Left ventricular dysfunction in children with fulminant enterovirus 71 infection: an evaluation of the clinical course

Seroprevalence of anti-SARS-CoV-2 IgG antibodies in HIV-positive and HIV-negative patients in clinical settings in Douala, Cameroon

Background

The asymptomatic nature of COVID-19 coupled with differential testing are confounders in the assessment of SARS-CoV-2 incidence among people living with HIV (PLWH). As various comorbidities increase the risk of SARS-CoV-2 infection, it is crucial to assess the potential contribution of HIV to the risk of acquiring COVID-19. Our study aimed to compare the anti-SARS-CoV-2 IgG seroprevalence among people living with and without HIV.

Methods

PLWH were enrolled in the HIV units of two health facilities in Douala, Cameroon. Participants were consecutively enrolled, among which 47 were people living with HIV and 31 were HIV-negative patients. SARS-CoV-2 antibody tests were performed on all participants. Overall, medical consultation was conducted. For HIV-positive participants only, viral load, antiretroviral regimen, duration of HIV infection, and duration of antiretroviral treatment were retrieved from medical records.

Results

We found an overall SARS-CoV-2 IgG seroprevalence of 42.31% within the study population, with a SARS-CoV-2 IgG seroprevalence of 44.6% for PLWH and 38.7% among those without HIV infection; no significant statistical difference was observed. Adjusting for sex, HIV status, and BCG vaccination, the odds of previous SARS-CoV-2 infection were higher among married persons in the study population. Sex, BCG vaccination, and HIV status were not found to be associated with SARS-CoV-2 IgG seropositivity.

Conclusions

Our findings support the lack of association between HIV status and susceptibility to SARS-CoV-2 infection. The ARV regimen, suppressed viral load, and Tenofovir boasted ARV regimen might not affect the body's immune response after exposure to SARS-CoV-2 among PLWH. Thus, if HIV is well treated, the susceptibility to COVID-19 in PLWH would be like that of the general population.

Current status of hand-foot-and-mouth disease

Hand-foot-and-mouth disease (HFMD) is a viral illness commonly seen in young children under 5 years of age, characterized by typical manifestations such as oral herpes and rashes on the hands and feet. These symptoms typically resolve spontaneously within a few days without complications. Over the past two decades, our understanding of HFMD has greatly improved and it has received significant attention. A variety of research studies, including epidemiological, animal, and in vitro studies, suggest that the disease may be associated with potentially fatal neurological complications. These findings reveal clinical, epidemiological, pathological, and etiological characteristics that are quite different from initial understandings of the illness. It is important to note that HFMD has been linked to severe cardiopulmonary complications, as well as severe neurological sequelae that can be observed during follow-up. At present, there is no specific pharmaceutical intervention for HFMD. An inactivated Enterovirus A71 (EV-A71) vaccine that has been approved by the China Food and Drug Administration (CFDA) has been shown to provide a high level of protection against EV-A71-related HFMD. However, the simultaneous circulation of multiple pathogens and the evolution of the molecular epidemiology of infectious agents make interventions based solely on a single agent comparatively inadequate. Enteroviruses are highly contagious and have a predilection for the nervous system, particularly in child populations, which contributes to the ongoing outbreak. Given the substantial impact of HFMD around the world, this Review synthesizes the current knowledge of the virology, epidemiology, pathogenesis, therapy, sequelae, and vaccine development of HFMD to improve clinical practices and public health efforts.

Recent advances in enterovirus A71 pathogenesis: a focus on fatal human enterovirus A71 infection

Enterovirus A71 (EV-A71) is one of the major pathogens responsible for hand, foot, and mouth disease (HFMD). Many HFMD outbreaks have been reported throughout the world in the past decades. Compared with other viruses, EV-A71 infection is more frequently associated with severe neurological complications and even death in children. EV-A71 can also infect adults and cause severe complications and death, although such cases are very uncommon. Although fatal cases of EV-A71 infection have been reported, the underlying mechanisms of EV-A71 infection, especially the mode of viral spread into the central nervous system (CNS) and mechanisms of pulmonary edema, which is considered to be the direct cause of death, have not yet been fully clarified, and more studies are needed. Here, we first summarize the pathological findings in various systems of patients with fatal EV-A71 infections, focussing in detail on gross changes, histopathological examination, tissue distribution of viral antigens and nucleic acids, systemic inflammatory cell infiltration, and tissue distribution of viral receptors and their co-localization with viral antigens. We then present our conclusions about viral dissemination, neuropathogenesis, and the mechanism of pulmonary edema in EV-A71 infection, based on pathological findings.

