A cluster of fulminant myocarditis cases in children, Baltimore, Maryland, 1997

[Lethal lymphocytic myocarditis-an underestimated diagnosis in infancy and childhood?]

In the past, histological diagnosis of (post-)viral myocarditis was based on the so-called Dallas criteria, which have been criticized because of high interobserver variability and sampling error. Immunohistochemical qualification and quantification of interstitial intramyocardial leucocytes was established and standard values concerning adults were published. Fatal casualties due to a viral myocarditis are rare as far as babies and children are concerned (sudden unexpected death in infancy; SUDI). Cases of sudden unexpected death in the first year of life are frequently regarded as sudden infant death syndrome (SIDS). To diagnose myocarditis when there are only single focal lymphocytic infiltrates in the myocardium, the number of samples taken by autopsy is relevant. But even in babies, immunohistochemical qualification and quantification of interstitial lymphocytes and macrophages can lead to standard values allowing diagnosis of myocarditis. Depending on the course of a viral infection, molecular pathological detection of viral genome in the myocardium is possible to support the diagnosis. Using the mentioned methods gradually, there are more cases of suspected SIDS, which are in fact cases of virus-induced myocarditis as cause of death. Primary enteroviruses (coxsackie viruses) and adenoviruses were found but also Epstein-Barr virus and PVB-19.

Acute Myocarditis in Children: An Overview of Treatment and Recent Patents

BACKGROUND

Pediatric myocarditis is rare but challenging. This overview summarized the current knowledge and recent patents on childhood myocarditis.

METHODS

Clinical queries and keywords of "myocarditis" and "childhood" were used as search engine.

RESULTS

Viral infections are the most common causes of acute myocarditis. Affected children often have a prodrome of fever, malaise, and myalgia. Clinical manifestations of acute myocarditis in children can be nonspecific. Some children may present with easy fatigability, poor appetite, vomiting, abdominal pain, exercise intolerance, respiratory distress/tachypnea, dyspnea at rest, orthopnea, chronic cough with wheezing, chest pain, unexplained tachycardia, hypotension, syncope, and hepatomegaly. Supraventricular arrhythmias, ventricular arrhythmias, and heart block may be present. A subset of patients have fulminant myocarditis and present with cardiovascular collapse, which may progress to severe cardiogenic shock, and even death. A high index of suspicion is crucial to its diagnosis and timely management. Cardiac magnetic resonance imaging is important in aiding clinical diagnosis while, endomyocardial biopsy remains the gold standard. The treatment consists of supportive therapy, ranging from supplemental oxygen and fluid restriction to mechanical circulatory support. Angiotensinconverting enzyme inhibitors, angio-tensin II receptor blockers, β-blockers, and aldosterone antagonists might be used for the treatment of heart failure while, immunosuppression treatments remain controversial. There are a few recent patents targeting prevention or treatment of viral myocarditis, including an immunogenic composition comprising a PCV-2 antigen, glutathione-S-transferase P1, neuregulins, NF-[kappa] B inhibitor, a pharmaceutical composition which contains 2-amino-2- (2- (4-octyl phenyl) - ethyl) propane 1,3-diol, a composition containing pycnojenol, Chinese herbal concoctions, and a Korean oral rapamycin. Evidence of their efficacy is still lacking.

CONCLUSION

This article reviews the current literature regarding etiology, clinical manifestations, diagnosis, and management of acute myocarditis in children.

Diagnosis and Management of Myocarditis: An Evidence-Based Review for the Emergency Medicine Clinician

BACKGROUND

Myocarditis is a potentially fatal condition that can be misdiagnosed in the emergency department (ED) setting.

OBJECTIVE

The purpose of this narrative review article is to provide a summary of the background, pathophysiology, diagnosis, and management of myocarditis, with a focus on emergency clinicians.

