Janice Reis Ciacci Zanella

Isolamento e caracterização do vírus da influenza pandêmico H1N1 em suínos no Brasil

Influenza A virus (IAV) infections are endemic in pork producing countries around the world. The emergence of the pandemic 2009 human H1N1 influenza A virus (pH1N1) raised questions about the occurrence of this virus in Brazilian swine population. During a 2009-2010 swine influenza virus research project at Embrapa Swine and Poultry (CNPSA), an outbreak of a highly transmissible H1N1 influenza A virus disease was detected in a pig herd in Santa Catarina State, Brazil. The virus caused a mild disease in growing pigs and sows without mortality. Three clinically affected piglets were euthanized. Gross lesions included mild to moderate consolidation of cranioventral areas of the lung. Microscopically, the lesions were characterized by necrotizing obliterative bronchiolitis and bronchointerstitial pneumonia. Immunohistochemistry using a monoclonal antibody against type A influenza virus nucleoprotein revealed positive staining in the nuclei of the bronchiolar epithelial cells. Lung tissue from three piglets and nasal swabs from five sows and four piglets were positive for influenza A by RT-PCR. Influenza virus was isolated from one lung, later confirmed by the hemagglutination test (HA titer 1:128) and RT-PCR. Sequence analyses of Hemmaglutinin (HA) and Matrix (M) genes revealed that the virus was consistent with the pandemic (A/H1N1) 2009 influenza virus strain that circulated in humans. This is the first report of an outbreak of pandemic A/H1N1 influenza virus in pigs in Brazil.

Caracterization of Aujeszky's disease virus isolated from South Brazil in the last twenty years by restriction enzyme analysis

Aujeszkys disease virus (ADV) belongs to Herpesviridae family and is an important etiological agent which infects pigs causing economic losses in swine producing countries worldwide and international trade restrictions to products of swine origin. An eradication program for ADV was established in Santa Catarina State since 2001. The last outbreak was reported in July 2004 and since then none has been reported. The disease has been controlled with the use of a genetic modified vaccine and elimination of seropositives. Aiming the characterization of ADV isolated in the South of Brazil in the last twenty years (1983-2003), a retrospective study based on the genomic analysis of the isolates through a digestion of viral genomic DNA with restriction enzyme Bam HI was done. Thirty-seven ADV samples isolated from swine from the States of Santa Catarina, Parana and Rio Grande do Sul were analyzed. These isolates were compared to the reference strains NIA-4, Bartha and Begonia. The most predominant genomic arrangement was type II found in 33 samples isolated in Santa Catarina State and in one isolate from Rio Grande do Sul State. Genomic arrangement type I, characteristic of vaccine strains was identified in 2 isolates from Parana State and in 1 isolate from Rio Grande do Sul State.

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.

Surto de Circovirose (síndrome definhante multissistêmica de suínos desmamados) no estado do Rio de Janeiro

The first outbreak of Postweaning Multisystemic Wasting Syndrome (PMWS) in swine, which occurred in southeastern Brazil, in the state of Rio de Janeiro, is described. The disease, which affects mainly weaned about 4 month-old pigs, caused the death of at least 14 animals. The property, where the outbreak occurred, had inadequate sanitary and management conditions. Clinically the disease was characterized by wasting, poor development, cough, tachypnoea, dispnoea, diarrhoea, ataxia, tremors after stimulation, decubitus and convulsions. The course of the disease was acute or subacute. The most important post-mortem findings were enlarged lymphnodes, non-collapsed lungs, with consolidated areas mainly in the cranial lobes. Histological lesions consisted mainly of lymphohistiocytic infiltration with multinucleate giant cells in lymph nodes, spleen, Peyers patches, kidney, lung and liver, depletion or lymphoid hyperplasia, as well as lymphohistiocytic interstitial pneumonia and areas of secondary bronchopneumonia. The diagnosis was established through observations of the symptoms and typical lesions, and was confirmed by immunohistochemical examination and PCR. The objective of this study was to characterize the epidemiological, clinical and pathological aspects of the outbreak of PMWS, because of the severe direct or indirect economical losses caused by the disease to the world pig industry.

Distribution of antibodies against influenza virus in pigs from farrow-to-finish farms in Minas Gerais state, Brazil

Swine influenza virus (SIV) is the cause of an acute respiratory disease that affects swine worldwide. In Brazil, SIV has been identified in pigs since 1978. After the emergence of pandemic H1N1 in 2009 (H1N1pdm09), few studies reported the presence of influenza virus in Brazilian herds.