Catecholamine-Induced Secondary Takotsubo Syndrome in Children With Severe Enterovirus 71 Infection and Acute Heart Failure: A 20-year Experience of a Single Institute

Background: Acute heart failure (AHF) is the major cause of death in children with severe enterovirus 71 (EV71) infection. This study aimed to report our clinical experience with EV71-related AHF, as well as to discuss its pathogenesis and relationship to Takotsubo syndrome (TTS).

Methods: A total 27 children with EV71-related AHF between 1998 and 2018 were studied. The TTS diagnosis was based on the International Takotsubo Diagnostic Criteria.

Results: Acute heart failure-related early death occurred in 10 (37%) of the patients. Sinus tachycardia, systemic hypertension, and pulmonary edema in 100, 85, and 81% of the patients, respectively, preceded AHF. Cardiac biomarkers were significantly increased in most patients. The main echocardiographic findings included transient and reversible left ventricular (LV) regional wall motion abnormality (RWMA) with apical ballooning. High concentrations of catecholamines either preceded or coexisted with AHF. Myocardial pathology revealed no evidence of myocarditis, which was consistent with catecholamine-induced cardiotoxic damage. Patients with EV71-related AHF who had received close monitoring of their cardiac function, along with early intervention involving extracorporeal life support (ECLS), had a higher survival rate (82 vs. 30%, p = 0.013) and better neurological outcomes (59 vs. 0%, p = 0.003).

Conclusion: EV 71-related AHF was preceded by brain stem encephalitis-related hypercatecholaminemia, which resulted in a high mortality rate. Careful monitoring is merited so that any life-threatening cardiogenic shock may be appropriately treated. In view of the similarities in their clinical manifestations, natural course direction, pathological findings, and possible mechanisms, TTS and EV71-related AHF may represent the same syndrome. Therefore, we suggest that EV71-related AHF could constitute a direct causal link to catecholamine-induced secondary TTS.

Recent advances in the understanding of enterovirus A71 infection: a focus on neuropathogenesis

Introduction: Hand, foot, and mouth disease caused by enterovirus A71 (EV-A71) is more frequently associated with neurological complications and deaths compared to other enteroviruses.Areas covered: The authors discuss current understanding of the neuropathogenesis of EV-A71 based on various clinical, human, and animal model studies. The authors discuss the important advancements in virus entry, virus dissemination, and neuroinvasion. The authors highlight the role of host immune system, host genetic factors, viral quasispecies, and heparan sulfate in EV-A71 neuropathogenesis.Expert opinion: Comparison of EV-A71 with EV-D68 and PV shows similarity in primary target sites and dissemination to the central nervous system. More research is needed to understand cellular tropisms, persistence of EV-A71, and other possible invasion routes. EV-A71 infection has varied clinical manifestations which may be attributed to multiple receptors usage. Future development of antivirals and vaccines should target neurotropic enteroviruses. Repurposing drug and immunomodulators used in combination could reduce the severity of EV-A71 infection. Only a few drugs have been tested in clinical trials, and in the absence of antiviral and vaccines (except China), active virus surveillance, good hand hygiene, and physical distancing should be advocated. A better understanding of EV-A71 neuropathogenesis is critical for antiviral and multivalent vaccines development.

Continuous hemodiafiltration as a rescue therapy for patients with cardiopulmonary failure caused by enterovirus-71: a retrospective observational study in a PICU

Background

Hand, foot and mouth disease (HFMD) remains a burdensome health issue in mainland China. Enterovirus71 (EV-A71) is the main pathogen of severe HFMD. Continuous hemofiltration improves fluid overload, restores kidney function and alleviates inflammatory reactions. The aim of the present study was to evaluate the effects of continuous veno-venous hemodiafiltration (CVVHDF) on severe HFMD caused by EV-A71(EV-A71-HFMD) in a pediatric intensive care unit (PICU).

Methods

A retrospective observational study was performed in a tertiary university PICU from January 2012 to December 2016. Children with severe EV-A71-HFMD complicated by cardiopulmonary failure were included. The patients were divided into a CVVHDF group and a conventional therapy (control) group (non-CVVHDF). The demographics, characteristics, and outcomes between the groups were collected and analyzed.

