Myocarditis complicating cytomegalovirus mononucleosis

Performance of prediction rules and guidelines in detecting serious bacterial infections among Tanzanian febrile children

Background

Health-workers in developing countries rely on clinical algorithms, such as the Integrated Management of Childhood Illnesses (IMCI), for the management of patients, including diagnosis of serious bacterial infections (SBI). The diagnostic accuracy of IMCI in detecting children with SBI is unknown. Prediction rules and guidelines for SBI from well-resourced countries at outpatient level may help to improve current guidelines; however, their diagnostic performance has not been evaluated in resource-limited countries, where clinical conditions, access to care, and diagnostic capacity differ. The aim of this study was to estimate the diagnostic accuracy of existing prediction rules and clinical guidelines in identifying children with SBI in a cohort of febrile children attending outpatient health facilities in Tanzania.

Methods

Structured literature review to identify available prediction rules and guidelines aimed at detecting SBI and retrospective, external validation on a dataset containing 1005 febrile Tanzanian children with acute infections. The reference standard, SBI, was established based on rigorous clinical and microbiological criteria.

Results

Four prediction rules and five guidelines, including IMCI, could be validated. All examined rules and guidelines had insufficient diagnostic accuracy for ruling-in or ruling-out SBI with positive and negative likelihood ratios ranging from 1.04–1.87 to 0.47–0.92, respectively. IMCI had a sensitivity of 36.7% (95% CI 29.4–44.6%) at a specificity of 70.3% (67.1–73.4%). Rules that use a combination of clinical and laboratory testing had better performance compared to rules and guidelines using only clinical and or laboratory elements.

Conclusions

Currently applied guidelines for managing children with febrile illness have insufficient diagnostic accuracy in detecting children with SBI. Revised clinical algorithms including simple point-of-care tests with improved accuracy for detecting SBI targeting in tropical resource-poor settings are needed. They should undergo careful external validation against clinical outcome before implementation, given the inherent limitations of gold standards for SBI.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4371-y) contains supplementary material, which is available to authorized users.

Presumed Systemic Inflammatory Response Syndrome in the Pediatric Emergency Department

OBJECTIVE

The aim of this study was to examine the incidence and outcomes of patients presenting with systemic inflammatory response syndrome (SIRS) in the pediatric emergency department (PED).

METHODS

This was a descriptive, retrospective cohort study of all patients from birth to 18 years presenting to the PED of a single center on 16 days distributed over 1 year. The presence of presumed SIRS (pSIRS, defined as noncore temperature measurement and cell count when clinically indicated) and sepsis was determined for all study patients. Patients were followed up for 1 week.

RESULTS

The incidence of pSIRS was 15.3% (216/1416). Suspected or proven infection was present in 37.1% (n = 525) of the study population and 76.4% (n = 165) with pSIRS, with no cases of severe sepsis or septic shock. Sensitivity and specificity of pSIRS for predicting infection were 31.4% (95% confidence interval [CI], 27.5%-35.6%) and 94.3% (95% CI, 92.5%-95.7%), respectively. Although patients with pSIRS had a relative risk of 2.4 (95% CI, 1.6-3.5; P < 0.0001) for admission, 74% were discharged home with no subsequent PED visits. Of defined sepsis cases, 75% were discharged home without return.

CONCLUSIONS

Presumed SIRS and sepsis are relatively common in the PED. Use of pSIRS to screen for sepsis risks missing infection, whereas using pSIRS in the current sepsis definition results in overinclusion of nonsevere illness.

Validation of "Signs of Inflammation in Children that Kill" (SICK) score for immediate non-invasive assessment of severity of illness

Objective

To validate the SICK scoring system's ability to differentiate between individuals with higher and lower probabilities of death

Method

We performed a one year two-centre prospective evaluation of all children aged between one month and 12 years referred to the Paediatric team at St Stephens Hospital in Delhi and admitted to the Paediatric Department at West Middlesex University Hospital in London. We calculated SICK scores at presentation and correlated them with subsequent in-hospital mortality. We used discrimination by areas under receiver operating characteristic (ROC) curves to measure performance.

