Nonpolio enteroviruses and the febrile young infant: epidemiologic, clinical and diagnostic aspects

Performance of blood enterovirus and parechovirus polymerase chain reaction testing in young febrile infants: a prospective multicentre observational study

OBJECTIVES

To analyse the performance of blood enterovirus and parechovirus PCR testing (ev-PCR) for invasive bacterial infection (IBI) (isolation of a single bacterial pathogen in a blood or cerebrospinal fluid culture) when evaluating well-appearing infants ≤90 days of age with fever without a source (FWS).

METHODS

We describe the well-appearing infants ≤90 days of age with FWS and normal urine dipstick. We performed a prospective, observational multicentre study at five paediatric emergency departments between October 2020 and September 2023.

RESULTS

A total of 656 infants were included, 22 (3.4%) of whom were diagnosed with an IBI (bacteraemia in all of them and associated with meningitis in four). The blood ev-PCR test was positive in 145 (22.1%) infants. One patient with positive blood ev-PCR was diagnosed with an IBI, accounting for 0.7% (95% CI 0.02 to 3.8) compared with 4.1% (95% CI 2.6 to 6.2) in those with a negative test (p=0.04). All four patients with bacterial meningitis had a negative blood ev-PCR result. Infants with a positive blood ev-PCR had a shorter hospital stay (median 3 days, IQR 2-4) compared with 4 days (IQR 2-6) for those with negative blood ev-PCR (p=0.02), as well as shorter duration of antibiotic treatment (median 2 days, IQR 0-4 vs 2.5 days, IQR 0-7, p=0.01).

CONCLUSIONS

Young febrile infants with a positive blood ev-PCR are at a low risk of having an IBI. Incorporating the blood ev-PCR test into clinical decision-making may help to reduce the duration of antibiotic treatments and length of hospital stay.

High Detection Frequency of Vaccine-Associated Polioviruses and Non-Polio Enteroviruses in the Stools of Asymptomatic Infants from the Free State Province, South Africa

Enterovirus (EV) infections are widespread and associated with a range of clinical conditions, from encephalitis to meningitis, gastroenteritis, and acute flaccid paralysis. Knowledge about the circulation of EVs in neonatal age and early infancy is scarce, especially in Africa. This study aimed to unveil the frequency and diversity of EVs circulating in apparently healthy newborns from the Free State Province, South Africa (SA). For this purpose, longitudinally collected faecal specimens (May 2021-February 2022) from a cohort of 17 asymptomatic infants were analysed using metagenomic next-generation sequencing. Overall, seven different non-polio EV (NPEV) subtypes belonging to EV-B and EV-C species were identified, while viruses classified under EV-A and EV-D species could not be characterised at the sub-species level. Additionally, under EV-C species, two vaccine-related poliovirus subtypes (PV1 and PV3) were identified. The most prevalent NPEV species was EV-B (16/17, 94.1%), followed by EV-A (3/17, 17.6%), and EV-D (4/17, 23.5%). Within EV-B, the commonly identified NPEV types included echoviruses 6, 13, 15, and 19 (E6, E13, E15, and E19), and coxsackievirus B2 (CVB2), whereas enterovirus C99 (EV-C99) and coxsackievirus A19 (CVA19) were the only two NPEVs identified under EV-C species. Sabin PV1 and PV3 strains were predominantly detected during the first week of birth and 6-8 week time points, respectively, corresponding with the OPV vaccination schedule in South Africa. A total of 11 complete/near-complete genomes were identified from seven NPEV subtypes, and phylogenetic analysis of the three EV-C99 identified revealed that our strains were closely related to other strains from Cameroon and Brazil, suggesting global distribution of these strains. This study provides an insight into the frequency and diversity of EVs circulating in asymptomatic infants from the Free State Province, with the predominance of subtypes from EV-B and EV-C species. This data will be helpful to researchers looking into strategies for the control and treatment of EV infection.

Enteroviral Infections in the First Three Months of Life

Enteroviruses (EVs) are an important source of infection in the paediatric age, with most cases concerning the neonatal age and early infancy. Molecular epidemiology is crucial to understand the circulation of main serotypes in a specific area and period due to their extreme epidemiological variability. The diagnosis of EVs infection currently relies on the detection of EVs RNA in biological samples (usually cerebrospinal fluid and plasma, but also throat swabs and feces) through a polymerase chain reaction assay. Although EVs infections usually have a benign course, they sometimes become life threatening, especially when symptoms develop in the first few days of life. Mortality is primarily associated with myocarditis, acute hepatitis, and multi-organ failure. Neurodevelopmental sequelae have been reported following severe infections with central nervous system involvement. Unfortunately, at present, the treatment of EVs infections is mainly supportive. The use of specific antiviral agents in severe neonatal infections has been reported in single cases or studies including few neonates. Therefore, further studies are needed to confirm the efficacy of these drugs in clinical practice.

