Clinical significance of enteroviruses in serious summer febrile illnesses of children

Emergence and circulation of enterovirus B species in infants in southern China: A multicenter retrospective analysis

BACKGROUND

Enteroviruses (EV) are common and can cause severe diseases, particularly in young children. However, the information of EV infection in infants in China is limited due to the vast population size and extensive geographical area of the country. Here, we conducted a retrospective multicenter analysis of available EV data to assess the current epidemiological situation in the infant population in southern China.

METHODS

The study enrolled infants with suspected EV infection from 34 hospitals across 12 cities in southern China between 2019 to 2022, and the confirmation of EV was done using RT-PCR and VP1 gene sequencing.

RESULTS

Out of 1221 infants enrolled, 330 (27.03%) were confirmed as EV-infected. Of these, 260 (78.79%) were newborns aged 0-28 days. The EV belonged to three species: EV-B (80.61%), EV-A (11.82%), and human rhinovirus (7.58%). Newborns were more susceptible to EV-B than older infants (p < 0.001). Within EV-B, we identified 15 types, with coxsackievirus (CV) B3 (20.91%), echovirus (E) 11 (19.70%), and E18 (16.97%) being the most common. The predominant EV types changed across different years. EV infection in infants followed a seasonal pattern, with a higher incidence from May to August. Furthermore, perinatal mother-to-child EV transmission in 12 mother-newborn pairs were observed.

CONCLUSION

Our study is the first to demonstrate the emergence and widespread circulation of EV-B species, mainly CVB3, E11, and E18, in southern China, primarily affecting young infants. This research provides valuable insights for future epidemic assessment, prediction, as well as the elimination of mother-to-child transmission.

Seasonal Testing, Results, and Effect of the Pandemic on Coxsackievirus Serum Studies

Coxsackieviruses (CVs) are common causes of infections and can be life-threatening. Unfortunately, rigorous studies guiding the clinician in interpreting CV serum antibody titer testing is lacking. To explore the epidemiology of circulating CVs and the serological test utility in aiding diagnosis of CV infections in our community, we obtained results of CV immunologic diagnostic tests between 2018 and 2022 from a regional healthcare database. For CV type A, rare individuals had positive CF (complement fixation) tests whereas all 16 individuals with IFA testing showed at least one positive serotype. For CV type B CF testing, 52.2% of 222 patients had at least one serotype positive, with B5 being most common and also the most common with higher titers (14.8% with ≥1:32). We found a significant reduction in seropositivity rate during the pandemic in 2020 compared to 2018, which continued through 2022 (OR: 0.2, 95% CI: 0.08-0.49, p-value < 0.001). During the pandemic, the seasonal pattern of positive tests varied from the pre-pandemic pattern. Testing for CVs was increased after the first year of the pandemic. Overall, the variability by month and seasonal change in our data support that CF testing can be used to identify recent CVB infection.

Detection of enterovirus in cerebrospinal fluids without pleocytosis in febrile infants under 3 months old reduces antibiotherapy duration

Background

Infants under 3 months old with fever often receive empirical antibiotic treatment. Enterovirus is one of the leading causes of infection and aseptic meningitis but is not systematically screened. We aimed to evaluate enterovirus positive RT-PCR proportion in cerebrospinal fluid (CSF) with no pleocytosis and its impact on antibiotic treatment duration.

Methods

During the enterovirus endemic season, from 2015 to 2018, we retrospectively studied infants under 3 months old, consulting for fever without cause, with normal CSF analysis, and receiving empirical antibiotic treatment. Clinical and biological data were analyzed, notably enterovirus RT-PCR results. The primary outcome was the duration of antibiotic therapy.

Results

92 patients were recruited. When tested, 41% of infants were positive for enterovirus, median antibiotic duration was reduced in enterovirus positive in comparison to negative patients with respectively 1.9 [interquartile range (IQR), 1.7-2] vs. 4.1 [IQR, 2-6], p < 0.001. No clinical nor biological features differed according to the enterovirus status.

Conclusion

In this population, enterovirus positive CSF are frequent despite the absence of pleocytosis. However, its research was not guided by clinical or biological presentations. Systematic and routine use of enterovirus RT-PCR during enterovirus season, regardless of CSF cell count, could reduce the prescription of antibiotics in febrile infants under 3 months old without clinical orientation.

World-Wide Prevalence and Genotype Distribution of Enteroviruses

Enteroviruses (EVs) are highly prevalent viruses world-wide, causing a wide range of diseases in both children and adults. Insight in the global prevalence of EVs is important to define their clinical significance and total disease burden, and assists in making therapeutic decisions. While many studies have been conducted to describe epidemiology of EVs in specific (sub)populations and patient cohorts, little effort has been made to aggregate the available evidence. In the current study, we conducted a search in the PubMed and Embase (Ovid) databases to identify articles reporting EV prevalence and type distribution. We summarized the findings of 153 included studies. We found that EVs are highly prevalent viruses in all continents. Enterovirus B was the most detected species worldwide, while the other species showed continent-specific differences, with Enterovirus C more detected in Africa and Enterovirus A more detected in Asia. Echovirus 30 was by far the most detected type, especially in studies conducted in Europe. EV types in species Enterovirus B-including echovirus 30-were often detected in patient groups with neurological infections and in cerebrospinal fluid, while Enterovirus C types were often found in stool samples.

Successful containment of horizontal enterovirus infection in a neonatal unit in Singapore through diagnosis by polymerase chain reaction (PCR) and direct sequence analysis

BACKGROUND

Enterovirus (EV) outbreaks often coincide with seasonal peaks in the community. However, they may also sporadically occur in neonatal units. Identification of EV infection in neonates can be challenging, as they tend to present with mild or nonspecific symptoms. This study reports an EV outbreak in the Neonatal Unit at KK Women's and Children's Hospital, Singapore.

METHODS

This is a single-center, retrospective cohort study of neonates who had positive results for EV during the outbreak. Demographic characteristics, clinical presentations and outcomes were analyzed. Control measures used to limit the spread of infection are reported.

RESULTS

A total of 7 cases of EV infection were identified. Their median birth weight and gestational age were 1240 g (750 -2890 g) and 28 weeks (26-35 weeks), respectively. Symptoms occurred at a median age of 48 days (9-103 days). All cases presented initially with recurrent apnea and 4 needed assisted ventilator support with CPAP (2) and mechanical ventilation (2). Serious complications occurred in 3 infants (2 with necrotizing enterocolitis and 1 with meningitis) and none died. EV was detected from rectal swabs (n = 6), CSF (n = 2) and nasopharyngeal swabs (n = 2). Viral subtyping uniformly revealed echovirus 25. Surveillance of all exposed infants by nasopharyngeal swabs was implemented, along with strict contact precautions and cohorting measures.

CONCLUSIONS

Premature infants with EV are more prone to serious complications, which can lead to significant morbidity. Thus, early recognition of symptoms, rapid diagnosis and prompt implementation of infection control measures are key to prevent further spread of infection.

