Evaluation of nasal swab and nasal wipe for detection of Influenza A in swine using Bayesian latent class analysis.

Influenza A virus (IAV) is an important pathogen in Brazilian swine herds, and monitoring the viral circulation is essential to control and reduce the transmission. Surveillance programs for IAV are often based on individual piglets level sampling, making the evaluation of the available diagnostic tools crucial to assessing IAV circulation in herds. Thus, two sample collection methodologies were compared in pig herds in southern Brazil to detect IAV by RT-qPCR: nasal swab (NS) and nasal wipe (NW). A Bayesian latent class model (BLCM) was set for two tests and two populations. The NW and NS used are more specific (higher than 95 % for both) than sensitive. The sensitivity for NW was lower than the NS, 84.14 % (70 % - 95 %; posterior probability interval (PPI): 95 %) and 87.15 % (73 % - 97 %; PPI: 95 %), respectively, and the specificity was 95 % (90 % - 99 %; PPI: 95 %) and 99 % (96 % - 100 %; PPI: 95 %), respectively. Although the wipe sample collection loses both sensitivity and specificity compared with nasal swab, differences in test performance were very limited and PPIs largely overlapped. Therefore NW can also be considered a valuable tool. The decision about the use of both techniques should be based on the trade-off between their performance limitations and feasibility in routine monitoring.

One health approach for the surveillance of novel swine viral diseases / Uma abordagem de saúde única para a vigilância de novas doenças virais de suínos

The novel coronavirus pandemic highlighted the importance of discussing and monitoring emerging diseases to scientific society, particularly in the case of zoonotic diseases. Diseases emerge in nature and infect living beings current on all continents, even in the current scenario of biomedical research evolution. Among the most studied emerging animal diseases are the swine viral diseases, due to their high occurrence and severity. Added to this, is the economic impact on the health of pigs and in some cases on human health. The challenges of swine health include endemic diseases, foodborne and transboundary diseases. Idiopathic vesicular diseases and subclinical diseases have also been identified, either alone or in combination with other infections. Several factors have contributed to these phenomena, but failures in biosecurity, biocontainment, and herd immunity imbalances are critical and must be addressed. Viruses evolve naturally, through mutation, rearrangement, or recombination, either to become more virulent or more transmissible, or not. This review will discuss the broad field of emerging swine viral infections, how monitoring the evolution of these viral agents is of supreme importance. Also, when should a new disease or emerging agent is considered a risk to swine production? Although the evolution of pork production systems is admirable, animal diseases continue to account for 20% of the losses. Therefore, international organizations work with member countries to prevent animal diseases, ensure food supply, maintain household income, health, and preserve the future. One Health is not just a concept, but an action of surveillance and control that all countries must implement.

A pandemia do novo coronavírus enfatizou a importância que a discussão e a vigilância de doenças emergentes representam para a sociedade científica, especialmente no caso de doenças zoonóticas. Mesmo no atual cenário de evolução da pesquisa biomédica, as doenças surgem na natureza e infectam os seres vivos em todos os continentes. Entre as doenças animais emergentes mais estudadas estão as doenças virais suínas, devido à sua alta ocorrência e gravidade. Soma-se a isso o impacto econômico na saúde dos suínos e, em alguns casos, na saúde humana. Os desafios da saúde suína incluem doenças endêmicas, doenças transmitidas por alimentos e doenças transfronteiriças. Além disso, doenças vesiculares idiopáticas e doenças subclínicas foram identificadas isoladamente ou em co-infecções. Vários fatores desencadearam esses fenômenos, mas falhas na biossegurança, biocontenção e desequilíbrio na imunidade do rebanho são fundamentais e devem ser corrigidos. Os vírus evoluem naturalmente, por mutação, rearranjo ou recombinação, para se tornarem mais virulentos ou mais transmissíveis, ou não. Esta revisão discutirá o amplo campo de infecções virais suínas emergentes e como o monitoramento da evolução desses agentes virais é de suma importância. Além disso, quando considerar uma nova doença ou agente emergente um risco para a suinocultura. A evolução dos sistemas de produção de suínos é admirável, mas as doenças dos animais ainda respondem por 20% das perdas. Portanto, as organizações internacionais trabalham com os países membros para prevenir doenças animais, garantir o abastecimento de alimentos, manter a renda familiar, a saúde e preservar o futuro. Saúde Única não é apenas um conceito, mas uma ação de vigilância e controle que todos os países devem implementar.

