VILKA MIKROORGANISMER EXPONERAS VI FÖR VID FÄSTINGBETT-RISKER?

Pia Forsberg

Professor emerita Infektionsmedicin

Department of Clinical and Experimental Medicine

Linköping University

TICK-BORNE MICROBES

Bacteria

Borrelia spp.

Anaplasma phagocytophilum

Rickettsia spp.

Candidatus Neoehrlichia mikurensis

Bartonella spp.

Francisella tularensis

Parasites and viruses

Babesia spp.

Toxoplasma gondii

TBE virus

Nairovirus

Few studies have investigated

the incidence of infection

by tick-borne microbes

after a tick bite

E.G.

BORRELIA BURGDORFERI SENSU LATO

No investigations of Borrelia in ticks that have bitten humans have been performed in Sweden

E.G. BORRELIA BURGDORFERI SENSU LATO

but worldwide: 20 % on the Dutch island of Ameland (Jacobs et al., 2008)

10 % in the western part of Switzerland (Nahimana et al., 2004)

1% in Texas, United States (Williamson et al., 2010)

BUT

Serological and clinical data were not notified

No attempts to quantify Borrelia cells were made

Duration of feeding was empirically estimated by direct observation of the ticks

THE

TBD STING

STUDY

AIMS

How large is the RISK to become infected/develop disease after a

tick bite?

How many of the ticks that have bitten humans contain

tick-borne microbes - which?

AIMS

What tick-borne microbes are present in ticks from Nordic countries?

Geographical differences?

Species/subtypes of microbes?

Do the risk of developing disease correlate with the ticks:

Quantity of microbes?

Species/subtype of microbes?

Feeding time duration?

TBD STING STUDY

2007 - 2015

10 000 fästingar DNA

3 mån studieperiod

5500 bitna individers blod x 2

5500 enkäter x 2

18år, mest kvinnor, 60-65 år

> 60 vårdcentraler Norge

Sverige

Åland, Finland

Questionnaires

Tick

Blood sample

Hmm...

Intressant

Real-time PCR

Tick-borne microbes?

Serology

Immune response?

Antibody production?

STUDY DESIGN

Health status?

Clinical diagnosis?

• 3 months follow-up

• Collection of

additional ticks

• Health records

ANNONSEN + MASSMEDIAL KOMMUNIKATION

Questionnaires

Tick

Blood sample

Hmm...

Intressant

Real-time PCR

Tick-borne microbes?

Serology

Immune response?

Antibody production?

STUDY DESIGN

Health status?

Clinical diagnosis?

• 3 months follow-up

• Collection of

additional ticks

• Health records

Blood sample

0mo. + 3mos.

Health status?

Clinical outcome?

2 ELISA tests

(anti-flagellum

& anti-C6)

New production of

antibodies?

Borrelia-caused infection? Line immunoblot

(8 antigens, 4 species)

Questionnaires

0mo. + 3mos.

+ medical records

ANALYSING THE TICK-BITTEN INDIVIDUALS - SEROLOGY AND CLINICAL OUTCOME

Jeremy Gray, Gerold Stanek, Michael Kundi, Elena Kocianova

International Journal of Medical Microbiology 295 (2005) 567-572

DinoLite USB-microscope

> 24h

< 24h

Photo & measure

Scutal index, SI = A/B

Coxal index, CI = A/c

Analysing the ticks

TICKS IN SWEDEN

11 species– Ixodes ricinus > 95%

Ticks are active down to 4°C

Life stages: egg, larva, nymph and adult

Food for parasitoid wasps, beetles, birds, ants and spiders

Lack eyes but have a good ”sense of smell”

RESULTS BORRELIA SPP.

WHAT DID THE TICKS CONTAIN?

26% of the 2154 ticks were Borrelia positive

50%

20%

6%

4%

2% 1%

0.5%

0.5% 16%

Detected Borrelia species, n=556

B. afzelii

B. garinii

B. valaisiana

B. burgdorferi

B. miyamotoi

B. spielmanii

B. lusitaniae

mixed species

untypeable

* p < 0.05

** p < 0.01

*** p < 0.001

BORRELIA SPECIES AND CELL QUANTITY

BORRELIA

26% (n=428/1546) were bitten by Borrelia-positive ticks

BORRELIA

In total:

2.1% (n=32) of all 1546 participants

developed LB.

2.5% (n=39) of all participants developed

asymptomatic infection (seroconversion)

BORRELIA INFECTION

22

428 bitten by Borrelia-positive

ticks

32 (7.5%)

Borrelia-infected individuals

16

LB cases

16 seroconversions (no LB cases)

396

uninfected individuals

1118 bitten by Borrelia-negative

ticks

39 (3.5%)

Borrelia-infected individuals

16

LB cases

23 seroconversions (no LB cases)

1079

uninfected individuals

CLINICAL MANIFESTATIONS

32 participants received a LB diagnosis during the 3 months study period

27 (84%) EM

2 (6%) NB

2 (6%) non-specific LB

1 (3%) Borrelia lymphocytoma

23

SELF-REPORTED NON-SPECIFIC SYMPTOMS

23% (349/1546) of all participants reported non-specific symptoms possibly associated with LB

Of which 20.3% (n=71) visited health care

24

Symptoms:

