A cross-sectional study of swine influenza in intensive and extensive farms in the northeastern region of the state of São Paulo,Brazil

Swine influenza (SI) is a seasonal infectious disease highly important to the world pig industry. Loss of daily weight gain, increased costs for the prevention and treatment of secondary infections are the main economic losses associated with the presence of this disease. However, some epidemiological features of SI remain quite unclear. This study focused on assessing the prevalence of swine influenza virus (SIV) infection in intensive and extensive pig herds and associating risk factors. A set of 601 blood samples of five intensive farrow-to-finish farms and 361 blood samples from 56 extensive farms were analyzed using an indirect ELISA kit CIVTEST SUIS INFLUENZA®, Hipra (Amer, Spain), in order to detect anti-SIV antibodies. In total, 24.13 % of samples from intensive herds were positive, while no positive samples were detected in extensive rearing herds. Sow and weaning piglets had the highest prevalence values. In the intensive rearing system, occurrence of reproductive disorders and exposure to recently introduced animals were positively associated with the disease occurrence in swine herds. The findings highlight the importance of sows in the epidemiology of the disease and bring information about risk factors involved in the occurrence of swine influenza in intensive herds.     

Occurrence of Neospora caninum antibodies in sera from dogs of the city of São Paulo,Brazil

Neospora caninum is an important cause of abortion in dairy cattle worldwide. Dogs are important in the epidemiology of this parasite because they are the only hosts known to excrete N. caninum oocysts. In order to understand the prevalence of N. caninum in dogs, sera from 500 owned dogs and from over 600 feral street dogs from the city of S?o Paulo, Brazil were assayed for antibodies to N. caninum. Sera were examined by the Neospora agglutination test (NAT) using mouse-derived tachyzoites. Antibodies (> or =1:25) to N. caninum were found in nearly 10% (49/500) of owned dogs and in 25% (151/611) of stray dogs. NAT titers for owned dogs were 1:25 in 28 (5.6%) dogs, 1:50 in 20 (4%) dogs, and > or =1:500 in 1 (0.2%) dog. NAT titers for stray dogs were 1:25 in 79 (12.9%) dogs, 1:50 in 68 (11.1%) dogs, and > or =1:500 in 4 (0.6%) dogs. These data indicate that feral dogs may be important in the epidemiology of N. caninum infection.     

Gastrointestinal parasitic worms in equines in the Paraíba Valley, State of São Paulo, Brazil

Over a period of 12 years, from 1988 to 2000, a total of 20 individual equines (16 horses and 4 mules) were selected at random, from 10 municipalities in the Paraíba Valley, in the State of São Paulo, Brazil, and then subjected to necropsy for collection of gastrointestinal worms. Individual samples of 10% of the intestinal contents were also taken for counting and identifying the species present, and to establish the prevalence of worms in equine species in the Paraíba Valley. In the sample considered, the presence of parasites ranged from 155 to 1249 worms. Tapeworms (Cestoidea) were present in about 85% of the animals studied, and roundworms (Nematoda) in 100% of the individuals. All the tapeworms collected were of one single species, Anoplocephala perfoliata. In the case of the roundworms, the prevalence of individual species was: 100% for Cyathostomineae, 90% for Oxyuris equi, 70% for Strongylus vulgaris, 45% for S. edentatus, 15% for Strongylus equinus, 60% for Triodontophorus sp., 50% for Gyalocephalus capitatus, 15% for Oesophagodontus robustus and Craterostomum acuticaudatum, and 5% each for Parascaris equorum, Probstimayria vivipara, Habronema muscae, and Trichostrongylus axei. No specimens of flukes (Trematoda) were found in any of the animals studied.     

Detection of pseudocowpox virus in water buffalo (Bubalus bubalis) with vesicular disease in the state of São Paulo,Brazil, in 2016

Background: Parapoxviruses are zoonotic viruses that infect cattle, goats and sheep; there have also been reports of infections in camels, domestic cats and seals.

Objective: The objective of this report was to describe a case of vesicular disease caused by pseudocowpox virus (PCPV) in water buffalo (Bubalus bubalis) in Brazil.

Animals: Sixty buffalo less than 6 months old exhibited ulcers and widespread peeling of the tongue epithelium. There were no cases of vesicular disease in pigs or horses on the same property.

