of TOSV and SFSV antibodies in a healthy population from Corsica. In this cross-sectional study, participants were enrolled from the medical staff at University of Corsica Pasquale Paoli (UCPP) and from general practitioners of the Corsican Sentinelles Network. The seroprevalence study was based on virus microneutralization (MN). A total of 240 patients were tested for TOSV and SFSV. Altogether, 54 serum samples were confirmed for TOSV infection (seroprevalence = 22.5%). None of the samples were positive for SFSV (0/240). The main place of residence was significantly associated with TOSV seropositivity (p-value = 0.005). The overall rate of TOSV antibody seroprevalence observed in our study suggests a more intense circulation of TOSV in Corsica, with a rate significantly higher than the 8.7% reported in Corsica in 2007 from blood donors. The absence of seropositivity to SFSV seems to confirm the low circulation of this virus in Corsica and in continental France. The increasing circulation of TOSV reported here should encourage the implementation of surveillance systems to control phlebovirus infection. Full article

The sandfly-borne Toscana phlebovirus (TOSV), a close relative of the sandfly fever Sicilian phlebovirus (SFSV), is one of the most common causes of acute meningitis or meningoencephalitis in humans in the Mediterranean Basin. However, most of human phlebovirus infections in endemic areas either are asymptomatic or cause mild influenza-like illness. To date, a vertebrate reservoir for sandfly-borne phleboviruses has not been identified. Dogs are a prime target for blood-feeding phlebotomines and are the primary reservoir of human sandfly-borne Leishmania infantum. However, there are no definitive studies to assess whether dogs play a significant role as a reservoir host for human phlebovirus survival in the environment. Here, we have evaluated the susceptibility of domestic dogs to infection by TOSV and SFSV following the direct inoculation of the infectious virus. After experimental infection, the presence of viral RNA was investigated in plasma, urine, saliva, conjunctiva, faeces, semen, and bone marrow samples from 0 to 91 days postinoculation (dpi), as well as in plasma, saliva, and tears samples at 760 dpi. None of the challenged dogs developed clinical signs of infection with either TOSV or SFSV. SFSV RNA was never detected. TOSV RNA was not in any of the specimen types, except for plasma samples that showed low viral loads, although irregularly. None of the dogs developed detectable neutralizing antibodies after a single challenge dose of either TOSV or SFSV. However, a second challenge dose of virus given 56 days later elicited neutralizing antibodies, implying that the first inoculation of virus primed the animals for an anamnestic response following the second challenge. These results demonstrated that healthy domestic dogs are not highly susceptible to infection by TOSV or SFSV and do not develop significant viremia or excrete virus following infection. Consequently, dogs are unlikely natural reservoir hosts of infection and do not appear to play a significant role in phlebovirus transmission cycles. Full article

Phlebotomine sand fly-borne pathogens such as Leishmania spp. and phleboviruses are emerging threats to humans and animals worldwide. The aim of this work was to evaluate the exposure of cats from Portugal to Toscana virus (TOSV) and Sandfly Fever Sicilian virus (SFSV) and assess the associated risk factors. The possible association between exposure to Phlebotomus perniciosus saliva with TOSV and SFSV was also investigated. Out of 369 cats tested, 18 (4.9%, n = 365) were seropositive for TOSV, and eight (2.2%, n = 367) were seropositive for SFSV. Multivariate logistic regression analysis showed that cats presenting clinical signs that were compatible with leishmaniosis and antibodies to TOSV had a significantly higher risk of being SFSV seropositive. The presence of antibodies to sand fly-borne viruses in cats indicate that these animals are frequently exposed to sand flies and transmitted pathogens. Data suggest that cats can be used to qualitatively monitor human exposure to TOSV and SFSV in endemic areas. The clinical impact of SFSV in cats’ health should be investigated. The identification of the sand fly species responsible for the circulation of TOSV and SFSV in nature and the evaluation of the vectorial competence of P. perniciosus to SFSV should also be addressed. Full article