Enteroviral infection in neonates

Enteroviruses generally cause mild and self-limited diseases, but they have been found to affect neonates much differently, and often more severely than older children. Clinical manifestations are difficult to differentiate from those of bacterial sepsis, such as fever, poor feeding, lethargy, respiratory distress and cardiovascular collapse. Severe life threatening complications, including hepatic necrosis with coagulopathy, meningoencephalitis and myocarditis, usually present during the first week of life. Factors affecting severity and outcome include virus serotype, mode of transmission, and presence or absence of passively acquired, serotype-specific maternal antibodies. Echoviruses and coxsackievirus B viruses are most common serotypes associated with the neonatal sepsis. An awareness of the clinical syndromes, recognition of the risk factors and monitoring parameters associated with severe cases and use of rapid reverse-transcriptase polymerase chain reaction test for viral load may help physicians in diagnosing severe cases in a timely manner. Prompt aggressive treatment including early intravenous immunoglobulin treatment may help in reducing morbidity and mortality. Enterovirus infections in neonates are common and should be routinely considered in the differential diagnosis of febrile neonates, particularly during enterovirus season. This article provides an overview of what is known about non-polio enteroviruses in neonates including epidemiology, transmission, clinical presentation, diagnosis, and treatment.

Epidemiology of Sepsis-like Illness in Young Infants: Major Role of Enterovirus and Human Parechovirus

BACKGROUND

Sepsis-like illness is a main cause for hospital admission in young infants. Our aim was to investigate incidence, epidemiology and clinical characteristics of enterovirus (EV) and human parechovirus (HPeV) infections in young infants with sepsis-like illness.

METHODS

This is a prospective observational cohort study in which infants younger than 90 days of age, presenting with sepsis-like symptoms in a secondary care children's hospital, underwent a full sepsis work-up. Clinical signs and infectious indices were recorded. EV or HPeV RNA was detected by polymerase chain reaction in plasma and/or cerebrospinal fluid (CSF).

RESULTS

Infants were diagnosed with EV, HPeV, fever of unknown origin or severe infection. EV and HPeV were detected in 132 of 353 (37%) and 52 of 353 (15%) of cases, respectively. EV and HPeV have distinct seasonability. Some differences in clinical signs and symptoms occurred between children with EV and HPeV infection but were of limited clinical value. CSF pleocytosis occurred in 44% of EV positive infants, and only in 13% of those with HPeV infection.

CONCLUSIONS

EV and HPeV infections are major causes of sepsis-like illness in infants < 90 days of age. Neither clinical characteristics nor laboratory indices were predictive for EV/HPeV infection. CSF pleocytosis occurs, but not in all patients. Testing for EV and HPeV in all young infants with sepsis-like illness is strongly advised.

Enteroviruses and Parechoviruses

Infections with enteroviruses and human parechoviruses are highly prevalent, particularly in neonates, where they may cause substantial morbidity and mortality. Individuals with B-cell-related immunodeficiencies are at risk for severe enteroviral infections, usually a chronic and fatal meningoencephalitis. In transplant recipients and patients with malignancy, enterovirus infections typically involve the respiratory tract, but cases of severe, disseminated infection have been described. The mainstay of diagnosis for enterovirus and human parechovirus infections involves the use of molecular diagnostic techniques. However, routine nucleic acid-detection methods for enteroviruses will not detect human parechoviruses. Laboratory diagnosis of these viral infections is important in determining a patient's prognosis and guiding clinical management.

Contemporary infectious exanthems: an update

An exanthem is a skin rash that may be associated with mucous membrane eruption, fever or other symptoms. It may develop as manifestation of an infectious disease or as adverse reaction to drugs. Beside the ‘classical exanthems’ commonly occurring in childhood, other exanthems, defined as ‘atypical’ for the different morphology and causal agents, may occur. Among the atypical exanthems with infectious etiology, viral, bacterial, parasitic and helminth infections are implicated. We describe herein etiology and epidemiology of the atypical exanthems caused by infectious agents. In case of exanthem, to make a correct etiological diagnosis is crucial for both the patient and community concerning issues such as time off school, immunizations and risk in pregnancy and immunocompromised individuals.

Cerebral imaging and neurodevelopmental outcome after entero- and human parechovirus sepsis in young infants

Enterovirus (EV) and human parechovirus (HPeV) are major causes of sepsis-like illness in infants under 90 days of age and have been identified as neurotropic. Studies about acute and long-term neurodevelopment in infants with sepsis-like illness without the need for intensive care are few. This study investigates cerebral imaging and neurodevelopmental outcome following EV and HPeV infection in these infants. We studied infants under 90 days of age who were admitted to a medium care unit with proven EV- or HPeV-induced sepsis-like illness. In addition to standard care, we did a cerebral ultrasound and cerebral magnetic resonance imaging (MRI), as well as neurodevelopmental follow-up at 6 weeks and 6 months and Bayley Scale of Infant and Toddler Development 3rd edition (BSID-III) investigation at 1 year of age. Twenty-six infants, 22 with EV and 4 with HPeV, were analysed. No abnormalities were detected at cerebral imaging. At 1 year of age, two infants had a moderate delay on both the motor and cognitive scale, one on the cognitive scale only and three others on the gross motor scale only.

CONCLUSION

Although our study population, especially the number of HPeV positive infants is small, our study shows that these infants do not seem to develop severe neurodevelopmental delay and neurologic sequelae more often than the normal Dutch population. Follow-up to school age allows for more reliable assessments of developmental outcome and is recommended for further studies to better assess outcome. What is known: • Enterovirus and Human Parechovirus infections are a major cause of sepsis-like illness in young infants. • After intensive care treatment for EV or HPeV infection, white matter abnormalities and neurodevelopmental delay have been described. What is new: • In our 'medium care' population, no abnormalities at cerebral imaging after EV- or HPeV-induced sepsis-like illness have been found. • At 1 year of age, infants who had EV- or HPeV-induced sepsis-like illness do not seem to develop severe neurodevelopmental delay and neurologic sequelae more often than the normal population.

Enterovirus infection in febrile neonates: A hospital-based prospective cohort study

AIM

This study aims to investigate clinical characteristics and microbiological results and to assess the predictors for enterovirus infection in febrile neonates.

METHODS

A prospective cohort study was conducted on 334 febrile patients (age: 0.33-28 days) in 2011-2012 years. Enterovirus RNA was detected by reverse transcription polymerase chain reaction on faeces or cerebrospinal fluid (CSF). Clinical characteristics were compared, and non-conditional logistic regression analysis was performed to determine independent predictors for enterovirus infection.

RESULTS

There were 131 episodes of neonatal enterovirus infection (39.22%). Forty-eight (36.64%) developed respiratory symptoms, 69 (52.67%) had diarrhoea, 22 (16.79%) had poor feeding and 34 (25.95%) had rash. Eighteen (13.74%) had lower platelet counts, and CSF specimens were positive for enterovirus RNA in 44.27% (58/131) whose CSF revealed a mean white blood cell counts of 100.38 ± 147.97 cells/mm(3) (range: 2-668 cells/mm(3) ). The positivity of stool 38.92% (130/334) was significantly higher than that of CSF specimens 26.24% (58/221) for enterovirus RNA (P < 0.01). By logistic regression analysis, the following independently predicted enterovirus infection: abnormal CSF test (odds ratio (OR): 12.426, 95% confidence interval (CI): 5.633-27.413), thrombocytopenia (OR: 3.647, 95% CI: 1.312-10.136), duration of fever >3.25 (d) (OR: 2.293, 95% CI: 1.279-4.113), highest temperature >38.35 (°C) (OR: 2.094, 95% CI: 1.342-4.123) and negative bacterial culture (OR: 5.073, 95% CI: 1.504-17.114).

CONCLUSIONS

Our data indicated that enteroviruses should be routinely considered in the differential diagnosis of febrile neonates. The factors, which may predict the risk of neonatal enterovirus infection, were abnormal CSF test, thrombocytopenia, duration of fever >3.25 (d), highest temperature >38.35 (°C) and negative bacterial culture.