Investigation of hemotropic Mycoplasmas in fetuses and sows with reproductive failure.

Swine eperythrozoonosis or porcine hemoplasmosis is an infectious disease caused mainly by Mycoplasma suis and is distributed worldwide. This study investigated the occurrence of porcine hemothropic mycoplasmas (PHMs) in fetuses and sows with reproductive failure. Two hundred and seventy-six samples (80 sows' blood and 196 fetal tissue samples) from 27 farms with reproductive disorders were evaluated. The PHMs DNA was detected in 15 out of 80 (18.7%) sows but it was not detected in the fetuses. The bacterial load ranged from 1.32 × 102 to 2.61 × 105 copies/µL. From the 27 tested herds, 11 (40.7%) showed at least one positive sow per farm. The majority of the reproductive problems observed in PMHs positive sows were stillborn fetuses (46.7%) and stillborn associated with fetal mummification (26.7%). So, we evidenced that porcine hemoplasmas circulate among sows in Brazilian herds, however, its real impact on reproductive problems remains unknown.

Análise do desempenho do sistema de vigilância sanitária animal no surto de doença vesicular em suínos no estado de Santa Catarina - Brasil / Analysis of the performance of the animal health surveillance system in the outbreak of swine vesicular disease in the state of Santa Catarina - Brazil

Background: The occurrence of vesicular disease associated with Senecavirus A in a pig-producing region of Santa Catarina increased in 2015, reflected by the number of syndromic notifications to the official animal health service. In view of the recurrence of this event in 2018, the objectives of this study were to analyze the official data related to cases of suspected vesicular disease in pigs and to evaluate whether the experience in conducting the investigations of 2015 was incorporated into the years subsequent to 2015. We addressed this goal by analysis of the performance parameters of the state animal health surveillance system. Materials, Methods & Results: Descriptive analyses of data from official investigations of suspected vesicular disease in swine in different regions were carried out, and statistical models were used to: i) test the effect of the year on the age of the investigated injuries; ii) assess whether there was an association between the year and the type of outcome of the official investigation (discarded case or a probable case of vesicular disease, which resulted in the collection of samples for laboratory diagnosis and interdiction of the affected properties); iii) evaluate whether there was an association between the year and the detection of Senecavirus A RNA among the molecular analyses carried out after a case was classified as probable vesicular disease. From 05/22/2015 to 03/28/2019, there were 2093 notifications of suspected vesicular disease in pigs to the official service of Santa Catarina, with 1538 (73.5%) occurring in 2015 and 555 (26.5%) in subsequent years. After 2015, when compared to the base year, the chances of detecting late vesicular lesions (>3 days) were similar (increased 1.11 times, but there was no statistically significant association), in view of a panorama in which 55.29% of cases had the lesions classified as late throughout the analyzed period. The...

Porcine parvovirus VP1/VP2 on a time series epitope mapping: exploring the effects of high hydrostatic pressure on the immune recognition of antigens.

Porcine parvovirus (PPV) is a DNA virus that causes reproductive failure in gilts and sows, resulting in embryonic and fetal losses worldwide. Epitope mapping of PPV is important for developing new vaccines. In this study, we used spot synthesis analysis for epitope mapping of the capsid proteins of PPV (NADL-2 strain) and correlated the findings with predictive data from immunoinformatics. The virus was exposed to three conditions prior to inoculation in pigs: native (untreated), high hydrostatic pressure (350 MPa for 1 h) at room temperature and high hydrostatic pressure (350 MPa for 1 h) at - 18 °C, and was compared with a commercial vaccine produced using inactivated PPV. The screening of serum samples detected 44 positive spots corresponding to 20 antigenic sites. Each type of inoculated antigen elicited a distinct epitope set. In silico prediction located linear and discontinuous epitopes in B cells that coincided with several epitopes detected in spot synthesis of sera from pigs that received different preparations of inoculum. The conditions tested elicited antibodies against the VP1/VP2 antigen that differed in relation to the response time and the profile of structurally available regions that were recognized.

