High Yield Overview

LYME DISEASE - MUSCULOSKELETAL

Borrelia burgdorferi | Tick-Borne | Three-Stage Disease

IxodesTick vector (deer/black-legged)

KneeMost commonly affected joint (90%)

60%Develop arthritis if untreated

2-tierTesting: ELISA then Western blot

STAGES OF LYME DISEASE

Stage 1 - Early Localised

PatternErythema migrans (3-30 days post-bite)

TreatmentDoxycycline 100mg BD 14-21 days

Stage 2 - Early Disseminated

PatternMigratory arthralgia, carditis, neurological (weeks-months)

TreatmentDoxycycline or amoxicillin 21-28 days

Stage 3 - Late Disseminated

PatternLyme arthritis, chronic neurological (months-years)

TreatmentIV Ceftriaxone 2g daily 14-28 days

Post-Treatment Lyme Disease Syndrome

PatternPersistent symptoms after treatment

TreatmentSupportive care, no further antibiotics

Critical Must-Knows

Erythema migrans is pathognomonic - expanding annular rash with central clearing
Lyme arthritis typically presents as intermittent monoarthritis of the KNEE
Two-tier testing: ELISA screening then Western blot confirmation
Doxycycline first-line for early disease; IV Ceftriaxone for late/neurological
10-20% antibiotic-refractory Lyme arthritis may require synovectomy

Examiner's Pearls

"
Negative serology does not exclude early Lyme disease - treat clinically if EM present
"
Lyme arthritis is NOT septic arthritis - synovial WBC typically 25,000-50,000
"
Consider Lyme in any unexplained chronic monoarthritis of the knee
"
Post-treatment Lyme disease syndrome does NOT respond to further antibiotics

Clinical Imaging

Erythema Migrans - Pathognomonic Sign

Clinical photograph showing erythematous reaction around tick bite site — Clinical photograph demonstrating early erythematous reaction around a tick bite site. This represents the initial skin response at the site of Ixodes tick attachment and Borrelia burgdorferi inoculation. While not yet showing the classic 'bull's-eye' appearance of fully developed erythema migrans, this early localized reaction is the first visible manifestation of Lyme disease. The erythema typically expands centrifugally over days to weeks, often developing central clearing to create the pathognomonic target lesion. Early recognition and treatment at this stage with doxycycline prevents progression to disseminated disease and musculoskeletal complications.Credit: Pavan WO et al. via Int J Med Sci via Open-i (NIH) (Open Access (CC BY))

Critical Lyme Disease Exam Points

Two-Tier Testing Algorithm

ELISA first, then Western blot ONLY if ELISA positive or equivocal. Western blot alone has high false-positive rate. IgM appears 1-2 weeks, IgG at 4-6 weeks. Serology may be negative in first 2 weeks - treat clinically if erythema migrans present.

Differentiate from Septic Arthritis

Lyme arthritis is inflammatory, NOT septic. Synovial WBC 25,000-50,000 (vs greater than 50,000 in septic). Gram stain and culture NEGATIVE. Less systemically unwell. Joint aspiration essential to exclude true septic arthritis in acute presentations.

Geographic Consideration

Endemic areas: Northeastern/Upper Midwest USA, Europe, parts of Asia. NOT endemic in Australia - always ask about travel history. UK has low-level endemic transmission. Tick exposure 3-30 days before symptoms.

Antibiotic-Refractory Lyme Arthritis

10-20% fail to respond to oral and IV antibiotics. HLA-DR4 associated. Consider autoimmune mechanism. Options include NSAIDs, DMARDs (methotrexate, hydroxychloroquine), or arthroscopic synovectomy for refractory cases.

Stages of Lyme Disease - Musculoskeletal Features

Feature	Stage 1 - Early Localised	Stage 2 - Early Disseminated	Stage 3 - Late
Timing	3-30 days post-bite	Weeks to months	Months to years
Pathognomonic sign	Erythema migrans (70-80%)	Multiple EM lesions	None
Joint symptoms	None or mild arthralgia	Migratory polyarthralgia	Intermittent mono/oligoarthritis
Most affected joint	N/A	Multiple joints, fleeting	Knee (90%)
Serology	Often negative	Usually positive IgM	Positive IgM and IgG
First-line treatment	Doxycycline 14-21 days	Doxycycline 21-28 days	IV Ceftriaxone 14-28 days

Mnemonic

EARL - Early And Running LateClinical Stages

Erythema migrans

Stage 1 - pathognomonic rash

Arthralgia (migratory)

Stage 2 - fleeting joint pains

Radiculopathy/carditis

Stage 2 - neurological and cardiac

Lyme arthritis

Stage 3 - chronic monoarthritis

Memory Hook:EARL reminds you the disease progresses from Early to Late stages!

