Postmortem confirmation of Lyme carditis with polymerase chain reaction

Lyme Carditis: From Pathophysiology to Clinical Management

Cardiac involvement is a rare but relevant manifestation of Lyme disease that frequently presents as atrioventricular block (AVB). Immune-mediated injury has been implicated in the pathogenesis of Lyme carditis due to possible cross-reaction between Borrelia burgdorferi antigens and cardiac epitopes. The degree of the AVB can fluctuate rapidly, with two-thirds of patients progressing to complete AVB. Thus, continuous heart rhythm monitoring is essential, and a temporary pacemaker may be necessary. Routinely permanent pacemaker implantation, however, is contraindicated because of the frequent transient nature of the condition. Antibiotic therapy should be initiated as soon as the clinical suspicion of Lyme carditis arises to reduce the duration of the disease and minimize the risk of complications. Diagnosis is challenging and is based on geographical epidemiology, clinical history, signs and symptoms, serological testing, ECG and echocardiographic findings, and exclusion of other pathologies. This paper aims to explain the pathophysiological basis of Lyme carditis, describe its clinical features, and delineate the treatment principles.

CD4 T cell responses in persistent Borrelia burgdorferi infection

Infection of mice with Borrelia burgdorferi (Bb), a tick-transmitted spirochete and the pathogen that causes Lyme disease in humans, triggers CD4 T cell activation in secondary lymphoid tissues, from which they disseminate into various infected tissues. Despite their activation and the appearance of CD4 T cell-dependent antibody responses, Bb establishes persistent infection in natural Bb reservoir hosts in the absence of overt disease, raising the question of the effectiveness of the anti-Bb T cell responses. Reviewing the existing literature, we propose that CD4 T cells might constitute a host cell target of Bb-mediated immune evasion, rendering these cells ineffective in orchestrating effective inflammatory responses and in supporting highly functional Bb-specific antibody induction. Supporting the induction of more effective CD4 T cell responses may help overcome Bb persistence.

Borrelia burgdorferi and Borrelia miyamotoi in Atlantic Canadian wildlife

Borrelia burgdorferi and Borrelia miyamotoi are tick-vectored zoonotic pathogens maintained in wildlife species. Tick populations are establishing in new areas globally in response to climate change and other factors. New Brunswick is a Canadian maritime province at the advancing front of tick population establishment and has seen increasing numbers of ticks carrying B. burgdorferi, and more recently B. miyamotoi. Further, it is part of a region of Atlantic Canada with wildlife species composition differing from much of continental North America and little information exists as to the presence and frequency of infection of Borrelia spp. in wildlife in this region. We used a citizen science approach to collect a wide range of animals including migratory birds, medium-sized mammals, and small mammals. In total we tested 339 animals representing 20 species for the presence of B. burgdorferi and B. miyamotoi. We have developed new nested PCR primers and a protocol with excellent specificity for detecting both of these Borrelia species, both single and double infections, in tissues and organs of various wildlife species. The positive animals were primarily small non-migratory mammals, approximately twice as many were infected with B. burgdorferi than B. miyamotoi and one animal was found infected with both. In addition to established reservoir species, the jumping mouse (Napaeozapus insignis) was found frequently infected; this species had the highest infection prevalence for both B. burgdorferi and B. miyamotoi and has not previously been identified as an important carrier for either Borrelia species. Comprehensive testing of tissues found that all instances of B. burgdorferi infection were limited to one tissue within the host, whereas two of the five B. miyamotoi infections were diffuse and found in multiple systems. In the one coinfected specimen, two fetuses were also recovered and found infected with B. miyamotoi. This presumptive transplacental transmission suggests that vertical transmission in mammals is possible. This finding implies that B. miyamotoi could rapidly spread into wildlife populations, as well as having potential human health implications.