Methods: Samples were analysed by PCR and sequencing. Phylogenetic analysis in MEGA 7.01 was reconstructed using major envelope protein (B2L) by the Tamura three-parameter nucleotide substitution model and the maximum likelihood and neighbor joining models, both with 1000 bootstrap replicates. The genetic distance between the groups was analysed in MEGA using the maximum composite likelihood model. The rate variation among sites was modeled using gamma distribution.

Results: The presence of PCPV in the buffalo herd could be demonstrated in epithelium and serum. The minimum genetic distance between the isolated PCPV strain (262-2016) and orf virus and bovine papular stomatitis virus was 6.7% and 18.4%, respectively. The maximum genetic distance calculated was 4.6% when compared with a PCPV detected in a camel.

Conclusions/Clinical Importance: The peculiar position of the isolated strain in the phylogenetic trees does not necessarily indicate a different kind of PCPV that infects buffalo. More samples from cattle and buffalo in Brazil must be sequenced and compared to verify if PCPV from buffalo are genetically different from samples derived from cattle.     

Molecular identification of Cryptosporidium spp. from fecal samples of felines, canines and bovines in the state of São Paulo, Brazil

The objective of this study was to obtain information of epidemiological nature through genotypic characterization of Cryptosporidium isolates from dogs, cats and bovines from the state of São Paulo, Brazil. The extraction of DNA from oocysts was carried out and polymerase chain reaction was accomplished using specific primers to 18S rRNA gene. The amplicons were directed sequenced. Seven cat samples, nine dog samples and nine bovine samples were analysed. From the seven cat samples the genotypic analyses revealed Cryptosporidium felis in all. These were the first genotypic characterization of Cryptosporidium from domestic felines in Brazil. In nine sequenced samples from dogs, genotypic identities compatible with Cryptosporidium canis were revealed in all samples. The genotypic analyses in bovines revealed Cryptosporidium parvum in eight samples and Cryptosporidium bovis in another sample, the last one being a non-zoonotic species, not related to clinical symptoms and described for the first time in Brazil.     

Seasonal dynamics of ticks (Acari: Ixodidae) on horses in the state of São Paulo, Brazil

Natural tick infestations were assessed every 14 days on horses over a 2-year period. Amblyomma cajennense adult ticks were counted individually, without detachment from the horses. Larvae and nymphs of A. cajennense were collected using a rubber scraper that scratched engorged immature ticks from the host. Adult females of Anocentor nitens larger than 4mm length were counted on the horses. Blood samples were also obtained from the horses every 14 days and macroclimatic data were obtained for the study period. Infestations of A. cajennense demonstrated distinct peaks of activity for each of the three parasitic stages over each 12-month period, showing a 1-year generation pattern. Larvae predominated from April to July and nymphs from June to October. Adults predominated from October to March with a greater number of adult males than females. Although other studies on seasonal dynamics in the states of Rio de Janeiro and Minas Gerais were performed with the free-living stages of A. cajennense on pastures, the present study in the state of S?o Paulo, performed with the parasitic stages of A. cajennense on horses, showed similar results to those observed in other states. Infestations by A. nitens demonstrated distinct peaks of activity of adult females (>4 mm), suggesting different tick generations during the year. Infestation with A. nitens was much higher in the first year than the second year which may have been related to horse nutritional status and stocking rate. Although several climatic variables showed statistical significant correlation (r) with tick counts, the determination coefficients (R(2)) were always lower than 0.40, suggesting that any single significant variable (i.e. mean temperature) would not explain the tick distribution pattern over the year. The highest peaks of A. nitens females (>4 mm) were significantly associated with decrease in horse packed cell volumes (R(2)=0.603). The ears and the perineum, tail and groin region accounted for around 70% of all A. nitens females counted on the horses.     

Molecular evaluation of the incidence of Ehrlichia canis, Anaplasma platys and Babesia spp. in dogs from Ribeirão Preto, Brazil

Canine monocytic ehrlichiosis caused by Ehrlichia canis is endemic in many regions of Brazil. Since thrombocytopenia is a common finding in infected dogs, many clinicians tend to use it as an indication for antibiotic treatment. Polymerase chain reaction (PCR) and nested PCR were used to study the presence of E. canis, Anaplasma platys and Babesia spp. in thrombocytopenic and non-thrombocytopenic dogs from Ribeirão Preto, Brazil. Despite the high prevalence of E. canis infection among thrombocytopenic dogs, 46.7% of the thrombocytopenic dogs studied were either infected with Babesia spp. or A. platys or not infected with any of the three pathogens. There was a high incidence (25.4%) of E. canis infection in non-thrombocytopenic dogs. Although infection with E. canis should be considered in thrombocytopenic dogs, the final diagnosis needs to be confirmed by complementary tests such as blood smears and PCR to avoid the unnecessary use of antibiotics.     

