Myocarditis and Pericarditis following COVID-19 mRNA Vaccination: Practical Considerations for Care Providers

The mRNA vaccines against COVID-19 infection have been effective in reducing the number of symptomatic cases worldwide. With widespread uptake, case series of vaccine-related myocarditis/pericarditis have been reported, particularly in adolescents and young adults. Men tend to be affected with greater frequency, and symptom onset is usually within 1 week after vaccination. Clinical course appears to be mild in most cases. On the basis of the available evidence, we highlight a clinical framework to guide providers on how to assess, investigate, diagnose, and report suspected and confirmed cases. In any patient with highly suggestive symptoms temporally related to COVID-19 mRNA vaccination, standardized workup includes serum troponin measurement and polymerase chain reaction testing for COVID-19 infection, routine additional lab work, and a 12-lead electrocardiogram. Echocardiography is recommended as the imaging modality of choice for patients with unexplained troponin elevation and/or pathologic electrocardiogram changes. Cardiovascular specialist consultation and hospitalization should be considered on the basis of the results of standard investigations. Treatment is largely supportive, and myocarditis/pericarditis that is diagnosed according to defined clinical criteria should be reported to public health authorities in every jurisdiction. Finally, we recommend COVID-19 vaccination in all individuals in accordance with the Health Canada and National Advisory Committee on Immunization guidelines. In patients with suspected myocarditis/pericarditis after the first dose of an mRNA vaccine, deferral of a second dose is recommended until additional reports become available.

Myocarditis associated with campylobacter jejuni colitis: a case report

Myocarditis is a rare complication of acute diarrhea due to Campylobacter Jejuni infection. We present the case of 25-year-old male who presented with campylobacter jejuni colitis who subsequently had chest pain and elevated cardiac biomarkers. The patient developed acute myocarditis confirmed on cardiac magnetic resonance imaging.

Prevalence of Bartonella sp. in United States military working dogs with infectious endocarditis: a retrospective case-control study

OBJECTIVES

Bartonella infection has been associated with endocarditis in humans, dogs, cats and cattle. In order to evaluate the importance of this pathogen as a possible source of endocarditis in United States military working dogs (MWDs), we performed a retrospective case-control study on 26 dogs with histological diagnosis of culture negative endocarditis (n = 18), endomyocarditis (n = 5) or endocardiosis (n = 3) and 28 control dogs without any histological cardiac lesions.

METHODS

DNA was extracted from paraffin embedded cardiac valves and tissues from case and control dogs and submitted to PCR testing with primers targeting the Bartonella gltA gene. PCR-RFLP using four restriction endonucleases and partial sequencing was then performed to determine the Bartonella species involved.

RESULTS

Nineteen (73%) cases were PCR positive for Bartonella, including B. henselae (8 dogs), B. vinsonii subsp. berkhoffii (6 dogs), B. washoensis (2 dogs) and B. elizabethae (1 dog). Only one control dog was weakly PCR positive for Bartonella. Based on the type of histological diagnosis, 13 (72.2%) dogs with endocarditis, 3 (60%) dogs with endomyocarditis and all 3 dogs with endocardiosis were Bartonella PCR positive.

CONCLUSIONS

Bartonella sp. Infections were correlated with cardiopathies in US military working dogs. Systemic use of insecticides against ectoparasites and regular testing of MWDs for Bartonella infection seem highly appropriate to prevent such life-threatening exposures.

Acute myocarditis complicated with permanent complete atrioventricular block caused by Escherichia coli bacteremia: A rare case report

RATIONALE

Acute myocarditis complicated with complete atrioventricular block (CAVB) is rare in clinical scenario. We report an uncommon case of myocarditis complicated with permanent CAVB caused by Escherichia coli (E coli) bacteremia.

PATIENT CONCERNS

A 77-year-old woman presented at the emergency department with chest pain, dizziness, nausea, and cold sweats of 1-day duration. She had histories of type 2 diabetes mellitus, hyperlipidemia, and chronic kidney disease with regular medical therapy.

DIAGNOSIS

Both blood and urine cultures were positive for E coli. Regional inferior wall motion abnormalities on echocardiography, unexplained life-threatening arrhythmias, newly abnormal electrocardiogram, elevated cardiac troponins, and healthy coronary arteries on angiography were consistent with E coli-induced myocarditis.

INTERVENTIONS

The patient received implantation of a dual-chamber pacemaker because of irreversible CAVB.

OUTCOMES

The patient was discharged on day 8 and remained asymptomatic at 15 months of follow-up, with ST-segment normalization and normal left ventricular function.

LESSONS

This extremely rare case of E coli-induced myocarditis masquerading as acute STEMI and with permanent CAVB sequelae, highlights the importance of sensitivity to non-ischemia etiologies of ST-segment elevation and the potential impact of E coli sepsis on the cardiac conduction system.

