Tick Talk

March 29th 2012

Kieran Moore FCFP FRCPC

Objectives-through cases

• Epidemiology-LOCAL

• Engorged or not engorged pathway?

• Clinical presentation and treatment of lyme disease…basics

Ontario-Lyme cases

Patient 1 • 18 year old male presents with tick on groin

for unknown time.

• He had been to Lemoine’s point.

• No symptoms except local inflammation at bite.

• What do you do?

• What is his risk of Lyme disease?

Patient 1:Removal

Patient 1:Removal

Swinging!

Partially or unfed ticks

Fed ticks

Epidemiology

Black legged tick-ADULT

PATIENT-over 12

Engorged?24-72 hours

Adult tick

Decreased benefit of

prophylaxis

Nymph

Prophylaxis option

Non engorged!-less than 24

hours

Remove and monitor

Ixodes life cycle

Black legged tick-(98 percent IS), NEJM 482

Engorged, more than 72 hours,

248

Adult tick

0/97

Nymph

8/142 (3.2% overall)

> 72 hours, engorged, DOXY

235

1of 235 EM (0.4%)

Risk reduction-Primary Prevention

• RRR=1-0.4/3.2=87%

• ARR=2.8%

• NNT=1/ARR=36

• Meta analysis suggest NNT of 50

• Risk of EM/Lyme in a bite of IS-3.2 percent in Westchester County NY ( 2.2%) in meta analysis) -One in fifty chance

Key points-STUDY • Engorged nymph-72 hours

• Overall 2.2-3.2 percent risk doing nothing and waiting

• Non pregnant Adult patients only- not studied in children less than 12

• Doxy-30 % side effect profile

• A single dose of 200 mg DOXY within 72 hours can prevent the development of LYME disease

Black legged tick-0ver 12

y.o.=ADULT PATIENT

Engorged?-72 hours

Adult tick

Decreased benefit of prophylaxis

Nymph

Prophylaxis option

Non engorged! less than 24 hours

Remove and monitor

Patient 2

• 18 year old female presents with fever, arthralgia,rash, FAR after camping.

• She remembers a tick bite five days ago.

• What is your approach?

Lyme Disease

Timing-USA

PHAC study-FAR

CDC Symptoms

One to two weeks-3 to 30 days, can last 8 weeks

Expanding-5 cm or greater

FAR:Summer Palsy....Knee effusion

National Guideline

• Since there is currently no definitive test for Lyme disease, laboratory results should not be used to exclude an individual from treatment.

• Lyme disease is a clinical diagnosis and tests should be used to support rather than supersede the physician’s judgment.

• The early use of antibiotics can prevent persistent, recurrent, and refractory Lyme disease.

• REPORTABLE to Public health

Lyme Disease-Practice guidelines • Adult:

• First Line: Amoxil 500 tid or Doxy 100 bid

• Usual duration 14-21 days

• Children:

• Amoxil 50 mg/kg/day divided q8h

• Cefuroxime 30 mg/kg/day divided q12 h

• NOT CEPHALEXIN

IV therapy-CCA

• Acute neurological-radiculopathy, meningitis

• 3rd degree heart block

• Arthritis-effusion

• REFER

Lyme NEURO involvement

• Consider whenever neurologic disease occurs with constitutional symptoms-FAR

• 10-40 percent of symptomatic infections at ALL stages

• Blood tests may take 4-6 weeks to turn positive

Testing

Protection

Prevent

Conclusion

• Prophylaxis is based on risk and feed time-engorged versus not engorged

• Clinical diagnosis!

• Use guidelines!

• PLEASE CALL US-REPORTABLE