DISCUSSION

Myocarditis occurs when inflammation of the heart musculature causes cardiac dysfunction. Symptoms may range from mild to severe and are often preceded by a viral prodrome. Laboratory assessment and an electrocardiogram can be helpful for the diagnosis, but echocardiography is the ideal test in the ED setting. Some patients may also require advanced imaging, though this will often occur during hospitalization or follow-up. Treatment is primarily focused on respiratory and hemodynamic support. Initial hemodynamic management includes vasopressors and inotropes, whereas more severe cases may require an intra-aortic balloon pump, extracorporeal membrane oxygenation, or a ventricular assist device. Nonsteroidal anti-inflammatory drugs should be avoided while intravenous immunoglobulin is controversial.

CONCLUSION

Myocarditis is a serious condition with the potential for significant morbidity and mortality. It is important for clinicians to be aware of the current evidence regarding the diagnosis, management, and disposition of these patients.

Toll-Like Receptors: Are They Taking a Toll on the Heart in Viral Myocarditis?

Myocarditis is an inflammatory disease of the heart with viral infections being the most common aetiology. Its complex biology remains poorly understood and its clinical management is one of the most challenging in the field of cardiology. Toll-like receptors (TLRs), a family of evolutionarily conserved pattern recognition receptors, are increasingly known to be implicated in the pathophysiology of viral myocarditis. Their central role in innate and adaptive immune responses, and in the inflammatory reaction that ensues, indeed makes them prime candidates to profoundly affect every stage of the disease process. This review describes the pathogenesis and pathophysiology of viral myocarditis, and scrutinises the role of TLRs in every phase. We conclude with directions for future research in this field.

The use of extracorporeal membrane oxygenation in children with acute fulminant myocarditis

Acute fulminant myocarditis (AFM) occurs as an inflammatory response to an initial myocardial insult. Its rapid and deadly progression calls for prompt diagnosis with aggressive treatment measures. The demonstration of its excellent recovery potential has led to increasing use of mechanical circulatory support, especially extracorporeal membrane oxygenation (ECMO). Arrhythmias, organ failure, elevated cardiac biomarkers, and decreased ventricular function at presentation predict requirement for ECMO. In these patients, ECMO should be considered earlier as the clinical course of AFM can be unpredictable and can lead to rapid haemodynamic collapse. Key uncertainties that clinicians face when managing children with AFM such as timing of initiation of ECMO and left ventricular decompression need further investigation.

The landscape of extrapulmonary manifestations of human parainfluenza viruses: A systematic narrative review

Human parainfluenza virus (HPIV) infection is associated with every kind of respiratory tract illnesses, including the common cold, laryngotracheobronchitis (i.e. croup), tracheobronchitis, bronchiolitis, and pneumonia, in both children and adults. Although HPIVs are common respiratory pathogens, there are increasing reports about extrapulmonary manifestations of HPIVs infection. Each of the HPIVs could produce infection of other organs (central nervous system, heart, myocardium, etc.) in all age groups who are either immunocompetent or immunocompromised. This review aimed at summarizing the available data on clinical manifestations of HPIV infection outside the respiratory tract from 1961 to 2020. The findings support the possibility of extrapulmonary infections that were thought to be due to rare host genetic or immunologic defects in infected patients. These findings highlight the fact that extrapulmonary dissemination of HPIV can occur, but the association is not clearly demonstrated. Our data support the hypothesis that HPIV infection is one of the possible causes of these alterations and may even be the direct cause in some cases.

Intravenous immunoglobulin for presumed viral myocarditis in children and adults

BACKGROUND

This is an update of a previous review. Case reports and case series have described dramatic responses to intravenous immunoglobulin (IVIG) in people with presumed viral myocarditis, and its administration has become commonplace.

OBJECTIVES

The primary objective of this review was to compare event-free (death, requirement for a cardiac transplant, or placement of a left ventricular assist device) or overall (death) survival of adults and children with presumed viral myocarditis treated with IVIG versus those who did not receive IVIG. A secondary objective was to determine if a group of patients with presumed viral myocarditis could be identified (on the basis of age, duration of symptoms, acuity of onset of symptoms, cardiac function at presentation, virological results, or the presence or absence of histological evidence of acute myocarditis on cardiac biopsy in patients in whom a biopsy was performed) who would be the most likely to benefit from IVIG.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, DARE, CINAHL, Web of Science Core Collection, and LILACS in July 2019, and two trial registries in November 2019. We contacted authors of trials and checked reference lists of relevant papers. We applied no language restrictions.