Increasing Burden of Lyme Carditis in United States Children's Hospitals

We sought to characterize the shifting epidemiology and resource utilization of Lyme disease and associated carditis in US children's hospitals. We hypothesized that the Lyme carditis burden has increased and that hospitalizations for Lyme carditis are costlier than those for Lyme disease without carditis. The PHIS database was queried for Lyme disease encounters between January 1, 2007 and December 31, 2013. Additional diagnostic codes consistent with carditis identified Lyme carditis cases. Demographic, clinical, and resource utilization data were analyzed. All costs were adjusted to 2014 US dollars. Lyme disease was identified in 3620 encounters with 189 (5%) associated with carditis. Lyme disease (360 cases in 2007 vs. 672 in 2013, p = 0.01) and Lyme carditis (17 cases in 2007 vs. 40 in 2013, p = 0.03) both significantly increased in frequency. This is primarily accounted for by their increase within the Midwest region. Carditis frequency among cases of Lyme disease was stable (p = 0.15). Encounters for Lyme carditis are dramatically costlier than those for Lyme disease without carditis [median $9104 (3741-19,003) vs. 922 (238-4987), p < 0.001] The increase in Lyme carditis cases in US children's hospitals is associated with an increased Lyme disease incidence, suggesting that there has not been a change in its virulence or cardiac tropism. The increasing number of serious cardiac events and costs associated with Lyme disease emphasize the need for prevention and early detection of disease and control of its spread.

The cost of Lyme borreliosis

Background

Lyme borreliosis (LB) is the most frequently reported tick-borne infection in Europe and North America. The aim of this study was to estimate the cost-of-illness of LB in the Netherlands. We used available incidence estimates from 2010 for tick bite consultations and three symptomatic LB outcomes: erythema migrans (EM), disseminated LB and Lyme-related persisting symptoms. The cost was estimated using these incidences and the average cost per patient as derived from a patient questionnaire. We estimated the cost from a societal perspective, including healthcare cost, patient cost and production loss, using the friction cost method and a 4% annual discount rate. Tick bites and LB in 2010 led to a societal cost of €19.3 million (95% CI 15.6-23.4; 16.6 million population) for the Netherlands. Healthcare cost and production loss each constituted 48% of the total cost (€9.3 and €9.2 million/year), and patient cost 4% (€0.8 million/year). Of the total cost, 37% was related to disseminated LB, followed by 27% for persisting symptoms, 22% for tick bites and 14% for EM. Per outcome, for an individual case the mean cost of disseminated LB and Lyme-related persisting symptoms was both around €5700; for EM and GP consultations for tick bites this was €122 and €53. As an alternative to the friction cost method, the human capital method resulted in a total cost of €23.5 million/year. LB leads to a substantial societal cost. Further research should therefore focus on additional preventive interventions.

Successful treatment of fulminant Lyme myocarditis with mechanical circulatory support in a young male adult: a case report

We describe the case of fulminant myocarditis due to Lyme disease and use of mechanical circulatory support (MCS) for the treatment of the Lyme carditis associated with refractory cardiogenic shock. Fulminant Lyme myocarditis in young adult male patient led to a sudden onset of acute, severe biventricular heart failure with progressive cardiogenic shock, and multiorgan failure immediately after admission.

The previously healthy 28-year-old man was admitted to hospital with dyspnea, atrial flutter with 160/min ventricles rate, normotension, cardiomegaly, and incipient cardiogenic pulmonary edema on chest x-ray. Within the next 24 hours, the acute heart failure (AHF) progressed to the refractory cardiogenic shock with severe systemic hypotension, respiratory distress, anuria, liver congestion, and laboratory evidence of extremely high level of the anaerobic metabolism in the arterial blood (pH 7.16; HCO₃ 12.3 mmol/L; BE -14.6; lactates level 17 mmol/L). The transesophageal echo imaging showed severe dilatation and global biventricular akinesis, with left ventricular ejection fraction of 5%. The diagnosis of acute fulminant myocarditis of unknown etiology was reached. Since the patient did not respond rapidly to vasoactive and supportive therapy, MCS was immediately inserted. Broad differential diagnosis of fulminant myocarditis was considered and disseminated Borrelia infection was serologically confirmed and appropriate antimicrobial therapy was started from the fifth day after admission. MCS used over the next 26 days was successfully integrated with pharmacologic support and artificial ventilation in therapy. The patient was discharged from hospital after 65 days with a complete restoration of bilateral heart ejection fraction.

This case shows that the clinical course of the Lyme carditis can present uncommonly with profound cardiovascular collapse and the MSC implementation should be considered in the early stage of drug resistant hemodynamic instability. Rapid transfer to the cardiac center where the MCS is available for all patients with signs and symptoms of AHF due to confirmed or suspected Lyme carditis would be recommended, as this treatment could be the only life-saving method.