Mnemonic

ELISA WESTTwo-Tier Testing

ELISA first

Screening test - high sensitivity

Look at result

Only proceed if positive/equivocal

Immunoblot

Western blot is confirmatory

Specificity

Western blot adds specificity

Antibodies

IgM (early) and IgG (late)

Memory Hook:Do ELISA first, then head WEST (Western blot) for confirmation!

Mnemonic

DOXY CEFTRITreatment Selection

Doxycycline

First-line for early disease

Oral

Oral route for uncomplicated

eXclude

Exclude neurological/cardiac involvement

Young avoid

Avoid doxycycline in children under 8, pregnant

Ceftriaxone IV

For late/neurological disease

Memory Hook:DOXY for early, switch to CEFTRI for late or complicated disease!

Overview and Epidemiology

Lyme disease is a multisystem infectious disease caused by the spirochete Borrelia burgdorferi (and related species B. afzelii and B. garinii in Europe). It is the most common vector-borne disease in North America and Europe, transmitted by Ixodes species ticks (deer tick/black-legged tick).

Epidemiology:

Incidence: 300,000+ cases annually in the USA, 65,000+ in Europe
Endemic areas: Northeastern USA, Upper Midwest, Northern California, Europe, temperate Asia
Peak transmission: May-August (nymphal tick activity)
Musculoskeletal involvement: 60% of untreated cases develop Lyme arthritis
Knee involvement: 90% of Lyme arthritis cases affect the knee

Risk Factors:

Geographic exposure: Residence or travel to endemic areas
Outdoor activities: Hiking, camping, gardening in wooded/grassy areas
Tick exposure: Tick attachment greater than 36-48 hours required for transmission
Season: Late spring to early autumn (peak tick activity)

Not Endemic in Australia

Lyme disease is NOT endemic in Australia. While there is ongoing debate about "Australian Lyme-like illness," classic Borrelia burgdorferi Lyme disease requires travel history to endemic regions (USA, Europe, UK). Always ask about international travel in suspected cases.

Pathophysiology

Understanding the pathophysiology of Lyme disease explains its clinical stages and the rationale for treatment.

The Causative Organism

Borrelia burgdorferi sensu lato complex:

B. burgdorferi sensu stricto: North America and Europe - arthritis predominant
B. afzelii: Europe - skin manifestations (acrodermatitis chronica atrophicans)
B. garinii: Europe - neurological predominant

Spirochete characteristics:

Gram-negative spirochete with outer surface proteins (Osp)
OspA: Expressed in tick gut, target for vaccines
OspC: Upregulated during transmission to host
VlsE: Variable surface protein enabling immune evasion

Microscopic visualization of Borrelia burgdorferi spirochetes — Microscopic visualization of multiple Borrelia burgdorferi spirochetes demonstrating the characteristic corkscrew (spiral) morphology that gives the organism its name. The image shows both individual spirochetes and small clusters, with clear visualization of the helical structure. This distinctive spiral shape enables the organism to penetrate tissues and cross biological barriers (including synovial membranes, blood-brain barrier, and the placenta). The spirochete's motility and ability to change shape allow it to evade host immune responses and disseminate throughout the body, explaining the multi-system manifestations of Lyme disease including the musculoskeletal complications that develop in 60% of untreated patients.Credit: Ackermann R et al. via Yale J Biol Med via Open-i (NIH) (Open Access (CC BY))

Electron microscopy showing ultrastructural detail of Borrelia spirochete — High-resolution electron microscopy revealing the ultrastructural architecture of a Borrelia spirochete. This magnified view shows the detailed cell wall structure, the distinctive helical morphology, and the organism's elongated form. The spiral configuration is maintained by endoflagella (periplasmic flagella) located between the outer membrane and the cell cylinder, which enable the characteristic corkscrew motility. Understanding this ultrastructure is clinically relevant: the outer surface proteins (OspA, OspC, VlsE) embedded in the visible outer membrane are critical virulence factors and diagnostic targets. The spiral shape and flagellar apparatus facilitate tissue invasion and persistence in the synovial environment, contributing to the chronic inflammatory arthritis seen in late-stage Lyme disease.Credit: Burgdorfer W et al. via Yale J Biol Med via Open-i (NIH) (Open Access (CC BY))

