Search

Bluetongue Virus (BTV) and Epizootic Hemorrhagic Disease Virus (EHDV) are Orbiviruses primarily transmitted by their biological vector, Culicoides spp. Latreille, 1809 (Diptera: Ceratopogonidae). These viruses can infect a diverse range of vertebrate hosts, leading to disease outbreaks in domestic and wild ruminants worldwide. This study, conducted at the Belo Horizonte Municipal Parks and Zoobotany Foundation (FPMZB-BH), Minas Gerais, Brazil, focused on Orbivirus and its vectors. Collections of Culicoides spp. were carried out at the FPMZB-BH from 9 December 2021 to 18 November 2022. A higher prevalence of these insects was observed during the summer months, especially in February. Factors such as elevated temperatures, high humidity, fecal accumulation, and proximity to large animals, like camels and elephants, were associated with increased Culicoides capture. Among the identified Culicoides spp. species, Culicoides insignis Lutz, 1913, constituted 75%, and Culicoides pusillus Lutz, 1913, 6% of the collected midges, both described as competent vectors for Orbivirus transmission. Additionally, a previously unreported species in Minas Gerais, Culicoides debilipalpis Lutz, 1913, was identified, also suspected of being a transmitter of these Orbiviruses. The feeding preferences of some Culicoides species were analyzed, revealing that C. insignis feeds on deer, Red deer (Cervus elaphus) and European fallow deer (Dama dama). Different Culicoides spp. were also identified feeding on humans, raising concerns about the potential transmission of arboviruses at the site. In parallel, 72 serum samples from 14 susceptible species, including various Cervids, collected between 2012 and 2022 from the FPMZB-BH serum bank, underwent Agar Gel Immunodiffusion (AGID) testing for BTV and EHDV. The results showed 75% seropositivity for BTV and 19% for EHDV. Post-testing analysis revealed variations in antibody presence against BTV in a tapir and a fallow deer and against EHDV in a gemsbok across different years. These studies confirm the presence of BTV and EHDV vectors, along with potential virus circulation in the zoo. Consequently, implementing control measures is essential to prevent susceptible species from becoming infected and developing clinical diseases. [ABSTRACT FROM AUTHOR]

Summary: Mosquito‐borne arboviruses are a major public health concern worldwide and are responsible for emerging and re‐emerging diseases. Taken together, the arboviruses have a strong impact on public health and are the most common causes of equine encephalitis. In‐depth diagnostic investigation of equine viral encephalitis is of utmost importance for the epidemiological surveillance and control of this disease. Regarding neurological disorders in equids, in April–May 2018, at least 12 cases of equid mortality with acute neurological signs were reported in six farms from Espirito Santo state, Brazil. To investigate the aetiological agent of this neurological disease outbreak, central nervous system (CNS) fragments from two horses and two donkeys were submitted for virologic diagnosis. Rabies, equine herpesvirus‐1, and arbovirus‐associated encephalomyelitis were investigated using differential diagnosis techniques. West Nile virus (WNV) was detected by nested RT‐PCR in CNS fragments from each of the four animals in the study and confirmed by nucleotide sequencing. This is the first case of neurological disease in equids confirmed to be associated with WNV infection in Brazil. This finding unveils a new and urgent field of research and the need to understand the epidemiological and clinical characteristics of the disease and the risk to public health. [ABSTRACT FROM AUTHOR]

Bovine vaccinia (BV), caused by Vaccinia virus (VACV), is a zoonosis characterized by exanthematous lesions in the teats of dairy cows and the hands of milkers and is an important public health issue. Severe VACV-induced lesions in the teats and udder of cows and buffaloes could lead to mastitis and other secondary infections, thereby reducing productivity and resulting in economic losses to the dairy industry. In Brazil, BV re-emerged in the late 1990s and is now endemic in most of the Brazilian territory. In the last 15 years, much effort has been made to know more about this disease and its epidemiology, etiologic agents, and interactions with the host and the environment. In this review, we describe the known dynamics of VACV infection in cattle and the viral shedding routes, as well as the relevance of BV for animal and public health. [ABSTRACT FROM AUTHOR]

Porcine circovirus 3 (PCV3) is an emerging virus that was first identified in the United States in 2016. Since its first detection, PCV3 has already been found in America, Asia, and Europe. Although PCV3 has already been described in Brazil, knowledge of its detection and sequence variation before 2016 is limited, as well as its distribution in the main swine producing regions of Brazil. In this study, 67 porcine clinical samples collected from nine states in Brazil between 2006 and 2007 were analyzed for PCV3 infection by PCR. Results showed that 47.8% of the samples were PCV3 positive, across all nine states. Of the PCV3-positive samples, 37.5% were also positive for PCV2. Interestingly, no clinical signs were associated with samples that were detected singularly with PCV3 infection. Moreover, the positive PCV3 rate in healthy pigs was higher (29.8%) than that found in unhealthy pigs (17.9%), suggesting that most pigs could live with PCV3 infection without any clinical sign in the analyzed samples. Nucleotide sequence analysis showed that PCV3 strains obtained in this study shared 94.44% to 99.83% sequence identity at the open reading frame 2 (ORF2) gene level with available strains from different countries. PCV3 Brazilian sequences collected in 2006 and 2007 shared 97.94% to 99.62% identity with the strains obtained in 2016. The results of neutrality and selective pressure tests indicated that the PCV3 Cap protein seems unable to tolerate high levels of variation on its sequence. Phylogenetic analysis grouped the Brazilian strains in PCV3a and PCV3b genotypes clusters, both including strains collected in America, Asia, and Europe. Taking the results together, multiple events of introduction of PCV3 may have occurred in Brazil, and Brazilian PCV3 strains may show genetic stability over the past 10 years. [ABSTRACT FROM AUTHOR]

Bovine vaccinia (BV) is a zoonosis caused by Vaccinia virus (VACV), which affects lactating cows and milkers. VACV DNA and infectious particles have been detected in milk of naturally infected cows. However, the period and pattern of VACV shedding in milk is unknown, as is whether the presence of VACV in milk is due to a localized or a systemic infection. To address those questions, eight lactating cows were inoculated with VACV in previously scarified teats. The experiment was divided in two phases. In Phase 1, milk samples were collected daily for 33 days, and in Phase 2, four animals from the first phase were immunosuppressed. In both phases, milk was collected with a sterile catheter on even days and by hand milking on odd days. All animals showed typical BV lesions in the inoculated teats. All milk samples were subjected to nested polymerase chain reaction (PCR) and real-time quantitative PCR to detect VACV DNA. PCR-positive samples were subjected to virus isolation. VACV DNA was intermittently detected in milk in both phases and infectious viral particles could be detected only in phase 2, on the 69th, 73rd, 74th, 77th, 79th, and 81st days postinfection. Despite the possibility of propagation of VACV through milk, it is known that milk continues to be drawn and marketed normally during outbreaks of the disease. The detection of both VACV DNA and infectious particles in milk samples draws attention to the potential public health risk associated with the consumption of milk from BV outbreaks. Detection of VACV in the milk from noninfected teats demonstrated that VACV shedding in milk might be related to a systemic infection. Moreover, it was shown that VACV DNA and viral infectious particles could be detected in milk even after healing of the lesions, demonstrating that VACV may cause a persistent infection in cattle.