A human-like H1N2 influenza virus detected during an outbreak of acute respiratory disease in swine in Brazil.

Passive monitoring for detection of influenza A viruses (IAVs) in pigs has been carried out in Brazil since 2009, detecting mostly the A(H1N1)pdm09 influenza virus. Since then, outbreaks of acute respiratory disease suggestive of influenza A virus infection have been observed frequently in Brazilian pig herds. During a 2010-2011 influenza monitoring, a novel H1N2 influenza virus was detected in nursery pigs showing respiratory signs. The pathologic changes were cranioventral acute necrotizing bronchiolitis to subacute proliferative and purulent bronchointerstitial pneumonia. Lung tissue samples were positive for both influenza A virus and A(H1N1)pdm09 influenza virus based on RT-qPCR of the matrix gene. Two IAVs were isolated in SPF chicken eggs. HI analysis of both swine H1N2 influenza viruses showed reactivity to the H1δ cluster. DNA sequencing was performed for all eight viral gene segments of two virus isolates. According to the phylogenetic analysis, the HA and NA genes clustered with influenza viruses of the human lineage (H1-δ cluster, N2), whereas the six internal gene segments clustered with the A(H1N1)pdm09 group. This is the first report of a reassortant human-like H1N2 influenza virus derived from pandemic H1N1 virus causing an outbreak of respiratory disease in pigs in Brazil. The emergence of a reassortant IAV demands the close monitoring of pigs through the full-genome sequencing of virus isolates in order to enhance genetic information about IAVs circulating in pigs.

Vacinas com marcadores antigênicos contra o vírus da rinotraqueíte infecciosa bovina e o vírus da doença de Aujeszky{ review] / Vaccines with antigenic markers against bovine herpesvírus type-1 and pseudorabies vírus: [review]

Vacinas contra o herpes vírus bovino tipo-1 (IBRV, vírus da rinotraqueíte infecciosa) e o herpesvírus suíno (PRV, vírus da doença de Aujeszky) têm sido amplamente utilizadas em vários países para minimizar as perdas associadas à essas infecções. As vacinas tradicionais, no entanto, induzem uma resposta humoral indistinguível da resposta à infecção natural, o que não permite a distinção entre animais vacinados dos infectados naturalmente. Isto tem dificultado o estabelecimento de medidas de controle e erradicação dessas enfermidades. Nos últimos anos, a manipulação genética desses vírus tem permitido a obtenção de mutantes com marcadores antigênicos específicos. A estratégia consiste na deleção de uma ou mais glicoproteínas do envelope viral que não são essenciais para a replicação do vírus e o uso desses mutantes como vacinas. A utilização de um teste sorológico específico para a glicoproteína deletada permite a distinção entre animais vacinados dos infectados com o vírus de campo. A utilização de vacinas com marcadores antigênicos, também chamadas de vacinas diferenciais, tem sido a base de programas de controle e erradicação da doença de Aujeszky em vários países e começa a ser utilizada no controle da rinotraqueíte infecciosa bovina. Este artigo apresenta uma breve revisão sobre as bases moleculares e biológicas das vacinas diferenciais para o IBRV e PRV, assim como possíveis aplicações dessas vacinas no controle dessas enfermidades no Brasil em um futuro próximo.

Vaccination has been widely used to minimize the economic losses caused by bovine herpesvírus type-1 (IBRV) and pseudorabies virus (PR V) infections. The traditional vaccines, however, induce a humoral response that is indistinguishable from that induced by the natural infection. The impossibility of distinction between vaccinated and naturally infected animais has impaired the establishment of control and eradication programs for these diseases. In the last years, the genetic manipulation of infectious agents has allowed the development of mutants that are detective in expression of specific envelope glycoproteins. The strategy consists of deletion of one or more non-essential viral envelope glycoproteins and the use of these mutants as vaccines. By using a serologic test that is specific for the deleted glycoprotein, it is possible to differentiate the vaccinated animais from those that have been naturally infected. The use of these genetically engineered vaccines, also known as marker vaccines, has been the basis for control and eradication programs of Aujeszky's disease in several countries and has recently begun to be utilized for IBRV. This article presents a brief review on the molecular and biological basis of the differential vaccines against IBRV and PRV and the possible applications of such vaccines in the control of these infections in the near future in Brazil.