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Copyright 2007, The Johns Hopkins University and Diane Griffin. All rights reserved. Use of these materials permitted only in accordance with license rights granted. Materials provided “AS IS”; no representations or warranties provided. User assumes all responsibility for use, and all liability related thereto, and must independently review all materials for accuracy and efficacy. May contain materials owned by others. User is responsible for obtaining permissions for use from third parties as needed.
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Lyme Disease and Its Epidemiology
Diane E. Griffin, MD, PhDJohns Hopkins University
3
Diane E. Griffin, MD, PhD
Professor and Chair, Department of Molecular Microbiology and ImmunologyResearch interests fall in the area of pathogenesis of viral diseases, with a particular focus on measles and alphavirus encephalitisEditor for Field’s VirologyPresident-elect, American Society for Microbiology
Section A
Background/History
5
First Recognition of Lyme Arthritis in Connecticut, 1976
6
Characteristics of the First 52 Cases Identified
7
Site Affected/total Prevalence per 100 children
Old LymeRoad ARoad B
4/51
4/65
7.8
7.7
East HaddamRoad CRoad D
4/265/33
15.412.1
Total 17/175 9.7
Prevalence of Lyme Arthritis on Four Roads in Connecticut
8
Lyme Arthritis: Associated Symptoms (12 Patients)
MalaiseChills and feverHeadacheStiff neckBackacheMyalgiasNausea and vomitingSore throat
75%75%50%50%33%25%25%8%
Source: Steere, A. C., et al. (1977, June). Ann Intern Med, 86(6), 685–698.
9
Typical Lyme Arthritis
Photo by Dr. Alan Steere, Massachusetts General Hospital, Boston.
10
Typical Skin Lesion: Erythema Migrans (EM)
Source: CDC
11
Secondary Lyme Disease: Cardiac Manifestations
Atrioventricular blockPrimaryWenckebachComplete
90%40%30%
T wave inversion 50%
12
Bell’s Palsy Due to Lyme Disease
Source: CDC
13
Secondary Lyme Disease: Neurologic Manifestations
MeningitisEncephalitisCranial neuropathyRadiculitis
80%40%50%25%
14
Time Course of Various Lyme Disease Clinical Syndromes
15
Patients Neighbors P
Male 53 44
Rural environment 47 45
Woods activities 77 61
Pets 86 81
Pet cats 63 39 <0.01
Ticks on pets 70 27 <0.0001
Farm animals 26 11 <0.05
Tick bites 44 26 <0.05
Mosquito bites 72 70
Source: Steere, A. C., Broderick, T. F., and Malawista, S. E. (1978, October). Am J Epidemiol, 108(4), 312–321.
Case-Control Study
Lyme disease patients and neighbors, 1977
16
Seasonal Incidence of Lyme Disease in the U.S.
17
Disease Transmission
18Source: Steere
et al. (1978). Am J Epidemiol, 108, 312.
Lyme Disease: Attack Rates on Each Side of River, 1977
Rate per 1,000 residents
East side of Connecticut River 2.8
West side of Connecticut River 0.1
19
Ticks Found on Each Side of the Connecticut River
l. scapularis D. variabilis l. scapularis D. variabilis
Humans 8 37 33 20
Dogs 2 78 27 95
Cats 12 17 3 5
White-footed mice 29 26 498 143
Voles 0 5 3 2
Chipmunks 3 0 2 0
Raccoons 0 10 3 69
Skunks 0 0 1 6
Dragging 0 0 8 43
Total 54 173 578 373
West East
Section B
Identification of the Etiologic Agent of Lyme Disease and Its Distribution
21
Willy Burgdorfer, PhD
Medical entomologistRocky Mountain LaboratoriesBitterroot Mountains, Montana
22
Where Burgdorfer Studied Ticks in the Summer of 1981
23
Spirochetes Seen in the Midgut of Deer Ticks
Spirochetes seen in the midgut of deer ticks collected on Shelter Island
From Burgdorfer
W, et al. Lyme disease-a tick-borne spirochetosis? Science, 1982;216:1317. Reprinted with permission from AAAS. All rights reserved.
24
Source Days sick Culture 2 weeks Culture 2 weeks
Blood 2 16 64 16 512
Skin 25 64 32 32 128
Spinal fluid 70 32 32 512 1024
IgM
titer IgG
titer
Isolation of B. burgdorferi from Patients with Lyme Disease
Titers of antibody against spirochetes isolated from three patients
Source: Steere
et al. (1983). N Engl J Med, 308, 733.
25
Distribution of Erythema Migrans Cases in Europe
26
Distribution of Ixodes ricinus in Europericinus
27Source: Berglund et al. (1995). N Engl J Med, 333, 1319.