SELECTION CRITERIA

We included studies if (1) participants had a clinical diagnosis of acute myocarditis with a left ventricular ejection fraction (LVEF) ≤ 0.45, left ventricular end-diastolic diameter (LVEDD) > 2 standard deviations (SDs) above the norm, or a left ventricular shortening fraction (LVSF) > 2 SDs below the mean, with duration of cardiac symptoms < 6 months; (2) participants had no evidence of non-infectious or bacterial cardiac disease; and (3) participants were randomly assigned to receive at least 1 g/kg of IVIG versus no IVIG or placebo. We excluded studies if (1) participants had received immunosuppression before outcome assessment; or (2) onset of myocarditis was reported to have occurred < 6 months postpartum.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results and extracted data. We assessed risk of bias with the Cochrane 'Risk of bias' tool. We conducted meta-analysis for two outcomes (overall survival and improvement in LVEF) with two adult trials. Other meta-analyses were not possible because only three relevant trials were included, and researchers analysed markedly different populations and used different outcome measures.

MAIN RESULTS

In this update we added two trials to the two previously included trials. A quasi-randomised trial was previously included due to a paucity of evidence from randomised trials; however, with the addition of two new randomised trials, it was removed from this update. For two adult trials, the overall risk of bias was unclear with very low-certainty evidence for all outcomes. The first trial studied 62 adults with recent-onset dilated cardiomyopathy randomly assigned to receive IVIG or an equivalent volume of 0.1% albumin in a blinded fashion. The effect on event-free survival between groups was uncertain (risk ratio (RR) of any event 1.76, 95% confidence interval (CI) 0.48 to 6.40). The second trial studied 41 adults with acute myocarditis randomised to either high-dose IVIG (1 to 2 g/kg over two days) or no treatment. The IVIG group reported greater survival time after 60 days (no raw data, P < 0.01), but the evidence is uncertain. We pooled the reported number of deaths in both trials, with no evidence of a difference between groups (RR 0.91, 95% CI 0.23 to 3.62, I² = 31%, very low-certainty evidence). The evidence on the effect of IVIG treatment on LVEF (pooled mean difference (MD) -0.01, 95% CI -0.06 to 0.05) after 12 months and an unknown time frame is uncertain. The results for functional capacity, assessed by peak oxygen consumption at 12 months, were uncertain (MD -0.80, 95% CI -4.57 to 2.97). The results for infusion-related side effects were also uncertain due to a very large CI (RR 20.29, 95% CI 1.25 to 329.93). Lastly, there was uncertain evidence addressing failure to attain complete recovery (RR 0.46, 95% CI 0.19 to 1.14).  Evidence for improvement in LVEDD, left ventricular shortening fraction, and hospitalisation status in adults was not reported.  In the single included paediatric trial, the overall risk of bias was low with very low-certainty evidence for all outcomes. The trial included 86 children in Egypt presenting with acute myocarditis. Children were randomly assigned to 1 g/kg IVIG daily for two consecutive days or placebo followed by echocardiography one and six months post randomisation for recording of LVEDD and LVSF. The evidence for overall survival after six months was uncertain (risk of death RR 0.48, 95% CI 0.20 to 1.15). The evidence was also uncertain for improvement in LVEDD and LVSF after six months (LVEDD MD -4.00, 95% CI -9.52 to 1.52; LVSF no raw data).  Evidence for improvement in LVEF, functional capacity, side effects, complete recovery, and hospitalisation status in children was not reported.  AUTHORS' CONCLUSIONS: Evidence from two trials of very low certainty and with unclear risk of bias provides contradictory evidence on the use of IVIG in the treatment of adults with presumed viral myocarditis. One trial reported that use of IVIG results in longer survival time after 60 days, whilst the other trial found that IVIG does not provide an appreciable benefit. The evidence of a difference in event-free or overall survival, LVEDD, or LVSF is of very low certainty in a single paediatric trial with a low risk of bias. Until higher-quality studies with low risk of bias and larger sample sizes have demonstrated benefit in a particular group of patients, the evidence for treatment with IVIG for presumed viral myocarditis is uncertain. Further studies of the pathophysiology of myocarditis would lead to improved diagnostic criteria, which would facilitate future research.

