Prevalence and genetic diversity of Shibuyunji virus, a novel tick-borne phlebovirus identified in Zambia.

Tick-borne pathogens are an emerging public health threat worldwide. However, information on tick-borne viruses is scanty in sub-Saharan Africa. Here, by RT-PCR, 363 ticks (Amblyomma, Hyalomma and Rhipicephalus) in the Namwala and Livingstone districts of Zambia were screened for tick-borne phleboviruses (TBPVs). TBPVs (L gene) were detected in 19 (5.2%) Rhipicephalus ticks in Namwala. All the detected TBPVs were Shibuyunji viruses. Phylogenetically, they were closely related to American dog tick phlebovirus. This study highlights the possible role of Rhipicephalus ticks as the main host of Shibuyunji virus and suggests that these viruses may be present outside the area where they were initially discovered.

Four Year Surveillance of the Vector Hard Ticks for SFTS, Ganghwa-do, Republic of Korea.

The seasonal abundance of hard ticks that transmit severe fever with thrombocytopenia syndrome virus was monitored with a collection trap method every April to November during 2015-2018 and with a flagging method every July and August during 2015-2018 in Ganghwa-do (island) of Incheon Metropolitan City, Republic of Korea. This monitoring was performed in a copse, a short grass field, coniferous forest and broad-leaved forest. A total of 17,457 ticks (8,277 larvae, 4,137 nymphs, 3,389 females, and 1,654 males) of the ixodid ticks comprising 3 species (Haemaphysalis longicornis, H. flava, and Ixodes nipponensis) were collected with collection traps. Of the identified ticks, H. longicornis was the most frequently collected ticks (except larval ticks) (94.26%, 8,653/9,180 ticks (nymphs and adults)), followed by H. flava (5.71%, 524/9,180) and Ix. nipponensis (less than 0.04%, 3/9,180). The ticks collected with collecting traps were pooled and assayed for the presence of SFTS virus with negative results. In addition, for monitoring the prevalence of hard ticks, a total of 7,461 ticks (5,529 larvae, 1,272 nymphs, 469 females, and 191 males) of the ixodid ticks comprising 3 species (H. longicornis, H. flava, and Ix. nipponensis) were collected with flagging method. H. longicornis was the highest collected ticks (except larval ticks) (99.53%, 1,908/1,917 ticks (nymphs and adults)), followed by H. flava (1.15%, 22/1,917).

[Recent topics in the research field of severe fever with thrombocytopenia syndrome (SFTS)].

Seven years have passed since the discovery of a novel infectious disease, severe fever with thrombocytopenia syndrome (SFTS) caused by a novel Phlebovirus, SFTS virus (SFTSV), in PR China. It was also confirmed that SFTS was endemic to Japan through an identification of a woman, who died of SFTSV infection in Yamaguchi prefecture in late 2012. Approximately 6 years have passed since the discovery of SFTS-endemicity in Japan. At present, SFTS is endemic to PR China, South Korea and western Japan. SFTSV is maintained between several species of ticks such as Haemaphysalis longicornis and wild and domestic animals in nature. Therefore, we cannot escape from the risk of being infected with SFTSV. Based on the similarity in the characteristics of the clinical symptoms including the high case fatality rate, mode of infection to humans, pathology and virology between SFTS and Crimean-Congo hemorrhagic fever (CCHF), SFTS should be classified as viral hemorrhagic fever. Although the time from the discovery of SFTS is still short, there have been many scientific reports on the epidemiological, clinical, and/or pathological, and virological studies on SFTS. Favipiravir was reported to show an efficacy in the prevention and treatment of SFTSV infections in an animal model. A clinical study to evaluate the efficacy of favipiravir in the treatment of SFTS patients has been initiated in Japan. Specific and effective treatment with antiviral drugs for and preventive measures of SFTS with vaccination shoued be developed through scientific, clinical, and basic research.

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.

Isolation, full genomic characterization and neutralization-based human seroprevalence of Medjerda Valley virus, a novel sandfly-borne phlebovirus belonging to the Salehabad virus complex in northern Tunisia.