Blood enterovirus polymerase chain reaction testing in young febrile infants

OBJECTIVE

To analyse the impact of blood enterovirus and human parechovirus PCR (ev-PCR) testing in young infants with fever without a source (FWS).

DESIGN

Observational study, subanalysis of a prospective registry.

SETTING

Paediatric emergency department.

PATIENTS

Infants ≤90 days of age with FWS seen between September 2015 and August 2019 with blood ev-PCR, blood and urine cultures and urine dipstick test performed.

MAIN OUTCOME MEASURES

Prevalence of invasive bacterial infection (IBI: bacterial pathogen in blood or cerebrospinal fluid) in infants with positive or negative ev-PCR test results. Secondarily, we also compared length of stay and antibiotic treatment in hospitalised infants.

RESULTS

Of 703 infants, 174 (24.7%) had a positive blood ev-PCR and none of them were diagnosed with an IBI (vs 2.6% (95% CI 1.3% to 4.0%) of those with a negative result, p=0.02). Prevalence of non-IBI (mainly urinary tract infection) was also lower among infants with a positive blood ev-PCR (2.3% (95% CI 0.1% to 4.5%) vs 17.6% (95% CI 14.3% to 20.8%), p<0.01).Overall, 258 infants were hospitalised (36.6%) and 193 (74.8%) of them received antibiotics. Length of hospital stay and antibiotic treatment were shorter in those with a positive blood ev-PCR (median: 3 days vs 5 days and 1 day vs 5 days, respectively; p<0.01). Differences remained statistically significant among well-appearing infants >21 days old with normal urine dipstick.

CONCLUSION

Blood ev-PCR identifies a group of infants under 90 days of age with FWS at very low risk of IBI. This test may help to guide clinical decision making in young febrile infants.

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.

Neonatal Enterovirus: A Case Report in a Term Infant Requiring Air Evacuation

Enterovirus infections in neonates have the potential to cause a cascade of devastating clinical complications that can lead to death. Because of vague maternal symptom presentations, the diagnosis may not be obvious to antepartum adult providers. Clinicians evaluating infants in the newborn nursery and following initial hospital discharge must be alert for this potential infection. Common newborn issues, such as hyperbilirubinemia and weight loss, may be early signs of a more life-threatening diagnosis. Enterovirus infections may be responsible for a continuum of critical diagnoses in the neonate. Utilization of viral panels during the initial rule-out sepsis evaluation may provide rapid diagnosis and, ultimately, earlier response times to devastating clinical symptoms. Antepartum history and presenting features of enteroviral infections warrant rapid diagnosis with viral polymerase chain reaction detection panels to potentially reduce antibiotic usage and inpatient length of stay. The purpose of this case report is to review risk factors, presentation, and management of neonatal enterovirus infections. As this infant was born in a remote setting and required air evacuation, the logistics of this transport are also discussed.

Pulmonary hemorrhage due to Coxsackievirus B infection-A call to raise suspicion of this important complication as an end-stage of enterovirus sepsis in preterm twin neonates

BACKGROUND

Prematurity is an important risk factor for the fulminate form of neonatal enteroviral infection. Pulmonary hemorrhage is a morbid complication that should be anticipated and managed aggressively due to its fatal outcome.

OBJECTIVE

To emphasize the significance of pulmonary hemorrhage as a complication of severe enterovirus infection in preterm neonates.

STUDY DESIGN

This report is a description of the clinical history, medical management and clinical outcomes of two pairs of preterm twin newborns (30 weeks and 36 weeks) with fulminant infection due to Coxsackievirus B (CBV) infection.

RESULTS

Maternal fever was reported in both deliveries and it was a factor in the decision for urgent cesarean section of the 30-week twins. Three of the four infants failed to survive. Their clinical course involved multiple organ system failure complicated with profound disseminated intravascular coagulopathy and pulmonary hemorrhage. Pulmonary bleeding leading to hypovolemic shock and respiratory failure was the direct cause of death in two cases.

