Pediatric Echovirus Clinical Presentation

Updated: Jan 07, 2021
  • Author: Jorge M Quinonez, MD; Chief Editor: Russell W Steele, MD  more...
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Presentation

History

Because echovirus (EV) has been found in the stools of healthy individuals, most children with EV and other enteroviral infections are assumed to be asymptomatic. Finding the virus in the stools of healthy individuals, however, may be misleading because enterovirus can be excreted in feces for a long time, and no clear indication exists of what happened during the initial infection. Patients may have symptoms with infection, but the symptoms may be trivial and not recognized.

Nonfocal, acute febrile illness is the most common presentation of symptomatic enteroviral infection in young infants and children.

Enteroviral infections are the most common cause of hospital admission for suspected sepsis in children aged 2-3 months during summer and fall.

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Physical Examination

EV causes a remarkable range of diseases. Benign forms of disease are well recognized by clinicians (eg, nonspecific exanthems, herpangina) and do not warrant major diagnostic or therapeutic actions. Severe forms of disease, such as meningitis, encephalitis, neonatal sepsis, myocarditis, and chronic infection with meningoencephalitis in patients with altered immunity, are strong reasons for concern.

  • Nonspecific, acute febrile illness: Several studies have shown enterovirus can account for more than 50% of summer and fall emergency department visits for fever of unknown origin in infants and young children.

    • Fever onset is usually abrupt and without a prodrome, often exceeding 39° C. Fever, which may be the sole presentation, often is accompanied by irritability. High temperatures, irritability, and the nonspecific nature of the illness prompt the hospitalization of many infants for suspected bacterial sepsis. At least 50% of these patients have a history of poor feeding, and 25% of infants have vomiting or diarrhea. Affected infants resume feeding within 2 days of initial symptoms, and their GI manifestations are not the reason for hospital admission.

    • A large number of these patients have had thorough evaluations that included blood, urine, and cerebrospinal fluid (CSF) cultures and have received antibiotics for 48-72 hours while awaiting culture results. Differentiating patients infected with enterovirus from those with bacterial infections is impossible based solely on clinical findings.

    • Most young patients recover from the febrile episode in 2-10 days without complications.

  • Exanthems

    • Skin rashes are more common with EV infections than with infections from other enteroviruses. The first exanthematous disease induced by an enterovirus was linked to EV-16.

    • Exanthems may be maculopapular, morbilliform, macular, petechial, or papulopustular in nature.

    • Likelihood of an exanthem being present appears directly related to the EV type causing infection. For example, EV-6, which has been among the most prevalent serotypes causing infection during the past 25 years, is associated only sporadically with skin manifestations. Conversely, infections with EV-5, EV-9, and EV-25 are associated with skin rashes in as many as 35% of patients.

    • Skin findings with EV infections are self-limited and without sequelae.

  • Viral meningitis

    • As many as 90% of community-acquired viral meningitis cases result from EVs or coxsackie B viruses. CNS involvement is most likely with infections by EV serotypes 4, 6, 9, 11, 13, 16, and 30. More than 10,000 cases of enteroviral meningitis are reported annually to the Centers for Disease Control and Prevention (CDC), and actual numbers probably are 10 times higher.

    • Infants younger than 3 months have the highest incidence of recognized meningitis. This diagnosis is not based on specific neurological findings; instead, young infants are more likely to undergo a lumbar puncture for evaluation of a fever. Most young children with meningitis present with fever and irritability.

    • Older children with meningitis typically present with fever and severe headache. Headaches in older children and adults can be sufficiently severe to require narcotics for pain control.

    • Nuchal rigidity occurs in less than two thirds of patients and does not occur in infants.

    • Patients can have symptoms of photophobia, nausea, and vomiting.

    • About 10% of hospitalized infants with echoviral meningitis have neurologic manifestations (eg, seizures, altered mental status, increased intracranial pressure).