Results

Twenty-nine patients with severe EV-A71-HFMD were enrolled. The 28-day mortality was 17.6% (3/17) in the CVVHDF group and 33.3% (4/12) in the non-CVVHDF group, with no statistical significance between the two groups (P = 0.403). The median interval between CVVHDF initiation and PICU admission was 6 (4,8.5) hrs, and the median duration of CVVHDF was 48 (36, 64) hrs. The left ventricular ejection fraction (LVEF) and cardiac index (CI) in the CVVHDF group were improved after treatment. The plasma levels of catecholamines and renin-angiotensin-aldosterone system (RAAS) substances in the CVVHDF group were significantly decreased after treatment. The decreased catecholamines and RAAS substances included adrenalin (169.8 [145.5, 244.6] vs. 148.0 [109.0, 208.1] ng/L, P = 0.033), dopamine (152.7 [97.0, 191.1] vs. 96.0 [68.0, 160.9] ng/L, P = 0.026), angiotensin II (185.9 [125.2, 800.0] vs. 106.0 [90.8, 232.5] ng/L, P = 0.047), aldosterone (165.7 [94.0, 353.3] vs. 103.3 [84.3, 144.3] ng/L, P = 0.033), and renin (1.12 [0.74, 3.45] vs. 0.79 [0.52, 1.25] μg/L/h, P = 0.029),

Conclusions

CVVHDF reduced the levels of catecholamines and RAAS substances and improved cardiovascular function. Continuous hemodiafiltration may represent a potential therapy in patients with severe EV-A71-HFMD complicated with cardiopulmonary failure.

The Effectiveness of Different Doses of Intravenous Immunoglobulin on Severe Hand, Foot and Mouth Disease: A Meta-Analysis

OBJECTIVE

To conduct a meta-analysis of evidence from randomized controlled trails (RCTs) of different doses of intravenous immunoglobulin (IVIG) in children with severe hand, foot and mouth disease (HFMD) to provide the scientific basis for clinical practice.

METHODS

A search of PubMed-Medline, CNKI, Wanfang, and VIP database (until June 30, 2017) was performed and Software RevMan5.3 was used to evaluate the effect of different doses of IVIG on HFMD in RCTs. We used random-effects models (or fixed-effects models) and generic inverse variance methods to process quantitative data, followed by a leave-one-out method for sensitivity analysis.

RESULTS

From a total of 420 entries identified via searches, 8 RCTs involving 1,450 patients were included in the final analysis. The results of the meta-analysis showed that compared with conventional therapy alone, conventional therapy combined with IVIG had shorter fever clearance time, shorter rash regression time, and shorter clinical cure time. Subgroup analyses showed that the high-dose group (1 g/kg/day) had shorter fever clearance time (p < 0.05), shorter rash regression (p< 0.05), shorter remission time of neurological symptoms (p < 0.05), but longer clinical cure time (p > 0.05).

CONCLUSION

The high-dose group has a better prognosis; however, the advantages and disadvantages should be carefully considered when deciding the doses in the treatment of severe HFMD.

Association of Chemotactic Chemokine Ligand 5 Polymorphisms with the Risk of Developing Severe Enterovirus 71 Infection

Respiratory damage is a main manifestation of severe Enterovirus 71 (EV71) infection. Polymorphisms of -403G/A (rs2107538), -28C/G (rs2280788), and In1.1T/C (rs2280789) in chemotactic chemokine ligand 5 (CCL5) have linked with many respiratory diseases. In this study, we explored the possible correlation of CCL5 polymorphisms with severe EV71 infection. Blood samples were obtained from 87 children hospitalized for EV71 infection. Fifty-seven healthy children were enrolled as asymptomatic controls. Genotype and allele frequencies were analyzed by logistic regression analysis. There were statistically significant differences in polymorphisms of CCL5 -403G/A and In1.1T/C for dominant model (P = 0.016; P = 0.027) and additive model (P = 0.010; P = 0.019) between patients with severe EV71 infection and asymptomatic controls. With ordinal logistic regression model analysis, statistically significant differences were found between polymorphisms of CCL5 (-403G/A) (P = 0.034) with the severity of EV71 infection after adjusting for age. The frequency of A-C-C haplotype was significantly higher in EV71 infection patients than controls (P = 0.032). These results suggest that CCL5 -403G/A and In1.1T/C polymorphisms may contribute to severe EV71 infection and individuals with haplotype of A-C-C may exhibit higher risk of developing severe EV71 infection. These findings may provide insights into pathogenic and protective mechanisms of severe EV71 infection.