Frequency of enterovirus detection in blood samples of neonates admitted to hospital with sepsis-like illness in Kuwait

This study investigated the role of enteroviruses in sepsis-like illness among neonates in Kuwait. Serum samples from 139 consecutive neonates presenting with sepsis-like illness during a three and a half-year-period whose blood cultures were negative for bacterial pathogens were tested. Enterovirus RNA was detected by single-step reverse-transcription PCR (RT-PCR). Specific genotypes were identified by direct DNA sequencing of enteroviral genome. Serotype-specific antibodies in serum samples from some selected patients were detected by virus neutralization test using coxsackievirus B types (CBVs). All 139 neonates presented with sepsis-like illness and blood samples were uniformly negative for aerobic/anaerobic bacterial cultures. Fifty-six (40%) neonates had further complications of sepsis including carditis (n = 34) and multi-organ involvement (n = 22). Enterovirus RNA was detected by RT-PCR in 34 of 139 (24%) serum samples which is among the highest frequency reported so far in non-epidemic settings. Genotyping identified CBVs as most common enteroviruses, causing 19 of 34 (56%) enteroviral sepsis episodes in neonates. Of 34 carditis cases, 18 were positive for CBVs by serotyping including all 10 enterovirus RNA-positive samples. Only one fatality was observed due to liver failure in a neonate with hepatitis. Our data showed that enteroviruses are responsible for 24% of neonatal sepsis cases due to non-bacterial causes in Kuwait. The data indicate that enteroviruses should be considered in the differential diagnosis of sepsis-like illness among neonates, particularly those with negative blood cultures for bacterial pathogens.

Meningitis, Viral

This article provides an overview of the pathogenesis, epidemiology, causes, clinical presentation, laboratory diagnosis, and treatment of the most common causes of viral meningitis in the United States. It also summarizes other infectious and noninfectious causes of lymphocytic or aseptic meningitis.

Prospective comparison of the detection rates of human enterovirus and parechovirus RT-qPCR and viral culture in different pediatric specimens

BACKGROUND

Reverse-transcriptase quantitative real-time polymerase chain reaction (RT-qPCR) has become the gold standard for the diagnosis of human enterovirus (EV) and parechovirus (HPeV) infections. The detection rate of RT-qPCR in different pediatric body specimens has not been compared prospectively in a multicentre study.

OBJECTIVES

This study compared the diagnostic detection rates of EV and HPeV RT-qPCR and viral culture in different specimens (feces, nasopharynx, blood, urine and cerebrospinal fluid (CSF)) of pediatric patients.

STUDY DESIGN

This prospective, multicenter study performed an EV and HPeV RT-qPCR on nasopharynx, blood, urine, feces and CSF specimens and a viral culture on nasopharynx, feces and CSF specimens in symptomatic children<16 years.

RESULTS

Of 285 included children EV was detected in 140 (49%) and HPeV in 44 (15%) children. Both EV and HPeV RT-qPCR had a higher sensitivity and negative predictive value than EV and HPeV viral culture, respectively. EV and HPeV RT-qPCR in feces specimen had the highest sensitivity (99.2% and 95.1%) of all specimens. Pooling results of specimens increased the detection rate for both viruses.

CONCLUSION

Of all specimens, RT-qPCR in feces had the highest detection rate for both EV and HPeV in symptomatic pediatric patients. An EV was detected in all EV positive patients if a RT-qPCR was performed on both feces and CSF specimens or in both feces and urine specimens. HPeV was detected in all HPeV positive patients if a RT-qPCR was performed on both feces and CSF specimens, feces and nasopharynx specimens or CSF and nasopharynx specimens.

Enteroviral testing and length of hospital stay for children evaluated for lyme meningitis

BACKGROUND

In Lyme disease-endemic areas, many children with aseptic meningitis are hospitalized while awaiting Lyme serology results. Although Lyme serology takes several days, an enteroviral polymerase chain reaction (EV PCR) test takes only a few hours to return results.

OBJECTIVE

Our aim was to measure the impact of EV PCR testing on duration of stay for children evaluated for Lyme meningitis.

METHODS

A retrospective cohort study was performed with children evaluated for Lyme meningitis at 3 Emergency Departments located in Lyme disease-endemic areas. We defined Lyme meningitis using the Centers for Disease Control and Prevention criteria (either positive Lyme serology test result or an erythema migrans rash). The duration of stay was compared by EV PCR test result (positive, negative, and not obtained).

RESULTS

There were 423 study patients identified, 117 (28%) of whom had Lyme meningitis and 209 (49%) had an EV PCR test performed. Median length of stay varied by the EV PCR test status: children with a positive EV PCR test (n = 103; 28 h; interquartile range 17-48 h), those with a negative EV PCR test (n = 106; 72 h; interquartile range 48-120 h), and those who did not have an EV PCR test obtained (n = 214; 48 h; interquartile range 24-96 h; p ≤ 0.001).

CONCLUSIONS

Rapid EV PCR testing could assist clinical decision making by Emergency Physicians, avoiding potentially unnecessary hospitalization and parenteral antibiotics for children at low risk of Lyme meningitis.

Enterovirus reverse transcriptase polymerase chain reaction assay in cerebrospinal fluid: an essential tool in meningitis management in childhood

BACKGROUND

Enteroviruses (EV) are the main aetiological agents of aseptic meningitis in children and a common cause of febrile illnesses in young infants in summer. A rapid diagnosis is essential to rule out other conditions. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay performed in cerebrospinal fluid (CSF) has proved to be a very fast and useful tool.

METHODS

We collected demographic, clinical and laboratory data of children (aged 11-years or younger) with EV RT-PCR (Cepheid(®) Xpert EV) positive in CSF from December 2007 to July 2010, to describe EV meningitis in children and to determine the role of this assay.

RESULTS

We included 92 children (mean age 2.5 years), 32% of whom were neonates. There was no pleocytosis in the CSF of 18.5% (36% in newborn) of the patients, and 23 (25%) were discharged to home from the Emergency Room after the positive results. Length of hospital stay was 2 days (>2 years) versus 4.5 days in newborns (P<0.0001). Antibiotic treatment was prescribed in 38% (75% <3 months), but in 40% of these, it was stopped after the positive results. Mean EV RT-PCR information time was 7h (4-18h). All children had a good clinical outcome.

CONCLUSIONS

EV RT-PCR assay in CSF has played an essential role in the management of children with EV meningitis, allowing earlier discharges and decreasing avoidable inappropriate antibiotic treatments. This test should be considered as part of the initial study of children with aseptic meningitis, especially during epidemic seasons.

Detection of viruses in young children with fever without an apparent source

OBJECTIVE

Fever without an apparent source is common in young children. Currently in the United States, serious bacterial infection is unusual. Our objective was to determine specific viruses that might be responsible.

METHODS

We enrolled children aged 2 to 36 months with temperature of 38°C or greater without an apparent source or with definite or probable bacterial infection being evaluated in the St Louis Children's Hospital Emergency Department and afebrile children having ambulatory surgery. Blood and nasopharyngeal swab samples were tested with an extensive battery of virus-specific polymerase chain reaction assays.