Manifestation Erythema
migrans
Neurobor-
reliosis Arthritis Acroderma-
titis
Lympho-
cytoma Carditis
Erythema
migrans 1,075 40 10 1 9 1
Neurobor-
reliosis 40 176 8 2 3 1
Arthritis 10 8 65 8 1 0
Acroderma-
titis 1 2 8 34 0 0
Lympho-
cytoma 9 3 1 0 26 0
Carditis 1 1 0 0 0 5
≥
3 mani-
festations 3 5 6 2 2 0
Total no. (%) 1,139 (77) 235 (16) 98 (7) 47 (3) 41 (3) 7 (<1)
Manifestations Differ in Europe and the U.S.Distribution of manifestations of Lyme disease in 1,471 patients
in Southern Sweden*
*The numbers of cases with only one manifestation of disease are
indicated in boldface
type. Six patients had three or more manifestations, and their
data are presented on a
separate line.
28
Borrelia burgdorferi species
B. burgdorferi sensu latoB. burgdorferi sensu strictoB. afzeliiB. garinii
Borrelia burgdorferi Species
29Source: Pachner
et al. (2004, September). Ann Neurol, 56(3), 361–370.
Lyme Neuroborreliosis
Summarized differences in neurologic manifestations of Lyme disease
30
Lyme Disease Incidence in the U.S.
31Source: CDC.
Lyme Disease: Reported Cases by County, U.S., 2001
32
Annual Incidence of Reported Cases, by Age and Sex
Source: CDC.
Section C
Natural Cycle and Reservoir of the Organism
34
Nymph
Male
Female
Ixodes scapularis Ticks
Source: CDC.
35
Abundance of differentstages of Ixodes ticksat different times of year
Abundance of Different Stages by Time of Year
36
White-tailed deer White-footed mouse
Hosts for Ixodes scapularis
Photo by Chili Bob. Some rights reserved.Photo by martytdx. Some rights reserved.
37
Tick Cycle in Relation to B. burgdorferi Transmission
38
Changes in North American Wildlife Populations
Species 1935* 1985
Bison 12,800 65,000
California Condor 60 6,
North American Elk 225,000 500,000
Pronghorn Antelope 40,000 750,000
Trumpeter Swan 73 10,000
White-tailed Deer 5 million 14.7 million
Whooping Crane 29 138
Wild Turkey 31,250 2.5 million
*Estimates by US Fish and Wildlife Service
39Source: Burgdorfer
et al. (1985). Am J Trop Med Hyg, 34(5), 925–930.
Percent Ixodes Ticks Positive for B. burgdorferi, by Location
Shelter Island, New York Up to 100%
Southeast Connecticut 35%
Northern California 1–2%
40
Distribution of Ixodes scapularis and Ixodes pacificus
41
Maintenance of the Natural Cycle: East and WestMaintenance of the natural cycle is different in the eastern & western U.S.
42
National Lyme Disease Risk Map
Source: CDC
43
Effect of Duration of Attachment
Transmission of B. burgdorferi by nymphal ticks—effect of duration of attachment
Hours of attachment
No. of infected ticks fed Mice infected/total
36 14.4 ±
3.5 1/14
42 16.4 ±
4.7 3/12
48 13.0 ±
3.7 6/8
Conclusion: Ticks must remain attached for about 48 hours to transmit infection
44
Efficacy of OspA Lyme Disease Vaccine in 2 Trials
End of year 1
Sigal et al
Placebo group # subjects (cases)
Vaccine group # subjects (cases)
Measured Vaccine Efficacy (95% CI)
Study and Year
5149 (37) 5156 (12) 68 (36-85)Steere et al
Definite/probable 5467 (43/13) 5469 (22/2) 49 (15-69)/ 83 (32-97)
End of year 2
Sigal et al2 doses 1411 (5) 1379 (2) 0 (0-60)3 doses 3770 (26) 3745 (22) 92 (69-97)
Steere et al3 doses (def/prob) 5467 (66/15) 5469 (16/0) 76 (58-86)/
100 (26-100)
Efficacy of OspA Lyme Disease Vaccine in Two Trials
45
Osp
A Osp
C
Borrelia Osp
Expression of outer surface proteins (Osp) on Borrelia in the midgut of unfed ticks
Figure Source: Schwan
TG, et al. Induction of an outer surface protein on Borrelia
burgdorferi
during tick feeding. PNAS 1995;92:2909-13. Copyright (1995) National Academy of Sciences, U.S.A
46
How the Osp A Lyme Disease Vaccine Protects
47
Lyme Disease Prevention
Distribution of pyrethrin-impregnated cotton balls in habitat of white-footed mice−
Kills ticks overwintering
with mice
48Source: Shapiro et al. (1992). N Engl J Med, 327, 1769.
Lyme Disease Prevention
Treatment Ticks infected Persons with LD
Placebo 23/159 (14%) 2/173 (1.2%)
Amoxicillin 30/185 (16%) 0/192 (0%)
49
Conclusions
Lyme disease is caused by a spirochetal bacteria, Borrelia burgdorferiThe reservoir host in the eastern U.S. is the white-footed mouseBorrelia is maintained in a geographically restricted natural cycle between ticks and mammalsHuman disease is determined by−
Exposure to infected ticks
−
The species of Borrelia causing infection