Co-infection of pigs with Hepatitis E and porcine circovirus 2, Saxony 2016

Hepatitis E virus (HEV) is a recognized zoonotic disease; autochthonous infections in Europe are caused to a great extent by HEV genotype 3. Pigs and wild boar are the main reservoirs for this genotype and normally they develop no or only subclinical symptoms with mild histopathological lesions. However, co-infections with other pig pathogens can lead to severe cases in pigs, including liver hemorrhage and necrosis. During a monitoring program 2016 in Saxony, Germany, farmed pigs with various clinical outcomes including fatalities were analysed for HEV and concurrent infections. We could detect eight HEV infected pigs from which six were co-infected with porcine circovirus 2 (PCV2). Phylogenetic analysis revealed HEV sub-genotypes 3e and 3f as well as PCV2 genotypes 2b and 2d. A direct correlation of the co-infection to the course of disease could not be determined, but the results provide hints that the immune modulatory effects of PCV2 combined with HEV influence the disease pattern in pigs.

Clinical infection in house rats (Rattus rattus) caused by Streptobacillus notomytis

Rat bite fever is an under-reported, under-diagnosed emerging zoonosis with worldwide distribution. Besides Spirillum minus, Streptobacillus moniliformis is the major causative microorganism although it usually colonises rats without any clinical signs. A group of house rats (Rattus rattus) kept in a zoo exhibition for educational purposes suffered from neurological signs including disorientation, torticollis, stall walking, ataxia and death. Gross pathological and histo-pathological examinations of the investigated rats revealed high-grade otitis interna et media, from which Streptobacillus notomytis was isolated in pure culture or as the predominant microorganism. This case series underlines a previously expressed hypothesis that R. rattus might be naturally colonised with S. notomytis, whereas the traditional rat bite fever organism, S. moniliformis, might be restricted to the Norway rat (Rattus norvegicus). However, the general paucity of Streptobacillus isolates, especially from their respective animal hosts, precludes definitive proof of these host tropisms. This is the first report of S. notomytis detection outside Asia and Australia and the first evidence for its role as a facultative pathogen in house rats.