RESULTS

One or more viruses were detected in 76% of 75 children with fever without an apparent source, 40% of 15 children with fever and a definite or probable bacterial infection, and 35% of 116 afebrile children (P < .001). Four viruses (adenovirus, human herpesvirus 6, enterovirus, and parechovirus) were predominant, being detected in 57% of children with fever without a source, 13% of children with fever and definite or probable bacterial infection, and 7% of afebrile children (P < .001). Thirty-four percent of 146 viral infections were detected only by polymerase chain reaction performed on blood. Fifty-one percent of children with viral infections and no evidence of bacterial infection were treated with antibiotics.

CONCLUSIONS

Viral infections are frequent in children with fever without an apparent source. Testing of blood in addition to nasopharyngeal secretions expanded the range of viruses detected. Future studies should explore the utility of testing for the implicated viruses. Better recognition of viruses that cause undifferentiated fever in young children may help limit unnecessary antibiotic use.

Evaluation of the precision of emergency department diagnoses in young children with fever

OBJECTIVE. To characterize causes of fever in children presenting to a pediatric emergency department (ED). METHODS. One-year retrospective review of ED records. Inclusion criteria were 2 to 36 months of age with a documented temperature ≥ 39°C. Exclusion criteria were elopement, repeat visit, and underlying diagnosis with a predisposition to infection. Medical records were reviewed using a predefined, study-specific, data abstraction tool. Based on diagnosis and pathogen detection, visits were assigned to 3 groups, laboratory confirmed pathogen and focal or nonfocal diagnosis without confirmed pathogen. RESULTS. A total of 1091 visits met inclusion criteria. Fourteen percent had a pathogen detected, 56% had a focal diagnosis without a confirmed pathogen, and 30% had a nonfocal diagnosis without confirmed pathogen. CONCLUSIONS. In a cohort of febrile children 2 to 36 months of age, only 14% had a confirmed pathogen. New rapid viral diagnostic techniques may provide an opportunity to improve diagnostic certainty in young children presenting with fever.

Low prevalence of invasive bacterial infection in febrile infants under 3 months of age with enterovirus infection

Infants under 3 months of age with fever without source (FWS) generally undergo a full, invasive septic evaluation to exclude invasive bacterial infection (IBI). Enterovirus (EV) infections are mostly banal and self-limiting and show a high prevalence rate at this age. We aimed to investigate the prevalence of IBI in EV-infected and uninfected infants under 3 months of age with FWS. This was a prospective observational cohort study of infants aged <90 days who were admitted because of FWS. As per protocol, blood and urine analysis and culture were obtained in all cases, and RNA EV from blood and/or cerebrospinal fluid samples was determined by real-time PCR. Three hundred and eighty-one previously healthy infants with FWS were included. EV infection was diagnosed in 64 children (16.8%; 95% confidence interval, 13.2-20.9%) and showed an uneventful evolution in all cases. Laboratory markers of infection were consistently lower in EV-infected patients; only one case of IBI (1.6%) was observed in an EV-infected patient as compared with 25.2% in EV-negative infants (p <0.001). Intravenous antibiotic use and length of stay were no different in EV-infected and uninfected patients. In our study, febrile infants (<90 days) diagnosed with EV infection showed a low risk of IBI when compared with uninfected patients. The systematic investigation of EV infection in young infants with FWS may allow a more conservative approach to the management of these patients. Further studies on this diagnostic approach are needed.

Lack of cerebrospinal fluid pleocytosis in young infants with enterovirus infections of the central nervous system

OBJECTIVES

To identify factors associated with cerebrospinal fluid (CSF) pleocytosis among infants aged 90 days or younger with enterovirus (EV) infections of the central nervous system (CNS).

METHODS

This is a retrospective cohort study performed at an urban academic children's hospital. Patients aged 90 days or younger with a positive CSF EV polymerase chain reaction (PCR) test result obtained during the EV seasons from 2000 to 2006 were included. Patients with concomitant serious bacterial illness or herpes simplex virus infection were excluded. Multivariable logistic regression was used to identify factors independently associated with CSF pleocytosis.

RESULTS

A total of 159 patients had a positive CSF EV PCR test result during the study period; 5 (3.1%) were excluded for concurrent serious bacterial infection. The median CSF white blood cell (WBC) count was 110/microL (interquartile range, 11-311/microL). Cerebrospinal fluid pleocytosis was present in 109 patients (71%). The proportion of infants with CSF pleocytosis accompanying EV CNS infections increased with age; CSF pleocytosis was present in 59%, 74%, and 90% of infants aged 0 to 28, 29 to 56, and 57 to 90 days, respectively (P = 0.007). Age and peripheral WBC count were independently associated with CSF pleocytosis.

CONCLUSIONS

Among infants with EV CNS infections, the absence of CSF pleocytosis is related to younger age and lower peripheral WBC counts, perhaps reflecting the decreased ability of younger infants to mount a robust inflammatory response to EV infection. Thus, CSF EV PCR testing may be warranted in select patients without CSF pleocytosis.

Clinical characteristics of human parechoviruses 4-6 infections in young children

BACKGROUND

Human parechoviruses (HPeVs) and enteroviruses (EVs) belong to the family Picornaviridae. EVs are known to cause a wide range of disease such as meningitis, encephalitis, and sepsis. HPeV1 and 2 have been associated with mild gastrointestinal or respiratory symptoms in young children. HPeV3 is associated with more severe neonatal infection. Little is known about the epidemiology and pathology of HPeV4-6 in children.

METHODS

We evaluated the clinical symptoms of the children with an HPeV 4, 5, or 6 infection. The patients with positive HPeV4-6 in stool samples were selected and available plasma or cerebrospinal fluid samples from these patients were tested for HPeV. Data on clinical symptoms, diagnosis, presence and duration of fever, medical history, mean age, use of antibiotics of the children infected with HPeV4-6 were retrospectively documented.

RESULTS

HPeV4-6 were found in 31 of the 277 HPeV positive children (11%). Coinfection with EV was seen in 8 patients. Fever was seen in 13 (42%) patients. Of the HPeV4-6 positive patients, 20 of the 31 children (64%) presented with gastrointestinal complaints and 18 of 31 (58%) patients had respiratory symptoms. The mean age was 14 months, 58% of the patients had an underlying disorder such as bronchomalacia or a cardiac disorder.

CONCLUSIONS

Symptomatic HPeV4-6 infections are seen in relative young children and are associated with respiratory and/or gastrointestinal symptoms. HPeV type 4 was detected more frequently than HPeV types 5 and 6.

Severe enterovirus disease in febrile neonates

INTRODUCTION

Fever in newborn infants may be due to an invasive infection with potential morbidity and mortality. Our aim was to describe the characteristics and outcome of group of febrile neonates with severe enterovirus infection compared to a group of neonates with severe bacterial infection.

PATIENTS AND METHODS

Prospective study including all neonates (<29 days old) admitted to a teaching hospital for fever (>38 degrees C), with positive bacterial cultures or enterovirus detection in sterile samples, from September 2003 to December 2004. Clinical information, analytical data at admission (complete leukocyte count and C-reactive protein concentrations), blood, urine, and cerebrospinal fluid culture results, molecular detection of enterovirus by polymerase chain reaction (PCR), and outcome were recorded.

RESULTS

Invasive bacterial infections were observed in 62 patients: urinary tract infection (n=57, including 8 cases of bacteremia), sepsis (n=3), and meningitis (n=2). Molecular tests for enterovirus were positive in 10 patients. C-reactive protein values were significantly higher in neonates with bacterial infection than in those with enterovirus infection (62,3 versus 9mg/L, P=0,008). Two patients with Streptococcus agalactiae meningitis, 1 with Staphylococcus aureus sepsis and 3 with enterovirus infection (manifested as myocarditis, hepatitis, and meningoencephalitis) required admission to the pediatric intensive care unit. Among these, 1 newborn with S. agalactiae and 2 of the 3 with enterovirus infection died.