CONCLUSIONS

This small series of preterm neonates with the diagnosis of CBV sepsis highlights the importance of correct diagnosis of maternal enterovirus infection in order to extend pregnancy and allow the fetus time to passively acquire protective antibodies. This report emphasizes the morbid complication of pulmonary hemorrhage as a result of enterovirus infection that should be anticipated and managed aggressively due to its potentially fatal outcome. Moreover, evaluation and observation of the asymptomatic twin is recommended in order to detect early signs of infection and deterioration in that sibling as well.

Laboratory diagnosis of CNS infections by molecular amplification techniques

The initial presentation of symptoms and clinical manifestations of CNS infectious diseases often makes a specific diagnosis difficult and uncertain, and the emergence of polymerase chain reaction-led molecular techniques have been used in improving organism-specific diagnosis. These techniques have not only provided rapid, non-invasive detection of microorganisms causing CNS infections, but also demonstrated several neurologic disorders linked to infectious pathogens. Molecular methods performed on cerebrospinal fluid are recognized as the new 'gold standard' for some of these infections caused by microorganisms that are difficult to detect and identify. Although molecular techniques are predicted to be widely used in diagnosing and monitoring CNS infections, the limitations as well as strengths of these techniques must be clearly understood by both clinicians and laboratory personnel.

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.

Asymptomatic (subclinical) meningitis in one of premature triplets with simultaneous enteroviral meningitis: a case report

Most enterovirus infection in the neonate and young infant is asymptomatic, but serious disease may occur, especially if acquired perinatally. We report the first case, to our knowledge, of asymptomatic enterovirus aseptic meningitis, and of concurrent enterovirus aseptic meningitis in premature triplets. Ten-week-old, 31-week-estimated gestational age premature triplet boys were diagnosed with enterovirus aseptic meningitis on the same day. Two of the triplets developed symptoms on the day of admission, while the third remained symptom free throughout the infection. All three recovered completely and are healthy more than a decade later.

Costs and infant outcomes after implementation of a care process model for febrile infants

OBJECTIVE

Febrile infants in the first 90 days may have life-threatening serious bacterial infection (SBI). Well-appearing febrile infants with SBI cannot be distinguished from those without by examination alone. Variation in care resulting in both undertreatment and overtreatment is common.

METHODS

We developed and implemented an evidence-based care process model (EB-CPM) for the management of well-appearing febrile infants in the Intermountain Healthcare System. We report an observational study describing changes in (1) care delivery, (2) outcomes of febrile infants, and (3) costs before and after implementation of the EB-CPM in a children's hospital and in regional medical centers.

RESULTS

From 2004 through 2009, 8044 infants had 8431 febrile episodes, resulting in medical evaluation. After implementation of the EB-CPM in 2008, infants in all facilities were more likely to receive evidence-based care including appropriate diagnostic testing, determination of risk for SBI, antibiotic selection, decreased antibiotic duration, and shorter hospital stays (P < .001 for all). In addition, more infants had a definitive diagnosis of urinary tract infection or viral illness (P < .001 for both). Infant outcomes improved with more admitted infants positive for SBI (P = .011), and infants at low risk for SBI were more often managed without antibiotics (P < .001). Although hospital admissions were shortened by 27%, there were no cases of missed SBI. Health Care costs were also reduced, with the mean cost per admitted infant decreasing from $7178 in 2007 to $5979 in 2009 (-17%, P < .001).

CONCLUSIONS

The EB-CPM increased evidence-based care in all facilities. Infant outcomes improved and costs were reduced, substantially improving value.

Clinical and analytical characteristics and short-term evolution of enteroviral meningitis in young infants presenting with fever without source

OBJECTIVE

The objective of this study was to describe the characteristics of the enteroviral meningitis diagnosed in a pediatric emergency department among infants younger than 3 months with fever without source and its short-term evolution.

METHODS

This was a retrospective, cross-sectional, 6-year descriptive study including all infants younger than 3 months who presented with fever without source and who were diagnosed with enteroviral meningitis.

RESULTS

A lumbar puncture was practiced at their first emergency visit in 398 (29.5%) of 1348 infants, and 65 (4.8%) were diagnosed with enteroviral meningitis, 33 of them (50.7%) between May and July. Among these 65 infants, 61 were classified as well-appearing; parents referred irritability in 16 (25.3%) of them (without statistical significance when compared with infants without meningitis). Forty-one (63.0%) had no altered infectious parameters (white blood cell [WBC] count between 5000 and 15,000/μL, absolute neutrophil count less than 10,000/μL, and C-reactive protein less than 20 g/L), and 39 (60%) had no pleocytosis. All of the 65 infants recovered well, and none of them developed short-term complications.