Enterovirus 71 infection-associated acute flaccid paralysis: a case series of long-term neurologic follow-up

The authors undertook long-term neurologic outcomes of 27 patients aged 0 to 15 years with enterovirus 71-related acute flaccid paralysis from June 1998 to July 2012. Motor function outcome was graded from class I (complete recovery) to class V (permanent paralytic limbs). Twelve of 20 patients (60%) who received intravenous immunoglobulin for treatment of acute flaccid paralysis had motor function outcomes in classes III to V. The median duration of follow-up was 6 months, during which time 7 of 13 patients (54%) with central nervous system infection, 3 of 6 patients (50%) with autonomic nervous system dysregulation, and 3 of 8 patients (37%) with heart failure showed motor function outcomes in classes III to V. These findings suggested that the usage of intravenous immunoglobulin and the severity of disease staging at disease onset might not be able to predict long-term motor function outcomes.

SYBR green real-time PCR for the detection of all enterovirus-A71 genogroups

Enterovirus A71 (EV-A71) has recently become an important public health threat, especially in South-East Asia, where it has caused massive outbreaks of Hand, Foot and Mouth disease every year, resulting in significant mortality. Rapid detection of EV-A71 early in outbreaks would facilitate implementation of prevention and control measures to limit spread. Real-time RT-PCR is the technique of choice for the rapid diagnosis of EV-A71 infection and several systems have been developed to detect circulating strains. Although eight genogroups have been described globally, none of these PCR techniques detect all eight. We describe, for the first time, a SYBR Green real-time RT-PCR system validated to detect all 8 EV-A71 genogroups. This tool could permit the early detection and shift in genogroup circulation and the standardization of HFMD virological diagnosis, facilitating networking of laboratories working on EV-A71 in different regions.

Epidemiology of enteroviral meningoencephalitis in neonates and young infants

AIM

To describe the epidemiology of enteroviral meningoencephalitis in northern New South Wales, Australia, with a specific focus on neonatal and young infant cases.

METHODS

A retrospective review of PCR-confirmed enteroviral meningoencephalitis cases in the Hunter New England Local Health District of northern NSW was conducted for the period 2008-2012.

RESULTS

One hundred nine patients met the case definition. There was summer seasonality, with 50% (55/109) of cases occurring between December and February. Neonates and young infants (<3 months of age) accounted for 42% (46/109) of cases, with 20% (9/46) being premature births. Fever (83%) was the most common presentation in this age group, followed by irritability (40%), feeding difficulties (40%) and rash (17%). All received at least one antibiotic during their admission, with 26% (12/46) also treated empirically with acyclovir. There was one death. Where testing was undertaken, cerebrospinal fluid (CSF) protein levels were high in 90% (28/31) of neonates and young infants, but the CSF white cell count was variable, with 57% <10/mm(3) and 21% >100/mm(3) .

CONCLUSION

Early diagnosis of enteroviral meningoencephalitis could alter management, potentially reducing the period of treatment with empirical antimicrobials and permitting earlier discharge.

Extracorporeal life support for critical enterovirus 71 rhombencephalomyelitis: long-term neurologic follow-up

Enterovirus 71 rhombencephalomyelitis with cardiopulmonary dysfunction has become an endemic problem in Taiwan since an epidemic outbreak in 1998. Such cases frequently involve significant morbidity and mortality. From October 2000-June 2008, we collected 10 consecutive patients diagnosed with enterovirus 71 rhombencephalomyelitis complicated by left heart failure, with or without pulmonary edema, and surviving more than 3 months after receiving extracorporeal life support. Follow-up neurologic outcomes were analyzed prospectively. The median duration of neurologic follow-up was 7 years and 2 months. Significant morbidities included bulbar dysfunction, respiratory failure, and flaccid quadriparesis. Eight patients exhibited bulbar dysfunction, and feeding tubes could be removed from four patients (median, 15.5 months). Respiratory failure was observed in seven patients. Three patients were gradually withdrawn from their tracheostomy tube (median period, 30 months). Intelligence tests revealed four patients with normal cognitive function, one with borderline cognitive function, and one with mild mental retardation. Four were bedridden survivors. Extracorporeal life support for critical enterovirus 71 rhombencephalomyelitis demonstrated decreased neurologic sequelae during long-term follow-up, allowing for decannulation of feeding and tracheostomy tubes, and resulting in improved cognitive function.

