Management of encephalomyocarditis virus infection in Italian pig farms: a case report

BACKGROUND

Encephalomyocarditis virus (EMCV) has been isolated from many animals, frequently as the cause of fatal myocarditis, but pigs are the most susceptible domestic specie. The virus was isolated in swine farms since 1958 in Panama and Europe from cases of sudden death in young pigs, and the main origin of outbreaks has been assumed to be local rodent populations. There is no treatment for the disease.

CASE PRESENTATION

The clinical case describes an outbreak of encephalomyocarditis virus in a farrowing (farm A) and a weaning (farm B) site, with mortality that reached 24.2% in suckling piglets and 7.7% in weaners. The farms were located in an endemic Italian area, and the outbreak was characterised by high mortality with sudden death and clinical signs due to heart failure (trembling, dispnea and fever). The rodents control program was the key action in managing the outbreak. However, in the weaning site, the lack of rodent program in some unexplored areas of the barn (false ceiling) was responsible of a longer time of resolution of the outbreak. An unusual support treatment approach from human medicine suggestion was also applied using acetylsalicylic acid for its antiphlogistic and antithrombotic effects.

CONCLUSIONS

To control the rodent population in a pig farm is often difficult and requires a deep knowledge also of the rodents habits. Considering the lack of treatment for the disease and the absence of available vaccines in several Countries, acetylsalicylic acid might be of interest for further studies as an important support for pigs' recovery.

Genetic analysis of human and swine influenza A viruses isolated in Northern Italy during 2010-2015

Influenza A virus (IAV) infection in swine plays an important role in the ecology of influenza viruses. The emergence of new IAVs comes through different mechanisms, with the genetic reassortment of genes between influenza viruses, also originating from different species, being common. We performed a genetic analysis on 179 IAV isolates from humans (n. 75) and pigs (n. 104) collected in Northern Italy between 2010 and 2015, to monitor the genetic exchange between human and swine IAVs. No cases of human infection with swine strains were noticed, but direct infections of swine with H1N1pdm09 strains were detected. Moreover, we pointed out a continuous circulation of H1N1pdm09 strains in swine populations evidenced by the introduction of internal genes of this subtype. These events contribute to generating new viral variants-possibly endowed with pandemic potential-and emphasize the importance of continuous surveillance at both animal and human level.

Sequence types and pleuromutilin susceptibility of Brachyspira hyodysenteriae isolates from Italian pigs with swine dysentery: 2003-2012

Swine dysentery is a mucohaemorrhagic colitis of pigs caused by infection with Brachyspira hyodysenteriae. The disease can be controlled by treatment with antimicrobial agents, with the pleuromutilins tiamulin and valnemulin being widely used. In recent years, the occurrence of B. hyodysenteriae with reduced susceptibility to these drugs has been increasing. The aim of this study was to determine temporal changes in genetic groups and pleuromutilin susceptibility amongst B. hyodysenteriae isolates from Italy. Multilocus sequence typing (MLST) was performed on 108 isolates recovered from 87 farms in different regions of Italy from 2003 to 2012, and their minimum inhibitory concentrations (MICs) for tiamulin and valnemulin were determined. Logistic regression was performed to assess associations between susceptibility to the two antimicrobial agents and genetic group, year and region of isolation. The isolates were allocated to 23 sequence types (STs), with five clonal clusters (Ccs) and seven singletons. More than 50% of isolates were resistant to both pleuromutilins (MIC >2.0 µg/mL for tiamulin and >1.0 µg/mL for valnemulin). All 10 isolates in ST 83 were resistant; these were first isolated in 2011 and came from nine farms, suggesting recent widespread dissemination of a resistant strain. Significant associations were found between the proportion of pleuromutilin susceptible isolates and the genetic group and year of isolation. Although resistant isolates were found in all Ccs, isolates in Ccs 2 and 7 were over five times more likely to be susceptible than those in the other Ccs. A significant trend in the reduction of susceptibility over time also was observed.