CONCLUSIONS

The symptoms in infants younger than 3 months with enteroviral meningitis were similar to those in infants with a self-limited febrile process without intracranial infection. C-reactive protein and WBC count were not good enteroviral meningitis predictors. Cerebrospinal fluid WBC count was normal in many of these infants, so performing a viral test is recommended for febrile infants younger than 3 months in which a lumbar puncture is practiced during warm months. The short-term evolution was benign.

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.

Épidémie estivale de méningites à entérovirus en 2005: expérience d'un service de pédiatrie générale

OBJECTIVE

To describe the clinical and biological characteristics of children presenting with enteroviral (EV) meningitis in a French paediatric unit during summer 2005.

METHODS

Retrospective study of children with EV meningitis from May to September 2005, diagnosed by PCR and/or viral culture in cerebrospinal fluid (CSF), serum or throat.

RESULTS

We reported 99 cases of EV meningitis (96 confirmed and 3 probable). The sex ratio was 2/1, and the median age was 5 years. Peak incidence was reached during the second week of July. The predominant symptom was meningism. ENT (16%), digestive (10%), cutaneous (15%) or respiratory (4%) symptoms were rare. Blood leucocyte count found a predominance of neutrophils (73%), and lymphopenia in half of the children. The mean value of CRP was 25,5 mg/l. The median leukocyte count in CSF was 65 cells/mm(3), with a prevalence of neutrophils in 60% of cases. Pleiocytosis was absent in 20 children. CSF protein level was increased in 20% of cases. The rate of hospitalization was 57,5%. Intravenous antibiotic treatment, initiated among 18 patients, was stopped in 66,6% of the cases on reception of PCR result. The latter result was obtained in 2,3 days on average.

CONCLUSION

The epidemic of 2005 EV meningitis was as widespread as that of summer 2000. Characteristics of these meningitis are strong proportion of CSF without pleiocytose and high prevalence of neutrophils in blood and CSF.

Neonatal enterovirus infections reported to the national enterovirus surveillance system in the United States, 1983-2003

BACKGROUND

Neonatal enterovirus (EV) infections lead to a wide range of clinical manifestations, from mild febrile illness to severe, sometimes fatal, sepsislike disease.

METHODS

To determine the relationship of EV serotypes with the risk of neonatal infection and its fatal outcome, we analyzed data reported to the National Enterovirus Surveillance System (NESS) during 1983-2003.

RESULTS

Of the 26,737 EV detections reported during this period, neonates accounted for 2544 (11.4% of those with known age). Serotypes most commonly isolated from neonates included echovirus (E) 11 (14.0% of EV with known serotype), coxsackievirus (CV) B2 (8.9%), CVB5 (7.5%), E6, E9 and CVB4 (6.8% each). CVB1-4, E11, and E25 were significantly more common, whereas CVA16, E4, E9, E21, E30, and human parechovirus 1 (formerly E22) were less common among neonates than among persons aged > or =1 month. Fatal outcome was noted for 3.3% of reports, with neonates at a higher risk of death than persons aged > or =1 month (11.5% versus 2.5%; odds ratio [OR] 5.1; 95% confidence interval [CI] = 3.3-7.8). Neonates infected with CVB4 were at a higher risk of death (OR 6.5; 95% CI = 2.4-17.7) than those infected with other EV.

CONCLUSION

EV are important neonatal pathogens associated with high risk of infection and death. Because of the limitations of the NESS (incomplete reporting, limited clinical data, bias towards more severe and younger cases), additional studies are needed to better evaluate the role of different EV in neonatal infections.

Molecular and epidemiologic analysis of enterovirus B neurological infection in Argentine children

BACKGROUND

Human enteroviruses are one of the major causes of central nervous system (CNS) infections in pediatrics.

STUDY DESIGN

We have studied 1242 children under 15 years old with suspicion of CNS infection from January 1998 to December 2003. CSF was obtained and molecular typing of human enterovirus B serotypes was performed by RT-PCR and sequencing of the N-terminal part of VP1 gene.