Fulminant enterovirus 71 infection: case report

A previously healthy 3-year-old boy presented with high-grade fever, dyspnoea, alteration of consciousness, tachycardia and shock. A few erythematous macules and papules were seen on his palms and soles. Echocardiogram showed poor left ventricular contraction. Cardiac enzymes and pro-B-type natriuretic peptide were elevated. Milrinone, low-dose dopamine and intravenous immunoglobulin were administered. The patient recovered after 5 days without cardiac or neurological sequelae. The serological results showed a four-fold rise of enterovirus 71. In children with severe EV71 infection, early recognition of cardiopulmonary involvement and aggressive treatment are crucial to successful management.

Extracorporeal life support for treatment of children with enterovirus 71 infection-related cardiopulmonary failure

PURPOSE

Enterovirus 71 (EV71) infection leading to cardiopulmonary failure (CPF) is rare, but usually fatal. In such cases, intensive cardiorespiratory support is essential for survival. In this study, we report our experience in the treatment of EV71-related CPF with extracorporeal life support (ECLS).

METHODS

This was a retrospective study of a total of 13 children, aged 16 +/- 10 months, with EV71-related hemodynamically unstable CPF, which was refractory to conventional treatments, who were rescued by transsternal ECLS from 2000 to 2008. The clinical manifestations and outcomes of the 13 children (present cohort) were compared with those of 10 children (past cohort) who had EV71-related CPF without ECLS between 1998 and 2000.

RESULTS

Among these 13 patients, 10 were successfully weaned off ECLS and survived. The myocardial recovery time was 71 +/- 28 (median, 69) h, and the ECLS duration was 93 +/- 33 (median, 93) h. Six surviving patients had a good neurological outcome at hospital discharge. All surviving patients had some neurological sequelae but showed improvement at follow-up, including dysphagia in nine, central hypoventilation in seven, limb weakness in six and seizure in three. The present cohort had better neurological outcomes (46 vs. 0%, P = 0.005) and a higher survival rate (77 vs. 30%, P = 0.024) than the past cohort, respectively.

CONCLUSIONS

Patients with EV71-related CPF supported by ECLS had a higher survival rate and fewer neurological sequelae than those who only received conventional treatments. ECLS is an effective alternative method for treatment of children with refractory EV71-related CPF.

Identification and validation of clinical predictors for the risk of neurological involvement in children with hand, foot, and mouth disease in Sarawak

Background

Human enterovirus 71 (HEV71) can cause Hand, foot, and mouth disease (HFMD) with neurological complications, which may rapidly progress to fulminant cardiorespiratory failure, and death. Early recognition of children at risk is the key to reduce acute mortality and morbidity.

Methods

We examined data collected through a prospective clinical study of HFMD conducted between 2000 and 2006 that included 3 distinct outbreaks of HEV71 to identify risk factors associated with neurological involvement in children with HFMD.

Results

Total duration of fever ≥ 3 days, peak temperature ≥ 38.5°C and history of lethargy were identified as independent risk factors for neurological involvement (evident by CSF pleocytosis) in the analysis of 725 children admitted during the first phase of the study. When they were validated in the second phase of the study, two or more (≥ 2) risk factors were present in 162 (65%) of 250 children with CSF pleocytosis compared with 56 (30%) of 186 children with no CSF pleocytosis (OR 4.27, 95% CI2.79–6.56, p < 0.0001). The usefulness of the three risk factors in identifying children with CSF pleocytosis on hospital admission during the second phase of the study was also tested. Peak temperature ≥ 38.5°C and history of lethargy had the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 28%(48/174), 89%(125/140), 76%(48/63) and 50%(125/251), respectively in predicting CSF pleocytosis in children that were seen within the first 2 days of febrile illness. For those presented on the 3^rd or later day of febrile illness, the sensitivity, specificity, PPV and NPV of ≥ 2 risk factors predictive of CSF pleocytosis were 75%(57/76), 59%(27/46), 75%(57/76) and 59%(27/46), respectively.

Conclusion

Three readily elicited clinical risk factors were identified to help detect children at risk of neurological involvement. These risk factors may serve as a guide to clinicians to decide the need for hospitalization and further investigation, including cerebrospinal fluid examination, and close monitoring for disease progression in children with HFMD.