Results

We prospectively evaluated 3895 children in Delhi and 1473 children in London. The areas under the ROC curves were 84.8% in Delhi, 81.0% in London and 84.1% (95% CI 77.4 - 90.8%) for combined data. Hosmer-Lemeshow goodness of fit for the combined data was good (Hosmer-Lemeshow Chi-square = 2.13 (p = 0.345).

Conclusions

We propose the SICK score as a useful triage tool at initial presentation and highlight its particular suitability for resource poor settings.

Successful diagnosis and management of cytomegalovirus carditis

Cytomegalovirus (CMV)-associated carditis in the immunosuppressed patient carries a 60% mortality. Underlying pathogenesis is poorly understood but may involve either direct viral invasion or autoimmune cardiac damage triggered in response to the infection. Specific anti-cytomegalovirus therapy and/or anti-inflammatory drugs have been shown to benefit in cases where an early diagnosis was established. We report an unusual case of endo-pericarditis which was temporally related to acute cytomegalovirus infection diagnosed by the immediate early antigen detection in cell culture on whole blood.

Fatal cytomegalovirus myocarditis in a seronegative ALL patient

Fatal cytomegalovirus (CMV) myocarditis occurred in a 2 year old boy with acute lymphoblastic leukemia (ALL) in remission. The patient showed mild hepatic dysfunction and a rapid progress of pancytopenia after complete remission had been achieved. At the fifth week of complete remission, he presented signs of heart failure such as tachycardia, S4 gallop on auscultation and decreased ejection fraction on echocardiography. However, no significant electrocardiographic changes were recognized. In addition to the cardiac dysfunction, the patient presented a marked tachypnea and dyspnea associated with hypoxemia. These were dramatically improved by methylprednisolone pulse therapy (30 mg/kg per day, for 3 days) and CMV high titer immunoglobulin (400 mg/kg per day, for 3 days). On the sixth day after signs of respiratory failure were improved, the patient suddenly presented a paroxysmal atrial tachycardia followed by a fatal ventricular fibrillation. Although we could detect neither a specific IgM antibody, a significant increase of IgG antibody, nor CMV genome by DNA hybridization techniques during the course of the illness, microscopic examination of necropsy specimens of the heart showed a marked disruption and disintegration of muscle bands associated with cytomegalic inclusion bodies. Polymerase chain reaction (PCR) yielded a 305 bp amplification product in the heart and lung tissues, supporting the view that myocarditis was caused by CMV.

Cardiovascular diseases due to viruses

In acute myocardiopathy and pericardiopathy, Coxsackie virus B infections are increasingly recognized as a cause of primary myocardial disease and may cause chronic cardiovascular disease. With other viruses, such as cytomegaloviruses and rubella virus, transplacental infection during pregnancy may occur, and this can cause the congenital rubella syndrome, which involves heart abnormalities. Other viruses are now under study. Myocarditis was observed in a newborn infant infected with Coxsackie virus B3, which was isolated by tissue culture methods. Experimental infection of Coxsackie virus A and B was studied in suckling mice and the histopathologic changes in heart muscle were observed. Laboratory findings of viral infection are very useful for clinical diagnosis, however care needs to be taken with respect to the obtaining of specimens, diagnostic procedures, and the assessment of results.

Low molecular weight IgM in cytomegalovirus infections and cardiac patients

When 71 ischaemic heart disease and cardiomyopathy patients' sera were examined by the IFA (indirect fluorescent antibody) test, 18 of the 49 (36%) with CMV (cytomegalovirus) CF antibody appeared to contain a specific LMW (7S approx) IGM. This IgM was unrelated to the presence of RF (rheumatoid factor) demonstrable by agglutination of IgG-coated latex and by an immunofluorescence test, was not absorbed by heat-aggregated IgG and latex, nor did its demonstration appear to be complement dependent. It was demonstrable in acute CMV infection and in some cardiac patients, binds to HSV (herpes simplex virus) and CMV-infected cells.

Cytomegalovirus infection and the Guillain-Barré syndrome

A fatal case is described of the Guillain-Barré syndrome due to cytomegalovirus infection, which was associated with hepatitis, myocarditis and viral pneumonia. Previous cases, which have usually run a benign course, are reviewed. Attention is drawn to the possible adverse effect of steroid therapy.