Streptococcus suis in employees and the environment of swine slaughterhouses in S?o Paulo,Brazil: Occurrence,risk factors,serotype distribution,and antimicrobial susceptibility

Streptococcus suis is an important pathogen in the swine industry. This article is the first to report the occurrence, risk factors, serotype distribution, and antimicrobial susceptibility of S. suis recovered from employees and environmental samples of swine slaughterhouses in Brazil. Tonsillar swabs from all 139 pig-slaughtering employees and 261 environmental swabs were collected for detection of S. suis and serotyping by monoplex and multiplex polymerase chain reaction, respectively. Antimicrobial susceptibility was determined by the disk-diffusion method. Although S. suis was not detected in any of the tested employees, it was isolated from 25% of the environmental samples. Significant differences (P < 0.05) in the occurrence of S. suis were observed between slaughterhouses and between areas of low, medium, and high risk. The most frequent serotypes were 4 and 29, each accounting for 12% of the isolates, followed by 5, 12, 21, and 31, each accounting for 6%. High rates of susceptibility to the antimicrobials doxycycline (100%), ceftiofur (94%), ampicillin (81%), and cephalexin (75%) were observed. However, multidrug resistance was observed in all the isolates. Because S. suis is present in the environment of swine slaughterhouses, on carcasses and knives, as well as on the hands of employees in all areas, all employees are at risk of infection.     

Carbon Stocks and Fluxes in Rangelands of the Río de la Plata Basin

Grasslands are one of the most modified biomes on Earth. Land use changes had a large impact on carbon (C) stocks of grasslands. Understanding the impact of land use/land cover changes on C stocks and fluxes is critical to evaluate the potential of rangeland ecosystem as C sinks. In this article we analyze C stocks and fluxes across the environmental gradients of one of the most extensive temperate rangeland areas: the Río de la Plata Grasslands (RPG) in South America. The analysis summarizes information provided by field studies, remote sensing estimates, and modeling exercises. Average estimates of aboveground net primary production (ANPP) ranged from 240 to 316 g C· m^?2·yr^?1. Estimates of belowground NPP (BNPP) were more variable than ANPP and ranged from 264 to 568 g C· m^?2·yr^?1. Total Carbon ranged from 5 004 to 15 008 g C· m^?2. Plant biomass contribution to Total Carbon averaged 13% and varied from 9.5% to 27% among sites. The largest plant C stock corresponded to belowground biomass. Aboveground green biomass represented less than 7% of the plant C. Soil organic carbon (SOC) was concentrated in the slow and passive compartments of the organic matter. Active soil pool represented only 6.7% of the SOC. The understanding of C dynamics and stocks in the RPG grasslands is still partial and incomplete. Field estimates of ANPP and BNPP are scarce, and they are not based on a common measurement protocol. Remotely sensed techniques have the potential to generate a coherent and spatially explicit database on ANPP. However, more work is needed to improve estimates of the spatial and temporal variability of radiation use efficiency. The absence of a flux tower network restricts the ability to track seasonal changes in C uptake and to understand fine-scale controls of C dynamics.     

Risk factors to tick infestations and their occurrence on horses in the state of São Paulo, Brazil

From December 1998 to March 1999, 40 stud farms were studied in the state of S?o Paulo, Brazil. During visits to farms, horses reared under grazing conditions were examined for the presence of ticks. On each farm visit, horse pastures were closely inspected and a questionnaire was given to the farm supervisor with the purpose of gaining information about ecological and management variables (independent variables) that could be associated with the presence and infestation levels of ticks on the farm (dependent variables). Three tick species were found during the study. Anocentor nitens, Amblyomma cajennense and Boophilus microplus were present on horses from 38 (95%), 20 (50%) and four (10%) farms, respectively. All farms that had A. cajennense or B. microplus infestations also had A. nitens infestations. Only one of the four farms with B. microplus infestations on the horses also had A. cajennense infestations. Two farms had all horses free of ticks. There was a strong association between the presence of infestation by B. microplus on horses and the simultaneous use of a grazing area by cattle and horses (P = 0.000). There was no statistical association between any of the independent variables and the presence or infestation level of A. nitens on the horses (P > 0.20). The presence of A. cajennense was statistically associated with the presence of at least one mixed overgrowth pasture in the farm (P = 0.001). A mixed overgrowth pasture means the presence of undesired plants such as bushes and shrubs in the pasture. The presence of high levels of A. cajennense on horses was also associated with the presence of at least one mixed overgrowth pasture in the farm (P = 0.026). The regular use of acaricides was statistically associated with the presence of ticks on the horses (P < 0.05), making this procedure a result of the inefficacy of controlling ticks on the farms. The occurrence of human infestation by ticks was statistically associated with the presence of A. cajennense on the horses (P=0.000). The presence of at least one mixed overgrowth pasture on the farm was associated (P = 0.000) to either higher horse densities and to farms that did not mow all the pastures once a year, indicating that mowing all the pastures at least once a year can be considered a protective factor against the presence of mixed overgrowth pastures on the farm, and consequently, against the presence of A. cajennense on the horses.     