Manifestations of Lyme carditis

The first data of Lyme carditis, a relatively rare manifestation of Lyme disease, were published in eighties of the last century. Clinical manifestations include syncope, light-headedness, fainting, shortness of breath, palpitations, and/or chest pain. Atrioventricular (AV) electrical block of varying severity presents the most common conduction disorder in Lyme carditis. Although is usually mild, AV block can fluctuates rapidly and progress from a prolonged P-R interval to a His-Purkinje block within minutes to hours and days. Rarely, Lyme disease may be the cause of endocarditis, while some studies and reports, based on serological and/or molecular investigations, have suggested possible influence of Borrelia burgdorferi on degenerative cardiac valvular disease. Myocarditis, pericarditis, pancarditis, dilated cardiomyopathy, and heart failure have also been described as possible manifestations of Lyme carditis. The clinical course of Lyme carditis is generally mild, short term, and in most cases, completely reversible after adequate antibiotic treatment.

Fatal pyogranulomatous myocarditis in 10 Boxer puppies

Over a period of 5 years, 10 pure-bred Boxer puppies, 9-16 weeks old, were presented with a history of sudden death and were diagnosed with pyogranulomatous myocarditis. The myocarditis was characterized by a mixed infiltrate composed predominantly of neutrophils and macrophages. In our retrospective study, original case records and archived materials were examined. All dogs were positive for Borrelia burgdorferi on immunohistochemistry (IHC). There was no evidence of infectious agents in formalin-fixed, paraffin-embedded (FFPE) heart tissue sections stained with hematoxylin and eosin, Ziehl-Neelsen, Gram, Grocott methenamine silver, Warthin-Starry, Von Kossa, and Steiner-Chapman stains. IHC for Chlamydia sp., Toxoplasma gondii, Neospora caninum, West Nile virus, and canine parvovirus also yielded a negative result in all dogs. Polymerase chain reaction testing for vector-borne pathogens on heart tissue from 9 of the dogs (1 frozen and 8 FFPE samples) yielded positive results for 1 dog with B. burgdorferi as well as Anaplasma phagocytophilum in another dog. Subsequently, 2 additional cases were found in a French Bulldog and a French Bulldog-Beagle mix that had identical morphology, test results, age, and seasonality to these 10 Boxer dogs. The similarities in the seasonality, signalment of the affected dogs, and the gross and microscopic lesions suggest a common etiology. Positive IHC and morphologic similarities to human Lyme carditis indicate that B. burgdorferi is likely the agent involved. An additional consideration for these cases is the possibility of a breed-specific autoimmune myocarditis or potential predisposition for cardiopathogenic agents in young Boxers.

Cardiac Tropism of Borrelia burgdorferi: An Autopsy Study of Sudden Cardiac Death Associated with Lyme Carditis

Fatal Lyme carditis caused by the spirochete Borrelia burgdorferi rarely is identified. Here, we describe the pathologic, immunohistochemical, and molecular findings of five case patients. These sudden cardiac deaths associated with Lyme carditis occurred from late summer to fall, ages ranged from young adult to late 40s, and four patients were men. Autopsy tissue samples were evaluated by light microscopy, Warthin-Starry stain, immunohistochemistry, and PCR for B. burgdorferi, and immunohistochemistry for complement components C4d and C9, CD3, CD79a, and decorin. Post-mortem blood was tested by serology. Interstitial lymphocytic pancarditis in a relatively characteristic road map distribution was present in all cases. Cardiomyocyte necrosis was minimal, T cells outnumbered B cells, plasma cells were prominent, and mild fibrosis was present. Spirochetes in the cardiac interstitium associated with collagen fibers and co-localized with decorin. Rare spirochetes were seen in the leptomeninges of two cases by immunohistochemistry. Spirochetes were not seen in other organs examined, and joint tissue was not available for evaluation. Although rare, sudden cardiac death caused by Lyme disease might be an under-recognized entity and is characterized by pancarditis and marked tropism of spirochetes for cardiac tissues.

