The emergence of CWD in Europe in 2016 and the first natural infection in wild reindeer warranted disease management. This led to the testing of 2424 hunted or culled reindeer during 2016-2018, from the infected subpopulation in the Nordfjella mountain range in Southern Norway. To identify any association between PRNP variation and CWD susceptibility, we characterized the open reading frame of the PRNP gene in 19 CWD positive reindeer and in 101 age category-and sex-matched CWD negative controls. Seven variant positions were identified: 6 single nucleotide variants (SNVs) and a 24 base pair (bp) deletion located between nucleotide position 238 and 272, encoding four instead of five octapeptide repeats. With a single exception, all variant positions but one were predicted to be nonsynonymous. The synonymous SNV and the deletion are novel in reindeer. Various combinations of the non-synonymous variant positions resulted in the identification of five PRNP alleles (A-E) that structured into 14 genotypes. We identified an increased CWD risk in reindeer carrying two copies of the most common allele, A, coding for serine in position 225 (Ser225) and in those carrying allele A together with the 24 bp deletion. ARTICLE HISTORY

and J. V age. 2019. The demographic pattern of infection with chronic wasting disease in reindeer at an early epidemic stage.Abstract. Infection patterns linked to age and sex are crucial to predict the population dynamic effects of diseases in long-lived species. How such demographic patterns of infection arise is often multifactorial, although the cause is commonly seen as a combination of immune status as well as variation in pathogen exposure. Prion diseases are particularly interesting, as they do not trigger an adaptive immune response; hence, differences in pathogen exposure linked to behavior could be the prime determinant of the pattern of infection. In cervids, the fatal prion disease, chronic wasting disease (CWD), is spreading geographically, with economic and cultural consequences in affected areas in North America, and all infected individuals eventually die from disease-associated sequelae if they live long enough. Understanding the causes of the demographic pattern of infection with CWD is therefore urgent but is limited by the fact that reported data primarily come from related deer species in North America. The recent (detected 2016) emergence of CWD among wild alpine reindeer (Rangifer tarandus) in Norway with a different social organization, that is, no home range behavior and no matrilineal female groups, offers an opportunity to advance our understanding of how behavior influences the infection patterns. Testing of 1081 males and 1278 females detected 19 animals positive for abnormal prion protein in brain and/or lymphatic tissues. No calves and only one male yearling were infected, with the remaining positives being adults (representing 1.5% of adult males and 0.5% of adult females). We found a strong sex-biased infection pattern in reindeer (with infection 2.7 times more likely in adult males), which is similar to the results reported in mule deer and white-tailed deer. The hazard of being detected as positive increased with age in males. There was no close genetic relatedness among positive animals. The results were consistent with the within-group contact of males being a possible major route of transmission. We discuss the demographic pattern of infection with CWD in view of the lack of stable home range behavior and other key behavioral traits of reindeer relevant to understanding pathogen exposure in general.

Susceptibility to prion diseases is largely determined by the sequence of the prion protein gene ( PRNP ), which encodes the prion protein (PrP). The recent emergence of chronic wasting disease (CWD) in Europe has highlighted the need to investigate PRNP gene diversity in European deer species, to better predict their susceptibility to CWD. Here we report a large genetic survey of six British deer species, including red ( Cervus elaphus ), sika ( Cervus nippon ), roe ( Capreolus capreolus ), fallow ( Dama dama ), muntjac ( Muntiacus reevesii ), and Chinese water deer ( Hydropotes inermis ), which establishes PRNP haplotype and genotype frequencies. Two smaller data sets from red deer in Norway and the Czech Republic are also included for comparison. Overall red deer show the most PRNP variation, with non-synonymous/coding polymorphisms at codons 98, 168, 226 and 247, which vary markedly in frequency between different regions. Polymorphisms P168S and I247L were only found in Scottish and Czech populations, respectively. T98A was found in all populations except Norway and the south of England. Significant regional differences in genotype frequencies were observed within both British and European red deer populations. Other deer species showed less variation, particularly roe and fallow deer, in which identical PRNP gene sequences were found in all individuals analysed. Based on comparison with PRNP sequences of North American cervids affected by CWD and limited experimental challenge data, these results suggest that a high proportion of wild deer in Great Britain may be susceptible to CWD.

We report the first detection of methicillin-resistant Staphylococcus aureus isolates in pigs in Peru. The isolates belong to a livestock-associated lineage previously reported in North America and Europe, CC398, and a highly virulent USA300-like ST8-IV variant, which is the predominant community-associated lineage in Latin America.