Retrospective analysis of sero-prevalence and bait uptake estimations in foxes after oral rabies vaccination programmes at European level: Lessons learned and paths forward

Emmanuelle Robardet; Anna Zdravkova; Darinka Ilieva; Enel Hakmann; Ioanna Georgopoulou; Konstantia Tasioudi; Tiina Nokireki; Marja Isomursu; Ivana Lohman Jankovic; Ivana Lojkic; Martins Serzants; Zanete Zommere; Marius Masiulis; Ingrida Jaceviciene; Vlad Vuta; Marine Wasniewski; Dimitrios Dilaveris

doi:10.1016/j.vetmic.2023.109917

Retrospective analysis of sero-prevalence and bait uptake estimations in foxes after oral rabies vaccination programmes at European level: Lessons learned and paths forward

Vet Microbiol. 2024 Jan:288:109917. doi: 10.1016/j.vetmic.2023.109917. Epub 2023 Nov 25.

Authors

Emmanuelle Robardet¹, Anna Zdravkova², Darinka Ilieva³, Enel Hakmann⁴, Ioanna Georgopoulou⁵, Konstantia Tasioudi⁶, Tiina Nokireki⁷, Marja Isomursu⁷, Ivana Lohman Jankovic⁸, Ivana Lojkic⁹, Martins Serzants¹⁰, Zanete Zommere¹¹, Marius Masiulis¹², Ingrida Jaceviciene¹³, Vlad Vuta¹⁴, Marine Wasniewski¹⁵, Dimitrios Dilaveris¹⁶

Affiliations

¹ Anses, Nancy Laboratory for Rabies and Wildlife, EURL for Rabies, Bâtiment H, Technopôle Agricole et Vétérinaire, CS 40 009, 54220 Malzéville Cedex, France. Electronic address: [email protected].
² Bulgarian Food Safety Agency, 15 Pencho Slaveykov Blvd., Sofia 1606, Bulgaria.
³ National Diagnostic and Research Veterinary Institute, 15 Pencho Slaveykov Blvd., Sofia 1606, Bulgaria.
⁴ Veterinary and Food Board, Teaduse 2, Saku, Harjumaa 7550 Väike-Paala 3, Tallinn 11415, Estonia.
⁵ Department of Zoonoses, Animal Health Directorate, Directorate General of Veterinary Medicine, Ministry of Rural Development and Food, 46, Veranzerou str, PC 104 38 Athens, Greece.
⁶ Department of Molecular Diagnostics, FMD, Virological, Ricketsial and Exotic diseases, Athens Veterinary Centre, Ministry of Rural Development and Food, 25, Neapoleos str, PC 15341, Agia Paraskevi, Athens, Greece.
⁷ Finnish Food Authority, Mustialankatu 3, 00790 Helsinki, Finland; Finnish Food Authority, Elektroniikkatie 3, 90590 Oulu, Finland.
⁸ Ministry of Agriculture, Veterinary and Food Safety Directorate, Savska cesta 143, 10000 Zagreb, Croatia.
⁹ Croatian Veterinary Institute, Savska cesta 143, 10000 Zagreb, Croatia.
¹⁰ Food and Veterinary Service, Peldu street 30, Riga LV-1050, Latvia.
¹¹ Institute of Food Safety, Animal Health and Environment "BIOR", Lejupes iela 3, Riga LV-1076, Latvia.
¹² State Food and Veterinary Service, Siesiku str., 19 07170 Vilnius, Lithuania.
¹³ National Food and Veterinary Risk Assessment Institute, J. Kairiukscio str. 10, LT-08409 Vilnius, Lithuania.
¹⁴ Institute for Diagnosis and Animal Health, str dr staicovici nr, 63, 050557 Bucharest, Romania.
¹⁵ Anses, Nancy Laboratory for Rabies and Wildlife, EURL for Rabies, Bâtiment H, Technopôle Agricole et Vétérinaire, CS 40 009, 54220 Malzéville Cedex, France.
¹⁶ European Commission, Directorate-General for Health and Food Safety, B-1049 Brussels, Belgium.

PMID: 38039917
DOI: 10.1016/j.vetmic.2023.109917

Abstract

Rabies caused by the Classical Rabies Virus (Lyssavirus rabies abbreviated RABV) in the European Union has been close to elimination mainly thanks to Oral Rabies Vaccination (ORV) campaigns targeting wildlife (primarily red foxes). ORV programmes co-financed by the European Commission include a monitoring-component to assess the effectiveness of the ORV campaigns at national level. This assessment is performed by a random collection of red foxes in the vaccinated areas with control of antibodies presence by serological analysis and control of bait uptake by detection of biomarkers (tetracycline incorporated into the baits) in the bones and teeth. ORV programmes aim to a vaccine coverage high enough to immunize (ideally) 70 % of the reservoir population to control the spread of the disease. European Union (EU) programmes that led to almost elimination of rabies on the territory have been traditionally found to have a bait uptake average of 70 % (EU countries; 2010-2020 period) while the seroconversion data showed an average level of 40 % (EU countries; 2010-2020 period). To better understand variations of these indicators, a study was been set up to evaluate the impact of several variables (linked to the vaccination programme itself and linked to environmental conditions) on the bait uptake and the seroconversion rate. Thus, pooling data from several countries provides more powerful statistics and the highest probability of detecting trends. Results of this study advocate the use of a single serological test across the EU since data variation due to the type of test used was higher than variations due to field factors, making the interpretation of monitoring results at EU level challenging. In addition, the results indicates a negative correlation between bait uptake and maximum temperatures reached during ORV campaigns questioning the potential impact of climatic change and associated increase of temperatures on the ORV programmes efficiency. Several hypotheses requesting additional investigation are drawn and discussed in this paper.

Keywords: Bait uptake; Monitoring; Oral vaccination; Rabies; Red fox; Seroconversion.

MeSH terms

Administration, Oral
Animals
Foxes
Prevalence
Rabies Vaccines*
Rabies virus*
Rabies* / epidemiology
Rabies* / prevention & control
Rabies* / veterinary
Retrospective Studies
Vaccination / methods
Vaccination / veterinary

Substances

Rabies Vaccines