CONCLUSIONS

In our series, enterovirus infection was an important cause of severe invasive disease. Specific viral diagnosis can contribute to the management of febrile neonates.

Human parechovirus causes encephalitis with white matter injury in neonates

OBJECTIVE

To assess the role of human parechoviruses (HPeVs) as a cause of neonatal cerebral infection and to report neuroimaging findings of newborn infants with encephalitis caused by HPeVs.

METHODS

Clinical presentation, cranial ultrasonography, magnetic resonance imaging (MRI) findings, and neurodevelopmental outcome of 10 infants admitted to a neonatal intensive care unit and diagnosed with encephalitis caused by HPeVs are reported.

RESULTS

Nine of 10 infants, with a gestational age of 29 to 41 weeks, presented at 36 to 41 weeks postmenstrual age with clinical seizures. Seven had a fever and six had a rash. Clinical presentation was similar to that of infants with enterovirus infection. Cranial ultrasonography showed increased echogenicity in the periventricular white matter in all infants. Neonatal MRI confirmed white matter changes in nine infants, which changed to gliosis on later MRI. Outcome was variable with cerebral palsy in one, a suspect outcome at 18 months in one, learning disabilities at 7 years of age in one, epilepsy in one, and normal neurodevelopmental outcome in five children. Follow-up of one infant was only 9 months.

INTERPRETATION

HPeVs should be added to the list of neurotropic viruses that may cause severe central nervous system infection in the neonatal period. White matter injury can be visualized with cranial ultrasonography, but more detailed information is obtained with MRI and especially diffusion-weighted imaging. Because clinical presentation of HPeV encephalitis is similar to that of enterovirus, real-time polymerase chain reaction for both viruses should be performed in atypical presentation of neonatal seizures.

An enterovirus epidemic in infants in the summer and fall of 2006

The aim of this study was to evaluate the diagnostic procedures in infants presenting with febrile illness in the summer and fall of 2006. Infants younger than 90 days presenting with febrile illness were included. A sepsis evaluation was performed. Stool and/or cerebrospinal fluid were tested for enterovirus (polymerase chain reaction [PCR]). Twenty-four infants were included, with a median age of 36 days (range 5-87). Nineteen infants (79%) were diagnosed with enterovirus infection. In nine infants, both stool and cerebrospinal fluid were tested for enterovirus; both specimens were positive in three infants. In seven infants, only the stool and in three infants, only the cerebrospinal fluid was tested. The five infants without enterovirus infection were only partly tested; in four infants, only the stool and in one infant, only the cerebrospinal fluid was tested. Three infants (13%) were diagnosed with a urinary tract infection, one of which tested positive for enterovirus as well. Twenty-three infants received antibiotic treatment. The median duration of antibiotic treatment of infants without bacterial infection was 3.2 days. Thorough diagnostic evaluation for enterovirus in different specimens is important, as, often, only one specimen is positive for enterovirus. When enterovirus is diagnosed, patient management may be influenced.

Identification of HLA-A*01- and HLA-A*02-restricted CD8+ T-cell epitopes shared among group B enteroviruses

Acute enteroviral infections ranging from meningitis, pancreatitis to myocarditis are common and normally well controlled by the host immune system comprising virus-specific CD8+ cytotoxic T lymphocytes (CTL). However, in some patients enteroviruses and especially coxsackieviruses of group B are capable of inducing severe chronic forms of diseases such as chronic myocarditis. Currently, it is not known whether divergences in the CTL-related immune response may contribute to the different outcome and course of enterovirus myocarditis. A pre-requisite for the study of CTL reactions in patients with acute and chronic myocarditis is the identification of CTL epitopes. In order to define dominant enterovirus CTL epitopes, we have screened, by using gamma interferon (IFN-gamma) ELISPOT, 62 HLA-A*01- and 59 HLA-A*02-positive healthy blood donors for pre-existing CTL reactions against 12 HLA-A*01 and 20 HLA-A*02 predicted CTL epitopes derived from coxsackieviruses of group B. Positive CTL reactions were verified by FACS analysis in a combined major histocompatibility complex-tetramer IFN-gamma staining. A total of 14.8% of all donors reacted against one of the three identified epitopes MLDGHLIAFDY, YGDDVIASY or GIIYIIYKL. The HLA-A*02-restricted epitope ILMNDQEVGV was recognized by 25% of all tested blood donors. For this peptide, we could demonstrate specific granzyme B secretion, a strong cytolytic potential and endogenous processing. All four epitopes were homologous in 36-92% of group B enteroviruses, providing a strong basis for monitoring the divergence of T-cell-based immune responses in enterovirus-induced acute and chronic diseases.

Performance of the GeneXpert enterovirus assay for detection of enteroviral RNA in cerebrospinal fluid

BACKGROUND

The GeneXpert Dx System allows for automated extraction, processing, amplification and real-time detection of target nucleic acids.

OBJECTIVES

To evaluate the performance of the Cepheid Xpert enterovirus (EV) assay for detection of EV RNA compared to a nucleic acid sequence based amplification (NASBA) assay and a user-developed TaqMan RT-PCR assay.

STUDY DESIGN

Assays were evaluated using a 12-member proficiency panel and up to 138 CSF specimens. Samples in which EV RNA was detected by two or more assays were considered true positives.

RESULTS

The GeneXpert, NASBA, and TaqMan assays correctly identified 10, 8, and 7 of 12 proficiency panel members, respectively. For detection of EV RNA in CSF, the sensitivities of the GeneXpert, NASBA, and TaqMan were 100%, 87.5%, and 96%, respectively. There were no false positives. Two samples tested by GeneXpert and NASBA yielded indeterminate or invalid results and could not be resolved.

CONCLUSIONS

The Xpert EV assay is a sensitive and specific method for detection of EV RNA in CSF specimens. The ease of use, random access capability, and minimal hands-on time with the automated GeneXpert system affords laboratories with little molecular diagnostics expertise an opportunity to complete a clinically useful testing within 2.5 h.

Severe neonatal parechovirus infection and similarity with enterovirus infection

BACKGROUND

Enteroviruses (EV) are an important cause of neonatal disease including hepatitis, meningoencephalitis, and myocarditis that can lead to death or severe long-term sequelae. Less is known about severe neonatal infection caused by the parechoviruses (PeV) of which type 1 (PeV1) and type 2 (PeV2) were previously known as echovirus 22 and echovirus 23. They belong to the same family of Picornaviridae as the EV. Of the PeV, so far only PeV3 has been associated in 2 recent reports with severe neonatal infection including involvement of central nervous system.

METHODS

We compared the clinical signs, diagnosis, laboratory data, cerebral imaging, and neurodevelopmental outcome of 11 neonates with PeV infection with 21 infants with EV infection treated in our hospital between 1994 and 2006. The diagnosis of EV infection or PeV infection was confirmed by a positive EV and/or PeV real time-polymerase chain reaction on blood, cerebrospinal fluid, (CSF) or stool or a viral culture of stool, nasopharyngeal swab, and/or CSF.