RESULTS

According to the clinical syndromes, patients were grouped as aseptic meningitis (n=654, 52.6%), encephalitis (n=239, 19.2%), febrile seizures (n=153, 12.3%), febrile infant (n=84, 6.7%), neonatal disease (n=70, 5.6%),), acute flaccid paralysis (n=31, 2.4%) and acute disseminated encephalomyelitis (n=11, 0.9%). HEV was detected in 335/1242 CSF samples (26.97%) and was associated to aseptic meningitis (n=243, 72.5%); febrile infant (n=31, 9.2%); neonatal infection (n=26, 7.7%); encephalitis (n=25, 7.5%), febrile seizures (n=9, 2.68%); acute flaccid paralysis (n=1, 0.3%). Seasonal incidence of HEV-B species was analyzed showing that in Buenos Aires infections occur mainly during late spring and summer. Molecular serotyping was completed in 60/335 samples. Echovirus 30, Echovirus 9, Coxsackie B3 to B5 and Echovirus 33 were the most frequently identified.

CONCLUSIONS

We showed that HEV are responsible for a considerable proportion of hospitalizations in children with central nervous system compromise reaching 27% of overall etiology.

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.

Health risks of enteric viral infections in children

Children are at a greater risk of infections from serious enteric viral illness than adults for a number of reasons. Most important is the immune system, which is needed to control the infection processes. This difference can lead to more serious infections than in adults, who have fully developed immune systems. There are a number of significant physiological and behavioral differences between adults and children that place children at a greater risk of exposure and a greater risk of serious infection from enteric viruses. Although most enteric viruses cause mild or asymptomatic infections, they can cause a wide range of serious and life-threatening illnesses in children. The peak incidence of most enteric viral illnesses is in children <2yr of age, although all age groups of children are affected. Most of these infections are more serious and result in higher mortality in children than adults. The fetus is also affected by enterovirus and infectious hepatitis resulting in significant risk of fetal death or serious illness. In addition to the poliovirus vaccine, the only vaccine available is for hepatitis A virus (HAV). A vaccine for rotavirus has currently been withdrawn, pending review because of potential adverse effects in infants. No specific treatment is available for the other enteric viruses. Enteric viral infections are very common in childhood. Most children are infected with rotavirus during the first 2yr of life. The incidence of enteroviruses and the viral enteric viruses ranges from 10% to 40% in children and is largely dependent on age. On average, half or more of the infections are asymptomatic. The incidence of hepatitis A virus is much lower than the enteric diarrheal viruses. There is no current evidence for hepatitis E virus (HEV) acquisition in children in the U.S. Enteric viral diseases have a major impact on direct and indirect health care costs (i.e., lost wages) and amount to several billion dollars a year in the U.S. Total direct and indirect costs for nonhospitalized cases may run from $88/case for Norwalk virus to $1,193/case for enterovirus aseptic meningitis. Direct costs of hospitalization ran from $887/case for Norwalk virus to $86,899/case for hepatitis A. These costs are based on 1997-1999 data. Generally, attack rates during drinking water outbreaks are greater for children than adults. The exception appears to be hepatitis E virus where young adults are more affected. However, pregnant women suffer a high mortality, resulting in concurrent fetal death. Also, secondary attack rates are much higher among children, probably because of fewer sanitary habits among this age group. Overall, waterborne outbreaks of viral disease have a greater impact among children than adults. To better quantify the impact on children, the literature hould be further reviewed for case studies of waterborne outbreaks where data are available on the resulting illness by age group. The EPA and/or Centers for Disease Control should attempt to collect these data as future outbreaks are documented.

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.

Microorganisms resistant to free-living amoebae

Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens. Some of these amoeba-resistant bacteria (ARB) are lytic for their amoebal host, while others are considered endosymbionts, since a stable host-parasite ratio is maintained. Free-living amoebae represent an important reservoir of ARB and may, while encysted, protect the internalized bacteria from chlorine and other biocides. Free-living amoebae may act as a Trojan horse, bringing hidden ARB within the human "Troy," and may produce vesicles filled with ARB, increasing their transmission potential. Free-living amoebae may also play a role in the selection of virulence traits and in adaptation to survival in macrophages. Thus, intra-amoebal growth was found to enhance virulence, and similar mechanisms seem to be implicated in the survival of ARB in response to both amoebae and macrophages. Moreover, free-living amoebae represent a useful tool for the culture of some intracellular bacteria and new bacterial species that might be potential emerging pathogens.

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.

A season of aseptic meningitis in Germany: epidemiologic, clinical and diagnostic aspects

OBJECTIVE

We assessed epidemiologic, clinical and laboratory features of aseptic meningitis during one season of multiserotype enteroviral meningitis in East Germany in 70 consecutive patients with aseptic meningitis admitted to the Children's University Hospital Leipzig.