Transmission and Dissemination

Tick bite to disease:

Ixodes tick attaches and feeds (nymph or adult)
Spirochetes migrate from tick midgut to salivary glands
Transmission requires greater than 36-48 hours of attachment
Local infection at bite site causes erythema migrans
Haematogenous and lymphatic dissemination to distant sites

Joint involvement mechanism:

Spirochetes have tropism for synovial tissue
Bind to decorin and glycosaminoglycans in extracellular matrix
Induce Th1 inflammatory response
IL-17 and IFN-gamma drive synovial inflammation
Persistent inflammation despite spirochete clearance in some patients

Antibiotic-Refractory Arthritis

In 10-20% of Lyme arthritis cases, joint inflammation persists despite adequate antibiotic therapy. This is associated with HLA-DR4 and may represent an autoimmune phenomenon triggered by molecular mimicry between OspA and human LFA-1. Treatment shifts from antibiotics to immunomodulation.

Immune Response

Early infection: Innate immune response, neutrophil infiltration
Adaptive response: T-cell and B-cell activation, antibody production
IgM antibodies: Detectable 1-2 weeks after infection
IgG antibodies: Detectable 4-6 weeks, persist long-term
Molecular mimicry: OspA shares epitopes with human LFA-1 (implicated in refractory arthritis)

Clinical Presentation

Stage 1: Early Localised Disease (3-30 days)

Erythema migrans (EM):

Occurs in 70-80% of infected individuals
Expanding annular erythematous patch at bite site
"Bull's-eye" or target lesion appearance (central clearing)
Minimum size greater than 5cm for diagnosis
Usually painless, may have mild burning
Resolves spontaneously but indicates active infection

Associated symptoms:

Fatigue, malaise, low-grade fever
Headache, myalgia
Regional lymphadenopathy
Mild arthralgia (not true arthritis)

Stage 2: Early Disseminated Disease (Weeks to Months)

Musculoskeletal features:

Migratory polyarthralgia: Fleeting joint pains, multiple joints
Migratory myalgia: Muscle pain without weakness
Brief swelling episodes (days), then resolution
Moves from joint to joint
No permanent joint damage at this stage

Other manifestations:

Multiple EM lesions: Secondary skin lesions distant from bite
Carditis: AV block (first to complete), myocarditis (4-10%)
Early neuroborreliosis: Facial palsy (bilateral in 25%), meningitis, radiculopathy (Bannwarth syndrome)

Stage 3: Late Disseminated Disease (Months to Years)

Lyme Arthritis:

Develops in approximately 60% of untreated patients
Intermittent oligoarthritis progressing to chronic monoarthritis
Knee affected in 90% of cases
Large effusion, often out of proportion to pain
Episodes last weeks to months
Can cause erosive joint damage if untreated

Examination findings:

Large, cool effusion (less inflammatory than septic)
Mild synovial thickening
Range of motion often preserved
Less pain than degree of swelling suggests
Baker's cyst may develop

Other late manifestations:

Late neuroborreliosis: Encephalopathy, polyneuropathy
Acrodermatitis chronica atrophicans (European species)

Post-Treatment Lyme Disease Syndrome (PTLDS)

Persistent symptoms after adequate antibiotic treatment
Fatigue, musculoskeletal pain, cognitive difficulties
Duration greater than 6 months post-treatment
NO evidence of ongoing infection
Further antibiotics NOT beneficial
Management is supportive

Investigations

Laboratory Studies

Two-Tier Serological Testing (CDC Recommended):

Step 1 - ELISA or IFA (Screening):

High sensitivity (greater than 90% in late disease)
Lower sensitivity in early disease (40-60%)
If NEGATIVE and early disease suspected, treat clinically and repeat in 2-4 weeks
If POSITIVE or EQUIVOCAL, proceed to Step 2

Step 2 - Western Blot (Confirmation):

Detects antibodies to specific Borrelia proteins
IgM criteria: 2 of 3 bands (23, 39, 41 kDa) - valid only in first 4 weeks
IgG criteria: 5 of 10 bands - use after 4 weeks of symptoms
More specific than ELISA alone
Do NOT perform Western blot without positive/equivocal ELISA

Serological Window

Serology is often NEGATIVE in early localised disease (first 2 weeks). If erythema migrans is present, diagnosis is CLINICAL and treatment should not await serology. Negative serology in early disease does not exclude Lyme.

