A survey of biosecurity measures and serological status for bovine viral diarrhoea virus and bovine herpesvirus 1 on dairy cattle farms in north-west and north-east Spain

BACKGROUND

Biosecurity is a key measure to reduce and prevent the introduction of diseases to farms and minimise spread of diseases within a herd. The aim of the study was to characterise the current application of biosecurity measures on dairy cattle farms in Spain along with their bovine viral diarrhoea and infectious bovine rhinotracheitis status.

METHODS

Data on biosecurity measures for 124 dairy herds were collected using a questionnaire. The sanitary status of these farms for bovine viral diarrhoea and infectious bovine rhinotracheitis was also assessed using antibody ELISA. Data were analysed using multiple correspondence analysis and a two-step cluster analysis.

RESULTS

Three main clusters of farms were identified: clusters 1 and 2 included herds of small and intermediate sizes. These, particularly cluster 1, showed the most deficiencies in the control of vehicles and visitors. However, laboratory tests were always performed on purchased animals. Cluster 3 had the largest herd sizes, with somewhat better biosecurity control of vehicles and visitors. However, farms in this cluster also purchased the most animals, sometimes without testing, and hired external workers more often.

CONCLUSION

The study indicated that, in the study population, there are serious shortcomings in the application of biosecurity measures on dairy farms, exposing them to disease transmission. This survey also highlights regional and herd size-related differences in the implementation of biosecurity. Collecting data is an important first step to identification of specific weaknesses in different farm typologies, and an adequate follow-up is needed to ensure that measures are implemented correctly on farms.

[Progressive multifocal leukoencephalopathy in elderly immunocompetent patients. Report of 2 cases]

INTRODUCTION

Progressive multifocal leukoencephalopathy is a disorder which is rare in immunocompetent patients.

OBJECTIVES

We report the cases of two elderly patients with serology, in one case positive for hepatitis C, and in the other with anti-DNA antibodies, and discuss the part these might play in causing progressive multifocal leukoencephalopathy.

CLINICAL CASES

Case 1. An 86 year old man had been found on serology investigations to be positive for hepatitis C virus. In November 1996 he complained of dysarthria and left hemi-negligence following an accidental fall. Since his clinical condition became worse he was admitted to hospital for further investigation. On neuroimaging studies the intracerebral lesions were increased. The only other finding confirmed was that of positive serology for hepatitis C virus. The patient deteriorated progressively and died 50 days after admission. Case 2. A 70 year old woman began to show progressive cognitive impairment and left hemiparesia in June 1996. Se was investigated in another centre and provisionally diagnosed as having vasculitis of the CNS, in view of her positive anti-DNA antibody and right frontoparietal hypodense lesion. Treatment had been started with corticosteroids. She was admitted to our hospital when her neurological deficits worsened. The immunological alterations were confirmed. On MRI the lesions in the white matter were seen to have progressed. The patient slowly improved. She was discharged from hospital in February 1997 in a semiconscious state, able to follow persons and things with her eyes, with global aphasia and with spastic tetraparesia which was mainly left-sided. She remains stable.

CONCLUSION

Progressive multifocal leukoencephalopathy is a condition which should be remembered when dealing with immunocompetent patients.

[Intraventricular hemorrhage due to the rupture of atherosclerotic dissecting aneurysm of the middle cerebral artery]

INTRODUCTION

We present a case of fusiform intracranial aneurysm where, apart from the unusual site, we draw attention to the form of clinical presentation, namely intraventricular haemorrhage. Clinical case. A 68 year-old-man with a history of smoking, hyperuricemia with seizures of gout treated with colchicine and allopurinol, and hypertension treated with captopril. Nine years previously he had a right capsulothalamic haematoma and presented (as a sequela of this) a left sensomotor deficit, with a good functional level. In December 1998 he was admitted for sudden onset of headache and deterioration of consciousness. He had right limb movements which were typical of decerebration and made intubation and mechanical ventilation necessary. Cerebral CT, with angiographic sequences, showed blood in the lateral ventricles and III ventricle, with ventricular dilation and a fusiform aneurysm of the left middle cerebral artery. In view of the neurological state of the patient, treatment of the aneurysm was postponed. After initial improvement, which permitted extubation, tetraparesia (predominantly right) and a pseudobulbar syndrome were seen. The patient had repeated respiratory infections and died from sepsis caused by Pseudomona aeruginosa (of respiratory origin) three months after admission.

CONCLUSIONS

Fusiform intracranial aneurysms form 9% of all aneurysms. Localization to the middle cerebral artery is infrequent, the basilar trunk and internal carotid artery are commoner sites. In our case angio-CT was a useful non-invasive neuro-radiological technique.

[Nuclear resonance in intracranial venous thrombosis]

We have reviewed the nuclear resonance NR images in three patients with intracranial venous thrombosis. Tomodensitometric findings are not reliable in intracranial venous thrombosis and cerebral angiography is required for the diagnosis. The usefulness of NR for the investigation of venous disease has been recently demonstrated. Ten patients in whom a diagnosis of intracranial venous thrombosis was made with NR have been reported. Initially, the vacuum signal in the T1 enhanced sequences disappears and the thrombus becomes hypointense in the T2 enhanced sequences. In the following phase, proton relaxation is impaired by methemoglobin production and thrombosis appears as hyperintense in both the T1 and T2 enhanced sequences. During the resolution phase, the vacuum signal in the vascular lumen reappears and the hyperintensity of the thrombus signal becomes attenuated. In our study we have shown the different stages of intracranial venous thrombosis with NR. In addition, we have demonstrated the close relation between these images and the clinical evolution. NR is a useful noninvasive investigation in patients with suspected intracranial venous thrombosis.

Ischemic stroke in young adults. I. Analysis of the etiological subgroups

An ischemic stroke (IS) group including 386 patients under 50 years old is analysed taking into account different etiological subgroups and comparing risk factors against a control group of 100 people. The series points out the presence of 66.1% patients included in the inconclusive-atherothrombosis group, of which 22.7% had defined criteria of atheromatosis, while 11.6% were diagnosed of lacunar infarct. 13.5% of cases were considered as cardiac origin embolisms, and 14.1% were affected of mitral valve prolapse. The migraine group includes 4.9% of the patients while 17.6% belong to the miscellaneous group. The comparison of each of these groups with the control group showed significant differences for family history of stroke, personal history of peripheral arteriopathy, tobacco, arterial hypertension and previous IS.

[Carotid artery disease induced by irradiation]

We have evaluated 39 patients with ischemic strokes secondary to atherosclerotic disease of the extracranial carotid artery. Seven of them had been treated in the past with cervical radiotherapy for neoplastic diseases (radiotherapy group); the remaining 32 patients had not received radiation therapy (non-radiotherapy group). When the prevalence of risk factors was compared between the two groups, there was a significantly higher prevalence of peripheral arterial disease (p less than 0.05), hypertension (p less than 0.05) and atherogenicity index lower than 21.5% (p less than 0.05) in the non-radiotherapy group. Regarding angiographic data, the radiotherapy group showed a significantly higher occurrence of localized findings than the non-radiotherapy group (p less than 0.005). It is concluded that radiation-induced carotid disease is a clinical condition which may be individualized from the remaining patients with atherosclerotic carotid artery disease.

Spontaneous dissection of intracranial vertebral artery: clinical recovery with conservative treatment

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