Fatigue

Myalgia/

Arthralgia

Headache

Neck pain

Numbness

Radiating

pain

Vertigo

Cognitive

difficulties

Nausea

Loss of

appetite

Fever

Loss of

weight

CONCLUSION BORRELIA

Every fourth tick Borrelia infected

7 Borrelia species detected

2.1% was diagnosed with LB 84% EM

68.8 % of all seroconversions did not experience non-specific symptoms or developed LB

Wilhelmsson P et al Parasites & Vectors, 2013 Wilhelmsson P et al PLoS One, 2013

Wilhelmsson P et al Ticks Tick Borne Dis. 2016

RESULTS TBE-VIRUS

5 / 2167 ticks positive for TBE-

V

Åland Kalmar Åland Saringe

Month of tick-bite

August August September June July

Life stage Nymph Nymph Nymph Nymph Nymph

Feeding time (h) < 12 24-36 < 12 12-24 >60

Virus copies in tick

< 400 ~ 4200 < 400 ~ 1800 ~ 7 700 000

Location of tick Leg Waist Back thigh Leg Behind ear

Visited health care

No Yes (Borrelia) No No Yes

Symptoms No Yes (Borrelia) No No Yes

TBE vaccinated Yes Yes Yes No Vacc, after

Co-infection Borrelia No Anaplasma No Borrelia

Location: Åland

Results: TBE-V qPCR

Conclusion TBE-V

• Over all very low risk of TBE-V

• 5 / 2167 (0,23 %) ticks that had bitten persons were positive for TBE-V. One developed symptoms (not serious)

• To few for conclusions on feeding-time and virus copy number or the riskassesment

Lindblom P et al Ticks and Tick Borne Diseases, 2014

RESULTS ANAPLASMA PHAGOCYTOPHILUM

ANAPLASMA

1291 ticks were analysed

40 of 1291 (3.1%) were positive for A. phagocytophilum

0.8% of all ticks were co-infected with Borrelia and Anaplasma

24% of the Anaplasma positive ticks were co-infected with Borrelia

No symptoms

Henningsson AJ et al Ticks Tick Borne Dis. 2015

RESULTS RICKETTSIA SPP.

RICKETTSIA

473 ticks were analysed

23 of 473 (4.9%) were positive for Rickettsia helvetica

Kalmar (n=1/82)

Östergötland (4/98)

Jönköping (7/97)

Lidköping (11/98)

All samples from Åland were negative (98)!!!!!!

Vague symptoms, nausea, radiating pain more common in seroconverted persons.

Lindblom A et al European Journal of Clinical Microbiology and Infectious Diseases, 2013

Lindblom A et al PLoS One. 2016

RESULTS NEOEHRLICHIA

3248 tick-bitten individuals

103 to primary health care center (during study period 3 m)

2/103 pos PCR in blood (1,9%)

EM

Co-infection Borrelia (1) serology

Co-infection Anaplasma (1) serology

Grankvist A et al Emerg Infect Dis. 2015

RESULTS BABESIA 65/2098 ticks pos Babesia (3,1%) from 1769 bitten persons

B microti 50,8%

B venatorum 41,5%

B divergens 7,7%

46% of the 65 Babesia pos ticks were Co-infected with Borrelia

Number of Babesia / tick = <10 - 1miljon

Feeding time <24h - >72h

65 BITTEN PERSONS BY BABESIA POS TICK

PCR in blood neg

Serology:

no seroconversion during 3 months

6% had Babesia ab:s in the 1:st blood sample!!

10 persons had vague ospecific symptoms

To be submitted M

Lövmar et al

ON GOING INVESTIGATION

Francisella tularensis

Bartonella spp.

Toxoplasma gondii

TICK-BORNE MICROBES

Bacteria

Borrelia spp.

Anaplasma phagocytophilum

Rickettsia spp.

Candidatus Neoehrlichia mikurensis

Bartonella spp.

Francisella tularensis

Parasites and viruses

Babesia spp.

Toxoplasma gondii

TBE virus

Nairovirus

CO-INFECTIONS

TBD STING STUDY

Infectious Medicine, LiU

Pia Forsberg

Johanna Sjöwall

Liselott Lindvall

Lisa Gunnarsson

Clinical Immunology, LiU

Christina Ekerfelt

Linda Fryland

Mari-Anne Åkeson

Karin Söderman

Medical Microbiology, LiU

Per-Eric Lindgren

Peter Wilhelmsson

Pontus Lindblom

Others

Sven Bergström

Anna Jonsson Henningsson

Barbro Hedin Skogman

Johan Berglund

Katharina Ornstein

Ivar Tjernberg

Dag Nyman (Åland)

Marika Nordberg (Åland)

Peter Nolskog

Mats Haglund

Clas Ahlm

Knut Eirik Eliassen (Norway)

Harald Reiso (Norway)

Matilda Lövmar

and other collaborating partners

FINANCIAL SUPPORT

The Swedish Research Council

Linköping University

County Council of Östergötland

The Medical Research Council of Southeast Sweden

Wilhelm and Else Stockmann Foundation

Foundation for Åland Medical Research

of the Åland Culture Foundation

EU Interreg IV A, ScandTick

www.liu.se