Non-typhoidal Salmonella myocarditis in an immunocompetent young adult with diarrhea

Myocarditis is the inflammation of the heart muscle and it is caused by a wide range of infectious and non-infectious conditions. Non-typhoidal Salmonella infection, a common foodborne illness worldwide, only rarely causes myocarditis. We describe a case of an immunocompetent adult with Salmonella enterica serovar Typhimurium myocarditis who had a favorable outcome due to early recognition of the causative factor and prompt initiation of appropriate treatment.

Acute Myopericarditis Associated with Tickborne Rickettsia sibirica mongolitimonae

We report an unusual case of myopericarditis caused by Rickettsia sibirica mongolitimonae. Because of increasing reports of Rickettsia spp. as etiologic agents of acute myopericarditis and the ease and success with which it was treated in the patient reported here, rickettsial infection should be included in the differential diagnosis for myopericarditis.

Successful treatment of community-acquired methicillin-resistant Staphylococcus aureus purulent myopericarditis

A previously healthy 48-year-old active duty man, who had been treated for an elbow abscess 3 weeks earlier, presented to an emergency department in Bahrain with tachycardia, pericardial friction rub and jugular venous distention. Cardiac tamponade was confirmed on transthoracic echocardiogram and he was taken for emergent pericardiocentesis. Pericardial fluid cultures grew community-acquired methicillin-resistant Staphylococcus aureus Despite ongoing treatment with intravenous vancomycin, he developed a recurrent fibrinous pericardial effusion and constrictive pericarditis requiring pericardiectomy. Though he initially did well postoperatively, he developed drug reaction with eosinophilia and systemic symptoms syndrome in response to vancomycin. He was transitioned to ceftaroline and started on high-dose steroids. He recovered during a week-long admission and was discharged home. Several weeks later at follow-up he was doing well and had resumed moderate intensity exercise.

Streptococcus pneumoniae in the heart subvert the host response through biofilm-mediated resident macrophage killing

For over 130 years, invasive pneumococcal disease has been associated with the presence of extracellular planktonic pneumococci, i.e. diplococci or short chains in affected tissues. Herein, we show that Streptococcus pneumoniae that invade the myocardium instead replicate within cellular vesicles and transition into non-purulent biofilms. Pneumococci within mature cardiac microlesions exhibited salient biofilm features including intrinsic resistance to antibiotic killing and the presence of an extracellular matrix. Dual RNA-seq and subsequent principal component analyses of heart- and blood-isolated pneumococci confirmed the biofilm phenotype in vivo and revealed stark anatomical site-specific differences in virulence gene expression; the latter having major implications on future vaccine antigen selection. Our RNA-seq approach also identified three genomic islands as exclusively expressed in vivo. Deletion of one such island, Region of Diversity 12, resulted in a biofilm-deficient and highly inflammogenic phenotype within the heart; indicating a possible link between the biofilm phenotype and a dampened host-response. We subsequently determined that biofilm pneumococci released greater amounts of the toxin pneumolysin than did planktonic or RD12 deficient pneumococci. This allowed heart-invaded wildtype pneumococci to kill resident cardiac macrophages and subsequently subvert cytokine/chemokine production and neutrophil infiltration into the myocardium. This is the first report for pneumococcal biofilm formation in an invasive disease setting. We show that biofilm pneumococci actively suppress the host response through pneumolysin-mediated immune cell killing. As such, our findings contradict the emerging notion that biofilm pneumococci are passively immunoquiescent.

Immunohistochemical identification of Propionibacterium acnes in granuloma and inflammatory cells of myocardial tissues obtained from cardiac sarcoidosis patients

Background

Although rare, cardiac sarcoidosis (CS) is potentially fatal. Early diagnosis and intervention are essential, but histopathologic diagnosis is limited. We aimed to detect Propionibacterium acnes, a commonly implicated etiologic agent of sarcoidosis, in myocardial tissues obtained from CS patients.

Methods and results

We examined formalin-fixed paraffin-embedded myocardial tissues obtained by surgery or autopsy and endomyocardial biopsy from patients with CS (n = 26; CS-group), myocarditis (n = 15; M-group), or other cardiomyopathies (n = 39; CM-group) using immunohistochemistry (IHC) with a P. acnes-specific monoclonal antibody. We found granulomas in 16 (62%) CS-group samples. Massive (≥14 inflammatory cells) and minimal (<14 inflammatory cells) inflammatory foci, respectively, were detected in 16 (62%) and 11 (42%) of the CS-group samples, 10 (67%) and 10 (67%) of the M-group samples, and 1 (3%) and 18 (46%) of the CM-group samples. P. acnes-positive reactivity in granulomas, massive inflammatory foci, and minimal inflammatory foci were detected in 10 (63%), 10 (63%), and 8 (73%) of the CS-group samples, respectively, and in none of the M-group and CM-group samples.

Conclusions

Frequent identification of P. acnes in sarcoid granulomas of originally aseptic myocardial tissues suggests that this indigenous bacterium causes granuloma in many CS patients. IHC detection of P. acnes in massive or minimal inflammatory foci of myocardial biopsy samples without granulomas may be useful for differentiating sarcoidosis from myocarditis or other cardiomyopathies.

