Experimental Actinobacillus pleuropneumoniae challenge in swine: comparison of computed tomographic and radiographic findings during disease.

BACKGROUND: In pigs, diseases of the respiratory tract like pleuropneumonia due to Actinobacillus pleuropneumoniae (App) infection have led to high economic losses for decades. Further research on disease pathogenesis, pathogen-host-interactions and new prophylactic and therapeutic approaches are needed. In most studies, a large number of experimental animals are required to assess lung alterations at different stages of the disease. In order to reduce the required number of animals but nevertheless gather information on the nature and extent of lung alterations in living pigs, a computed tomographic scoring system for quantifying gross pathological findings was developed. In this study, five healthy pigs served as control animals while 24 pigs were infected with App, the causative agent of pleuropneumonia in pigs, in an established model for respiratory tract disease. RESULTS: Computed tomographic (CT) findings during the course of App challenge were verified by radiological imaging, clinical, serological, gross pathology and histological examinations. Findings from clinical examinations and both CT and radiological imaging, were recorded on day 7 and day 21 after challenge. Clinical signs after experimental App challenge were indicative of acute to chronic disease. Lung CT findings of infected pigs comprised ground-glass opacities and consolidation. On day 7 and 21 the clinical scores significantly correlated with the scores of both imaging techniques. At day 21, significant correlations were found between clinical scores, CT scores and lung lesion scores. In 19 out of 22 challenged pigs the determined disease grades (not affected, slightly affected, moderately affected, severely affected) from CT and gross pathological examination were in accordance. Disease classification by radiography and gross pathology agreed in 11 out of 24 pigs. CONCLUSIONS: High-resolution, high-contrast CT examination with no overlapping of organs is superior to radiography in the assessment of pneumonic lung lesions after App challenge. The new CT scoring system allows for quantification of gross pathological lung alterations in living pigs. However, computed tomographic findings are not informative of the etiology of respiratory disease.

[Comparison of the diagnostic significance of clinical, radiographic and ultrasonographic results after an experimental aerosol infection of pigs with Actinobacillus pleuropneumoniae]. / Vergleich der diagnostischen Aussagekraft klinischer, röntgenologischer und sonographischer Befunde bei der experimentellen Infektion des Schweines mit Actinobacillus pleuropneumoniae.

Scoring schemes for clinical, ultrasonographic and radiographic findings in pigs were developed based upon a standardized animal model for Actinobacillus pleuropneumoniae infection.The results of these methods were compared to each other as well as with the corresponding pathomorphological findings during necropsy. Altogether 69 pigs of different breeding lines (Hampshire, Pietrain and German Landrace were examined. Positive correlations were found between the results of all three methods as well as with the necropsy scores (p <0.0001). Different pathomorphological findings were detected either by radiographic or by ultrasonographic examination dependent upon the type of lung tissue alterations: Alterations of the pleura as well as sequestration of lung tissue on the lung surface could be clearly identified during the ultrasonographic examination while deep tissue alterations with no contact to the lung surface could be detected reliably by radiographic examination. Both methods complement each other, and the application of a combined ultrasonographic and radiographic examination of the thorax allows a comprehensive inspection of the lung condition. Particularly during the acute phase of the disease the extent of lung tissue damage can be estimated more precisely than by clinical examination alone.

[Subdural empyema and cerebritis as a sequela of dentogenous suppurative pansinusitis]. / Subdurales Empyem und Zerebritis als Folge einer dentogenen, eitrigen Pansinusitis.

BACKGROUND: Complications and local extension of dentogenous and paranasal sinus infections most often involve the periorbit and frontal cranium. Because of the widespread use of antibiotics, intracranial extension of maxillofacial sinusitis is rarely seen today. Nevertheless, the clinician must be aware of the potential for these complications, because late recognition of this condition and delay in treatment can increase morbidity and mortality rates. CASE REPORT: A case report of sinogenic intracranial complications is presented, with sinogenic empyema, cerebritis, and subdural empyema. The mechanisms and potential for intracranial spread of infection from the frontal, sphenoid, and ethmoid sinuses are discussed. The management of complications is outlined, including the use of computed tomography and the role of surgical drainage.