RESULTS

Patients, age 1 to 16 years, typically presented with headache, emesis and fever, whereas signs of meningeal irritation were only moderately expressed in one-half of the patients. The median number of leukocytes in the CSF was 151 cells/mm(3) (range, 2 to 1,820) with a high percentage of polymorphonuclear cells (PMNs). Initial blood counts showed mild leukocytosis and pronounced PMN predominance (78.9 +/- 1.3%). The percentage of PMNs in the peripheral blood decreased in favor of mononuclear cells after 3 days to a pattern more compatible with viral infection as opposed to that suggestive for bacteria in the beginning. Mean cerebrospinal fluid values of protein, glucose and lactate and the C-reactive protein were mildly elevated or normal. Nonpolio enteroviruses were detected in 30 of 70 patients. Subsequent serotyping revealed echovirus type 13 (13 patients), type 6 (2), type 30 (1) and coxsackie B virus type 5 (2). There were no differences in demographic or clinical data between enterovirus positive and negative patients.

CONCLUSIONS

Even though individual laboratory values do not solely allow discrimination between viral and bacterial meningitis, the combined epidemiologic, clinical and laboratory data facilitate the diagnosis of aseptic meningitis in most cases. Viral diagnostics, identifying echovirus type 13 that thus far has not been associated with epidemics of meningitis, adds important epidemiologic information.

Molecular Techniques in the Diagnosis of Central Nervous System Infections

Development of polymerase chain reaction (PCR)-based molecular techniques has initiated a revolution in the field of diagnostic microbiology. These techniques have not only provided rapid, noninvasive detection of microorganisms that cause central nervous system (CNS) infections, but have also demonstrated that several neurologic disorders are linked to infectious agents. While PCR-based techniques are predicted to be widely used in diagnosing and monitoring CNS infections, the limitations, as well as strengths, of these techniques must be clearly understood by both clinicians and laboratory personnel to ensure proper utilization.

Enterovirus infections: a review of clinical presentation, diagnosis, and treatment

The enteroviruses, RNA viruses of the Picornaviridae family, are ubiquitous pathogens which include more than 70 different serotypes that infect people of all ages and tend to occur seasonally in the summer and fall. Clinical manifestations may vary diversely with one serotype, while multiple serotypes can present with identical symptoms and may mimic bacterial infections. Most enterovirus infections cause benign, self-limiting disease; however, they can also produce severe and sometimes fatal illnesses such as meningitis, encephalitis, myocarditis, neonatal sepsis, and polio. Severe enterovirus infections are being diagnosed and treated earlier with better prognostic outcomes due to the advances of polymerase chain reaction technology in accurately detecting virus in patient fluids as well as the recent development of new antiviral therapies.

Epidemiological survey of neonatal non-polio enterovirus infection in the Netherlands

The epidemiological, virological, and clinical data of 119 infants less than 30 days of age with enteroviral infection collected from January 1993 to November 1995 by the diagnostic virology laboratories were analyzed retrospectively. Ninety-eight isolates (83%) were obtained in the period of May 1 to December 1 with a peak in the summer months. Sixty-five percent (n = 78) of neonates became ill within the first 2 weeks of life. Echoviruses and Coxsackie virus type B were isolated most frequently, in 77 (65%) and 29 (24%) infants, respectively. Diagnosis was made by viral isolation from stool, nasopharyngeal swab, cerebrospinal fluid, and blood. One hundred four (87%) infants developed fever and 25 (21%) infants had diarrhea. A clinical diagnosis of sepsis was made in 42 (35%) infants and meningitis was diagnosed in 28 (24%) cases. The great majority of sepsis cases (36/86%) occurred in infants less than 15 days of age. In conclusion, non-polio enteroviruses (especially echoviruses) are a common and underreported cause of neonatal infection in the Netherlands in the summer months and are associated with a clinical diagnosis of sepsis or meningitis cases in the first 2 weeks of life in a high proportion of cases.

Enterovirus infections: diagnosis and treatment

Enteroviruses cause infections that present in diverse ways and affect people of all ages. Infections peak during summer and fall epidemics and cause 10 to 15 million symptomatic infections annually in the United States. The 70 enteroviral serotypes cause illness that ranges from nonspecific fevers and rashes to life-threatening myocarditis or central nervous system disease. These common infections create a significant burden on our society and healthcare system. New developments in rapid diagnosis of enterovirus infections using polymerase chain reaction (PCR) positively affect patient management and have the potential to reduce the healthcare impact of enterovirus infection. The future holds promise for effective antiviral drugs that can treat enterovirus infections and decrease their significant morbidity and mortality.