Haemophilus parasuis serovars isolated from pathological samples in Northern Italy

From January 2007 to December 2011, a total of 106 Haemophilus parasuis strains isolated from pigs were serotyped by agar gel diffusion test (DG). Serovar 4 was the most prevalent (24.5%), followed by serovar 13 (19.8%) and serovar 5 (11.3%). Twenty-nine strains were non-typeable (27.3%). The strains were divided into two groups, depending on whether they were isolated from specific pathological lesions of systemic disease such as polyserositis, arthritis or meningitis (73 cases of 106) or from the lower respiratory tract of pigs suffering from bronchopneumonia (33 cases of 106). Serovars 4 and 13 had a higher prevalence in systemic infection (polyserositis) than in respiratory disease only. Pasteurella multocida (14/106), Streptococcus suis (7/106), Actinobacillus pleuropneumoniae (4/106), Bordetella bronchiseptica (3/106) and Arcanobacterium pyogenes (3/106) were isolated in association with H. parasuis.

Survey of pleuritis and pulmonary lesions in pigs at abattoir with a focus on the extent of the condition and herd risk factors

Cranioventral pulmonary consolidation (enzootic pneumonia-like lesions) and chronic pleuritis (CP) are common findings in slaughtered pigs. Pleural lesions involving dorsocaudal lobes are suggestive of pleuropneumonia due to Actinobacillus pleuropneumoniae. In this report the results of an abattoir survey of pleuritis and pulmonary lesions in pigs is presented with a focus on herd risk factors. A total of 4889 animals, ranging in age from 9 to 10 months, from 48 batches of pigs belonging to an equal number of herds, were included in the study. Bronchopneumonic lesions suggestive of enzootic pneumonia (EP-like lesions) were detected in 46.4% of the examined lungs. The EP-like lesion average value for all lungs was 1.03 (95% CI 0.98-1.08), ranging from 0.17 to 2.56 among the 48 batches; 47.5% of lungs showed chronic pleuritis. Dorsocaudal pleuritis suggestive of recovered pleuropneumonia (SPES score ≥2) was found in 25.1% of the lungs. The mean SPES (slaughterhouse pleuritis evaluation system) value of the overall 4889 lungs was 0.83 (95% CI 0.78-0.86). The mean SPES value of the batches ranged from 0.04 to 1.87. The mean Actinobacillus pleuropneumoniae index of all studied batches was 0.61 (95% CI 0.51-0.71), ranging from 0 to 1.84. Blood samples were collected from each herd to evaluate antibody titres to Mycoplasma hyopneumoniae, A. pleuropneumoniae, Aujeszky's disease virus, porcine reproductive and respiratory syndrome virus (PRRSV), and swine influenza virus. Herd characteristics were recorded using a questionnaire given to the farmers. A multivariable analysis was conducted to identify risk factors for pleuritis and EP-like lesions. High dorsocaudal pleuritis was associated with A. pleuropneumoniae seroprevalence and history of A. pleuropneumoniae isolation from pneumonic lungs of dead animals. Vaccination of weaners at 3-5 weeks of age against PRRS using a modified live vaccine was associated with a reduction in the percentage of cranioventral pulmonary consolidation (EP-like lesions).