Coxsackievirus B heart infections and their putative contribution to sudden unexpected death: An 8-year review of patients and victims in the coastal region of Tunisia

Coxsackieviruses B (CV B) are known as the most common viral cause of human heart infections. Cardiac inflammations contribute to sudden unexpected death (SUD) significantly. The diagnosis remains difficult with the traditional diagnostic tests and must be substantially improved. This has prompted health professionals to seek new diagnostic procedures which may provide important clues regarding underlying etiology. The present study is based on patients with infectious heart diseases and SUD victims with no relevant pathologies. They were investigated for possible CV-B infection. Patients with coronary artery diseases and unnatural road and domestic accident victims served as controls. The samples were studied for CV-B applying PCR. Histopathology for inflammatory markers, immunohistochemistry (IHC) for immune inflammatory cells and the enteroviral VP1-capsid protein were performed. Overall, 102 patients and 87 SUD victims were studied. As controls, 100 patients and 54 SUD unnatural accident victims were enrolled. CV-B were detected in 28 patients and 15 SUD victims. The control group samples were completely virus negative. Compared to controls, IHC revealed a significant presence of T and B lymphocytes within the myocardium. Furthermore, enteroviral VP1-capsid protein were detected from samples by IHC. Applying a comprehensive combination of methods, our results demonstrate the involvement of CV-B in cases of heart infection suggesting they play a significant role in SUD. Our results emphasize the importance of opting for a combination of methods.

Intravenous immunoglobulin for presumed viral myocarditis in children and adults

BACKGROUND

This is an update of a previous review. Case reports and case series have described dramatic responses to intravenous immunoglobulin (IVIG) in people with presumed viral myocarditis, and its administration has become commonplace.

OBJECTIVES

The primary objective of this review was to compare transplant-free survival of adults and children with presumed viral myocarditis treated with IVIG versus those who did not receive IVIG. A secondary objective was to determine if a group of patients with presumed viral myocarditis could be identified (on the basis of age, duration of symptoms, acuity of onset of symptoms, cardiac function at presentation, virological results or the presence or absence of histological evidence of acute myocarditis on cardiac biopsy in patients in whom a biopsy was performed) who would be the most likely to benefit from IVIG.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 12 of 12), the Database of Abstracts of Reviews of Effects (DARE) (2013, Issue 4 of 4), MEDLINE (Ovid, 1946 to January Week 3 2014), EMBASE (Ovid, 1980 to Week 4 2014), the Cumulative Index to Nursing and Allied Health Literature (CINAHL) EBSCO, Web of Science (Thomson Reuters, 1970 to 24 January 2014), the Latin American and Caribbean Health Science Information Database (LILACS) (1982 to 30 January 2014), trials registries and conference proceedings. We contacted authors of trials and checked reference lists of relevant papers. We applied no language restrictions.

SELECTION CRITERIA

We included studies if (1) participants had a clinical diagnosis of acute myocarditis with a left ventricular ejection fraction (LVEF) ≤ 0.45, left ventricular end-diastolic diameter (LVEDD) > 2 standard deviations (SDs) above the norm or a shortening fraction (SF) > 2 SDs below the mean with duration of cardiac symptoms < 6 months; (2) participants had no evidence of non-infectious or bacterial cardiac disease; and (3) participants were randomly assigned to receive at least 1 g/kg of IVIG versus no IVIG or placebo. We excluded studies if (1) participants had received immunosuppression before outcome assessment; or (2) onset of myocarditis was reported to occur < 6 months post partum.

DATA COLLECTION AND ANALYSIS

Two review authors screened searches and extracted data independently. We assessed quality using the 'Risk of bias' tool. Meta-analysis was not possible because only two relevant studies were found, and researchers analysed markedly different populations.