[Tricuspid Valve Repair in a Patient with Isolated Tricuspid Valve Infective Endocarditis with Pulmonary Embolism;Report of a Case]

We report a case of 39-year-old man who developed tricuspid valve infective endocarditis with a complication of pulmonary embolism. He was transferred to our institution because of intermittent fever and enlargement of the vegetation of the tricuspid valve in spite of optimal antibiotics treatment. Computed tomography revealed pulmonary embolism, and transesophageal echocardiography showed a large and mobile vegetation (22×10 mm) on the tricuspid valve with moderate regurgitation. In addition, Streptococcus agalactiae was identified in blood cultures. The patient underwent surgical resection of the vegetation followed by tricuspid valve repair including De Vega's annuloplasty. Antibiotic therapy was continued for 4 weeks after surgery, and he was discharged on the 31st postoperative day. No endocarditis nor tricuspid valve dysfunction has re-occurred.

Lyme Carditis: A Case Involving the Conduction System and Mitral Valve

Lyme disease is the most common tick-borne infection in the Northern hemisphere. Cardiac manifestations of Lyme disease typically include variable atrioventricular nodal block and rarely structural heart pathology. The incidence of Lyme carditis may be underestimated based on current reporting practices of confirmed cases. This case of a 59-year-old man with Lyme carditis demonstrates the unique presentation of widespread conduction system disease, mitral regurgitation, and suspected ischemic disease. Through clinical data, electrocardiograms, and cardiac imaging, we show the progression, and resolution, of a variety of cardiac symptoms attributable to infection with Lyme. [Full article available at http://rimed.org/rimedicaljournal-2017-02.asp].

A rare situation in acute rheumatic carditis: Involvement of all four valves

Güvenç O, Çimen D. A rare situation in acute rheumatic carditis: Involvement of all four valves. Turk J Pediatr 2017; 59: 497-500. Acute rheumatic fever continues to be an important health problem, especially in countries that are socioeconomically underdeveloped. Carditis, which develops in approximately half of the patients, is responsible for both early-stage mortality as well as late-stage surgical treatment due to heart valve insufficiency or stenosis. The most frequent and severe valve involvement is with the mitral valve, while the aortic valve has the second highest incidence of involvement. Pulmonary and tricuspid valves are rarely involved. The literature cites a few adult cases in which all four valves are affected by rheumatic carditis; however, to the best of our knowledge, there have been no acute-stage rheumatic carditis pediatric cases reported. This article presents a 13-year-old male patient of Syrian origin who escaped to Turkey from the war in his country, and who was in the acute stage of rheumatic carditis in which all four valves were involved.

Sudden, unexpected death of a 15-year-old boy due to pancarditis: A case report and possible etiopathogenesis

BACKGROUND

Generally, rheumatic heart disease is, today, sporadic in developed countries, even though it continues to be a major health hazard in the developing ones. It is also a very rare cause of sudden unexpected death. We report a case of a 15-year-old boy who suddenly died at home. Since 3 days he had presented fever and chest pain. The family physician had diagnosed bronchitis and treated the boy with amoxicillin.

METHODS

Seven hours after death, a forensic autopsy were performed . Before the autopsy, anamnesis and some circumstantial data were collected from the boy's parents. During the autopsy, samples for histological, toxicological and molecular examinations were collected. The samples for the histology (brain, hypophysis, heart and pericardium, lungs, spleen, liver, kidney, adrenal glands) were formalin fixed and paraffin embedded. Each section was stained with Hematoxylin-Eosin. Immunostaining was also performed, with anti-CD 68, anti-CD3, anti-CD 20, anti-myeloperoxidase. Microbiological cultures were performed on cardiac blood, myocardium, pericardial effusion and cerebrospinal fluid samples collected during autopsy. Blood specimens were also processed through PCR, in order to reveal the presence of Enteroviruses, Chickenpox virus, Epstein Barr virus. Also chemical-toxicological examinations for the detection of the main medications and drugs were performed on blood samples.

RESULTS

The anamnesis, collected before the autopsy, revealed an acute pharyngitis few weeks before. The autopsy, and the following histological and immunochemical examinations suggested an immunological etiology. The immunohistochemistry, showing a strong positivity of antiCD68 antibodies, integrated with clinical-anamnestic information, leads to hypothesize a rheumatic carditis.

CONCLUSION

In light of this case, at least 3 main messages of great importance for the clinician can be deduced. First, an accurate anamnesis collected by the family physician could have led to the correct interpretation of the objective signs and the administration of an appropriate therapy. Second, a pharyngeal swab should be performed for cases involving sore throat in young children and adolescents, especially in cases involving repeated pharyngitis. Finally, apparently unremarkable findings revealed from objective examinations can be signs of a serious disease. Moreover, in some cases, these diseases can be lethal if they are not properly treated.