Other laboratory tests:

ESR/CRP: Mildly elevated in active disease
RF and anti-CCP: Negative (distinguishes from RA)
ANA: Usually negative
PCR: Can detect Borrelia DNA in synovial fluid (60-85% sensitivity)

Synovial Fluid Analysis

Joint aspiration is essential to exclude septic arthritis:

WBC count: 10,000-100,000/microL (typically 25,000-50,000)
Predominance: Neutrophils (may shift to lymphocytes in chronic)
Gram stain: NEGATIVE
Culture: NEGATIVE (routine culture does not grow Borrelia)
Crystals: NEGATIVE
PCR for Borrelia DNA: Positive in 60-85% of untreated cases

Distinguishing from septic arthritis:

Lower WBC count (usually less than 50,000 in Lyme)
Patient less systemically unwell
Less pain relative to swelling
PCR positive for Borrelia, culture negative

Imaging

Plain radiographs:

Usually normal in early Lyme arthritis
Soft tissue swelling
Effusion
May show erosions in chronic untreated disease

MRI:

Synovial thickening and enhancement
Joint effusion
May show Baker's cyst
Bone marrow oedema in severe cases
Useful to assess cartilage damage

Ultrasound:

Effusion quantification
Synovial hypertrophy
Guides aspiration

Management

Stage 1 and Stage 2 (Early Localised and Disseminated)

First-line - Doxycycline:

Dose: 100mg twice daily OR 200mg once daily
Duration: 10-14 days for EM; 14-21 days for early disseminated
Also treats co-infection with Anaplasma
Contraindicated in pregnancy, children under 8 years

Alternative agents:

Amoxicillin: 500mg three times daily (14-21 days) - for children, pregnant women
Cefuroxime axetil: 500mg twice daily (14-21 days) - second-line alternative
Azithromycin less effective, not recommended as first-line

Response to treatment:

EM resolves within days to weeks
Arthralgia typically resolves within 4 weeks
Serology may remain positive for years (not a treatment failure marker)

Tick prophylaxis (single dose):

Doxycycline 200mg single dose within 72 hours of tick removal
Only in high-risk endemic areas
Tick attached greater than 36 hours

This section covers early disease treatment approaches.

Surgical Management

Indications for Orthopaedic Intervention

Surgical intervention in Lyme disease is limited to refractory cases:

Antibiotic-refractory Lyme arthritis: Persistent synovitis after two courses of antibiotics
Diagnostic arthroscopy: When diagnosis uncertain
Joint damage: Rare end-stage arthropathy requiring arthroplasty

Arthroscopic Synovectomy Technique

Indication:

Antibiotic-refractory Lyme arthritis of knee
Greater than 3 months of persistent synovitis after adequate antibiotics
Failed medical management (NSAIDs, DMARDs)

Pre-operative workup:

Confirm two complete antibiotic courses administered
Repeat synovial fluid analysis (exclude ongoing infection)
Consider synovial biopsy if diagnosis uncertain
MRI to assess synovial burden

Technique:

Standard arthroscopic setup, supine with leg holder
Anteromedial and anterolateral portals
Systematic synovectomy of all compartments
Suprapatellar pouch, medial/lateral gutters
Posteromedial and posterolateral recesses if involved
Shaver and radiofrequency ablation for haemostasis
Thorough lavage

Post-operative care:

Immediate weight-bearing as tolerated
Early range of motion exercises
Physiotherapy for quadriceps strengthening
Continue DMARDs if initiated pre-operatively

Outcomes:

80-90% resolution of symptoms
May require repeat synovectomy in 10-15%
Rarely progresses to arthroplasty

This section covers the arthroscopic synovectomy approach.

Complications

Disease Complications

Musculoskeletal:

Chronic arthritis: Persistent joint inflammation
Erosive joint damage: In prolonged untreated cases
Post-infectious autoimmune arthritis: Antibiotic-refractory disease
Baker's cyst: Popliteal cyst from chronic effusion
Tendinopathy: Achilles, patellar tendon involvement

Cardiac:

Lyme carditis: AV block (1st, 2nd, 3rd degree) in 4-10%
Myocarditis: Rare, may require temporary pacing
Usually resolves with antibiotics

Neurological:

Facial palsy: Unilateral or bilateral (25% bilateral)
Meningitis: Lymphocytic meningitis
Radiculopathy: Bannwarth syndrome (painful radiculoneuritis)
Late encephalopathy: Cognitive impairment