MAIN RESULTS

In this update, review authors added one study to the study from the original review. The first relevant study involved 62 adults with recent-onset dilated cardiomyopathy randomly assigned to receive IVIG or an equivalent volume of 0.1% albumin in a blinded fashion. The overall risk of bias was unclear. The incidence of death or the requirement for cardiac transplant or placement of a left ventricular assist device was low in both groups (odds ratio (OR) for event-free survival 0.52, 95% confidence interval (CI) 0.12 to 2.30). Follow-up at six months and at 12 months showed equivalent improvement in LVEF (mean difference (MD) 0.00, 95% CI -0.07 to 0.07 at six months; MD 0.01, 95% CI -0.06 to 0.08 at 12 months). Functional capacity as assessed by peak oxygen consumption was equivalent in the two groups at 12 months (MD -0.80, 95% CI -4.57 to 2.97). Infusion-related side effects were more common in the treated group, but all were reported to be mild (OR 30.16, 95% CI 1.69 to 539.42).The second study added at this update included 83 children in India with suspected viral encephalitis and myocarditis. The overall risk of bias was high. The odds ratio for event-free survival was 7.39 (95% CI 0.91 to 59.86). Follow-up occurred only until hospital discharge, and LVEF was 49.5% in the treated group versus 35.9% in the placebo group (risk difference 13.6%, 95% CI 5.1 to 22.1%; P value = 0.001).

AUTHORS' CONCLUSIONS

Evidence from one trial does not support the use of IVIG for the treatment of adults with presumed viral myocarditis. The only paediatric trial had high risk of bias but suggested that benefit may be seen in the select group of children beyond the neonatal period who have viral encephalitis with myocarditis. Until higher-quality studies have demonstrated benefit in a particular group of patients, IVIG for presumed viral myocarditis should not be provided as routine practice in any situation. Further studies of the pathophysiology of myocarditis would lead to improved diagnostic criteria, which would facilitate future research.

Myocarditis in the setting of RSV bronchiolitis

Myocarditis in the pediatric population is commonly caused by viral pathogens, notably entero virus and adeno virus. Respiratory syncytial virus, although widespread among this population, is rarely associated with myocarditis. The incidence of myocarditis is unknown due to the variability of clinical presentation and diagnostic limitations. Data regarding prognosis is lacking in children. Patients should be monitored in a pediatric intensive care unit secondary to the risk of hemodynamic compromise. We present the case of fulminant myocarditis in a seven-month old female in the setting of respiratory syncytial virus bronchiolitis.

Myocarditis Outbreak among Adults, Illinois, 2003

An outbreak of myocarditis occurred among adults in Illinois in 2003. Diagnostic testing of myocardial tissues from 3 patients and comprehensive tests for enterovirus and adenovirus of other specimens from patients were inconclusive. Appropriate specimen collection from patients with idiopathic cardiomyopathy and further enhancement of diagnostic techniques are needed.

A systematic review of intravenous gamma globulin for therapy of acute myocarditis

Background

Intravenous gamma globulin (IVGG) is commonly used in the management of acute myocarditis. The objective of this study was to systematically review the literature evaluating this practice.

Methods

We conducted a comprehensive search (electronic databases, trials registries, conference proceedings, reference lists, contact with authors) to identify studies evaluating the use of IVGG in adults and children with a clinical or histologically proven diagnosis of myocarditis of possible viral etiology and symptoms of less than six months duration. Two reviewers independently screened the searches, applied inclusion criteria, and graded the evidence.

Results

Results were described qualitatively; data were not pooled because only one randomized controlled trial (RCT) with 62 patients was identified. The RCT showed no benefit with respect to cardiac function, functional outcome, or event-free survival. A small, uncontrolled trial (n = 10) showed significant improvement in LVEF from a mean of 24% to 41% 12 months after IVGG in nine survivors. A retrospective cohort study of pediatric patients showed improvement in cardiac function and a trend towards improved survival in patients receiving IVGG (n = 21) versus historic controls (n = 25). Ten case reports and two case series (total n = 21) described improvement in cardiac function after administration of IVGG; two case reports showed no benefit of IVGG. One case of hemolytic anemia was attributed to IVGG.