A new phlebovirus, Medjerda Valley virus (MVV), was isolated from one pool of Phlebotomus sp. (Diptera; Psychodidae) sandflies trapped in the vicinity of the Utique site, northern Tunisia. Genetic analysis based on complete coding of genomic sequences of the three RNA segments indicated that MVV is most closely related to members of the Salehabad virus species, where it is the fourth virus for which the complete sequence is available. A seroprevalence study was performed to search for neutralizing antibodies in human sera in the same region. The results demonstrate that in this area, MVV can readily infect humans despite low seroprevalence rates. Salehabad species viruses have generally been considered to be a group of viruses with little medical or veterinary interest. This view deserves to be revisited according to our human seroprevalence results, together with high animal infection rate of Adana virus and recent evidence of human infection with Adria virus in Greece. Further studies are needed to investigate the capacity of each specific member of the Salehabad virus species to cause human or animal diseases.

Severe fever with thrombocytopenia syndrome virus in ticks collected from humans, South Korea, 2013.

We investigated the infection rate for severe fever with thrombocytopenia syndrome virus (SFTSV) among ticks collected from humans during May-October 2013 in South Korea. Haemaphysalis longicornis ticks have been considered the SFTSV vector. However, we detected the virus in H. longicornis, Amblyomma testudinarium, and Ixodes nipponensis ticks, indicating additional potential SFTSV vectors.

The yield of temporary exclusion of blood donors, exposed to emerging infections abroad.

BACKGROUND AND OBJECTIVES: Emerging infections abroad pose a threat to the safety of blood, donated by travelling blood donors. In this study, the yield of donor deferral after travelling was evaluated, by comparing the estimated numbers of infected donors returning from various affected areas. METHODS: A deterministic model was applied to calculate the number of infected donors, returning from six areas affected by outbreaks: Greece - Macedonia (West Nile fever), Italy - Emilia Romagna (West Nile fever), Thailand (chikungunya), Latvia (hepatitis A), central Turkey (Sicilian sandfly fever) and Italy - Tuscany (Toscana sandfly fever). RESULTS: The estimated number of infections among returning blood donors was surprisingly low, ranging from 0·32 West Nile virus-infected donors per year returning from Macedonia (Greece) to approximately 0·005 infected donors per year returning respectively from Tuscany (sandfly fever), Latvia (hepatitis A) and central Turkey (sandfly fever). CONCLUSION: The yield of the temporary exclusion of blood donors travelling to a specific, affected area is low, but the continuous monitoring of emerging infections and the timely assessment of new threats are laborious and imperfect. Safety measures may be instituted after the greatest threat of a new outbreak has passed. A general deferral of travelling donors may be more appropriate than targeted measures. It can be argued that all donors who stayed outside their country or continent of residency should be deferred for 4 weeks.

[Severe fever with thrombocytopenia syndrome in Japan].

Severe fever with thrombocytopenia syndrome (SFTS) is characterized by sudden onset of fever, leukopenia, thrombocytopenia, and gastrointestinal tract symptoms and approximately 12% of patients die from disseminated intravascular coagulation and/or multiple organ failures. Agent of the disease is a novel bunyavirus SFTS virus, and is transmitted by bite of a possible vector tick, Haemaphysalis longicornis, and through direct contact with virus-containing patient body fluids, or through unknown routes. SFTS case reports have been limited in China, and more than two thousand cases were reported in 2011 and 2012. In late 2012, a woman living in Yamaguchi prefecture in Japan showed symptoms reminiscent of those of SFTS and died 6 days after the onset of symptoms. Virus was isolated from her acute serum in Vero cells and a next generation-sequencing identified it as SFTS virus. SFTS viral genome and proteins were detected in the patient's serum. Based on the first demonstration of SFTS in Japan, a retrospective study started. Until March of 2013, totally 8 patients were diagnosed as having SFTS and the most early case was in 2005. Phylogenetic analysis of virus sequences revealed that Japanese isolates form an independent branch distinct from Chinese isolates, indicating that SFTS has been present not only in China but also in Japan.