RESULTS

The 32 infants presented with sepsis-like illness and the most frequent signs were: fever, seizures, irritability, rash, and feeding problems. All patients received antibiotic treatment. Eleven of 21 infants infected with EV and 7 of 11 infants infected with PeV were full-term. Differentiation between the infants infected with EV and PeV on the basis of fever, irritability, rash, and seizures was not possible. Myocarditis was exclusively seen in 4 patients infected by EV. Eight of 11 patients with a PeV infection had meningoencephalitis of whom only 1 infant developed pleocytosis in the CSF. Serum C-reactive protein and CSF protein values were significantly higher in infants with EV infection than in those with PeV infection. Cerebral imaging of all infants with EV or PeV cerebral infection showed mild to severe white matter abnormalities. In 1 infant with EV infection and 3 infants with PeV infection, neurodevelopmental delay occurred. Mortality and long-term sequelae were mainly associated with myocarditis in the infants who were infected with EV (4 of 21).

CONCLUSIONS

It is not possible to distinguish neonatal PeV from EV infection on the basis of clinical signs. Neonates with PeV or EV infection present with sepsis-like illness and the most frequent signs are fever, seizures, irritability, rash, and feeding problems.

Detection of echovirus 18 in human breast milk

We detected enteroviral RNA and cultured infectious virus from a series of banked breast milk samples from the mother of an infant with neonatal sepsis; sequencing of the enterovirus isolate identified it as echovirus type 18. In this case, it is possible that enterovirus transmission occurred through the breast milk.

Basic rationale, current methods and future directions for molecular typing of human enterovirus

Enterovirus is a genus of the Picornaviridae family including more than 80 serotypes belonging to four species designed Human enterovirus A to D. The antigens of the structural proteins support the subdivision of enteroviruses into multiple serotypes. Comparative phylogeny based on molecular typing methods has been of great help to classify former and new types of enterovirus, and to investigate the diversity of enteroviruses and the evolutionary mechanisms involved in their diversity. By now, molecular typing methods of enterovirus rely mainly on the sequencing of an amplicon targeting a variable part of the region coding for the capsid proteins (VP1 and, alternatively, VP2 or VP4), either from a strain recovered by cell culture or, more recently, by direct amplification of a clinical or environmental specimen. In the future, microarrays are thought to play a major role in enterovirus typing and in the analysis of the determinants of virulence that support the puzzling diversity of the pathological conditions associated with human infection by these viruses.

Routine cerebrospinal fluid enterovirus polymerase chain reaction testing reduces hospitalization and antibiotic use for infants 90 days of age or younger

OBJECTIVE

The goal was to evaluate the impact of cerebrospinal fluid enterovirus polymerase chain reaction testing on the length of hospitalization and the duration of antibiotic use for infants < or = 90 days of age with suspected aseptic meningitis.

METHODS

This retrospective cohort study was conducted at an urban, tertiary-care children's hospital. Data were collected for 478 patients < or = 90 days of age for whom cerebrospinal fluid enterovirus polymerase chain reaction testing was performed during the enteroviral seasons of 2000 to 2006. The length of hospitalization and the duration of antibiotic use were assessed.

RESULTS

Cerebrospinal fluid enterovirus polymerase chain reaction test results were positive for 154 patients (34.8%). The mean length of stay was 3.65 days. The median polymerase chain reaction turnaround time was 23 hours. In multivariate analysis, having a positive cerebrospinal fluid enterovirus polymerase chain reaction result was associated with a 1.54-day decrease in the length of stay and a 33.7% shorter duration of antibiotic use. When patients were stratified according to the presence or absence of pleocytosis, both groups demonstrated significant reductions in the length of stay with positive cerebrospinal fluid enterovirus polymerase chain reaction results (1.32 and 1.38 days, respectively). Furthermore, increasing the polymerase chain reaction turnaround time by 24 hours increased the length of stay by 13.6% for patients with positive cerebrospinal fluid enterovirus polymerase chain reaction results.

CONCLUSIONS

Having positive cerebrospinal fluid enterovirus polymerase chain reaction results decreases the length of hospitalization and the duration of antibiotic use for young infants. These results support the routine use of this test during periods of peak enterovirus prevalence.

Inflammatory mediators for the diagnosis and treatment of sepsis in early infancy

Interleukin-6 (IL-6), interleukin-8 (IL-8), and procalcitonin (PCT) are important parameters in the diagnosis of sepsis and for differentiating between viral and bacterial infection in children. We compared the value of IL-6, IL-8, and PCT with C-reactive protein (CRP) in the diagnosis and treatment of late-onset sepsis among infants admitted to the neonatal intensive care unit (group I) and febrile infants admitted to general hospitals from home (group II). Group I was divided into subgroups Ia, positive blood culture (all Gram-positive cocci); Ib, negative blood culture; and Ic, controls. Group II was divided into subgroups IIa, systemic enterovirus infection, and IIb, no enterovirus infection. Enterovirus was identified by real-time (RT) polymerase chain reaction (PCR) and/or by culture in blood and cerebrospinal fluid (CSF). The positive predictive values of IL-6, IL-8, and PCT (78%, 72%, and 83%, respectively) were better than that of CRP (63%) in the diagnosis of neonatal sepsis. After 48 h of antibiotic treatment, IL-6 and IL-8 levels significantly decreased and PCT stabilized in clinically recovered patients, suggesting that these markers may be useful in distinguishing patients in which antibiotic treatment may be discontinued. Among infants of subgroup IIa, 80%-90% had normal values of IL-6, IL-8, and PCT, whereas CRP was increased in 40%. In conclusion, IL-6, IL-8, and PCT are better parameters than CRP in the diagnosis and follow-up of neonatal sepsis due to coagulase-negative staphylococci (CoNS) and in the exclusion of bacterial infection among those with enteroviral infection among febrile infants presenting from home.

Real-time PCR in clinical microbiology: applications for routine laboratory testing

Real-time PCR has revolutionized the way clinical microbiology laboratories diagnose many human microbial infections. This testing method combines PCR chemistry with fluorescent probe detection of amplified product in the same reaction vessel. In general, both PCR and amplified product detection are completed in an hour or less, which is considerably faster than conventional PCR detection methods. Real-time PCR assays provide sensitivity and specificity equivalent to that of conventional PCR combined with Southern blot analysis, and since amplification and detection steps are performed in the same closed vessel, the risk of releasing amplified nucleic acids into the environment is negligible. The combination of excellent sensitivity and specificity, low contamination risk, and speed has made real-time PCR technology an appealing alternative to culture- or immunoassay-based testing methods for diagnosing many infectious diseases. This review focuses on the application of real-time PCR in the clinical microbiology laboratory.

Epidemiological study of non-polio enterovirus neurological infections in children in the region of Monastir, Tunisia

The epidemiological, virological, and clinical syndromes of 86 children younger than 13 years suspected of having neurological diseases and admitted to Fattouma Bourguiba Hospital of Monastir from January 2002 to November 2003 were analyzed. The presence of enterovirus was studied in cerebrospinal fluid (CSF) samples by reverse transcription-polymerase chain reaction (RT-PCR) and by isolation on cell culture. Sixty-one (71%) specimens were positive by RT-PCR, whereas 45 (52.3%) were detected by cell culture. Eighty percent (n = 36) of cultured enteroviruses were identified, whereas 20% were untyped. Echoviruses were isolated most frequently, with 32 cases (71.1%) in children. Echovirus 6 was the most commonly identified serotype (22.2%), followed by echovirus 13 (20%). The highest incidence on neurological infection (19.6%) occurred in children less than 6 months of age. The infected children were predominantly male (62.3%). Enteroviruses were detected in all the period of the year with the highest rate in the spring and summer months. Aseptic meningitis was the most commonly diagnosed disease (49%).

