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