HOW TO TREAT 29 support clinicians in their structure of assessment and management of patients with a wide range of symptoms . 17
WIN
MALDIVES trip valued $ 14,000 Join to enter .
Already a member , simply log in .
HOW TO TREAT 29 support clinicians in their structure of assessment and management of patients with a wide range of symptoms . 17
PREVENTION
PREVENTION of tick bite is the most simple and effective way to prevent Lyme disease and other tick-borne diseases . As ticks live in bushy , wooded areas and areas with long grass , avoiding activities in these areas or use of protective measures during outdoor activities is essential to prevent tick bites . Appropriate protective clothing includes covering skin as much as possible with long-sleeve shirts , long pants tucked into socks , and boots . When walking along trails , walk in the centre of the track and avoid brushing against vegetation . Use of insect repellent containing DEET or picaridin , or permethrin-treated clothing and camping gear is also recommended .
Although using the protective measures mentioned will help deter tick bites , it is important to check for the presence of any ticks on clothing , skin and pets following return from tick-prone areas . Ticks can be carried on clothing , pets or backpacks , fall off and search for a new host to attach to — sometimes surviving up to 1-2 weeks . 28 If attached ticks are found , they should be immediately removed with cryotherapy or insecticide , rather than tweezers as the risk of transmission of B . burgdorferi sl increases with the duration of tick attachment . Clothing should be washed in hot water or placed in a hot dryer for 20 minutes to kill any ticks that may be present .
PROGNOSIS
THE prognosis of appropriately treated Lyme disease is very good . In most cases , independent of the stage of disease , appropriate antimicrobial treatment can cure infection and symptoms will resolve completely . Minimal or no response to treatment is often an indication that the diagnosis of Lyme disease may not be correct . However , some patients — despite appropriate therapy — may experience post-treatment Lyme disease syndrome ( PTLDS ). Symptoms of pain , fatigue or difficulty thinking that last more than six months post-treatment are considered PTLDS . The pathophysiology is not clear , and there is no specific treatment other than supportive care . 29 Patients usually improve over time without specific treatment or further antibiotics . There have been various recommendations for prolonged antibiotic therapy ; however , most studies have shown no benefit in patients with PTLDS , and there are numerous documented adverse outcomes , including death , from prolonged antibiotic therapy . 5 , 30-32
THE FUTURE
LYME disease incidence is increasing around the world , and clinical trials are underway to produce a vaccination against some B . burgdorferi sl species . Previously , a Lyme disease vaccine called LYM- Erix ( available only in the US ) targeted the outer surface protein A ( OspA ) of B . burgdorferi sl and provided a 76 % reduction in Lyme disease with a three-dose schedule . 33 Unfortunately , in 2002 , within three years of being launched , the vaccine
How to Treat Quiz . was voluntarily withdrawn from the market . This vaccine provided narrow coverage for only the most common North American B . burgdorferi species . Also , a lack of data in children , uncertainty over the duration of protection and reported adverse effects made the vaccine unpopular . 34
As of August 2022 , the newest Lyme disease vaccine candidate , VLA15 , is undergoing a phase III clinical study . This multivalent protein subunit vaccine targets the OspA of the most common B . burgdorferi sl species in North America and Europe , and participants will be aged five and older . Hopefully , this will be more successful than its predecessor .
Development is also underway on a monoclonal antibody for Lyme disease pre-exposure prophylaxis . A group from the University of Massachusetts medical school MassBiologics , US , has commenced phase I studies on an anti-OspA human monoclonal antibody ( HuMAb ). This HuMAb is designed to prevent transmission of the B . burgdorferi sl by targeting and killing the spirochaete during the blood meal of a tick . The HuMAb is designed to last 8-9 months and to be administered annually . 35 Phase II and III clinical studies are planned in the near future , aiming for availability for use as pre-exposure prophylaxis in 2024 .
CASE STUDY
EMILY , 18 , is a recently returned traveller from Europe . She presents with a six-day history of a blanching , erythematous circular rash over her left popliteal region , which
IS THIS LYME DISEASE ?
has progressed to involve multiple lesions over her limbs and torso . This is associated with mild arthralgia , severe occipital headache and a fever that has lasted 48 hours . She had sustained a tick bite 2-3 weeks earlier while hiking in Norway . The duration of tick attachment was unknown , but the tick was removed in its entirety . No prophylactic antibiotics were given at the time .
On examination , Emily is afebrile and haemodynamically stable . There are multiple erythematous target-like skin lesions over her left leg , abdomen and back , with an eschar visible on the left popliteal region . Emily has normal cardiac and musculoskeletal examinations . The cranial nerve examination is normal , and an ECG does not show any conduction abnormalities .
A presumptive diagnosis of early disseminated Lyme disease is made , and the patient is started on oral doxycycline . Serological testing is performed for B . burgdorferi IgM and IgG , rickettsial antibodies and Q fever phase I and phase II antibodies . Lyme diagnosis is confirmed with the detection of anti – B . burgdorferi IgM and IgG antibodies by EIA , IFA and on a confirmatory immunoblot assay . Rickettsial and Q fever serology are both negative . Other blood tests — including inflammatory markers , FBC , LFTs and renal function — are within normal limits , and an echocardiogram is also normal . A lumbar puncture is considered but not performed as Emily has a normal neurological examination and neuroborreliosis is considered unlikely .