Conclusion

There is insufficient data from methodologically strong studies to recommend routine use of IVGG for acute myocarditis. Future randomized studies that take into account the etiology of acute myocarditis will be required to determine the efficacy of IVGG.

Coxsackievirus B3 sequences in the myocardium of fatal cases in a cluster of acute myocarditis in Greece

AIM

The investigation of three fatal cases during a nationwide cluster of cases of an upper respiratory tract infection (URTI) associated with myocarditis and/or pericarditis in Greece in 2002.

METHODS

In the three women who died, necropsies were performed and tissue sections were taken for histological examination, antigen detection by immunohistochemistry and indirect immunofluorescence assay (IFA), amplification of viral genomes by nested reverse transcription polymerase chain reaction (RT-PCR), and sequence analysis.

RESULTS

All samples showed histological signs of active myocarditis. Immunohistochemistry revealed the presence of the enterovirus VP1 family of proteins and IFA revealed the presence of coxsackievirus B3 antigen. Nested RT-PCR amplified enteroviral alleles of the 5'-untranslated region which were identical to each other and to the coxsackievirus B3 sequences.

CONCLUSIONS

This study provides pathological evidence of enteroviral infection among fatal myocarditis cases in a nationwide URTI cluster of cases associated with myocarditis and/or pericarditis.

Intravenous immunoglobulin for presumed viral myocarditis in children and adults

BACKGROUND

Case reports and case series have described dramatic responses to IVIG in adults and children with presumed viral myocarditis. Administration of IVIG has become commonplace in the management of this condition.

OBJECTIVES

To compare the outcome of patients with presumed viral myocarditis treated with IVIG to patients who did not receive IVIG.

SEARCH STRATEGY

We searched CENTRAL (Issue 2, 2003), MEDLINE/PubMed (1966-2003), EMBASE (1988-2003), CINAHL (1982-2003), Web of Science (1975-2003), trials registries and conference proceedings. We contacted authors of trials and checked reference lists of relevant papers.

SELECTION CRITERIA

Studies were included if: (1) patients had a clinical diagnosis of acute myocarditis with either a left ventricular ejection fraction (LVEF) <= 0.45, LVEDD of >2 SDs above the norm, or a shortening fraction (SF) >2 SDs below the mean and the duration of cardiac symptoms was less than six months; (2) patients had no evidence of non-infectious or bacterial cardiac disease; and, (3) patients were randomised to receive at least 1 gm/kg of IVIG versus no IVIG or placebo. Studies were excluded if: (1) patients had received immunosuppression prior to outcome assessment; or, (2) onset of myocarditis was less than six months postpartum.

DATA COLLECTION AND ANALYSIS

Searches were screened and inclusion criteria applied independently by two reviewers. Quality was assessed by two reviewers using the Jadad scale and allocation concealment. Data were extracted independently by two reviewers. Meta-analysis was not possible because only one relevant study was found.

MAIN RESULTS

The relevant study involved 62 adults with acute myocarditis randomized to receive IVIG or an equivalent volume of 0.1% albumin in a blinded fashion. The incidence of death or requirement for cardiac transplant or placement of a left ventricular assist device was low in both groups (OR for event-free survival was 0.52 ,95% CI 0.12 to 2.30). Follow-up at six and 12 months showed equivalent improvement in LVEF (mean difference 0.00, 95% CI -0.07 to 0.07 at six months, mean difference 0.01, 95% CI -0.06 to 0.08 at 12 months). Functional capacity as assessed by peak oxygen consumption was equivalent in the two groups at 12 months (mean difference -0.80, 95% CI -4.57 to 2.97). Infusion-related side effects were more common in the treated group, but all appeared to be mild (OR 30.16, 95% CI 1.69 to 539.42).

AUTHORS' CONCLUSIONS

Evidence from one trial does not support the use of IVIG for the management of adults with presumed viral myocarditis. There are no randomized paediatric trials. Further studies of the pathophysiology of this entity would lead to improved diagnostic criteria which would facilitate future research.