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.

First detection of Leishmania infantum in Phlebotomus kandelakii using molecular methods in north-eastern Islamic Republic of Iran.

Shirvan district in north-eastern Islamic Republic of Iran is a new focus of visceral leishmaniasis. This study aimed to identify the vector(s), the parasite and the species composition of sand flies in the district during July-September 2009 using polymerase chain reaction techniques. In all, 2088 sand flies were collected from 3 villages. Nine sand fly species were identified: Phlebotomus kandelakii (Shchurenkova), P. major (Annandale), P. halepensis (Theodor), P. papatasi (Scopoli), P. sergenti (Parrot), P. longidactus (Parrot), P. caucasicus (Marzinovsky), Sergentomyia sintoni (Pringle) and S. sumbarica (Perfil'ev). P. sergenti and P. kandelakii were the most prevalent Phlebotomus species at 31.3% and 10.0% respectively. Of 59 female P. kandelakii, 2(3.4%) were naturally infected with L. infantum. This is the first finding of natural infection of P. kandelakii by L. infantum in this region suggesting P. kandelakii may be the vector of L. infantum in the area although it is the second most prevalent phlebotomine species.

[An overview of Toscana virus infections]. / Toskana Virus Enfeksiyonlarina Genel Bakis

Toscana virus which is an arbovirus transmitted to humans by sandflies (Phlebotomus spp.), can cause febrile illness and meningitis mainly during summer. It has a tropism for central nervous system and is a major cause of meningitis and encephalitis in endemic countries. Majority of the clinical and epidemiologic studies on Toscana virus have been reported from Italy, France, Spain, Portugal and other Mediterranean countries. Although Toscana virus infections has been identified, data on virus activity in Turkey are limited. In this review article, the epidemiological, clinical and laboratory features of Toscana virus as a cause of febrile diseases, meningitis and encephalitis during summer in Turkey were discussed.

Seroprevalence of Toscana Virus and Sandfly Fever Sicilian Virus in European Bat Colonies Measured Using a Neutralization Test.

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.

Clinically Important Phleboviruses and Their Detection in Human Samples.

The detection of phleboviruses (family: Phenuiviridae) in human samples is challenged by the overall diversity and genetic complexity of clinically relevant strains, their predominantly nondescript clinical associations, and a related lack of awareness among some clinicians and laboratorians. Here, we seek to inform the detection of human phlebovirus infections by providing a brief introduction to clinically relevant phleboviruses, as well as key targets and approaches for their detection. Given the diversity of pathogens within the genus, this report focuses on diagnostic attributes that are generally shared among these agents and should be used as a complement to, rather than a replacement of, more detailed discussions on the detection of phleboviruses at the individual virus level.

Isolation and Identification of a Novel Phlebovirus, Hedi Virus, from Sandflies Collected in China.

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.

Co-Circulation of Phleboviruses and Leishmania Parasites in Sand Flies from a Single Site in Italy Monitored between 2017 and 2020.

Sand flies transmit Leishmania infantum, which is responsible for causing leishmaniasis, as well as many phleboviruses, including the human pathogenic Toscana virus. We screened sand flies collected from a single site between 2017 and 2020 for the presence of both phleboviruses and Leishmania. The sand flies were sampled with attractive carbon dioxide traps and CDC light traps between May and October. We collected more than 50,000 sand flies; 2826 were identified at the species level as Phlebotomus perfiliewi (98%) or Phlebotomus perniciosus (2%). A total of 16,789 sand flies were tested in 355 pools, and phleboviruses were found in 61 pools (6 Toscana virus positive pools, 2 Corfou virus positive pools, 42 Fermo virus positive pools, and 7 Ponticelli virus positive pools, and 4 unidentified phlebovirus positive pools). Leishmania was found in 75 pools and both microorganisms were detected in 16 pools. We isolated nine phleboviruses from another 2960 sand flies (five Ponticelli viruses and for Fermo viruses), not tested for Leishmania; the complete genome of a Fermo virus isolate was sequenced. The simultaneous detection in space and time of the Fermo virus and L. infantum is evidence that supports the co-circulation of both microorganisms in the same location and partial overlap of their cycles. A detailed characterization of the epidemiology of these microorganisms will support measures to limit their transmission.