Diagnosis and outcomes of enterovirus infections in young infants

BACKGROUND

Enterovirus (EV) infections commonly cause fever in infants younger than 90 days of age. The polymerase chain reaction (PCR) has improved our ability to diagnose EV infections.

OBJECTIVE

To evaluate the utility of blood and cerebrospinal fluid (CSF) specimens for the diagnosis of EV infections by PCR and to describe a large cohort of EV-infected infants.

DESIGN/METHODS

Febrile infants younger than 90 days of age evaluated for sepsis at Primary Children's Medical Center in Salt Lake City, UT, were enrolled in a prospective study designed to identify viral infections from December 1996 to June 2002. All patients had bacterial cultures of blood, urine and CSF. Testing for EV was performed by PCR and/or viral cultures. Patients who were positive for EV were identified for this study.

RESULTS

Of 1779 febrile infants enrolled, 1061 had EV testing and 214 (20%) were EV-positive. EV infections were diagnosed by PCR of blood, CSF or both in 93% of infants. PCR testing was positive in blood in 57%, and blood was the only positive specimen for 22% of EV infected infants. PCR of CSF was positive in 74%. The mean age of infants with EV infection was 33 days, with 18% younger than 14 days and 5% younger than 7 days. Fifty percent of EV-positive infants had CSF pleocytosis. Of EV PCR-positive infants, 91% were admitted, and 2% required intensive care. Possible serious EV disease was diagnosed in <1%, and there were no deaths. Twelve infants (5.6%) had concomitant urinary tract infection, and 3 (1%) had bacteremia.

CONCLUSIONS

EV infections are common in febrile infants younger than 90 days. Blood and CSF are equally likely to yield positive results by PCR, but the combination of both specimens improved the diagnostic yield.

Early differentiation of Lyme from enteroviral meningitis

BACKGROUND

Differentiating Lyme meningitis from enteroviral meningitis remains difficult because both occur mostly in the summer and early fall. This distinction is clinically important because pathogen-specific diagnostic test results are not available immediately and only patients with Lyme meningitis require parenteral antibiotic therapy.

OBJECTIVES

The objective of this study was to identify clinical and laboratory features that might help clinicians distinguish patients with Lyme meningitis from those with enteroviral meningitis.

METHODS

This cross-sectional study compared patients diagnosed with Lyme or enteroviral meningitis evaluated at a large children's hospital between January 1, 1999 and September 20, 2002.

RESULTS

Twenty-four patients with Lyme meningitis and 151 patients with enteroviral meningitis had median ages of 10.5 and 5.5 years, respectively (P < 0.0001). There was an equal proportion of boys with Lyme (63%) and enteroviral meningitis (62%; P = 1.0). The duration of symptoms before evaluation was longer for patients with Lyme meningitis (12 days) than with enteroviral meningitis (1 day; P < 0.0001). Cranial neuropathy was a presenting feature in 71% of children with Lyme meningitis. Cranial neuropathy, erythema migrans rash or papilledema occurred in 88% of patients with Lyme meningitis; no patients with enteroviral meningitis exhibited any of these findings (P < 0.0001). Lyme meningitis was unlikely when cerebrospinal fluid neutrophils exceeded 10% (negative predictive value, 99%).

CONCLUSIONS

We identified several clinical and laboratory features that may permit early differentiation of Lyme from enteroviral meningitis. These results may assist clinicians with decisions regarding additional testing and empiric antibiotic therapy.

Evaluation of a commercially available reverse transcription-PCR enzyme immunoassay (Enterovirus Consensus kit) for the diagnosis of enterovirus central nervous system infections

A commercial reverse transcription (RT)-PCR amplification method was compared with culture for the diagnosis of enterovirus meningitis. In total, 99 cerebrospinal fluid (CSF) specimens were examined with the Enterovirus Consensus kit and shell vial culture. RT-PCR allowed the amplification of enterovirus cDNA and its detection in a microtitre plate by hybridisation. Clinical information and CSF analysis were used to resolve the discrepancy in results. The detection limit of the RT-PCR assay was determined with the Third European Union Concerted Action Enterovirus Proficiency Panel. There were 34 true-positive CSF specimens. Of these, RT-PCR detected 33 (sensitivity 97%), while culture detected 19 (sensitivity 54.5%). RT-PCR failed to detect one culture-positive specimen that contained inhibitors. When samples from the Third European Union Concerted Action Enterovirus Proficiency Panel were tested, the RT-PCR method gave identical results to those expected. The Enterovirus Consensus kit was rapid and statistically more sensitive than culture (p < 0.01) for the detection of enteroviruses in CSF, and may offer considerable benefits in the clinical management of patients with enterovirus meningitis.

Molecular methods for diagnosis of viral encephalitis

Hundreds of viruses cause central nervous system (CNS) disease, including meningoencephalitis and postinfectious encephalomyelitis, in humans. The cerebrospinal fluid (CSF) is abnormal in >90% of cases; however, routine CSF studies only rarely lead to identification of a specific etiologic agent. Diagnosis of viral infections of the CNS has been revolutionized by the advent of new molecular diagnostic technologies to amplify viral nucleic acid from CSF, including PCR, nucleic acid sequence-based amplification, and branched-DNA assay. PCR is ideally suited for identifying fastidious organisms that may be difficult or impossible to culture and has been widely applied for detection of both DNA and RNA viruses in CSF. The technique can be performed rapidly and inexpensively and has become an integral component of diagnostic medical practice in the United States and other developed countries. In addition to its use for identification of etiologic agents of CNS disease in the clinical setting, PCR has also been used to quantitate viral load and monitor duration and adequacy of antiviral drug therapy. PCR has also been applied in the research setting to help discriminate active versus postinfectious immune-mediate disease, identify determinants of drug resistance, and investigate the etiology of neurologic disease of uncertain cause. This review discusses general principles of PCR and reverse transcription-PCR, including qualitative, quantitative, and multiplex techniques, with comment on issues of sensitivity, specificity, and positive and negative predictive values. The application of molecular diagnostic methods for diagnosis of specific infectious entities is reviewed in detail, including viruses for which PCR is of proven efficacy and is widely available, viruses for which PCR is less widely available or for which PCR has unproven sensitivity and specificity, and nonviral entities which can mimic viral CNS disease.

Presentation, diagnosis, and management of enterovirus infections in neonates

The nonpoliovirus enteroviruses commonly infect newborns, with consequences ranging from asymptomatic infection and benign illness, to severe, life-threatening disease. Frequently occurring symptoms include fever, irritability, lethargy, anorexia, and rash. Although most illnesses are mild, severe disease develops in a subset of newborns infected in the first 2 weeks of life. Severe disease may consist of sepsis, meningoencephalitis, myocarditis, pneumonia, hepatitis, and/or coagulopathy. Substantial mortality rates have been reported, and long-term sequelae may occur among survivors. Risk factors and clinical features associated with severe disease include absence of neutralizing antibody to the infecting serotype, maternal illness prior to or at delivery, prematurity, illness onset within the first few days of life, multiorgan disease, severe hepatitis, positive serum viral culture, and specific infecting serotype (e.g. group B coxsackieviruses and echovirus 11). Whereas the mainstay of diagnosis has traditionally been viral isolation in tissue culture, the polymerase chain reaction has been demonstrated to be more sensitive than culture, highly specific, and rapid. Immunoglobulin has been used as a therapeutic agent for neonates with enterovirus disease; however, clinical efficacy has not been proven. Specific antiviral therapy for enteroviruses is in development. Pleconaril is an investigational agent that inhibits viral attachment to host cell receptors and uncoating of viral nucleic acid. It has broad and potent anti-enterovirus activity, excellent oral bioavailability, and is well tolerated. Some clinical trials have demonstrated benefit in children and adults with enterovirus meningitis, and in adults with upper respiratory tract infections caused by picornaviruses (rhinoviruses or enteroviruses). Data summarizing compassionate use for severe enterovirus diseases (including neonatal sepsis) also suggest possible benefit. Limited pharmacokinetic data are available in infants and neonates. A multicenter, placebo-controlled, randomized trial of pleconaril in neonates with severe hepatitis, coagulopathy, and/or myocarditis is currently being conducted.