Comparison of heart failure in children with enterovirus 71 rhombencephalitis and cats with norepinephrine cardiotoxicity

The mechanism of heart failure in patients with enterovirus 71 rhombencephalitis (brain stem encephalitis) remains unknown. Our previous reports hypothesized that a catecholamine storm induced by rhombencephalitis may account for the heart failure. The aim of this study was to develop a novel feline model of norepinephrine cardiotoxicity and compare the resulting heart failure to that in children with enterovirus 71 rhombencephalitis. Nine of 75 children (12%) with enterovirus 71 rhombencephalitis (5 boys and 4 girls; age, 4-28 months; median age, 16 months) were complicated with left ventricular hypokinesia (ejection fraction, 31 +/- 9%). Six cats (weight, 3.03 +/- 0.64 kg) were administered intravenous norepinephrine 30 microg/kg/min for 3 hours. Echocardiography assessed the left ventricular diameter and function before and after the administration of norepinephrine. Pathology studies included hematoxylin and eosin stain and in situ terminal deoxyribonucleotidyl transferase-mediated dUTP nick end-labeling assay. In the feline model, norepinephrine induced significant left ventricular dilatation (end diastolic diameter from 1.18 +/- 0.19 to 1.62 +/- 0.22 cm, p = 0.001; endsystolic diameter from 0.54 +/- 0.09 to 1.36 +/- 0.32 cm, p = < 0.001) and hypokinesia (ejection fraction from 87.5 +/- 4.1 to 35.2 +/- 16.3%, p = 0.001). Heart specimens from 4 patients and six cats showed similar pathology findings, including myocardial hemorrhage, cardiomyocyte apoptosis, and coagulative myocytolysis, which is characterized by sarcoplasmic coagulation, granulation, vacuolization, myofibrillar waving, and disruption. Both groups showed no significant inflammatory reaction. In conclusion, heart failure in patients with enterovirus 71 rhombencephalitis is similar to that in cats with norepinephrine cardiotoxicity. Norepinephrine cardiotoxicity may play a role in the pathogenesis of heart failure in enterovirus 71 rhombencephalitis.

Critical management in patients with severe enterovirus 71 infection

OBJECTIVE

The aim of this study was to analyze clinical details occurring in children with severe enterovirus 71 (EV71) infection and synthesize the critical care experience for patients with severe EV71 infection.

METHODS

A retrospective clinical, laboratory, and hemodynamic study was performed in a pediatric intensive care unit in a university hospital. From March 1998 to April 2000, seven consecutive pediatric patients with severe EV71 infection were retrospectively analyzed as the comparison group. From May 2000 to March 2003, eight consecutive patients with severe EV71 infection who had received the protocol therapy were enrolled as the study group. Detailed information about clinical treatment and pharmacological therapy was collected for comparison.

RESULTS

The clinical presentations and laboratory findings between the comparison and the study groups were not significantly different. The amount of intravenous fluid in the first 24 h was significantly higher in the comparison group (9.2+/-5.0 vs 4.9+/-1.3 mL/kg per h). More patients in the study group received low doses of dopamine infusion, patients in the comparison group received more epinephrine, and none of them received milrinone. The acute-stage and long-term survival rates were higher in the study group (100% vs 43%, 87% vs 29%).

CONCLUSION

Early cardiopulmonary support may prevent the vicious cycle of cardiopulmonary failure and improve the clinical outcome of severe EV71 infection. Milrinone may be the ideal inotropic agent for these patients. Echocardiography, a central line, and an arterial line could be an alternate method to replace direct intracardiac hemodynamic monitoring for guiding critical management.

Predictors of unfavorable outcomes in enterovirus 71-related cardiopulmonary failure in children

BACKGROUND

Enterovirus 71 (EV71) can sometimes cause fatal or disabling diseases in children; therefore EV71-infected children with cardiopulmonary failure were investigated at Chang Gung Children's Hospital to discover the prognostic predictors.

METHODS

We investigated 27 EV71-infected children with cardiopulmonary failure from May 2000 to September 2001 and analyzed their clinical data to find predictors associated with unfavorable outcomes of deaths or ventilator dependence.

RESULTS

Of the 27 patients, 8 (30%) died and 10 (37%) were ventilator-dependent. Troponin I levels correlated most strongly with fatality, with 5 of the 6 children with troponin I levels >40 ng/ml dying (P = 0.001). Other factors correlated with fatality were cerebrospinal fluid white blood cell count > or =100/microL (P = 0.002) and initial systolic pressure < or =100 mm Hg (P = 0.05). Of the 19 survivors, 10 (53%) were left with central hypoventilation, dysphagia and/or limb weakness plus atrophy. The factors associated with ventilator dependence included higher inotrope equivalent (P < 0.001), duration of hypotension > or =40 hours, initial blood systolic pressure < or =100 mm Hg, positive EV71 isolation and age > or =12 months.