During the first week of therapy , Emily develops worsening headaches , and a lumbar puncture
is performed to assess for neuroborreliosis . The CSF cell count and protein level are within normal limits . A non-contrast CT brain is normal . No further testing is performed , and Emily is continued on oral doxycycline for a total of 21 days . At follow-up , four weeks after treatment was initiated , she has had a near complete resolution of symptoms and has returned to normal daily activity .
CONCLUSION
LYME disease , an infection caused by the spirochaetes of the B . burgdorferi sl complex , is transmitted during the blood meal of an Ixodes sp . tick . Although endemic in countries of the Northern Hemisphere — including the US , Europe and parts of Asia — there is no evidence of locally acquired Lyme disease .
Other tick-borne infections , including rickettsiosis and Q fever , are present in Australia and should be considered in those with tick bite – associated illnesses that are locally acquired .
Serological diagnosis of disseminated Lyme disease is established by demonstrating the development of anti – B . burgdorferi sl IgG antibodies . However , in a region of low disease prevalence , such as Australia , serological studies may result in false-positive or non-specific reactivity , so restrict testing to those with epidemiological risk factors for Lyme disease .
GPs are crucial to the diagnosis and management of Lyme disease . We know that early treatment leads to better outcomes . But in those with Lyme disease – like illness or DSCATT , antimicrobial therapy — particularly prolonged IV therapies — can cause serious harm . As patients often present to their GP first , having knowledge of the diagnosis and management of Lyme disease is essential .
GO ONLINE TO COMPLETE THE QUIZ ausdoc . com . au / how-to-treat
1 . Which THREE statements regarding Lyme disease are correct ? a The diagnosis may be difficult in those without erythema migrans and no evident history of tick exposure . b The causative organism is endemic in the US , Europe , Australia and parts of Asia . c The infection has three distinct clinical stages : early , disseminated and late . d Early antibiotic treatment usually leads to a full recovery .
2 . Which THREE are the classical early clinical manifestations of Lyme disease ? a Headache . b Fever . c Erythema migrans . d Lymphadenopathy .
3 . Which TWO statements regarding Lyme disease are correct ? a The general consensus is that there is no locally acquired classic Lyme disease in Australia . b B . burgdorferi sl complex has been detected in low numbers in New Zealand .
c Lyme disease occurs more frequently in tropical climates . d There are several locally acquired tick-borne illnesses that have some overlap in clinical manifestations .
4 . Which THREE statements regarding the aetiology and pathogenesis of Lyme disease are correct ? a There is no evidence of vertical transmission during pregnancy . b The ticks can acquire a B . burgdorferi sl infection during a blood meal from an infected animal . c Human-to-human transmission can occur via infected blood and saliva . d B . burgdorferi sl initially invades the skin and then gains access to the lymphatic or blood vessels and disseminates .
5 . Which TWO factors increase the
risk of Lyme disease ? a Younger / smaller ticks . b Exposure to vector-competent ticks . c Longer duration of tick attachment . d Late winter to early spring .
6 . Which ONE is the most common manifestation of late disease ? a Fever and chills . b Arthritis . c Multiple small erythema migrans skin lesions . d Cranial nerve palsies .
7 . Which ONE symptom / sign is the hallmark of Lyme disease ? a Myalgias . b Lymphadenopathy . c Erythema migrans . d Arthralgias .
8 . Which THREE are required for the prompt diagnosis of Lyme disease ? a Appropriate epidemiological
EARN CPD OR PDP POINTS
• Read this article and take the quiz via ausdoc . com . au / how-to-treat
• Each article has been allocated one hour by the RACGP and ACRRM .
• RACGP points are uploaded every six weeks and ACRRM points quarterly .
risk factors for acquisition of B . burgdorferi sl infection . b Corresponding clinical manifestations . c Supportive serological or molecular testing . d Culture of B . burgdorferi sl from skin lesions .
9 . Which THREE are differential diagnoses of Lyme disease ? a Skin conditions . b Atypical pneumonia . c Rickettsial infections . d Arthritides .
10 . Which THREE are appropriate in the management of Lyme disease ? a Prevention of tick bite is the most simple and effective way to prevent Lyme disease . b Prophylactic antibiotics for patients bitten by Ixodes sp . in an endemic area for B . burgdorferi sl and the tick was attached for longer than 36 hours . c Prophylactic antibiotics for patients bitten by Ixodes sp . in Australia . d Oral antibiotics in patients with a tick bite who develop erythema migrans .
RESOURCES
• CDC — Lyme Disease bit . ly / 3F5eWYy
• Department of Health and Aged Care — Tick bite diseases and symptoms attributed to tick bites bit . ly / 3VaOLVO
— Inquiry into the growing evidence of an emerging tickborne disease that causes a Lyme-like illness for many Australian patients bit . ly / 3F9JGYt
— An Australian guideline on the diagnosis of overseas-acquired Lyme disease / borreliosis bit . ly / 3gHvwEg
— Debilitating Symptom Complexes Attributed to Ticks ( DSCATT ) clinical pathway bit . ly / 3Fu0KXZ
• IDSA — IDSA 2020 guidelines for the prevention , diagnosis and treatment of Lyme disease bit . ly / 3gIXFef
Acknowledgements The authors wish to thank Dr Nicholas Coatsworth , infectious diseases specialist at Canberra Health Services , for providing the case study for this article .
References Available on request from howtotreat @ adg . com . au