Disseminação do vírus da doença de Aujeszky, envolvendo o comércio de reprodutores suínos de reposição

ABSTRACT It was reported the spreading of the infection caused by the virus of Aujesky’s disease (VAD) by the commercialization of breeders originated from two pigs farms GRSC (Farms of Certified Swine Breeders - FCSB) which had an outbreak of Aujeszky’s disease. After the positive diagnosis of Aujesky’s disease, the pigs traded from 37 to 45 day before the outbreaks were removed from the herd, bled for serological exams for the VAD and sent to slaughterhouses. The herds which received these pigs were serologically tested for the VAD, 17 to 37 days after the removal of the animals. Serological tests were also performed in pigs lodged at neighboring cages to those which had been lodged with the pigs bought and a sampling test was done six months later. Thus, 52 flocks bought pigs from the farms 1 and 2. From those, 37 (69.8%) received at least one serum-positive pig for the VAD. Only seven (18.9%) of them were infected and 30 (81.1%) pigs showed no indications of infection by the VAD. The occurrence of VAD in FCSB farms represents huge potential for spreading of the VAD, by the trade of replacement pigs. The traceability investigation and removal of the animals traded before the diagnosis, with immediate removal of the positive lots of pigs at the destiny herd, avoided the spread of the infection. Keywords: swine, disease, virus, Aujeszky, epidemiology

Zoonoses emergentes e reemergentes e sua importância para saúde e produção animal

The factors for disease emergence or reemergence are little known and understood, but the main one is the expansion of the human population. Other factors include climate change, globalization, and intensification of animal production. This is disturbing, given that 75% of emerging or reemerging human diseases of the last century are zoonoses, that is, animal diseases, which, besides causing human and animal fatalities, affect the economy of countries. It is estimated that the impact of animal diseases exceeds 20% of the losses in animal production worldwide. Brazil is a major agricultural producer and has most of its territory in the tropical region, harboring the greatest environmental biodiversity of the globe. Studies have pointed the Amazon region as a hot spot where diseases have emerged or will emerge. In this context, the formation of a cooperation network with strategic actions for monitoring, research, communication, and training is recommended. It is essential to foster partnerships in the areas of health, agriculture, and environment for a prompt national and global response. The objective of this work was to address the main factors involved in the emergence or reemergence of zoonoses, as well as future threats and the strategic importance of Brazilian research and surveillance.

Uso do plasma suíno ultrafiltrado na recuperação de leitões com sinais clínicos de circovirose

The effect of the ultra-filtered spray-dried porcine plasma, associated to a commercial acid in the drinking water was tested for recovering pigs with clinical signs of the porcine postweaning multisystemic wasting syndrome (PMWS). Forty piglets with clinical signs of the PMWS were used following a selection at 20 days after their housing in one finishing facility. They were divided in four treatment groups (T) of 10 pigs each: T1 - chlorine treated water ad libitum (control); T2 - solution prepared with 2.5% of plasma diluted in water; T3 - acid (Selko® ) diluted in water at the concentration of 12 ml/10l; T4 - solution prepared with 2.5% of plasma diluted and the acid (Selko® ) diluted in water at the concentration of 12 ml/10l. The pigs received no medication and were euthanized at 28 or 40 days after the beginning of the experiment for serological and pathological tests. Differences at the weight gain and in the clinical-pathological situation were not observed among the treatments. However, pigs from T4 were in better clinical-pathological situation. The pigs of all four treatments showed a good recovery, although they were not medicated. Even though, it was observed a high frequency of lesions compatible to PMWS in the lungs, kidneys and lymph nodes. It was concluded that the plasma spray-dried associated to the acid did not improve the performance and the clinical-pathological situation of pigs with clinical signs of PMWS.The effect of the ultra-filtered spray-dried porcine plasma, associated to a commercial acid in the drinking water was tested for recovering pigs with clinical signs of the porcine postweaning multisystemic wasting syndrome (PMWS). Forty piglets with clinical signs of the PMWS were used following a selection at 20 days after their housing in one finishing facility. They were divided in four treatment groups (T) of 10 pigs each: T1 - chlorine treated water ad libitum (control); T2 - solution prepared with 2.5% of plasma diluted in water; T3 - acid (Selko® ) diluted in water at the concentration of 12 ml/10l; T4 - solution prepared with 2.5% of plasma diluted and the acid (Selko® ) diluted in water at the concentration of 12 ml/10l. The pigs received no medication and were euthanized at 28 or 40 days after the beginning of the experiment for serological and pathological tests. Differences at the weight gain and in the clinical-pathological situation were not observed among the treatments. However, pigs from T4 were in better clinical-pathological situation. The pigs of all four treatments showed a good recovery, although they were not medicated. Even though, it was observed a high frequency of lesions compatible to PMWS in the lungs, kidneys and lymph nodes. It was concluded that the plasma spray-dried associated to the acid did not improve the performance and the clinical-pathological situation of pigs with clinical signs of PMWS.

Principais ameaças sanitárias endêmicas da cadeia produtiva de suínos no Brasil

Brazil stands out as the fourth largest producer and exporter of pork. The occurrence of certain diseases in animal production is one of the most important factors for swine production. Swine pathogens can be divided into three groups: agents of foodborne illnesses of animal origin; agents of strategically important diseases for the health protection system; and agents of diseases responsible for losses in animal production. Some diseases, such as classical swine fever and foot‑and‑mouth disease, impact heavily the export market; endemic or enzootic diseases deteriorate production rates and increase production costs, reducing competitiveness; and foodborne illnesses, despite not affecting production indexes, can cause damages to human health and harm commercial relations. Brazil, being an exponent in the production and export of pork and derivatives, must be aware of some aspects related to laboratory infrastructure, biosecurity measures, and care necessary to prevent certain, still exotic, diseases from infecting the Brazilian herd. This review addresses the main endemic or enzootic diseases that cause losses in pork production in Brazil.