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Shuni virus is associated with neurologic and febrile illness in animals and humans. To determine potential vectors, we collected mosquitoes in South Africa and detected the virus in species of the genera Mansonia, Culex, Aedes, and Anopheles. These mosquitoes may be associated with Shuni virus outbreaks in Africa and emergence in other regions.

International audience; Oropouche fever is a zoonotic dengue-like syndrome caused by Oropouche virus. In August–September 2020, dengue-like syndrome developed in 41 patients in a remote rainforest village in French Guiana. By PCR or microneutralization, 23 (82.1%) of 28 tested patients were positive for Oropouche virus, documenting its emergence in French Guiana.

We screened nonequine animals with unexplained neurologic signs or death in South Africa during 2010-2018 for Shuni virus (SHUV). SHUV was detected in 3.3% of wildlife, 1.1% of domestic, and 2.0% of avian species. Seropositivity was also demonstrated in wildlife. These results suggest a range of possible SHUV hosts in Africa.

We report the discovery of a new orthobunyavirus, Cristoli virus, by means of shotgun metagenomics. The virus was identified in an immunodepressed patient with fatal encephalitis. Full-length genome sequencing revealed high-level expression of a virulence factor, possibly explaining the severity of the infection. The patient’s recent history suggests circulation in France.

Despite the lack of evidence for symptomatic human infection with Maguari virus (MAGV), its close relation to Cache Valley virus (CVV), which does infect humans, remains a concern. We sequenced the complete genome of a MAGV-like isolate (OBS6657) obtained from a febrile patient in Pucallpa, Ucayali, Peru, in 1998. To facilitate its classification, we generated additional full-length sequences for the MAGV prototype strain, 3 additional MAGV-like isolates, and the closely related CVV (7 strains), Tlacotalpan (1 strain), Playas (3 strains), and Fort Sherman (1 strain) viruses. The OBS6657 isolate is similar to the MAGV prototype, whereas 2 of the other MAGV-like isolates are located on a distinct branch and most likely warrant classification as a separate virus species and 1 is, in fact, a misclassified CVV strain. Our findings provide clear evidence that MAGV can cause human disease.

In 2015 and 2016, we observed 15 malformed calves that were exposed to intrauterine infection with Shamonda virus, a Simbu serogroup orthobunyavirus, in Japan. Characteristic manifestations were arthrogryposis and gross lesions in the central nervous system. Our results indicate that this arbovirus should be considered a teratogenic virus in ruminants.

A recent report suggested that 2 novel bunyaviruses discovered in insects in Côte d’Ivoire caused lethal disease in swine in South Korea. We conducted cell culture studies and tested serum from pigs exposed to mosquitoes in Côte d’Ivoire and Ghana and found no evidence for infection in pigs.

Infection with La Crosse virus can cause meningoencephalitis, but it is not known to cause acute flaccid paralysis (AFP). During 2008-2014, nine confirmed or probable La Crosse virus disease cases with possible AFP were reported in Ohio, USA. After an epidemiologic and clinical investigation, we determined no patients truly had AFP.

We conducted phylogeographic modeling to determine the introduction and spread of Guaroa virus in South America. The results suggest a recent introduction of this virus into regions of Peru and Bolivia over the past 60–70 years and emphasize the need for increased surveillance in surrounding areas.

We performed a serologic investigation to determine whether orthobunyaviruses commonly infect humans in the Yucatan Peninsula of Mexico. Orthobunyavirus-specific antibodies were detected by plaque reduction neutralization test in 146 (18%) of 823 persons tested. Further studies are needed to determine health risks for humans from this potentially deadly group of viruses.

To determine which agents cause neurologic disease in horses, we conducted reverse transcription PCR on isolates from of a horse with encephalitis and 111 other horses with acute disease. Shuni virus was found in 7 horses, 5 of which had neurologic signs. Testing for lesser known viruses should be considered for horses with unexplained illness.

In 2011, an unidentified disease in cattle was reported in Germany and the Netherlands. Clinical signs included fever, decreased milk production, and diarrhea. Metagenomic analysis identified a novel orthobunyavirus, which subsequently was isolated from blood of affected animals. Surveillance was initiated to test malformed newborn animals in the affected region.

California serogroup (CSG) viruses, such as Jamestown Canyon and snowshoe hare viruses, are mosquitoborne pathogens that cause febrile illness and neurologic disease. Human exposures have been described across Canada, but infections are likely underdiagnosed. We describe a case of neuroinvasive illness in a New Brunswick, Canada, patient infected with a CSG virus.

An Oropouche virus strain was isolated from a novel host (Callithrix sp.) in Arinos, Minas Gerais State, southeastern Brazil. The virus was identified by complement fixation test and confirmed by reverse transcription–polymerase chain reaction. Phylogenetic analysis identified this strain as a genotype III isolate previously recognized only in Panama.