Unexpected hazard of illegal immigration: Outbreak of viral myocarditis exacerbated by confinement and deprivation in a shipboard cargo container

We present a group of 18 illegal immigrant stowaways who arrived in a shipboard cargo container suffering from gastroenteritis, dehydration, and malnutrition and showing evidence of viral myocarditis in 3 of 4 fatalities. Our investigation included an evaluation of the 2-week ocean voyage, analysis of medical records and laboratory results of the survivors, autopsies on the decedents, and viral studies on their heart tissue. Of 3 stowaways who died shipboard, 2 showed lymphocytic myocarditis and 1 could not be evaluated histologically due to decomposition. A fourth stowaway died 4 months after arrival with dilated cardiomyopathy and lymphocytic myocarditis. Reverse-transcriptase polymerase chain reaction and nucleotide sequencing of viral isolates from the decedents' heart tissues demonstrated Coxsackie virus B3 genome. We believe that these cases represent an outbreak of viral myocarditis, exacerbated by acute dehydration and malnutrition, due to confinement within the shipping container. Our evidence indicates that close confinement promoted the spread of the virus, and nutritional deprivation increased the stowaways' vulnerability. Furthermore, our observations support the conclusion, based on experimental studies, that nutritionally induced oxidative stress increased the virulence of the etiologic viral agent. In summary, these cases represent a potential infectious disease hazard of illegal immigration.

Role of virus-induced myocardial affections in sudden infant death syndrome: a prospective postmortem study

The cause of sudden infant death syndrome (SIDS) is an unresolved problem of high relevance. Previous studies indicate a role of infections. In our prospective study, we investigated the frequency of virus-induced myocardial affections in SIDS. Postmortem samples from SIDS victims and control subjects were investigated prospectively. Pediatric cases of unnatural death served as controls. Samples were studied for enteroviruses, adenoviruses, parvovirus B19, and Epstein-Barr virus applying PCR. Immunohistochemical investigations for inflammatory cells, the necrosis marker C5b-9((m)) complement complex, and the enteroviral capsid protein VP1 were performed. Overall, 62 SIDS victims were studied. As controls, 11 infants were enrolled. Enteroviruses were detected in 14 (22.5%), adenoviruses in 2 (3.2%), Epstein-Barr viruses in 3 (4.8%), and parvovirus B19 in 7 (11.2%) cases of SIDS. Control group samples were completely virus negative. Compared with controls, immunohistochemical investigations partially revealed a significant increase in the number of T lymphocytes in SIDS myocardial samples (p < 0.05). Furthermore, cases with elevated numbers of leukocytes and macrophages, microfocal C5b-9((m))(+) necroses, and enteroviral VP1 capsid protein within the myocardium were detected. Applying a comprehensive combination of molecular and immunohistochemical techniques, our results demonstrate a clearly higher prevalence of viral myocardial affections in SIDS. Our results emphasize the importance of PCR-based diagnosis of viral myocardial affections. We suggest preliminary criteria for cellular immunohistochemical diagnosis of viral myocardial affections derived from our findings. For future investigations in SIDS, we suggest a comprehensive approach that includes PCR and immunohistochemistry. Our results offer novel strategies for diagnosis of pediatric myocardial viral affections.

Coxsackie B3 myocarditis in 4 cases of suspected sudden infant death syndrome: diagnosis by immunohistochemical and molecular-pathologic investigations

Immunohistochemical and molecular-pathologic techniques have improved the diagnosis of myocarditis as compared with conventional histologic staining methods done according to the Dallas criteria. Most investigations were carried out on adults, and only a few authors investigating childhood deaths applied these modern methods, used for diagnosing myocarditis. We report on four children under one year of age, who suddenly died without prodromal symptoms. Their deaths were attributed to SIDS (sudden infant death syndrome). Immunohistochemical (LCA, CD68, CD45R0, MHC-class-II-molecules, VP1-capsid-protein of enteroviruses) and molecular-pathologic (RT-PCR) investigations, however, suggested that death was caused by a coxsackie-B3-myocarditis. In the future, these methods should be used for investigating cases with suspicion of SIDS.