Epidemiology of Lyme disease

Lyme disease is the most common vector-borne illness in North America and Europe. The etiologic agent, Borrelia burgdorferi sensu lato, is transmitted to humans by certain species of Ixodes ticks, which are found widely in temperate regions of the Northern hemisphere. Clinical features are diverse, but death is rare. The risk of human infection is determined by the geographic distribution of vector tick species, ecologic factors that influence tick infection rates, and human behaviors that promote tick bite. Rates of infection are highest among children 5 to 15 years old and adults older than 50 years.

Lyme carditis

Lyme disease is a common disease that uncommonly affects the heart. Because of the rarity of this diagnosis and the frequent absence of other concurrent clinical manifestations of early Lyme disease, consideration of Lyme carditis demands a high level of suspicion when patients in endemic areas come to attention with cardiovascular symptoms and evidence of higher-order heart block. A majority of cases manifest as atrioventricular block. A minority of Lyme carditis cases are associated with myopericarditis. Like other manifestations of Lyme disease, carditis can readily be managed with antibiotic therapy and supportive care measures, such that affected patients almost always completely recover.

Lyme carditis--diagnosis, treatment and prognosis

BACKGROUND

There are 60,000 to 100,000 new cases of borreliosis in Germany each year. This infectious disease most commonly affects the skin, joints, and nervous system. Lyme carditis is a rare manifestation with potentially lethal complications.

METHODS

This review is based on selected publications on the clinical manifestations, diagnosis, and treatment of Lyme carditis, and on the authors' scientific and clinical experience.

RESULTS

Lyme carditis is seen in 4% to 10% of all patients with Lyme borreliosis. Whenever the clinical suspicion of Lyme carditis arises, an ECG is mandatory for the detection or exclusion of an atrioventricular conduction block. Patients with a PQ interval longer than 300 ms need continuous ECG monitoring. 90% of patients with Lyme carditis develop cardiac conduction abnormalities, and 60% develop signs of perimyocarditis. Borrelia serology (ELISA) may still be negative in the early phase of the condition, but is always positive in later phases. Cardiac MRI can be used to confirm the diagnosis and to monitor the patient's subsequent course. The treatment of choice is with antibiotics, preferably ceftriaxone. The cardiac conduction disturbances are usually reversible, and the implantation of a permanent pacemaker is only exceptionally necessary. There is no clear evidence at present for an association between borreliosis and the later development of a dilated cardiomyopathy. When Lyme carditis is treated according to the current guidelines, its prognosis is highly favorable.

CONCLUSION

Lyme carditis is among the rarer manifestations of Lyme borreliosis but must nevertheless be considered prominently in differential diagnosis because of the potentially severe cardiac arrhythmias that it can cause.

Lyme Disease: What the Wilderness Provider Needs to Know

Lyme disease is a multisystem tickborne illness caused by the spirochete Borrelia burgdorferi and is the most common vectorborne disease in the United States. Prognosis after initiation of appropriate antibiotic therapy is typically good if treated early. Wilderness providers caring for patients who live in or travel to high-incidence Lyme disease areas should be aware of the basic biology, epidemiology, clinical manifestations, and treatment of Lyme disease.

Putting Heart Block Back in the "Lyme Light"

We report a case of syncope in a young patient who presented with high-degree, variable atrioventricular heart block. Despite having no other classic manifestations of Lyme disease, she was treated with intravenous ceftriaxone for Lyme carditis on high clinical suspicion due to geographic location. The heart block resolved within 24 h of treatment. Although rare, we demonstrate the importance of considering Lyme carditis in patients who present with new-onset heart block and a history of living in an endemic area. Initiation of empiric antibiotic therapy can lead to rapid resolution of this condition. .

Lyme disease: a case report of a 17-year-old male with fatal Lyme carditis

Lyme disease is a systemic infection commonly found in the northeastern, mid-Atlantic, and north-central regions of the United States. Of the many systemic manifestations of Lyme disease, cardiac involvement is uncommon and rarely causes mortality. We describe a case of a 17-year-old adolescent who died unexpectedly after a 3-week viral-like syndrome. Postmortem examination was remarkable for diffuse pancarditis characterized by extensive infiltrates of lymphocytes and focal interstitial fibrosis. In the cardiac tissue, Borrelia burgdorferi was identified via special stains, immunohistochemistry, and polymerase chain reaction. The findings support B. burgdorferi as the causative agent for his fulminant carditis and that the patient suffered fatal Lyme carditis. Usually, Lyme carditis is associated with conduction disturbances and is a treatable condition. Nevertheless, few cases of mortality have been reported in the literature. Here, we report a rare example of fatal Lyme carditis in an unsuspected patient.