TandemHeart as a Bridge to Recovery in Legionella Myocarditis

Legionnaires' disease is the designation for pneumonia caused by the Legionella species. Among the rare extrapulmonary manifestations, cardiac involvement is most prevalent, in the forms of myocarditis, pericarditis, postcardiotomy syndrome, and prosthetic valve endocarditis. Mechanical circulatory support has proved to be a safe and effective bridge to myocardial recovery in patients with acute fulminant myocarditis; however, to our knowledge, this support has not been used in infectious myocarditis specifically related to Legionellosis. We describe a case of Legionella myocarditis associated with acute left ventricular dysfunction and repolarization abnormalities in a 48-year-old man. The patient fully recovered after left ventricular unloading with use of a TandemHeart percutaneous ventricular assist device. In addition, we review the English-language medical literature on Legionella myocarditis and focus on cardiac outcomes.

Unusual presentation of listerial myocarditis and the diagnostic value of cardiac magnetic resonance

Listeria monocytogenes is an infrequent cause of bacterial myocarditis. Myocarditis without evidence of endocarditis is even rarer. Management in such cases involves early diagnosis, antibiotic therapy, and emergency treatment of arrhythmias. We report the case of a 47-year-old man who presented with features of acute ST-segment-elevation myocardial infarction complicated by ventricular tachycardia that necessitated urgent electrical cardioversion. Contrast-enhanced cardiac magnetic resonance images revealed hypertrophy, necrosis, and a mass that was determined to be an abscess caused by L. monocytogenes. Antibiotic treatment led to resolution of the listerial myocarditis. In addition to reporting our patient's case, we discuss the comparative advantages of cardiac magnetic resonance versus transthoracic echocardiography in characterizing myocarditis, upon presentation and in follow-up evaluation.

Sinus pause in association with Lyme carditis

Lyme disease is the most prevalent tick-borne disease in the United States. It is caused by the spirochete Borrelia burgdorferi. Cardiac involvement is seen in 4% to 10% of patients with Lyme disease. The principal manifestation of Lyme carditis is self-limited conduction system disease, with predominant involvement of the atrioventricular node. On rare occasions, Lyme carditis patients present with other conduction system disorders such as bundle branch block, intraventricular conduction delay, and supraventricular or ventricular tachycardia. We report the unusual case of a 59-year-old man who presented with new-onset symptomatic sinus pauses one month after hiking in upstate New York. To our knowledge, this is the first case report from North America that describes the relationship between symptomatic sinus pause and Lyme carditis.

[Lyme carditis]

Untreated Lyme disease can affect the heart in up to 10% of patients. Its clinical outcome and severity vary, ranging from asymptomatic minor conduction disturbances to potentially fatal arrhythmias and severe heart failure. A history of a tick bite or a typical previous skin lesion (Erythema migrans) may be absent; clinicians should therefore keep a low threshold of suspicion when facing cardiac manifestations in a patient potentially exposed to the disease in endemic areas. We report the case of a patient with Lyme carditis expressed by variable degrees of atrio-ventricular block and review the literature.

Microtubule inhibition therapy by colchicine in severe myocarditis especially caused by Epstein-Barr and cytomegalovirus co-infection during a two-year period: a novel therapeutic approach

The co-infection of Epstein-Barr virus and Cytomegalovirus rarely gains multi-pathogenicity and leads to viral myocarditis. Also, it may lead to progressive heart failure or sudden death. We present a case series of five patients who were monitored for the impact of low-dose colchicine therapy as adjunct to conventional heart failure therapy. Epstein-Barr virus, Cytomegalovirus and other viral antibodies were determined by enzyme-linked immunosorbent assay method. Adjuvant low-dose colchicine therapy (2x0.5 mg twice daily) was prescribed for addition to the conventional heart failure therapy of these patients and it wsa continued for two years. Ejection fractions of echocardiographic examinations in all patients were 21%, 18%, 25%, 20% and 21% before low-dose colchicine therapy. After two years of treatment, the values increased to 59%, 45%, 40%, 25% and 41%, respectively. The early implementation of low-dose colchicine in these patients seemed to have beneficial effects on overall survival.

[Cardiac arrest due to torsades de pointes ventricular tachycardia in a patient with Lyme carditis]

A 45-year-old female presented with third degree atrioventricular block and was diagnosed with Lyme carditis. Despite appropriate antibiotic treatment and continuous ventricular pacing, she suffered sudden cardiac arrest due to torsades de pointes ventricular tachycardia. Although rare, severe and potentially fatal ventricular tachyarrhythmias can occur in patients with Lyme borreliosis.

