title: Experimental Infection of Ornithodoros erraticus sensu stricto with Two Portuguese African Swine Fever Virus Strains. Study of Factors Involved in the Dynamics of Infection in Ticks.
abstract: African swine fever (ASF) is a frequently devastating hemorrhagic disease of domestic pigs and wild boar and Ornithodoros erraticus sensu stricto argasid ticks are the only biological vectors of African swine fever virus (ASFV) known to occur in Europe. Recently this disease emerged in Eastern Europe and Russian Federation, showing a huge potential for a rapid spread between countries. There is some risk of re-emergence of ASF in the countries where these ticks exist, that can contribute for the persistence of infection and compromise control measures. In this study we aimed to identify factors that determine the probability of infection and its dynamics in the tick vector Ornithodoros erraticus sensu stricto, with two Portuguese strains of ASFV. Our results suggest that these ticks have a high likelihood of excreting the two haemadsorbing ASF viruses of different host origins and that, in field surveys, the analysis of adults and 5th nymphal stage can provide the best chance of detecting virus infection. The results also indicate that infection of pigs with highly virulent ASF viruses will promote higher rates of infection and a higher likelihood for virus excretion by ticks. Nevertheless, there is also a risk, although lower, that ticks can become infected on pigs that have overcome the acute phase of infection, which was simulated in our study by membrane feeding ticks with low titres of virus. We believe these results can be valuable in designing and interpreting the results of ASF control programmes, and future work can also be undertaken as our dataset is released under open access, to perform studies in risk assessment for ASFV persistence in a region where O. erraticus sensu stricto ticks are present.
authors.affiliation: Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Ribeiro
authors.affiliation: FAO Regional Office for Asia and the Pacific, 39 Phra-Atit Road, 10200 Bangkok, Thailand.
authors.forename: Joachim
authors.initials: J
authors.lastname: Otte
authors.affiliation: Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.
authors.forename: Sara
authors.initials: S
authors.lastname: Madeira
authors.affiliation: The Pirbright Laboratory, Institute for Animal Health, Ash Road, Woking, Surrey, GU24 0NF, United Kingdom.
authors.forename: Geoff H
authors.initials: GH
authors.lastname: Hutchings
authors.affiliation: Centre for Interdisciplinary Research in Animal Health (CIISA), Faculty of Veterinary Medicine, University of Lisbon, Lisbon, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Boinas
mesh_terms: D000357:African Swine Fever / Q000635:transmission* / Q000821:virology; D000358:African Swine Fever Virus / Q000145:classification / Q000472:pathogenicity*; D000818:Animals; D005260:Female; D008297:Male; D009758:Nymph / Q000254:growth & development / Q000821:virology; D026861:Ornithodoros / Q000254:growth & development* / Q000378:metabolism / Q000821:virology*; D011174:Portugal; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000635:transmission / Q000821:virology