    • The classic results of CSF analysis are a mononuclear pleocytosis (100-300 cells/mm3), mildly elevated protein levels, and glucose concentrations within reference ranges. Higher WBC counts with a predominance of neutrophils occur early in the course of disease.

    • Illness duration typically is less than a week.

    • Despite current studies of antiviral drug therapies, standard treatments are limited to alleviating symptoms. Although the short-term prognosis appears good for young children with echoviral and other enteroviral meningitis, controversy continues about long-term cognitive, developmental, and language abnormalities among children who suffered meningitis in early life. Some prospective reports have indicated virtually no measurable long-term effects, even among patients who had neurologic findings during their illness.

  • Encephalitis

    • Clearly distinguishing encephalitis from enteroviral meningitis is important. Encephalitis is more rare, is a more devastating acute disease, and has long-term sequelae.

    • EV and other enteroviruses account for 10-20% of documented viral-caused encephalitis. Common serotypes that cause encephalitis include EV types 4, 6, 9, 11, and 30. EVs are more commonly associated with a global encephalitis and generalized neurological depression.

    • Clinical manifestations range from altered mental status to coma and decerebration. Some patients manifest with focal disease (eg, partial motor seizures, hemichorea, cerebellar ataxia), symptoms that may suggest a diagnosis of herpes simplex encephalitis. Brain imaging by CT scan or MRI and electroencephalography usually show the extent of involvement. The results of CSF analysis in patients with encephalitis are similar to the results from patients with only aseptic meningitis.

    • The prognosis for neonates with disseminated encephalitis is poor, and many die. The prognosis for similarly affected children and older patients is better, but fatalities sometimes occur.

  • Other neurological syndromes

    • Although rare, EV can cause a syndrome of acute motor weakness and paralysis indistinguishable from poliomyelitis. Sporadic cases of acute paralysis have been reported with EV-6 and EV-9. The myelitis caused by EV usually is less severe than that caused by poliovirus.

    • Guillain-Barré syndrome has been associated with EV-6 and EV-22 infections. Acute cerebellar ataxia has been related to infection with EV-6 and EV-9. Acute transverse myelitis has occurred in patients with EV-5 infection.

    • Chronic meningoencephalitis can occur in association with coxsackievirus or EV in patients who have acquired or congenital B-lymphocyte function defects. These patients present with an insidious course, manifested by headache, lethargy, motor dysfunction, or seizures. Symptoms may fluctuate in severity, wane, or gradually progress. Persistent pleocytosis and high protein levels in CSF are typical. Recovery of the virus from several other tissues suggests the possibility of disseminated disease. Prognosis for these patients generally is poor. The results of using intravenous immunoglobulin (IVIG) to treat these patients have been inconsistent.

  • Muscle and joint infections

    • EV infections sporadically involve muscles; both focal and generalized myositis has been described. Patients usually present with myalgia associated with elevated levels of skeletal muscle enzymes in serum. The course is self-limited and hastily resolves.

    • In patients with B-lymphocyte dysfunction, skeletal muscles can become chronically infected, manifested by a dermatomyositislike syndrome. Although other enteroviruses can be the cause, EV infection is most common.

    • EV-9 is associated with both acute and subacute arthritis.

  • Pleurodynia (ie, Bornholm disease)

    • First described more than 2 centuries ago, pleurodynia is characterized by fever and spasmodic pain in the chest wall or upper abdomen. The hallmark of pleurodynia is its paroxysmal nature.

    • Spasmodic periods persist from a few minutes to half an hour or longer. Pain can be severe, and patients often appear pale and diaphoretic, sometimes leading physicians treating older adults to consider the possibility of a myocardial infarction. Patients present with shallow, frequent respirations that usually suggest pleural inflammation or pneumonia. Physical examination rarely reveals pleural friction rubs; pleural effusions occur in fewer than 10% of patients. Pain usually is more severe at presentation and gradually wanes over 4-6 days, although pain occasionally persists 3 weeks. Analgesics and restricted physical activity usually suffice to reduce pain. Abdominal wall involvement occurs almost exclusively in children and often mimics appendicitis or peritonitis.