Strain-specific variation of the decorin-binding adhesin DbpA influences the tissue tropism of the lyme disease spirochete

Lyme disease spirochetes demonstrate strain- and species-specific differences in tissue tropism. For example, the three major Lyme disease spirochete species, Borrelia burgdorferi sensu stricto, B. garinii, and B. afzelii, are each most commonly associated with overlapping but distinct spectra of clinical manifestations. Borrelia burgdorferi sensu stricto, the most common Lyme spirochete in the U.S., is closely associated with arthritis. The attachment of microbial pathogens to cells or to the extracellular matrix of target tissues may promote colonization and disease, and the Lyme disease spirochete encodes several surface proteins, including the decorin- and dermatan sulfate-binding adhesin DbpA, which vary among strains and have been postulated to contribute to strain-specific differences in tissue tropism. DbpA variants differ in their ability to bind to its host ligands and to cultured mammalian cells. To directly test whether variation in dbpA influences tissue tropism, we analyzed murine infection by isogenic B. burgdorferi strains that encode different dbpA alleles. Compared to dbpA alleles of B. afzelii strain VS461 or B. burgdorferi strain N40-D10/E9, dbpA of B. garinii strain PBr conferred the greatest decorin- and dermatan sulfate-binding activity, promoted the greatest colonization at the inoculation site and heart, and caused the most severe carditis. The dbpA of strain N40-D10/E9 conferred the weakest decorin- and GAG-binding activity, but the most robust joint colonization and was the only dbpA allele capable of conferring significant joint disease. Thus, dbpA mediates colonization and disease by the Lyme disease spirochete in an allele-dependent manner and may contribute to the etiology of distinct clinical manifestations associated with different Lyme disease strains. This study provides important support for the long-postulated model that strain-specific variations of Borrelia surface proteins influence tissue tropism.

Lyme disease, the most common vector-borne disease in the United States, is caused by a bacterium, Borrelia burgdorferi. This bacterium infects the skin at the site of the tick bite and then can spread to other tissues, such as the heart, joints or nervous system, causing carditis, arthritis or neurologic disease. To colonize human tissues, the pathogen produces surface proteins that promote bacterial attachment to these sites. For example, DbpA binds to decorin, a component of human tissue. Different Lyme disease strains differ in the particular tissues they colonize and the disease they cause, but we do not understand why. Different strains also make distinct versions of DbpA that bind decorin differently, so variation of DbpA might contribute to strain-to-strain variation in clinical manifestations. To test this, we infected mice with Lyme disease strains that were identical except for the particular DbpA variant they produced. We found that the strains colonized different tissues and caused different diseases, such as arthritis or carditis. These results provide the first solid evidence that variation of an outer surface protein, in this case DbpA, influences what tissues are most affected during Lyme disease.

MicroRNA-146a provides feedback regulation of lyme arthritis but not carditis during infection with Borrelia burgdorferi

MicroRNAs have been shown to be important regulators of inflammatory and immune responses and are implicated in several immune disorders including systemic lupus erythematosus and rheumatoid arthritis, but their role in Lyme borreliosis remains unknown. We performed a microarray screen for expression of miRNAs in joint tissue from three mouse strains infected with Borrelia burgdorferi. This screen identified upregulation of miR-146a, a key negative regulator of NF-κB signaling, in all three strains, suggesting it plays an important role in the in vivo response to B. burgdorferi. Infection of B6 miR-146a-/- mice with B. burgdorferi revealed a critical nonredundant role of miR-146a in modulating Lyme arthritis without compromising host immune response or heart inflammation. The impact of miR-146a was specifically localized to the joint, and did not impact lesion development or inflammation in the heart. Furthermore, B6 miR-146a-/- mice had elevated levels of NF-κB-regulated products in joint tissue and serum late in infection. Flow cytometry analysis of various lineages isolated from infected joint tissue of mice showed that myeloid cell infiltration was significantly greater in B6 miR-146a-/- mice, compared to B6, during B. burgdorferi infection. Using bone marrow-derived macrophages, we found that TRAF6, a known target of miR-146a involved in NF-κB activation, was dysregulated in resting and B. burgdorferi-stimulated B6 miR-146a-/- macrophages, and corresponded to elevated IL-1β, IL-6 and CXCL1 production. This dysregulated protein production was also observed in macrophages treated with IL-10 prior to B. burgdorferi stimulation. Peritoneal macrophages from B6 miR-146a-/- mice also showed enhanced phagocytosis of B. burgdorferi. Together, these data show that miR-146a-mediated regulation of TRAF6 and NF-κB, and downstream targets such as IL-1β, IL-6 and CXCL1, are critical for modulation of Lyme arthritis during chronic infection with B. burgdorferi.

[Acute myocarditis complicating Mediterranean spotted fever. A case report]

Mediterranean spotted fever (MSF) due to Rickettsia conorii is the most important tick-borne disease occurring in North Africa. The first description of MSF was made by Conor and Brush in 1910 in Tunisia. Clinical diagnosis relies on the association of fever, rash and inoculation's scar during summertime. Prognosis in MSF is usually good, however malignant forms were described. These forms occur in patients with comorbidities. G6PD deficiency is a classic ground for severe forms of MSF. Myocarditis is an uncommon complication in MSF; only few cases were reported in the literature. We report a new case of myocarditis complicating MSF in a 15-year-old patient with G6PD deficiency. The patient presented with fever and rash, evocative of MSF; he reported chest pain and the electrocardiogram showed ST segment elevation in anterior leads. Troponin level was elevated. Echocardiogram showed left ventricular dysfunction with 40% ejection fraction. Serologic tests confirmed R. conorii recent infection. Antibiotic treatment with vibramycine and rifadine was started. Patient also received classic treatment of myocarditis with left ventricular dysfunction associating CEI, ß-bloquers and diuretics. Evolution was favourable with complete recovery of left ventricular function. Myocarditis is an uncommon but severe complication of MSF. Early diagnosis and treatment allow favorable evolution.