Third-degree heart block associated with lyme carditis: review of published cases

Lyme carditis is an uncommon manifestation of Lyme disease that most commonly involves some degree of atrioventricular conduction blockade. Third-degree conduction block is the most severe form and can be fatal if untreated. Systematic review of the medical literature identified 45 published cases of third-degree conduction block associated with Lyme carditis in the United States. Median patient age was 32 years, 84% of patients were male, and 39% required temporary pacing. Recognizing patient groups more likely to develop third-degree heart block associated with Lyme carditis is essential to providing prompt and appropriate therapy.

Common misconceptions about Lyme disease

Lyme disease, infection with Borrelia burgdorferi, is a focally endemic tick-transmitted zoonosis. During the 3 decades since the responsible spirochete was identified, a series of misconceptions and misunderstandings have become widely prevalent, leading to frequent misdiagnosis and inappropriate treatment. Persistent misconceptions concern the reliability of available diagnostic tools, the signs and symptoms of nervous system involvement, the appropriate choice and duration of antimicrobial therapy, the curability of the infection, and the cause of symptoms that may persist in some patients after treatment. Concern about disparate perspectives led the Institute of Medicine to review the subject. In this article we review the principal misconceptions, discussing their origins and the best currently available scientific evidence related to each one.

Lyme endocarditis

Lyme borreliosis is a common tick-borne disease with a wide variety of clinical manifestations. Cardiac involvement has been reported during both the acute phase (atrioventricular block, pericarditis) and the chronic stage (dilated cardiomyopathy), but is rare (<5%). Here we describe the first case of Borrelia afzelii Lyme endocarditis, in a 61-year-old man living in an endemic area of France. The diagnosis was confirmed by detection of B. afzelii DNA in the mitral valve by specific real-time PCR. He was treated empirically with amoxicillin for 6 weeks and remains well 12 months later.

Detection of Borrelia burgdorferi sensu lato in endomyocardial biopsy specimens in individuals with recent-onset dilated cardiomyopathy

AIMS

Recent studies in patients with dilated cardiomyopathy (DCM) have detected the genome of Borrelia burgdorferi sensu lato (BBSL) in endomyocardial biopsy (EMB) specimens using a qualitative polymerase chain reaction (PCR), suggesting a causal link between Lyme disease and DCM in areas in which Lyme disease is endemic. We aimed to study this relationship using a comprehensive molecular analysis detecting BBSL in EMB samples.

METHODS AND RESULTS

We performed a comprehensive histopathological, immunohistochemical, ultrastructural, and molecular analysis targeting cardiotropic viruses and BBSL in EMB specimens of 41 individuals with recent-onset DCM and 15 controls with end-stage coronary artery disease. Specifically, quantitative PCR and electron microscopy of EMB specimens were employed. In addition, autoantibodies and manifestation of autoimmune diseases were evaluated in both groups. Individuals with recent-onset DCM presented more frequently with myocardial BBSL persistence as compared with the control group (24% vs. 0%, P = 0.035). In contrast, the prevalence of parvovirus B19 and cytomegalovirus was similar in both groups. Sequence analysis of borrelial DNA revealed the following genospecies: Borrelia burgdorferi sensu stricto in three patients (30%), Borrelia afzelii in two patients (20%), and Borrelia garinii in four patients (40%), the results being inconclusive in one case. BBSL-positive DCM patients had a higher prevalence of organ-specific autoimmune diseases in comparison with the remaining DCM patients (50% vs. 16%, P = 0.030).

CONCLUSION

Myocardial persistence of BBSL may be involved in the pathophysiology of DCM in individuals living in areas in which Lyme disease is endemic.

Detection of Borrelia bissettii in cardiac valve tissue of a patient with endocarditis and aortic valve stenosis in the Czech Republic

Molecular analysis of a clinical sample confirmed the presence of Borrelia bissettii DNA in cardiac valve tissue from a patient with endocarditis and aortic valve stenosis. This evidence strongly supports the involvement of B. bissettii in Lyme disease in Europe.