Serologic evidence for canine distemper virus (CDV) has been described in grey wolves but, to our knowledge, virus strains circulating in wolves have not been characterized genetically. The emergence of CDV in several non-dog hosts has been associated with amino acid substitutions at sites 530 and 549 of the hemagglutinin (H) protein. We sequenced the H gene of wild-type canine distemper virus obtained from two free-ranging Iberian wolves (Canis lupus signatus) and from one domestic dog (Canis familiaris). More differences were found between the two wolf sequences than between one of the wolves (wolf 75) and the dog. The latter two had a very high nucleotide similarity resulting in identical H gene amino acid sequences. Possible explanations include geographic and especially temporal proximity of the CDV obtained from wolf 75 and the domestic dog, taken in 2007-2008, as opposed to that from wolf 3 taken more distantly in 1998. Analysis of the deduced amino acids of the viral hemagglutinin revealed a glycine (G) and a tyrosine (Y) at amino acid positions 530 and 549, respectively, of the partial signaling lymphocytic activation molecule (SLAM)-receptor binding region which is typically found in viral strains obtained from domestic dogs. This suggests that the CDV found in these wolves resulted from transmission events from local domestic dogs rather than from wildlife species.
7 February 2021 in Current Clinical Microbiology Reports
The objective of this study was i) to quantify the risk of hepatitis E for Swiss consumers by specified pork products and ii) to estimate the total burden of human food-borne hepatitis E in Switzerland. A quantitative risk assessment from slaughter to consumption was carried out according to the Codex Alimentarius framework. In the hazard characterization, assumptions were made due to the lack of a dose-response relationship for oral exposure to hepatitis E virus (HEV). The prevalence of HEV in 160 pig livers of 40 different Swiss fattening farms was examined and determined to be 1.3% (CI 0.3%; 4.4%). This result was used as input in the risk assessment model, together with data from other published studies. The annual burden of hepatitis E was estimated in terms of Disability Adjusted Life Years (DALY), using data about hepatitis E cases diagnosed between 2010 and 2015 at two major hospitals located in the canton Ticino. Only the risk of foodborne hepatitis E from products containing pork liver was evaluated, as those containing only pork meat could not be evaluated because of lack of data on HEV load in pork. Assuming that successful oral infection occurs in 1% of servings contaminated with high HEV loads (>105 genome copies), and that acute illness develops in 5% of susceptible consumers, the most likely annual number of foodborne hepatitis E cases in Switzerland was estimated to be 1481 (95% CI 552; 4488) if all products containing pork liver were considered. If only high-risk products, such as plain pork liver and liver sausages (e.g. Saucisse au Foie), were considered, the annual number of cases was estimated to be 176 (95% CI 64; 498). We were unable to calculate the total burden of hepatitis E in Switzerland due to lack of data. Yet, for the canton Ticino, it was shown that a significant increase had occurred from 50 DALY per 100,000 inhabitants in 2015. This change could partly be due to an increased reporting and higher awareness among medical practitioners. Extrapolation to other regions could be accomplished if detailed information on food consumption patterns were available. Notification of HEV cases and attempts of cases source attribution would improve the basis for risk assessments.
1 July 2008 in Journal of Veterinary Diagnostic Investigation
Canine parvovirus (CPV) has been evolving, generating new genetic and antigenic variants throughout the world. This study was conducted to determine the types of CPV circulating in dogs in Figueira da Foz, Portugal. Thirty fecal samples, collected between 2006 and 2007 from dogs with clinical signs of CPV infection, were tested for CPV by a rapid, in-clinic, enzyme-linked immunosorbent assay (ELISA)/immunomigration test, by conventional real-time polymerase chain reaction (PCR), and by minor-groove binding TaqMan PCR. Of the 29 PCR-positive samples, 15 were identified as CPV-2b and 14 as CPV-2c. No CPV-2a was detected. The sensitivity of the ELISA test was 82.76% compared with the PCR assays. No significant associations were found between CPV type, clinical outcome, breed, vaccination status, or age.
Mutations were analysed in the major capsid protein VP60 of the rabbit haemorrhagic disease virus (RHDV), a calicivirus responsible for high mortality rates in both wild and domestic European rabbits (Oryctolagus cuniculus). Likelihood of positive selection was estimated using the PAML software applied to 43 non-identical complete sequences of the major capsid protein. Three codons showed signs of positive selection (with posterior probabilities over 95%), one of them is located in the region containing the major antigenic determinants (region E). The presence of positively selected codons (PSCs) in other regions may suggest the existence of other antigenic regions on the major capsid protein that stimulate protective immune responses. At all the 3 PSCs, variation contributes to putative N-glycosylation sites of the protein. An N-glycosylation site is deleted in the non-pathogenic strain RCV. Some of the substitutions at PSCs may alter the polarity and the charge of the protein with possible implications in the protein structure and host interaction. The detection of PSCs should allow a better understanding of the interaction between RHDV and the rabbit immune system.