More complications occur in macrolide-resistant than in macrolide-sensitive Mycoplasma pneumoniae pneumonia

We sought to understand the situation of macrolide-resistant genotypes of Mycoplasma pneumoniae, and analyze the relationship between macrolide-resistant genotypes and clinical manifestations of Mycoplasma pneumoniae pneumonia (MPP). Full-length sequencing of the 23S rRNA gene of M. pneumoniae was performed in 235 nasopharyngeal aspirates (NPAs) from children with MPP. We also retrospectively compared the clinical characteristics of macrolide-resistant (MR) M. pneumoniae infections and macrolide-sensitive (MS) M. pneumoniae infections. A total of 206 patients had point mutations in the M. pneumoniae 23S rRNA gene, and these patients are referred to as MR patients. The remaining 29 patients without point mutations are referred to as MS patients. Among 206 MR patients, 199 (96.6%) had A2063G mutations, 6 had A2063T mutations, and the remaining patients had an A2064G mutation. Among the clinical manifestations, we found that the median fever durations were 8 days (range, 0 to 42 days) and 6 days (0 to 14 days) (P < 0.01), the median hospitalization durations were 8 days (2 to 45 days) and 6 days (3 to 16 days) (P < 0.01), and the median fever durations after macrolide therapy were 5 days (0 to 42 days) and 3 days (0 to 10 days) (P < 0.01), respectively, in the MR and MS groups. We also found that the incidence of extrapulmonary complications in the MR group was significantly higher than that in the MS group (P < 0.05). Moreover, the radiological findings were more serious in the MR group than in the MS group (P < 0.05). The increasing prevalence of MR M. pneumoniae has become a significant clinical issue in the pediatric patients, which may lead to more extrapulmonary complications and severe clinical features and radiological manifestations.

Myocarditis associated with Campylobacter jejuni

Myocarditis is frequently associated with a multitude of different viral infections but much less commonly a bacterial source. We present the case of a 33-year-old male with Campylobacter jejuni enteritis who subsequently developed myocarditis confirmed on cardiac MRI.

[Cardiac involvement in adults with echinococcosis]

Experiments have established that the first target for echinococcus is the liver and lung and that for pathogenic fungi and protozoa is the heart. Adult patients with hepatic hydatid disease complicated by paecilomycosis have been found to have atypical paecilomycosis-associated myocarditis, the treatment of which was developed by the authors, by using antibiotics, fungicides, and homeopathic remedies.

Cardiac involvement in leptospirosis

Leptospirosis is a neglected global disease with significant morbidity and mortality. Cardiac complications such as chest pain, arrhythmias, pulmonary oedema and refractory shock have been reported in patients with severe disease. However, the frequency and extent of cardiac involvement in leptospirosis, are under-reported and poorly understood. Multiple factors may contribute to clinical manifestations that suggest cardiac involvement, causing diagnostic confusion. A variety of electrocardiographic changes occur in leptospirosis, with atrial fibrillation, atrioventricular conduction blocks and non-specific ventricular repolarization abnormalities being the most common. Electrolyte abnormalities are likely to contribute to electrocardiographic changes; direct effects on Na(+)-K(+)-Cl(-) transporters in the renal tubules have been postulated. Echocardiographic evidence of myocardial dysfunction has not been adequately demonstrated. The diagnostic value of cardiac biomarkers is unknown. Histopathological changes in the myocardium have been clearly shown, with myocardial inflammation and vasculitis present in postmortem studies. Nonetheless, the pathophysiology of cardiac involvement in leptospirosis is poorly understood. Cardiac involvement, demonstrated electrocardiographically or clinically, tends to predict poor outcome. No specific therapies are available to prevent or treat cardiac involvement in leptospirosis; current management is based on correction of deranged homeostasis and supportive therapy. Evidence suggests that direct myocardial damage occurs in patients with severe leptospirosis, and further studies are recommended to elucidate its pathophysiology, clinical features and contribution to overall prognosis, and to identify appropriate diagnostic investigations and specific therapies.

What is the outcome of rheumatic carditis in children with Sydenham's chorea?

We evaluated the echocardiographic features of 69 children diagnosed with Sydenham's chorea at the first attack of acute rheumatic fever. By echocardiography, carditis was detected in 71% of cases and silent carditis was shown in 28.9% of cases at initial presentation. Most patients had mild or moderate valvular regurgitation. Sixty-three cases were followed from 1-10 years. The improvement rate in valvulitis in cases with silent carditis (29.4%) was not different than in cases with clinical carditis (18.5%) (p > 0.05). Persistence of valvular pathologies occurred in 72.2% of cases with carditis in the long-term follow-up (> 2 years). Most patients (88.8%) complied with secondary prophylaxis, so relapse of carditis was exclusively prevented in our patients. Recurrence of chorea was identified in 20.6% of cases and was not associated with clinical or laboratory evidence for streptococcal reinfection. Patients with chorea usually had mild carditis, and carditis showed resolution. Relapse of carditis in our population was exclusively prevented with secondary prophylaxis. Recurrence of chorea was not rare, despite regular treatment with benzathine penicillin.

