Lyme Disease Melissa Muston Chris Watkins

Lyme Disease (Borreliosis)  A complex multi-organ disorder caused by a gram-negative spirochete bacterium called Borrelia burgdorferi  Endemic in most northeastern states, with 95% of cases occurring in New York, New Jersey, Connecticut, & Pennsylvania  Signs may appear months after initial exposure and may be vague or non- specific  Diagnosis can be difficult

Etiology  Caused by Borrelia burgdorferi (gram-negative spirochete bacterium)  Transmitted through the bite of a tick in the genus Ixodes (blacklegged tick)  Tick must be attached to host for minimum of 48 hours for infection to occur

History

History  Recognized as a separate entity in 1976 because of geographic clustering of children in Lyme, Connecticut area (Lyme arthritis)  Bacterium was discovered in 1982 by Dr. Willy Burgdorfer and other colleagues  Number of reported cases has increased steadily & it is now the most commonly reported arthropod-borne illness in the US

Signalment  Affects all ages and breeds of dogs, cats, horses, cows, and goats and is a zoologic disease  Animals that spend time outdoors in tick- infested areas are at greatest risk (northeastern states)

Transmission  Through the bite of a tick in the genus Ixodes (blacklegged ticks)  Zoonotic disease, but must be transmitted directly from tick bite, not from infected animal to human

Clinical Signs  Fever  Anorexia  Lethargy  Lymphadenopathy  Episodic lameness  Presence or absence of myocardial abnormalities  Rash around site of tick bite  Nephritis (esp. in Labrador Retrievers)

Clinical Signs in Dogs  Most common: Fever and Arthritis, which causes sudden lameness, pain, and swelling in one or more joints  In severe cases, infection can cause kidney failure and death (not common)

Clinical Signs in Humans  Erythema migrans * ”bull’s-eye” rash around bite site * 3-30 days post tick bite  Fever  Headache  Fatigue  Bell’s (facial) palsy  Infection can spread to joints, heart, and nervous system if not treated

Erythema Migrans (EM)

Bell’s (facial) Palsy  Loss of muscle tone on one or both sides of the face is called facial or “Bell’s” palsy

Diagnostic Tests in the Past   No test can document clinical illness resulting from Borrelia burgdorferi infection   If a dog presents with fever and joint pain, tests cannot definitively prove that Lyme disease is the cause of the clinical signs.   Clinical suspicion increases if the patient has a history of exposure to Ixodes spp ticks & responds to treatment (determinations are subjective)   B. burgdorferi can be detected in joint fluids or tissues using polymerase chain reaction or culture tests (VERY expensive and not practical in clinic)  Previous ELISA tests -antibody titers greater than 64– but  Previous ELISA tests -antibody titers greater than 64– but cannot distinguish vaccine induced antibodies from those resulting from natural exposure

Diagnostic Tests   Idexx SNAP 3Dx and SNAP 4Dx   Detected an outer membrane protein on anitbodies, called VIsE   Mapped the protein, found variable and invariable regions   Found a peptide on the sixth invariable region of the VlsE protein (known as C6)   C6 peptide is expressed when the B. burgdorferi organism infects a dog but is not contained in Lyme vaccines   Therefore, detection of antibodies w/ C6 peptide indicates infection, regardless of vaccine history

Recommended Treatment  Anitibiotics- *Doxycycline*Amoxycillin*Cefuroxime  Anti-inflammatory drugs for pain and swelling *NSAIDs *Cortizone (rarely used)

Prognosis  In most cases, antibiotic therapy will completely eliminate the infection  In some severe or late stage cases, antibiotic therapy may not completely eliminate the organism and some animals may be permanently infected leading to chronic cases and continued flare-ups  May have relapses

Prevention  Vaccination before exposure (only in endemic areas)  Reducing exposure to ticks!!  Using tick preventive products!!  Check animal for ticks daily and remove any ticks found immediately  ****There is currently no vaccine available for humans against Lyme Disease  Avoid exposure and use tick repellent (DEET)

Client Education  Possible human infection from ticks  No antibiotic is 100% effective in eliminating the organism *infected animals may have relapses of symptoms even after treatment  Vaccination of dogs already exposed is ineffective  Use tick repellents for animals traveling to infested areas

Case Study

References    llanimal/reference-laboratories/quantc6-research- review.pdf llanimal/reference-laboratories/quantc6-research- review.pdf llanimal/reference-laboratories/quantc6-research- review.pdf  me_disease/diagnosis.htm me_disease/diagnosis.htm me_disease/diagnosis.htm  e_study_and_self-assessment_on_Lyme_disease e_study_and_self-assessment_on_Lyme_disease e_study_and_self-assessment_on_Lyme_disease  e_Study_and_self-assessment_on_Lyme_disease e_Study_and_self-assessment_on_Lyme_disease e_Study_and_self-assessment_on_Lyme_disease