Treatment Complications

Jarisch-Herxheimer reaction: Fever, chills within 24 hours of antibiotic initiation (spirochete lysis)
Antibiotic-related: C. difficile colitis, photosensitivity (doxycycline)
PICC line complications: Infection, thrombosis (IV therapy)

Prognosis

Early treatment: Excellent prognosis, complete resolution expected
Late disease: 80-90% respond to oral or IV antibiotics
Antibiotic-refractory: 10-20%, responds to immunomodulation/synovectomy
PTLDS: May persist for months but eventually improves
Erosive arthritis: Rare with modern treatment

Evidence Base

Duration of Antibiotic Therapy for Lyme Arthritis

Steere AC et al. • N Engl J Med (2001)

Key Findings:

28 days of oral therapy effective in 85-90%
IV ceftriaxone for oral treatment failures
10-20% develop antibiotic-refractory arthritis

Two-Tier Testing for Lyme Disease Diagnosis

CDC Recommendation (Wormser GP et al.) • Clin Infect Dis (2006)

Key Findings:

ELISA followed by Western blot reduces false positives
IgM criteria: 2 of 3 bands in first 4 weeks
IgG criteria: 5 of 10 bands after 4 weeks
Western blot alone has unacceptable false positive rate

Antibiotic-Refractory Lyme Arthritis - Immunogenetic Basis

Steere AC et al. • Arthritis Rheum (2006)

Key Findings:

HLA-DR4 strongly associated with refractory disease
Molecular mimicry between OspA and human LFA-1
Further antibiotics not beneficial - need immunomodulation
Synovectomy effective for refractory cases

Synovectomy for Antibiotic-Refractory Lyme Arthritis

III

Schoen RT et al. • Arthritis Rheum (1991)

Key Findings:

80-90% success rate with synovectomy
Removes inflammatory tissue harbouring immune reaction
May need repeat procedure in 10-15%
Alternative to prolonged DMARD therapy

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

Scenario 1: Chronic Monoarthritis of the Knee

EXAMINER

"A 45-year-old man presents with a 3-month history of intermittent right knee swelling. He is a keen hiker and recently returned from a trip to Connecticut, USA. The knee has a large effusion but is not particularly painful. He is afebrile."

EXCEPTIONAL ANSWER

Thank you. This presentation of chronic monoarthritis in a patient with travel history to an endemic area for Lyme disease raises strong suspicion for Lyme arthritis. The knee is the most commonly affected joint, and the intermittent nature with large effusion but relatively little pain is characteristic. However, I must first exclude septic arthritis and other causes. I would aspirate the knee and send fluid for cell count, Gram stain, culture, crystals, and specifically request PCR for Borrelia burgdorferi. I expect an inflammatory aspirate with WBC around 25,000-50,000 but negative cultures. I would perform two-tier serology - ELISA followed by Western blot if positive. Given the 3-month history, I expect positive IgG Western blot. If Lyme arthritis is confirmed, I would treat with oral doxycycline 100mg twice daily for 28 days. I would counsel him that 80-90% respond to oral therapy, but he should return if symptoms persist beyond 4-8 weeks as he may need IV ceftriaxone.

KEY POINTS TO SCORE

Travel to endemic area (Connecticut) is key history

Knee most commonly affected (90%)

Aspiration essential - expect inflammatory but not septic WBC

Two-tier testing: ELISA then Western blot

28 days oral doxycycline first-line

COMMON TRAPS

✗Assuming septic arthritis without aspiration

✗Not asking about travel history

✗Ordering Western blot without ELISA

✗Treating with IV antibiotics first-line

LIKELY FOLLOW-UPS

"What if he fails oral therapy?"

"What is antibiotic-refractory Lyme arthritis?"

"What is the role of synovectomy?"

VIVA SCENARIOStandard

Scenario 2: Erythema Migrans with Negative Serology

EXAMINER

"A 32-year-old woman presents with an expanding circular rash on her thigh for 5 days after returning from camping in Germany. She has mild myalgia and fatigue. Lyme serology (ELISA) is negative."

