1. BORRELIOSIS

2. Phylogeny
• Phylum – Spirochete
• Named after French Biologist Amedee Borrel
• 36 known species
• 05 pathogenic :
– B. burgdorferi sensu stricto – Arthitogenic
– B. burgdorferi sensu lato Lyme’s
– B. garinii – Neurogenic
– B. afzelii - Cutaneous manifestations
– B. recurrentis – Relapsing Fever

3. Introduction
• 1900s, manifestation first reported in Europe
– associated it with tick bites (TBD)
• 1975 - outbreak in Lyme, Connecticut - ‘JRA’
• 1982 - Spirochetes from midgut of the black-legged tick
(Ixodes scapularis erst dammimi) and named Borrelia
burgdorferi after American scientist Willy Burgdorfer
• Commonest tick-borne infection (US) - >16000 / yr

4. Structure
• slender helical shaped bacteria
• Gram negative
• Motile
• Extracellular pathogen
• Aerobic or microaerophilic

5. Transmission
• Vector-borne disease – N Am / EU
• Rodents / Deer - black-legged tick (Ixodes scapularis) or
Western black-legged tick (Ixodes pacificus)
• Transmits B. burgdorferi while feeding on an uninfected
host
– the spirochetes are present in the midgut and migrate during
blood feeding to the salivary glands, from which they are
transmitted to the host via saliva.
• B. burgdorferi cannot penetrate intact skin

6. Exposure Risk
• Residential exposure to infected ticks during
property maintenance, recreation, and leisure
activity
• Outdoor occupations
• Forestry
• Landscaping

7. Ixodes sp
• a

8. Life Cycle
• aa

9. Pathogenesis
• Initial Inoculation
• Expression of Osp A / C
• Binding to TLR – 1 / 2
• Immunological Cascade
• Humoral (Ig M / G)
• Complement

10. Clinical Features
• aa
ACA ; BLC

11. Erythema Chronicum
Migrans (ECM)
• 90% develop ECM at the site of inoculation
• 1–36 (average 9) days after the bite
• local spread of the spirochaete  ring formation
EXPANDING @ few cms / wk
• Zone of clearing behind the advancing ring
producing a target-like morphology (BULL’S EYE
LESIONS)
• LAN + Constitutional Symptoms

12. • aa

13. Acrodermatitis Chronica
Atrophica (ACA)
• Syn – Herxheimer’s Disease
• late cutaneous manifestation of dissemination
• 01 or more years after the original infection
• Hands, feet, knees and elbows
• begins as an erythematous plaque, which slowly
enlarges and gradually becomes violaceous and
atrophic (‘tissue paper atrophy’)
• Spirochaetes have occasionally been cultured

14. • aa

15. DDx
• aa

16. DDx

17. Diagnosis
SEROLOGY
AB-based
• ELISA
• Western Blot
AG-based
• NAAT (PCR / bDNA / TMA / NASBA)
DIRECT ISOLATION
Stains (WSS / DIETERLE / GS / WGS )
HPE 17

18. HPE
ECM
• Focal epidermal spongiosis and parakeratosis can be
seen
• Tightly cuffed Dermal perivascular lymphocytic
infiltrate may contain Plasma Cells
ACA
• Epidermal Atrophy
• liquefaction degeneration of the basal layer and
telangiectasia of the papillary dermis
• Diffuse Dermal perivascular lymphocytic infiltrate
containing Plasma Cells
• Warthin–Starry stain identified spirochaetes in 40% of
cases of both morphologies

19. HPE

20. • aa

21. Dr.T.V.Rao MD 21

22. THANK YOU