[Tubercular myocarditis: two case reports and review of the literature]

We report here the cases of two patients developing tubercular myocarditis with a different clinical presentation, the first one with a myopericarditis, the second one presenting as pseudo-infarction complicated by cardiogenic shock. We discuss here the different anatomical and clinical presentations, the diagnostic approach, the indications of myocardic biopsy and the prognosis of this pathology.

Acute streptococcal myocarditis presenting as acute ST-elevation myocardial infarction

Acute streptococcal myocarditis is an uncommon diagnosis in the developed world. Its presentation masquerading as acute myocardial infarction is still uncommon. We describe a case of a young male presenting with a recent diagnosis of streptococcal pharyngitis followed by a classical presentation of post streptococcal myocarditis. This is an unusual presentation of acute rheumatic fever (ARF) masquerading as acute myocardial infarction, with a discussion on its diagnosis and management.

Perimyocarditis following streptococcal group A infection: from clinical cases to bioinformatics analysis

BACKGROUND

Streptococcal infection is known to be associated with non-suppurative complications, including rheumatic fever. A less well recognized complication is perimyocarditis.

METHODS

We report 4 cases of myocarditis in young males associated with acute streptoccal infection. Following this clinical observation we employed bioinformatic techniques to identify common epitopes between Streptococcus group A and human muscle proteins. We used Blast to search all the proteome (1697 proteins) of the Streptococcus pyogenes M1 GAS against the human proteome of 34,180 proteins.

RESULTS

4 patients with streptococcal A related myocarditis were treated and made a complete recovery. One cardiac protein, ATP2A2 (NP_733765.1)), a cardiac Ca2+ ATPase, shared an epitope with Streptococcus group A and a high probability of being presented on a MHC Class II molecule.

CONCLUSION

Streptococcal myocarditis may be a commoner entity than previously appreciated. Bioinformatic techniques have identified a suspected common epitope between the streptococcal proteins and a cardiac Ca2+ ATPase.

Outcomes of respiratory diphtheria in a tertiary referral infectious disease hospital

BACKGROUND

Diphtheria is a fatal disease and may cause serious complications if not recognized early and treated properly.

OBJECTIVES

To study the epidemiology, clinical features, complications, and outcomes in respiratory diphtheria.

MATERIALS AND METHODS

Diphtheria cases admitted in the infectious disease hospital, Beliaghata, Kolkata, India between January 2009 to January 2011 were evaluated in respect to demographic profile, immunization status, clinical features, complications, and outcomes.

RESULTS

200 diphtheria cases were studied. 150 (75%) patients had history of an adequate immunization, and 100 (50%) patients were from lower socio-economic groups. Common clinical features observed were throat pain in 148 (74%) cases and fever in 112 (56%) cases. Complications observed were myocarditis in 136 (68%) cases, neuropathy in 30 (15%) cases, and respiratory compromise in 14 (7%) cases. Death occurred in 5 (2.5%) patients.

CONCLUSIONS

diphtheria is still a public health problem in many developing countries. Strict public health measures like an increased immunization coverage, improvement of socio-economic status, easy availability of anti-diphtheritic serum (ADS), early recognition and effective treatment-all may reduce the incidence and mortality.

Complicated typhoid fever

Acute typhoid fever, caused by the gram negative bacterium Salmonella typhi may have a wide spectrum of clinical presentation. We report a young boy with typhoid fever, who developed myocarditis and splenic abscess, two of the unusual complications in the course of the disease. Judicious use of corticosteroid and antibiotic helped in achieving a favourable outcome.

Tubercular granuloma in the myocardium: an autopsy report

Granulomatous myocarditis is a rare disorder of the myocardium, and is usually associated with various inflammatory and autoimmune conditions. We report granulomatous myocarditis in an apparently healthy 58-year-old Indian man, who developed sudden chest pain and died while being escorted to the hospital. At the autopsy, no gross distinct cardiac lesions were observed. The histopathological sections from the left ventricular apex revealed a granuloma comprising a central area of caseous necrosis surrounded by lymphocytes, and epithelioid, plasma and Langhans giant cells. Myocardial tuberculosis was suspected as the underlying aetiology based on the histological features of the granuloma.

Epstein-Barr virus myocarditis as the first symptom of infectious mononucleosis

This case report describes a 20-year-old immunocompetent man with an episode of chest pain radiating into both arms, an increase in the level of myocardial enzymes, electrocardiogram abnormalities (widespread ST-segment elevation and q waves in leads V(4)-V(6)) and serological evidence for acute Epstein-Barr Virus infection preceding typical signs and symptoms of infectious mononucleosis.

