Lyme disease conference

Lyme disease in Scotland Roger Evans, Raigmore Hospital, NHS Highland 9 October 2013

Small beginnings

• 1988: cases noted by GPs, Immunofluorescence

testing on serum samples

• 1994: first referrals outside of NHS Highland

• 1995: two step testing protocol of EIA and WB.

• 2003: established national Lyme borreliosis

testing laboratory (SNLBTL) in Inverness.

0

1000

2000

3000

4000

5000

6000

Number of

samples

1988 1991 1994 1997 2000 2003 2006 2009 2012

Year

Number of Highland and referred serum samples for Lyme

borreliosis testing from 1988-2012

Referred

Highland

First referrals from

outside Highland

area

Introduction of 2-step

EIA / WB testing

protocol

Scottish National

LB testing laboratory

established

Number of seropositive LB cases diagnosed by SNBTL from 1999-2012

0

50

100

150

200

250

300

350

400

450

500

1999 2000 2001 2002 20032004 2005 2006 20072008 2009 2010 2011 2012

Year

Nu

mb

er

of

cases

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Total cases

Females

Males

Incidence/100,000

LB epidemiology

Reporting new cases

• In Scotland, Lyme borreliosis is not a

notifiable disease but Borrelia burgdorferi

is a notifiable organism (Public Health Act

2006)

• Current data: all first time Western blot

positive cases reported

• Current practice to send a questionnaire

from these patients to all clinicians

Are the data correct?

• LB is a clinical diagnosis supported by

laboratory results

– Does WB positive = active LB?

• Encouraging clinicians not to test for LB if

they present with erythema migrans (EM)

– Figures need revising: likely to be higher

• GPs do not refer all LB patients for testing

– Figures need revising: likely to higher (5-10x)

Current challenges

• Investigating avidity WB to identify

markers of active / early / past infection

– Encouraging results so far

• Revising reporting of LB cases to Health

Protection Scotland (HPS) to include those

patients with EM (not tested)

• GP R&D project: investigate the number of

cases not being referred by GPs

Tick collections

Results

• 159 ticks collected

• 25 isolates

• 7 identified so far

– B. burgdorferi sensu

stricto, B. garinii,

B.afzelii

• 7 culture +, PCR -

• 18 isolates for whole

genome sequencing to

be performed

Culture

Positive Negative

PCR

Positive 18 3

Negative 7 26

Site No. of

ticks

Culture

positive

%

prevalence

Urchany 115 22 19.1

Culloden 37 2 5.4

Inverness 6 1 16.7

Tick comments

• Culture positive, PCR negative

– Spatial sampling / low numbers (culture

became positive within 3-4 days)

– Other Borrelia sp.? Not B. miyamotoi as PCR

based on flagellin gene which can detect this

species

• Ecology value – is the Borrelia genome

changing over time?

Conclusions

• From small beginnings a competent, LB diagnostic laboratory has been established in Scotland

• Addressing the need for active Borrelia infection marker

• Revising epidemiology data to give more accurate picture of LB in Scotland

• Exploring whether other tick-borne infections are present in Scotland

Lyme disease conference

9 October 2013