Differences in the salivary effects of wild-caught versus colonized Phlebotomus papatasi (Diptera: Psychodidae) on the development of zoonotic cutaneous leishmaniasis in BALB/c mice.

Preimmunization of mice with salivary gland homogenate (SGH) of long-term colonized (F29) female Phlebotomus papatasi Scopoli (Diptera: Psychodidae) induced protection against Leishmania major Yakimoff & Schokhor (Kinetoplastida: Trypanosomatidae) co-inoculated with the same type of SGH. In contrast, preimmunization of mice with SGH of wild-caught female P. papatasi did not confer protection against L. major co-inoculated with the same type of SGH. Similarly, SGH from recently colonized (F1) female P. papatasi did not protect mice against L. major. These results suggest that when developing a sand fly saliva-based vaccine, the natural vector populations should be considered.

[Sandfly fever outbreak in a province at Central Anatolia, Turkey]. / Kirikkale ilinde saptanan tatarcik hummasi salgini

Sandfly fever virus (SFV), which is classified in Phlebovirus genus, Bunyaviridae family, is widely seen in the Middle East and Mediterranean basin. SFV has four serotypes known as Sicilian (SFSV), Cyprus (SFCV), Naples (SFNV) and Toscana virus (TOSV). Sandfly fever, which is transmitted to human by different species of sandflies, especially Phlebotomus spp., starts with acute onset of high fever and lasts for three days. Headache, anorexia and myalgia are the most common symptoms. The aim of this study was to present the clinical and laboratory findings of the patients who were diagnosed during sandfly fever outbreak in Kirikkale province (located in central Anatolia in Turkey) during July 2009. A total of 20 patients from different districts of Kirikkale province with the history of fly bite and with the clinical findings of fever, myalgia-arthralgia, headache, conjunctival hyperemia and gastrointestinal symptoms such as diarrhea and nausea-vomiting were admitted to the Infectious Disease Unit of State Hospital. All the patients were followed up after hospitalization. A sandfly fever outbreak has been considered in the area since the cases shared a common history of insect bite, similar clinical and laboratory features in a particular time interval. The first patients from each different districts were accepted as the "index case" and 11 patients' serum samples have been sent to Refik Saydam National Public Health Agency, Virology Reference and Research Laboratory, Ankara. Serum samples were analyzed by using a commercial mosaic immunofluorescence test (IFT) (Euroimmun, Germany) to detect IgM and IgG antibodies against SFSV, SFCV, SFNV and TOSV. SFV-IgM positivity was demonstrated in 8 out of 11 patients (Naples virus in 5, Sicilian virus in 3 cases), while all of the cases were IgG negative. Of seropositive patients, two were female and six were male with a mean age of 30.7 (age range: 16-53) years. Sandfly fever was diagnosed in five cases by the positive IgM results and in three cases by the detection of IgM seroconversion in the second samples collected 6 days later. Clinically, fever and myalgia-arthralgia were detected in all of the cases, diarrhea and nausea-vomiting in 7, headache in 5 and conjunctival hyperemia in 1 of 8 seropositive patients. The evaluation of laboratory findings revealed leukopenia (1800-3800 cell/µl) in all cases, thrombocytopenia (69000-140.000 cell/µl) in 7, elevated AST (42-271 IU/L) in 7, elevated ALT (46-173 IU/L) in 5, elevated CK (185-1560 U/L) in 6 and elevated CRP (5.18-83.6 mg/L in 5 of 8 patients. All the patients were treated symptomatically without any sequella and discharged with complete cure. Turkey is a country in the Mediterranean basin and it is known that there is a favorable sandfly fauna in Anatolia. Therefore sandfly fever should be considered in patients presenting with fever and arthralgia-myalgia and with a history of insect bite especially during summer months.

Sand fly fever: what have we learned in one hundred years?