The urokinase receptor (uPAR) facilitates clearance of Borrelia burgdorferi

The causative agent of Lyme borreliosis, the spirochete Borrelia burgdorferi, has been shown to induce expression of the urokinase receptor (uPAR); however, the role of uPAR in the immune response against Borrelia has never been investigated. uPAR not only acts as a proteinase receptor, but can also, dependently or independently of ligation to uPA, directly affect leukocyte function. We here demonstrate that uPAR is upregulated on murine and human leukocytes upon exposure to B. burgdorferi both in vitro as well as in vivo. Notably, B. burgdorferi-inoculated C57BL/6 uPAR knock-out mice harbored significantly higher Borrelia numbers compared to WT controls. This was associated with impaired phagocytotic capacity of B. burgdorferi by uPAR knock-out leukocytes in vitro. B. burgdorferi numbers in vivo, and phagocytotic capacity in vitro, were unaltered in uPA, tPA (low fibrinolytic activity) and PAI-1 (high fibrinolytic activity) knock-out mice compared to WT controls. Strikingly, in uPAR knock-out mice partially backcrossed to a B. burgdorferi susceptible C3H/HeN background, higher B. burgdorferi numbers were associated with more severe carditis and increased local TLR2 and IL-1β mRNA expression. In conclusion, in B. burgdorferi infection, uPAR is required for phagocytosis and adequate eradication of the spirochete from the heart by a mechanism that is independent of binding of uPAR to uPA or its role in the fibrinolytic system.

Lyme borreliosis is caused by the spirochete Borrelia burgdorferi and is transmitted through ticks. Since its discovery approximately 30 years ago it has become the most important vector-borne disease in the Western world. The pathogenesis of this complex zoonosis is still not entirely understood. We here demonstrate that the urokinase receptor (uPAR) is upregulated in mice and humans upon exposure to B. burgdorferi in vitro and in vivo. Importantly, we describe the function of uPAR in the immune response against the spirochete; using uPAR knock-out mice, we show that uPAR plays an important role in phagocytosis of B. burgdorferi by leukocytes both in vitro as well as in vivo. In addition, we show that the mechanism by which uPAR is involved in the phagocytosis of B. burgdorferi is independent of ligation to its natural ligand uPA or uPAR's role in fibrinolysis. Our study contributes to the understanding of the pathogenesis of Lyme borreliosis and might contribute to the development of innovative novel treatment strategies for Lyme borreliosis.

Carditis associated with mycoplasma pneumoniae infection

Among 560 patients with serologically confirmed Mycoplasma pneumoniae infection, 25 (4.5%) had carditis (19 perimyocarditis, 6 pericarditis). During the acute phase 9 patients required intensive care. After an average of 16 months follow-up 11 patients with no previous signs of heart disease still had cardiac symptoms or signs. Thus carditis associated with M. pneumoniae infection is a serious disease, having cardiac sequelae more often than has hitherto been supposed. The pathogenesis of the carditis associated with M. pneumoniae infection is discussed, including the possibility that in some cases the elevated titre in the complement fixation test is non-specific. A summary is given of the 33 cases previously presented in the literature.

Clinical manifestations and diagnosis of lyme borreliosis

Lyme borrelosis is a multi-systemic disease caused byBorrelia burgdorferisensu lato. A complete presentation of the disease is an extremely unusual oberservation, in which a skin lesion follows a tick bite, the lesion itself is followed by heart and nervous system involvement, and later on by arthritis; late involvement of the eye, nervous system, joints and skin may also occur. Information on the relative frequency of individual clinical manifestations of Lyme borreliosis is limited; however, the skin is most frequently involved and skin manifestations frequently represent clues for the diagnosis. The only sign that enables a reliable clinical diagnoisis of Lyme borreliosis is a typical erythema migrans. Laboratory confirmation of a borrelial infection is needed for all manifestations of Lyme borreliosis, with the exception of typical skin lesions.

Chlamydophila pneumoniae myopericarditis in a child

An 11-year-old boy with serologically confirmed Chlamydophila pneumoniae infection presented with clinical, laboratory, and echocardiographic changes consistent with myopericarditis. No reports on C. pneumoniae myopericarditis in children are found in the medical literature. The boy, previously healthy, presented with fever, rash, constitutional symptoms, elevated acute phase reactants, elevated cardiac enzymes, and high brain natriuretic peptide levels. Hemodynamic instabilities, including hypotension and mild hypoxia, were noted. Two-dimensional echocardiographic findings showed mildly depressed left ventricular systolic function and small pericardial effusion. Requiring inotropic support, the boy was treated with azithromycin 10 mg/kg once daily for 7 days and a single dose of intravenous immunoglobulin 2 g/kg. He recovered fully with improved left ventricular systolic function before hospital discharge. An early definitive diagnosis is essential to knowing the etiology of pediatric myocarditis. Specific therapy may play role in the management and prognosis of this disorder.