Occurrence and molecular diagnosis of Cryptosporidium serpentis in captive snakes in S?o Paulo, Brazil

The present study aimed to determine whether Cryptosporidium oocysts were present in stools from captive snakes at Funda??o Parque Zoológico (Zoological Park Foundation) in S?o Paulo, Brazil. Two collections were performed; the first in July 2008 and the second in February 2009. Fecal samples were collected from 74 enclosures that housed 101 individuals of 23 snake species. The stool specimens collected from 16 out of the 74 enclosures (21.6%) contained Cryptosporidium spp. oocysts; all of them were confirmed as Cryptosporidium serpentis, using molecular techniques. Only in three (18.7%) out of the 16 enclosures with positive samples were there animals with clinical signs compatible with infection by C. serpentis, such as regurgitation and significant progressive weight loss. From the results, it was concluded that diagnostic examinations need to be performed periodically, even on clinically healthy animals, as a preventive measure.     

Detection of porcine circovirus genotypes 2a and 2b in aborted foetuses from infected swine herds in the State of S?o Paulo,Brazil

Background

Porcine circovirus type 2 (PCV2) has been associated with several disease complexes, including reproductive failure. The aim of this study was to identify the subtypes of PCV2 that are associated with reproductive failure in pigs from the State of São Paulo, Brazil and to investigate co-infections with other infectious organisms.

Findings

Samples of 168 aborted foetuses or mummified foetuses from five farrow-to-finish swine farms known to be infected with PCV2 and located in the State of São Paulo were tested for PCV2 by polymerase chain reaction (PCR). Positive samples were additionally tested for porcine parvovirus (PPV), Leptospira spp. and Brucella spp. by PCR. PCV2 was detected in 18 of the samples (10.7%). PPV, Brucella spp. and Leptospira spp were found in 2, 10 and 0 cases, respectively. Eleven PCV2 strains were sequenced and determined to be either genotype 2a (n = 1) or 2b (n = 10).

Conclusions

The findings indicate that the frequency of PCV2 infections in aborted porcine foetuses from the State of São Paulo is rather low (10.7%) and that co-infection with other pathogens is common and may be involved in PCV2 associated reproductive failure. No repeatable, characteristic amino acid motifs for regions of the PCV2 capsid protein seemed to be associated with abortion in sows.     

Brucellosis due to Brucella suis in a swine herd associated with a human clinical case in the State of S?o Paulo, Brazil

Brucella suis has been recognized as the major etiological agent of human brucellosis in areas free from Brucella melitensis infection. However, with changes in swine management, the occurrence of swine brucellosis has decreased as has the human incidence of B. suis infection. A swine brucellosis outbreak within a herd from Jaboticabal (S?o Paulo, Brazil) was detected in July 2006. The herd comprised approximately 300 sows and 1,500 finishing animals. Many sows within this herd experienced abortions, while others exhibited vaginal discharge; three sows suffered posterior paralysis. Among 271 sows, 254 (93.7%) tested positive for brucellosis by complement fixation, and among 62 randomly bled finishing animals, 17 (27.4%) also tested positive. The B. suis biovar 1 was cultured from 14 aborted fetuses and six sows. Brucella was identified using routine methods. Fourteen farm workers were tested using agglutination tests, with three workers showing evidence of Brucella antibody titers. A 39-year-old woman, who worked with maternal pigs and had direct contact with aborted fetuses, presented an agglutinating titer of 480?IU/mL and displayed clinical signs of infection. Our findings suggest that despite a reduction of swine brucellosis throughout Brazil, B. suis infection still occurs, thereby posing a zoonotic risk.     