EXCEPTIONAL ANSWER

Thank you. This is a classic presentation of early localised Lyme disease with erythema migrans. The expanding circular rash at a potential tick bite site, combined with systemic symptoms of myalgia and fatigue following exposure in an endemic area (Germany), is highly suggestive. Importantly, I would NOT rely on the negative serology to exclude the diagnosis. In early Lyme disease, serology is negative in 40-60% of cases because antibodies take 2-4 weeks to develop. Erythema migrans is pathognomonic, and the diagnosis is clinical. I would treat her empirically with doxycycline 100mg twice daily for 14 days. This will prevent progression to disseminated disease. I would counsel her about the excellent prognosis with early treatment, and advise her to return if she develops any joint symptoms, neurological symptoms like facial weakness, or palpitations suggesting cardiac involvement. Repeat serology is not necessary if she responds to treatment.

KEY POINTS TO SCORE

Erythema migrans is pathognomonic - clinical diagnosis

Serology often negative in early disease (40-60%)

Do not delay treatment for serology

Doxycycline 100mg BD for 14 days

Early treatment prevents disseminated disease

COMMON TRAPS

✗Waiting for positive serology before treating

✗Ordering Western blot after negative ELISA

✗Missing the diagnosis due to negative serology

✗Using azithromycin as first-line

LIKELY FOLLOW-UPS

"What if she is pregnant?"

"What would you do if she develops facial palsy?"

"When would you repeat serology?"

VIVA SCENARIOAdvanced

Scenario 3: Antibiotic-Refractory Lyme Arthritis

EXAMINER

"A 50-year-old man has persistent right knee synovitis despite completing 28 days of oral doxycycline and then 28 days of IV ceftriaxone. Synovial fluid PCR for Borrelia is now negative. He is HLA-DR4 positive."

EXCEPTIONAL ANSWER

Thank you. This is antibiotic-refractory Lyme arthritis, which occurs in 10-20% of cases. The key points are that he has completed two adequate courses of antibiotics (oral and IV), and the synovial PCR is now negative, indicating microbiological cure. His HLA-DR4 positivity is a known risk factor for this condition. The mechanism is believed to be an autoimmune response rather than persistent infection - possibly molecular mimicry between Borrelia OspA protein and human LFA-1. Further antibiotics will NOT help and are not recommended. My management would involve a stepwise approach: First, optimise anti-inflammatory therapy with NSAIDs such as naproxen. Second, consider intra-articular corticosteroid injection for symptomatic relief. Third, if inflammation persists, I would initiate DMARDs - typically methotrexate 15-25mg weekly or hydroxychloroquine. If medical management fails over 3-6 months, I would offer arthroscopic synovectomy, which has an 80-90% success rate in removing the inflammatory synovium. I would counsel him that this is not an infection anymore but an inflammatory condition that will eventually settle.

KEY POINTS TO SCORE

Antibiotic-refractory = persistent after oral AND IV courses

Negative PCR confirms no active infection

HLA-DR4 associated with refractory disease

Further antibiotics NOT indicated

Management: NSAIDs, steroids, DMARDs, then synovectomy

COMMON TRAPS

✗Prescribing more antibiotics

✗Not recognising HLA-DR4 association

✗Delaying DMARD initiation

✗Not offering synovectomy as definitive option

LIKELY FOLLOW-UPS

"What is the mechanism of refractory disease?"

"How would you perform synovectomy?"

"Is there a role for biologics?"

Australian Context

Lyme disease is NOT endemic in Australia, and classic Borrelia burgdorferi infection requires travel history to endemic regions such as North America, Europe, or parts of Asia. This is a critical point for Australian orthopaedic surgeons - any patient presenting with suspected Lyme disease must have a detailed travel history elicited.

There has been ongoing debate regarding "Australian Lyme-like illness" or "Debilitating Symptom Complexes Attributed to Ticks" (DSCATT). The Australian government commissioned the Senate Inquiry into Lyme-like Illness (2016) and subsequently established a Lyme Disease Advisory Committee. However, there is currently no scientific evidence that classical Lyme disease caused by Borrelia burgdorferi exists in Australia. Patients presenting with chronic symptoms attributed to tick bites should be investigated for other Australian tick-borne illnesses such as Queensland Tick Typhus (Rickettsia australis), or referred to infectious diseases for comprehensive assessment.

For Australian travellers returning from endemic areas, standard two-tier testing (ELISA followed by Western blot) is available through reference laboratories. Treatment follows international guidelines with doxycycline as first-line for early disease. Doxycycline and amoxicillin are available on the PBS for treatment of confirmed Lyme disease. IV ceftriaxone for late or neurological Lyme disease requires hospital-based administration or outpatient parenteral antimicrobial therapy (OPAT) programs available in major Australian centres.