To the Editor: In 2011, Schmallenberg virus (SBV) emerged in Europe (1); the virus spread into France in January 2012 (2). During January–March 2012, a total of >1,000 cases were reported in France, mainly in stillborn and newborn lambs with congenital malformations. In March 2012, neurologic disorders were detected in five 15-day-old puppies (Belgian shepherd) from a dog breeding kennel in northwestern France (Orne). We report data suggesting that these puppies were infected with SBV. In June 2012, the kennel veterinarian contacted a veterinary school (Unite de Medecine de l’Elevage et du Sport Breeding and Sport Medicine Unit, Maisons-Alfort, France) after neurologic signs of ataxia, exotropia, a head tilt, and stunted growth were observed in a litter of 5 puppies. Four of the puppies had died at 5–6 weeks of age. The veterinarian collected blood samples from the surviving puppy at 3 months of age, and the puppy was euthanized for necropsy. Severe torticollis was observed during the necropsy, but no other macroscopic signs were detected. The brain, including the cerebellum; a part of the spine; and cerebrospinal fluid (CSF) were collected for further investigation. Specific PCR analyses for canine coronavirus, Neospora caninum, Toxoplasma gondii, and canine minute virus were performed on CSF; all test results were negative. The brain tissue was fixed in formalin and processed for histologic examination. Features of degenerative encephalopathy, including neuronal vacuolation, neuropil vacuolation, and minimal gliosis, were observed. Because some clinical signs were evocative of SBV infection and the puppy was born in an area where the virus was circulating actively in cattle and sheep, veterinarians decided to investigate SBV as a possible etiology. Serum samples from the 3-month-old puppy and the dam were tested by virus neutralization test (VNT), according to the protocol used for ruminant serum. The results were negative for the puppy but positive (titer 128) for the mother. Specific competitive SBV ELISA (IDVet, Montpellier, France) against the SBV N protein showed similar results. Real-time reverse transcription PCR (RT-PCR) was performed (3) to detect the presence of the SBV genome in the cerebellum. Because the sample was paraffin-embedded, RNA was extracted from 5-µm sections, as described (4). All of the extracted cerebellum sections had positive test results (cycle threshold range 33−36); the extraction and PCR controls all showed negative results. To confirm these positive results, conventional RT-PCR was used to amplify a 573-nt sequence of the SBV S segment. The amplification product was sequenced, and a BLAST analysis was performed (www.ncbi.nlm.nih.gov/BLAST). An identity of 100% was obtained with the SBV small gene segment from a ruminant (GenBank accession no. {"type":"entrez-nucleotide","attrs":{"text":"KC108860","term_id":"443498566","term_text":"KC108860"}}KC108860). An immunohistochemical assay was also performed; the result was negative. The remaining 7 female dogs in the breeding kennel were tested for SBV in October 2012; 1 showed positive test results by VNT (titer 256), which confirmed that SBV was circulating in the kennel. This positive dam had a litter of puppies in December 2012, but no signs developed, and the puppies were not tested. In March 2013, repeat testing was done on serum samples from the 2 dogs that had shown positive results. Results for both animals were positive by VNT (titers 32 for the dam and 128 for the other dog) and ELISA. Taken together, specific SBV antibodies in the mother and the SBV genome in her puppy suggest that these dogs experienced SBV infection. The absence of detectable SBV antibodies in the puppy in this investigation suggests that transplacental infection occurred before the onset of fetal immune competence. Maternal infection probably occurred in January or February 2012; entomologic monitoring conducted in France showed the presence of Culicoides spp. midges, a vector of SBV, during this period in northwestern France. In addition, because the puppies were born in March 2012 and SBV antibodies were still detectable in the mother in March 2013, the duration of SBV antibodies in dogs appears to be >1 year. In cattle and sheep, the SBV genome persists in an infected fetus and is detectable after birth by real-time RT-PCR, despite gestation length (5,6). Few reports on orthobunyavirus infections in dogs are available. Two serologic studies from the United States (7) and Mexico (8) found antibodies against La Crosse virus, South River virus, and Jamestown Canyon virus in dogs. Two other reports described cases in which La Crosse virus was detected in canine littermates who had clinical encephalitis (9) or neurologic disorders (10). It is unclear if the apparent SBV infection we detected in these dogs was an isolated event or if other cases occurred elsewhere but were not detected because they were not investigated. Further serologic and clinical surveys are needed to estimate SBV prevalence in dogs and the virus’ involvement in the occurrence of neurologic signs in puppies.

Reemergence of Schmallenberg virus (SBV) occurred among lambs (n = 50) in a sheep flock in Belgium between mid-July and mid-October 2012. Bimonthly assessment by quantitative reverse transcription PCR and seroneutralization demonstrated that 100% of lambs were infected. Viremia duration may be longer in naturally infected than in experimentally infected animals.

Schmallenberg virus was detected in cattle and sheep in northwestern Europe in 2011. To determine whether wild ruminants are also susceptible, we measured antibody seroprevalence in cervids (roe deer and red deer) in Belgium in 2010 and 2011. Findings indicated rapid spread among these deer since virus emergence ≈250 km away.