Sand fly fever has severely impacted military missions in southern Europe and the Middle East for hundreds of years. After a brief respite following the malaria eradication programs of World War II, it has returned as a significant disease among residents in and travelers to the Mediterranean rim. It is a more severe disease now, with potential vectors in the United States. Sand fly fever is discussed in terms of its viruses, vectors, disease, control, and potential domestic impact.

Nosocomial person-to-person transmission of severe fever with thrombocytopenia syndrome.

OBJECTIVES: This study is an epidemiologic investigation of nosocomial severe fever with thrombocytopenia syndrome virus (SFTSV) transmission among healthcare workers (HCWs) after contact with an index patient. The aim of this study was to determine whether exposure to blood or bloody respiratory secretion is associated with human-to-human transmission of SFTSV. METHODS: Eleven days after the index patient died, two HCWs who had close exposure to the patient presented with typical symptoms of SFTS. An epidemiological investigation was conducted on all 25 HCWs who had been in close contact with the index patient. Clinical and laboratory data were collected, and transmission rate before and after the index patient had haemorrhagic manifestations was analysed. RESULTS: Among 25 HCWs who had direct contact with the index patient, five HCWs were confirmed to have SFTS. All five HCWs had contact to blood or bloody respiratory secretions of the index patient without adequate use of personal protective equipment (PPE). No HCW with contact before haemorrhagic manifestations of the index patient contracted SFTS. Overall, the transmission rate was higher for HCWs who had contact after the index patient had haemorrhagic manifestations (33.3%, five of 15 HCWs, vs. 0%, zero of ten HCWs, p 0.041). CONCLUSIONS: In HCWs who are inadequately protected, person-to-person transmission of SFTSV may be associated with contact with blood or bloody respiratory secretions. Therefore, universal precaution and full PPE is highly recommended for protection against SFTSV when there are signs of bleeding.

Experimental Infection of Sand Flies by Massilia Virus and Viral Transmission by Co-Feeding on Sugar Meal.

Background: Massilia virus (MASV) is a phlebovirus isolated from Phlebotomus perniciosus in various regions of southwestern Europe. It is closely related to human pathogens such as Toscana virus and sandfly fever Naples virus. The natural cycle of phleboviruses is poorly understood. Indeed, experimental studies demonstrate that transovarial and sexual transmission are not efficient enough for the maintenance of the virus in nature and to date there is no convincing evidence that a species of vertebrates is the reservoir of the virus. Here, we studied various transmission routes of MASV taking advantage of experimental colonies representing different species of sand flies. Methodology/Principal findings: In P. perniciosus, four sources of infection were compared: (i) Virus-seeded larval food to the first instar larvae (L1), or (ii) to the fourth instar larvae (L4), (iii) virus-seeded blood meal to adult females, and (iv) virus-seeded sugar meal to adults of both sexes. From 875 adults emerged from infected L1 and L4, only three were positive. In females infected by bloodmeal the infection rate was high before defecation, then it decreased drastically; MASV RNA was detected in only 5 out of 27 post-defecation. Surprisingly, the most efficient route of infection was observed after intake of virus-seeded sugar meal: 72% of females (79/110) and 52% of males (51/99) were found to be MASV RNA-positive. In addition, MASV-infected sandflies regurgitated virus particules into the sugar drop and MASV RNA was detectable in this drop for at least 24 h after regurgitation. MASV RNA was detected in about one third of the P. perniciosus exposed to this sugar drop contaminated by regurgitation. Sugar meal infection was also tested with six other species of sand flies. In males, there were no significant differences in infection rates when compared to P. perniciosus. In females, most species tested showed high infection rate at the beginning but then significant gradual decrease in infection rate during the experiment. Conclusions/Significance: We present the first description of arboviral infection of a dipteran vector using sugar meal. In all seven sand fly species tested, MASV was detected for two weeks post-infection. Our results showed that MASV can be transmitted between P. perniciosus either through co-feeding or via an infected sugar source such as plant sap. These newly described routes of horizontal transmission may play an important role in the circulation of phleboviruses in nature.