CONCLUSIONS

Poor prognostic factors were related to cardiovascular and neurologic damage; therefore physicians may consider advanced cardiovascular support for EV71-infected children with cardiopulmonary failure.

Cardiac complications of enterovirus rhombencephalitis

BACKGROUND

Epidemics of enterovirus 71 infection have caused the death of many children throughout the world. Rhombencephalitis, brain stem encephalitis, and heart failure were present in all of the fatal cases. However, no evidence of myocarditis was noted in the heart specimens, and the mechanism of heart failure remains unknown.

AIMS

To characterise the presentation of cardiac complications in children with enterovirus rhombencephalitis and discuss its pathogenesis.

METHODS

Ninety one consecutive patients with enterovirus rhombencephalitis underwent echocardiography. Of these, 17 patients (nine male, eight female; median age 14 months, range 4-57 months) with left ventricular dysfunction were studied.

RESULTS

Tachycardia was noted in all patients and systemic hypertension in 12. Muscle-brain fraction of creatine kinase was >5% in 14 patients. Plasma norepinephrine and epinephrine levels were significantly raised in the three patients in whom these were analysed. Electrocardiographic abnormalities were noted in eight patients. Pulmonary oedema was complicated in 15 patients. The initial ejection fraction of the left ventricle was 22-58% (mean 37%, SD 11%). All patients deteriorated to hypotensive shock within 12 hours and 13 died. Heart specimens from seven patients showed no evidence of myocarditis, but significant coagulative myocytolysis, myofibrillar degeneration, and cardiomyocyte apoptosis were observed.

CONCLUSIONS

Acute heart failure was noted in 19% of patients with enterovirus rhombencephalitis, which had a fatality rate of 77%. It was not caused by myocarditis but possibly by neurogenic cardiac damage.

Infectious causes of acute flaccid paralysis

PURPOSE OF REVIEW

Although acute flaccid paralysis (AFP) is more frequently seen in the tropics than in temperate regions, recent outbreaks of West Nile virus (WNV) in North America have drawn attention to this important presentation. Starting with anatomical and neurophysiological considerations, this article examines data on AFP caused by WNV, and considers recent data on paralysis caused by enteroviruses, and Guillain-Barré syndrome (GBS).

RECENT FINDINGS

Neurophysiological, radiological and pathological studies suggest WNV causes AFP by damaging anterior horn cells in the spinal cord. The clinical presentation is probably best described as a 'poliomyelitis-like illness', and the disease as 'WNV myelitis'. Other findings during the recent outbreaks include increasing recognition of a Parkinson's-disease like presentation, and descriptions of virus transmission in blood transfusions and transplanted organs. GBS is now recognized as several disorders characterized by immune-mediated attack on peripheral nerves: in acute inflammatory demyelinating polyneuropathy the myelin sheath and Schwann cell of sensory and motor nerves are targeted; acute motor axonal and acute motor and sensory axonal neuropathy often follow Campylobacter jejuni enteritis and are associated with antibodies against the ganglioside component of the nerve axolemmal membrane. In Asia-Pacific, enterovirus 71 has caused outbreaks of neurological diseases with AFP and encephalitis, but no single genogroup of virus appears responsible for severe disease.

SUMMARY

Despite the near eradication of poliomyelitis, AFP caused by viruses remains an important clinical presentation. Distinguishing direct viral causes from GBS is important for public health reasons, and to avoid inappropriate therapies.

Pulmonary edema of enterovirus 71 encephalomyelitis is associated with left ventricular failure: implications for treatment

Epidemics of enterovirus 71 infections caused the rapid death of many children in Malaysia in 1997 and in Taiwan in 1998. Pulmonary edema occurred in most of the fatal cases and was considered to be neurogenic. The role of the heart was rarely investigated before. Between January 1998-January 2001, 34 consecutive patients who were admitted to the intensive care unit due to enterovirus infection were studied prospectively. Patients were divided into two groups: group I with pulmonary edema, and group II without pulmonary edema. Comparisons were made between the two groups based upon demographic, neurological, and cardiovascular manifestations. Group I consisted of 11 patients (5 boys, 6 girls; mean age, 22.8 months), and group II of 23 patients (12 boys, 11 girls; mean age, 28.8 months). There were no significant differences between the two groups in comparing sex, age, body weight, neurological severity, intracranial pressure, cell count, protein and glucose levels in cerebral spinal fluid, and blood pressure. All group I patients had left ventricular dysfunction, and their ejection fractions were significantly lower than those of patients in group II (37 +/- 11% vs. 75 +/- 6%, P < 0.001). Group I heart rates were higher than those of group II (175 +/- 24 vs. 137 +/- 25, P < 0.001). In group I, 9 patients who received conventional treatment died, and the only two survivors received left ventricular assist devices. In conclusion, the pulmonary edema of fulminant enterovirus 71 infection is associated with left ventricular failure. Left ventricular function is the major determinant of outcome. Early recognition of heart failure and aggressive cardiac intervention are life-saving. Pediatr Pulmonol. 2003; 35:263-268.