Neonatal coxsackie B virus infection-a treatable disease?

Ten neonates with coxsackie B viral infection presented over a 3-month period. Clinical features included meningoencephalitis, thrombocytopenia, disseminated intravascular coagulopathy, cardiomyopathy, and hepatitis. Eight infants had multiorgan disease, four with severe myocardial dysfunction, of whom two died. All of the infants with severe disease developed symptoms within 7 days of age. In infants presenting within 10 days of birth, in all cases there were symptoms compatible with maternal infection prior to delivery. Severity was associated with perinatal transmission. Enteroviral polymerase chain reaction of CSF, urine, stool or throat swab was positive in nine of the ten babies. Seven of the infants were treated with a 7-day course of the new anti-picornaviral drug pleconaril (5 mg/kg 3 times daily).

CONCLUSION

These cases highlight the importance of not missing coxsackie B viral infection in the differential diagnosis of the septic neonate, especially as there is now a potential treatment.

Comparison of the NucliSens Basic kit (Nucleic Acid Sequence-Based Amplification) and the Argene Biosoft Enterovirus Consensus Reverse Transcription-PCR assays for rapid detection of enterovirus RNA in clinical specimens

Samples were tested for enterovirus by nucleic acid sequence-based amplification (NASBA) (NucliSens Basic kit; BioMerieux), reverse transcription-PCR (RT-PCR) (Enterovirus Consensus RT-PCR kit; Argene Biosoft), and virus isolation. Eighty-two samples were tested, and 44 were positive, 34 by both NASBA and RT-PCR and 5 each by NASBA or RT-PCR only. Two nasopharyngeal samples positive only by RT-PCR were determined to be rhinovirus. Of 42 enterovirus-positive samples, NASBA detected 39 (92.9%) and RT-PCR detected 37 (88.1%). The NucliSens Basic kit and the Argene Biosoft RT-PCR had comparable sensitivities for detection of enterovirus RNA, and both molecular methods were more sensitive than culture, which detected only 60.5% of positive samples. NASBA could be completed in 6.5 h versus 9 h for the Argene Biosoft RT-PCR kit.

Diagnosis of enterovirus infection in the first 2 months of life by real-time polymerase chain reaction

During summer and fall, enterovirus infections are responsible for a considerable proportion of hospitalizations of young infants. We prospectively studied the incidence of enterovirus infections via real-time polymerase chain reaction (PCR) in blood, feces, and cerebrospinal fluid samples from infants <or=60 days old who had received a clinical diagnosis of sepsis. Forty-five patients were included: 19 were admitted to the pediatric wards of 2 general hospitals, and 26 had been hospitalized since birth in the neonatal intensive care unit (NICU) of a tertiary care hospital. None of the NICU patients developed enteroviral disease. In contrast, an enterovirus was detected in 11 (58%) of the patients admitted to the 2 general hospitals, 10 of whom (53%) showed evidence of systemic infection. Enterovirus infections are an important cause of sepsis in infants admitted to the hospital. Real-time PCR in serum was a rapid and sensitive method for diagnosis of enterovirus infection.

Rapid and sensitive routine detection of all members of the genus enterovirus in different clinical specimens by real-time PCR

We developed a rapid and sensitive method for the routine detection of all members of the enterovirus genus in different clinical specimens by using real-time TaqMan quantitative PCR. Multiple primer and probe sets were selected in the highly conserved 5'-untranslated region of the enterovirus genome. Our assay detected all 60 different enterovirus species tested, whereas no reactivity was observed with the viruses from the other genera of the picornaviridae family, e.g., hepatovirus and parechovirus. Weak cross-reactivity was observed with 7 of the 90 different high-titer rhinovirus stocks but not with rhinovirus-positive clinical isolates. Analysis of a well-characterized reference panel containing different enteroviruses at various concentrations demonstrated that the enterovirus real-time TaqMan PCR is as sensitive as most of the currently used molecular detection assays. Evaluation of clinical isolates demonstrated that the assay is more sensitive than the "gold standard" method, i.e., viral culture. Moreover, the PCR assay can be used on different clinical specimens, such as plasma, serum, nose and throat swabs, cerebrospinal fluid, and bronchoalveolar lavage, without apparent inhibition. Our data demonstrate that the real-time TaqMan PCR is a rapid and sensitive assay for the detection of enterovirus infection. The assay has a robust character and is easily standardized, which makes it an excellent alternative for the conventional time-consuming viral culture.

Use of heat labile UNG in an RT-PCR assay for enterovirus detection

A reverse transcription-polymerase chain reaction (RT-PCR) assay was developed to replace the Roche AMPLICOR Enterovirus Test used in our laboratory from 1996 to 1999. The new assay design was optimized to match or exceed the performance of the Roche AMPLICOR Enterovirus test kit with respect to analytical sensitivity and specificity, contamination control, ease of use and availability of reagents. This new assay uses a heat labile form of the enzyme uracil DNA glycosylase (UNG) for amplicon contamination control and an RT-PCR enzyme mixture, enabling a one tube/one step amplification. RNA preparation was undertaken using a commercial extraction kit. End detection was accomplished using a probe-capture enzyme immuno assay (EIA) plate format. This EV RT-PCR assay exceeds the performance of the Roche AMPLICOR Enterovirus assay in a direct comparison. The combined enzymological approach has potential application to a wide variety of assays requiring sensitive RNA detection and stringent contamination control, including those utilizing real time detection methods.

The impact of an enteroviral RT-PCR assay on the diagnosis of aseptic meningitis and patient management

BACKGROUND

Enterovirus (EV) is a major cause of aseptic meningitis and non-specific febrile illness in children. Since the majority of patients are hospitalized for possible bacterial infection, a rapid test for the diagnosis of enteroviral meningitis (EVM) may reduce hospitalizations and unnecessary treatments.

OBJECTIVE

To review the impact of an EV reverse transcriptase-polymerase chain reaction (RT-PCR) assay for the diagnosis of EVM on patient management.

STUDY DESIGN

CSF from 1056 patients admitted to the hospital between 1998 and 2001 was tested using EV RT-PCR. The results were correlated with CSF counts, diagnosis, test turnaround time (TAT) and length of hospital stay (LOS).

RESULTS

EV RT-PCR was positive for 113 patients (11%). Of these cases, 92% occurred during the summer months and 77% were in children <19 years of age. Children <3 years old with EVM frequently had non-specific clinical findings and lacked pleocytosis. There was a significant correlation between decreasing LOS and TAT (r(2)=0.97, P<0.001).

CONCLUSION

RT-PCR testing for EVM is an important tool to aid in the diagnosis of children with non-specific febrile illness. This test impacted patient management as measured by shortened patient stays, which should translate into significant health care savings.