Demodectic mange in fattening pigs in São Paulo, Brazil

An investigation was conducted of mange in five Large White adult sows refractory to pyrethroid treatment (cypermethrin 15%). The most important clinical signs consisted of erythema, hyperkeratosis, alopecic macules, micaceous scaling, follicular pluging, and numerous comedones, especially on the facial region. Skin samples were scraped and punched. Elongate mites were found that were classified as Demodex sp., according to the morphological and histopathological characteristics. The protein, vitamin, and mineral levels contained in the rations were considered to be lower than those recommended to attend the requirements of fattening pigs. Adjustment of the rations was adopted, and the treatment of animals with ivermectin premix (450g/tonne of food) daily orally for a further 7 days was prescribed. The success of treatment was observed 15 days after adoption of these measures, when the beginning of remission of signs was observed. No mites were found on scrapings or biopsy punches after the treatment of the sows.     

Canine visceral leishmaniasis in São José de Ribamar, Maranhão State, Brazil

Here, we describe the situation of canine visceral leishmaniasis in two villages of S?o José de Ribamar in Maranh?o State/Brazil, where human cases have been registered. Blood samples of 36 household crossbred dogs from Sergio Tamer village and 43 dogs from Quinta village were collected and the serum used for serological diagnosis. An Indirect Fluorescent Antibody Test (IFAT) and enzyme-linked immunosorbent assay (ELISA) were used to detect antibodies against Leishmania. The clinical examination showed that 25% of the canine population of Quinta presented a poor body condition and in 39%, ectoparasites (ticks and fleas) were detected. In both tests, serology revealed that 21% (9 out of 43) of the dogs presented antibodies against Leishmania (55% were asymptomatic and 45% were symptomatic). In the Vila Sérgio Tamer, 25% (9 out of 36) of the dogs were seropositive for Leishmania (66.67% were asymptomatic and 33.33% were symptomatic), 33% presented poor body condition, and 22% have ectoparasites. The clinical signs more frequent were skin lesions. The statistical analysis showed that there was no statistical difference (p>0.05) between the seropositivity of the dogs from the two villages. The same was observed when the clinical signs were compared (p>0.05). Both villages have favorable conditions to maintain the cycle of leishmaniasis.     

Occurrence of Anti-Toxoplasma gondii Antibodies in Dogs in the Urban Area of Monte Negro,Rondônia,Brazil

The prevalence of anti-Toxoplasma gondii antibodies in dogs in an urban area of the municipality of Monte Negro, Rondônia, Brazil, was evaluated using an indirect immunofluorescent antibody test (IFAT). Blood samples were taken from 157 dogs living in 85 of the 94 blocks of the city. A seropositivity of 76.4% (120/157) was found and associations between the prevalence and the variables sex, age, type of raising and food were studied. The prevalence tended to increase with age (p<0.05); dogs over 24 months old had 85.5% (100/117) positivity, compared with 50% (20/40) in dogs less than 24 months old, showing postnatal exposure to the agent. It was also observed that dogs with access to the streets showed greater prevalence (84.9%) than companion animals (58.8%). There was no association between sex or the type of food (home-made or commercial) and anti-T. gondii antibodies.     

Prevalence and risk factors associated with goat gastrointestinal helminthiasis in the Sertão region of Paraíba State,Brazil

Gastrointestinal helminthiasis represents an obstacle to goat raising, causing severe damage to herds such as growth retardation, weight loss, and even death. In this study, we aimed to determine the prevalence and risk factors associated to goat gastrointestinal helminthiasis in the Sertão region of Paraíba State, Brazil. A total of 256 goats from 54 farms were systematically sampled. Blood and fecal samples were collected from each animal for egg per gram (EPG), larval culture, and packed cell volume (PCV) analyses. We found that 79.3 % of the goats investigated were parasitized with gastrointestinal helminths. Significant correlation (p?=?0.004) was observed between the EPG and PCV of the animals studied, and it was observed that the EPG increases as the PCV decreases. In the larval culture, the most prevalent helminth was Haemonchus sp. (83.2 %). Age and sex were significant variables (p?≤?0.20) for the development of gastrointestinal helminths: 86.8 % of animals over 36 months of age and 81.7 % of females were infected. The variable type of animal exploitation was also significant, with 90.3 % (p?≤?0.20) of the animals presenting double suitability (milk and meat). The Sertão region of Paraíba State presents high prevalence of gastrointestinal helminthiasis in goats, and age and type of animal exploitation are the most relevant risk factors to the development of these parasites.