    • Pleurodynia can occur in epidemics involving adults and children, or in sporadic form. EV-1 and EV-6 are associated with epidemics of pleurodynia, and almost all other EV types have been linked to sporadic cases.

  • Myopericarditis

    • EV's tropism for the heart is well established. Group B coxsackieviruses 2 and 5 traditionally have been linked to acute myopericarditis; however, many other enterovirus types, including EV, have been related to acute heart disease. Although enterovirus-induced myocarditis occurs in all age groups, the highest risk is among physically active adolescents and young adults.

    • Myopericarditis is clinically indistinguishable from diseases caused by other viruses (eg, adenoviruses, influenza A, mumps) that can infect the myocardium. Approximately 65% of patients report an upper respiratory infection preceding manifestations of substernal chest pain, fever, dyspnea, and exertion intolerance. Physical examination reveals a pericardial friction rub in as many as 80% of these patients and a gallop rhythm in 20%.

    • Electrocardiography (ECG) invariably reveals abnormal findings; ECG also can reveal acute ventricular dilatation and diminished ventricular ejection fraction. Cardiac enzyme serum levels are often high.

    • Although the acute course of myopericarditis can be complicated by arrhythmias and congestive heart failure (CHF), most patients recover without major sequelae. About 5% of cases are fatal. Approximately 10-30% of cases continue to show ECG abnormalities; about the same percentage of patients present with recurrent CHF that indicates permanent myocardial damage. Most affected patients need supportive care.

    • Corticosteroid use is controversial for cases of acute myocarditis; experts disagree about the benefits and potential adverse effects of systemic use. Some have reported benefits from administering high-dose IVIG, but this therapy remains far from the standard of care.

  • Neonatal infections

    • Neonates during their first 2 weeks of life are particularly susceptible to potentially lethal diseases caused by an EV infection. Vertical transmission from an infected mother or, more rarely, a nosocomial source is the most likely mechanism for acquiring infection.

    • Passive acquisition of immunoglobulin G (IgG) antibodies from the mother appears to determine the outcome of a neonatal infection more than any other factor. The critical issue is the amount of time between maternal infection and the delivery.

    • Neonates who are infected present with a sepsislike syndrome, with fever, irritability, lethargy, respiratory distress, and an exanthem. Many patients show radiographic evidence of pulmonary involvement, and CSF analysis provides evidence of meningitis. Major systemic manifestations can develop as the disease progresses, such as hepatic necrosis, myocarditis, and disseminated intravascular coagulation. CNS disease may progress to encephalitic characteristics with seizures and focal abnormalities. Because clinical features can imitate neonatal sepsis by bacterial agents and either disseminated or localized herpes simplex infection, patients are often treated for both possibilities.

    • EV-11 specifically has been linked to a clinical syndrome of disseminated sepsis in which the dominant feature is neonatal hepatitis, accompanied by extensive necrosis of the liver and overwhelming hepatic failure. Other serotypes able to cause neonatal liver disease include EV serotypes 6, 7, 9, 14, 17, 19, and 21. In addition, EV-6, EV-9, and EV-11 have been linked to a severe form of perinatal pneumonitis with a high mortality rate. Incidence of infant death due to perinatal EV infection is unknown, although some studies report high numbers. Mortality usually results from either overwhelming liver failure or myocarditis rather than CNS involvement.

  • Other infections

    • EV-4 and EV-11 have been reported as sporadic causes of mild cases of croup.

    • EVs have sporadic associations with bronchitis and bronchiolitis.

    • Pneumonia in children has been associated with infections with EV serotypes 6, 7, 9, 11, 12, 19, 20, and 30.

    • Conjunctivitis, whether alone or in conjunction with other symptoms, has been reported with EV serotypes 1, 6, 9, 20, and 30.

    • Several reports link echovirus and enterovirus infection to a risk of developing type 1 diabetes.

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