Acute neurogenic pulmonary edema: case reports and literature review

Neurogenic pulmonary edema (NPE) is an underdiagnosed clinical entity. Its pathophysiology is multifactorial but largely unknown. We report two cases of NPE and review the literature on NPE cases reported since 1990. A 21-year-old man had a seizure episode following cranioplasty. He became increasingly dyspneic, and clinical and laboratory signs of respiratory failure were evident. Chest radiography and computed tomography showed bilateral diffuse infiltrates. After supportive measures were taken, complete respiratory recovery occurred in 72 hours. A 52-year-old woman had several seizure episodes following subarachnoid hemorrhage due to a cavernoma. She became increasingly dyspneic upon arrival at the hospital. After tracheostomy and oxygen support were established, chest radiography showed bilateral diffuse infiltrates. Respiratory recovery was excellent, and the patient was eupneic with normal results of chest radiography 48 hours later. Fourteen reports (21 cases) were found. Thirteen patients were female, and the mean age of the patients was 31.6 years. The most frequent underlying factor was subarachnoid hemorrhage (42.9%). Symptom onset occurred <4 hours after the neurologic event in 71.4% of cases. One third of the patients presented with pink frothy sputum. Chest radiography showed bilateral diffuse infiltrates in 90.5% of cases. Supportive measures included oxygen support and vasoactive drugs. Recovery was usually very rapid: 52.4% of patients recovered in <72 hours. Almost 10% of patients died of NPE. Our two cases had clinical and laboratory features in common with most NPE cases. Physicians should remember NPE when neurologic patients suddenly become dyspneic. The mortality rate is high, but surviving patients usually recover very quickly.

Adenovirus type 21-associated acute flaccid paralysis during an outbreak of hand-foot-and-mouth disease in Sarawak, Malaysia

We report the virological and clinical features of 8 children who presented with adenovirus-associated acute flaccid paralysis (AFP) during an epidemic of enterovirus type 71 (EV71)-associated hand-foot-and-mouth disease (HFMD) in Sarawak, Malaysia, in 1997. Neutralization tests and phylogenetic analysis revealed adenovirus type 21 (Ad21), although DNA restriction digests suggested that this virus was different from the prototype Ad21. Four children had upper-limb monoparesis, 2 had lower-limb monoparesis (one of whom had changes in the anterior spinal cord noted on magnetic resonance imaging), and 2 had flaccid paraparesis. At follow-up, 4 children were noted to have made full recoveries and 3 had residual flaccid weakness and wasting. Neurophysiological investigation revealed a mixture of axonal and demyelinating features in motor and sensory nerves, with denervation. These findings suggest that Ad21 might cause AFP by anterior horn cell damage or neuropathy of the brachial or lumbosacral plexus. The occurrence of these unusual adenovirus infections during an outbreak of EV71-associated HFMD suggests that an interaction between the 2 viruses may have occurred.

Proinflammatory cytokine reactions in enterovirus 71 infections of the central nervous system

Enterovirus 71 (EV71) infection can lead to devastating clinical outcomes. An appreciation of the scientific relationship between cytokine response and patient mortality may help limit the risks posed by this deadly illness. We present the results of a study that compared the cerebrospinal fluid (CSF) and serum levels of interleukin-6 (IL-6) and interleukin-1beta (IL-1beta) in 24 patients with EV71 infection. Cases in this study involved diverse manifestations or complications, including encephalitis, poliomyelitis-like syndrome, meningitis, and pulmonary edema. CSF levels of IL-6 in study patients were found to be consistently higher during the first 2 days of central nervous system (CNS) involvement than afterward. Compared with patients who did not have pulmonary edema, patients who experienced pulmonary edema had dramatically varied blood values, including IL-6, white blood cell counts, and glucose levels. Our findings suggest that the combination of CNS and systemic inflammatory response may trigger EV71-related cardiopulmonary collapse.