Eggshell abnormalities were seen in the apex of eggs in two of three flocks of multi-age, Hy-Line layer chickens housed on a farm in Northern Italy. Approximately 1.3% to 1.8% of eggs in one flock were affected, amounting to 300-400 eggs per day; the abnormalities resulted in a great deal of breakage and spoilage of healthy eggs. The mean weight of eggs was also reduced. Egg abnormalities in a second flock were less severe. Mycoplasma synoviae was detected in birds from both of the affected flocks by serologic, cultural, and molecular techniques, but not in a third, adjacent flock where no eggshell abnormalities were seen. Treatment with tylosin, administered in the drinking water for 5 days, resulted in an immediate improvement of eggshell quality and egg weight. There was no evidence of infectious bronchitis virus in the flocks.

Since 1997, G1-lineage H9N2 avian influenza viruses have been circulating in Asia and later on in the Middle East, and they have been associated to mild respiratory disease, drops in egg production and moderate mortality in chickens, in particular in the presence of concurrent infections. In this study, we investigated the importance of the G1-lineage H9N2 A/chicken/Israel/1163/2011 virus as a primary pathogen in layers, analyzing its tropism and binding affinity for the oviduct tissues, and investigating the long-term impact on egg production. Besides causing a mild respiratory infection, the virus replicated in the oviduct of 60% of the hens causing different degrees of salpingitis throughout the organ, in particular at the level of the infundibulum, where the detection of the virus was associated with severe heterophilic infiltrate, and necrosis of the epithelium. Binding affinity assays confirmed that the infundibulum was the most receptive region of the oviduct. The drop in egg production was at its peek at 2 weeks post-infection (pi) (60% decrease) and continued up to 80 days pi (35% decrease). On day 80 pi, non-laying birds showed egg yolk peritonitis, and histopathological analyses described profound alteration of the infundibulum architecture, duct ectasia and thinning of the epithelium, while the rest of the oviduct and ovary appeared normal. Our results show that this H9N2 virus is a primary pathogen in layer hens, and that its replication in the infundibulum is responsible for acute and chronic lesions that limits the effective functionality of the oviduct, compromising the commercial life of birds.Electronic supplementary materialThe online version of this article (10.1186/s13567-018-0575-1) contains supplementary material, which is available to authorized users.

Viral encephalopathy and retinopathy (VER), otherwise known as viral nervous necrosis (VNN), is a neuropathological condition affecting > 40 species of fish. Although VER affects mainly marine fish, the disease has also been detected in certain species reared in freshwater environments. There are relatively few reports concerning the disease in freshwater species, and there is not much information on clinical signs. Nevertheless, the most common clinical findings reported from affected freshwater species are consistent with the typical signs observed in marine species. In this paper we describe the main clinical signs and the laboratory results associated with the detection of a betanodavirus in hybrid striped bass × white bass (Morone saxatilis × Morone chrysops) and largemouth bass Micropterus salmoides, reared in a freshwater environment. We also detected the virus by realtime PCR and isolated it in cell culture from a batch of pike-perch Sander lucioperca farmed in the same system.

In spring 2022, Europe faced an unprecedented heatwave, increasing the risk of West Nile virus (WNV) outbreaks. As early as 7 June 2022, WNV was detected in Culex mosquitoes in northern Italy, and – in the following days – in two blood donors, a patient with encephalitis, wild birds and additional mosquito pools. Genome sequencing demonstrated co-circulation of WNV lineage 2 and a newly introduced WNV lineage 1, which was discovered in the region in 2021.

Ranaviruses are considered a serious threat to lower vertebrates, including fish, amphibians and reptiles. However, epidemiological data on these agents are lacking, and further investigations are needed to understand the role of carriers and to update the list of susceptible hosts. We carried out various experimental infections under controlled conditions to contribute to the current knowledge on the susceptibility of black bullhead Ameiurus melas to European catfish virus (ECV) and other ranaviruses. A panel of 7 ranavirus isolates was used to challenge duplicate groups of A. melas juveniles maintained in aquaria supplied with running dechlorinated tap water. The experiments were performed at 15 and 25°C. The results confirmed the high susceptibility of A. melas to ECV infection. Furthermore, a significant mortality associated with the typical signs of systemic viral infections was observed in groups challenged with Epizootic haematopoietic necrosis virus (EHNV) at 25°C, and to a lesser extent, at 15°C. No significant mortality was recorded in fish challenged with European sheatfish virus (ESV), Frog virus 3 (FV3), Rana esculenta virus-like (REVlike), Bohle iridovirus (BIV) or short-finned eel virus (SERV). KEY WORDS: Ranavirus · Black bullhead · Epizootic haematopoietic necrosis virus · European catfish virus · European sheatfish virusResale or republication not permitted without written consent of the publisher