Ultrasonography and Cystic Hyperplasia-Pyometra Complex in the Bitch

Cystic endometrial hyperplasia-pyometra complex is the most frequent and important endometrial disorder encountered in bitches. The pathogenesis of the disease is related to the activity of progesterone [Feldman and Nelson, Canine and Feline Endocrinology and Reproduction (1996) W.B. Saunders, Philadelphia]. Cystic endometrial hyperplasia (CEH) is an abnormal response of the bitch's uterus to ovarian hormones [De Bosschere et al. Theriogenology (2001) 55, 1509]. CEH is considered by many authors to be an exaggerated response of the uterus to chronic progestational stimulation during the luteal phase of the oestrous cycle, causing an abnormal accumulation of fluid within the endometrial glands and uterine lumen (De Bosschere et al. 2001). The resulting lesions of pyometra are due to the interaction between bacteria and hormones. The aim of this study was to evaluate if transabdominal uterine ultrasonography can be a useful and reliable diagnostic method to confirm Dow's [Veterinary Record (1958) 70, 1102] and De Bosschere's histopathological classification of CEH-pyometra complex. The study was carried out on 45 bitches with pyometra, 10 purebreds and 35 crossbreeds, 1-15 years old, 20% of which had whelped at least once. None of these animals had received exogenous oestrogen or progesterone treatment. On admission the 45 animals were in the luteal phase of the oestrus cycle. Clinical signs, blood parameters, uterine ultrasonography, bacterial swabs and uterine histopathological results were recorded. Results suggest that ultrasonographic examination is a useful and reliable tool for the diagnosis of cystic endometrial hyperplasia.

Unusual hyperparathyroidism in a cat

A 5 month-old, male, domestic short hair cat was presented with inappetence and vomiting. it was depressed and reluctant to move. The cat had difficulties in keeping the standing position and grossly deformed thighs. Lytic changes and disruption of normal architecture of the bone were observed, involving mainly the femoral diaphyses. An inverse Ca/P ratio and kidney failure were diagnosed. The possibility of whether the bone changes could have been related to primary or secondary renal hyperparathyroidism is discussed.

A source of false-negative results in clenbuterol analysis in tissues of veal calves

The possibility of false-negative results in clenbuterol analysis was investigated in bovine tissues. An extraction procedure currently in use was adapted to process 100 specimens of different tissues each time. Its efficiency and accuracy were investigated radiometrically by means of a series of different molar concentration of the tritiated drug. In samples not submitted to extensive delipidation, unreliability of the analysis was evident. The measurement of tissue clenbuterol content, by a competitive ELISA, gave results numerically similar to those existing in literature, but with an accuracy high enough to minimize the frequency of false-negative results.

Ecological survey of Listeria in the Ferrara area (northern Italy)

A bacteriological survey was done on human and environmental specimens from the province of Ferrara in Northern Italy to determine the prevalence of Listeria spp. because no cases of listeriosis so far had been reported. Ten strains of Listeria spp. (1.9%) (7 L. monocytogenes, 3 L. innocua) were detected in 513 faecal specimens from asymptomatic humans, whereas none was recovered from 505 vaginal swabs of fertile women with discharges. Thirteen strains (9 L. monocytogenes, 4 L. innocua) were detected in 113 meat samples from retail outlets (11.5%), 4 strains (2 L. monocytogenes, 2 L. innocua) from 75 samples of frozen food (5.3%). Eleven Listeria strains (1 L. monocytogenes, 2 L. seeligeri, 1 L. welshimeri, 7 L. innocua) were isolated from 50 water samples of the river Po (22.0%); 15 strains (4 L. monocytogenes, 11 L. innocua) from 80 samples of other surface waters (18.8%); 1 strain (L. innocua) from 98 samples of groundwaters (1.0%); 14 strains (8 L. monocytogenes, 5 L. innocua, 1 L. seeliger) from 33 samples of urban sewage (42.4%). Only 35 (51.5%) of the Listeria isolates could be phage-typed. Analogies were observed between the distribution of Listeria and that of Salmonella, Yersinia and thermophilic Campylobacter in some materials in which these organisms were sought simultaneously.

[Isolation of Salmonella and Yersinia from human feces and surface water in the province of Ferrara in 1980]

The AA. report the strains of Salmonella and Yersinia isolated from human stools and surface waters in the Province of Ferrara during 1980.

[Isolation of Yersinia enterocolitica from drinking water and human feces]

Twelve strains of Yersinia enterocolitica (46.15%) were isolated from 26 water samples of the Po river (1.3-1.5 1), 3 strains (16.67%) were isolated from 18 water samples of the Reno river (500 ml) and 1 strain (2%) was isolated from 50 fecal specimens of healthy adult subjects. It is suggested that further studies are needed in order to determine the occurrence of Yersinia enterocolitica in Italy.