Ticks on the move to the north – increased risk for …...SVA tick collection 2018 –New species...
Transcript of Ticks on the move to the north – increased risk for …...SVA tick collection 2018 –New species...
Ticks on the move to the north – increased risk for new zoonotic infections?Ann Albihn1,2, Giulio Grandi1,2 and Anna Omazic1
1National Veterinary Institute (SVA), Uppsala, Sweden2Dept. Biomedical Sciences & Veterinary Public Health, Swedish University ofAgricultural Sciences, Uppsala, Sweden
One Arctic – One Health Conference 2019, Feb 7 – 9, Oulu, Finland
Climate change effects
on the epidemiology of
infectious diseases and
the impacts on Northern
societies
Foto: Carl-Johan UtsiAlso granted by;The Hjärre fondationFuture Animals/SLU
• Photos: Carl-Johan
Utsi
Ticks are central when studying climate sensitive infections (CSIs)
Arthropod vectorborne CSIs - subgroupsTransmission routes
• Literature search about 37 potential CSIs together with climate change expressions.
• Revealed 11 179 publications - evaluation of 660 abstracts
• The abstract review process were slightly modified from Moher et al., 2009
Omazic et al., in manuscript
Climate change expands the geographical distribution of ticks to higher latitudes and altitudes.
• Ticks are expanding northwards in Sweden (Jaenson et al., 2012)
• Their role as disease vectors in the north is unclear
One Arctic – One Health Conference 2019, Feb 7 – 9, Oulu, Finland
Which diseases?Tick-borne encephalitis (TBE) and Borreliosis (Lyme disease) are well known.But granulocytic anaplasmosis and babesiosis are of growing concern in Swe.
How to handle tick-borne diseases?Reduce tick-bites
Habitat modification, “dipping” and pour on profylax
Disease specific treatment/profylaxMedical treatmentVaccine available for TBEUnder development for some of the diseases
Ticks are vectors for several zoonotic diseases
Photo: Anders Lindström
Collection of ticks from the northern half of Sweden
• To investigate the northern expansion of ticks and tick-borne pathogens
• Through a citizen science study year 2018
• Ticks found on animals or humans
• Morphological species identification
• Microbiological analysis with FLUIDIGM, a microfluidic PCR-based technique for an array of pathogens
SVA tick collection 2018
Number of ticks/county
Ixodes ricinus or common tick
Results
• 4500 ticks were received.
• Expanded geographical distribution. Ticks
from all northern communities except one
(Arjeplog).
• Tick species identification, mainly Ixodes
ricinus as far as this
(in addition I. trianguliceps ).
No I.persulcatus (yet…).
SVA tick collection 2018 – New species detection as a side effect
• Hyalomma marginatum and H. rufipes
• About 35 ticks• Normal area is south of the Alps• Vector for several diseases• Large, quick, aggressive, beautiful• Mainly found on horses• Larva hitch-hike on migrating birds• Development to an adult possible
due to long and hot summer• Their possibility to over-winter is
doubtful
Hyalomma marginatum Photo Artportalen
Attention in media
Anaplasmosis in sheep
• The most widespread TBD among animals in northern Europe.
• Tick-borne fever, pasture fever, Ehrliciosis, granulocytic anaplasmosis, (sjodagg Norway)
• High fever, abortion, reduced weight gain and milk production, also subclinical infection.
• Most serious is immunosuppression, secondary infections with high mortality.
• Caused by Anaplasma phagocytophilum
• 300 000 lambs infected yearly in Norway (Stuen, 2016.)
• E.g. cattle, horse, cat, dog, goat, roedeermay also get infected/act as reservoirs
Photo A. Albihn
Babesiosis in cattle
• Significant problem in certain areas
• Piroplasmosis, summer disease
• Symptoms in adults not in calves -hematouria, abortion, death
• Mainly B. divergens
• 4% of ticks in southern Sweden carry Babesia spp (Karlsson & Andersson, 2016)
• Seroprevalence• in southern Sweden 53% (38/71)
(Andersson et al., 2017)
• in southern Norway 27% (Hasle et al., 2010)
• E.g. dear, dog, may also get infected
• Collection of Swedish official animal disease data
• Anaplasmosis no cases of the notifiable A. marginale
• A. phagocytophilum is not compulsory to report but310 cases were diagnosed at SVA on ruminants year 2008-2018.
• Babesiosis 24 cases year 2005-2016,
• Notifiable B. major or B. bovis,
• B. divergens is not compulsory to report
Foto: Anders Lindström
Retrospective data collection on Anaplasmosis and Babesiosis
Anaplasmosis noted by
the Swedish Farm and
Animal Health
organisation.
104 cases at post-mortem
examination, from
diseased animals and/or
diagnosed at the lab.
A. phagocytophilum
Trend to increasing
numbers and a northern
expansion over the years.
Anaplasmosis in sheep2004 – 2017
Location in
• Traditional county
multiple cases 2004-2011
• New county
mainly cases 2012-2017
Albihn, 2019, unpublished
Babesiosis noted by the
Swedish Farm and Animal
Health organisation.
143 cases diagnosed post-
mortem
B. divergens (in generall not
confirmed at the lab)
Trend to increasing numbers
and a northern expansion
over the years.
Babesiosis in cattle2004 – 2017
Location in
• Traditional county
multiple cases 2004-2011
• New county
mainly cases 2012-2017
Albihn, 2019, unpublished
Anaplasmosis and Babesiosis in humans
• Anaplasmosis (A. phagocytophilum) first European cases diagnosed in 1997, a few cases has also been diagnosed in Sweden
• Babesiosis - increasing numbers of seropositive humans
• Babesia (B. divergens and B. microti) in the southernmost Sweden (Skåne), (Svensson et al., 2018)• 16,3% 14/86 Borrelia infected group
• 2,5% 5/197 control group
• 11,5% of tick exposed humans in Germany (Hunfeld et al., 2012)
When diseases show up in new areas, the unawareness may compromise protection of a population and the recognition of clinical symptoms.
In an immunologically unprotected population, a new infection may cause more severe clinical symptoms and/or higher mortality rate.
With new knowledge regarding the northern distribution of ticks and TBD, we may be able to identify new risk areas and to suggest measures to minimize diseases.
Foto: Anders Lindström
Conclusion