Neonatal Enteroviral Infection - Causes, Symptoms, Diagnosis, and Management

Introduction:

Enterovirus is a group of picornaviruses (pico or small RNA virus) present in an infected patient’s cerebrospinal fluid and blood and shed in the stool and respiratory secretions. Infection is usually spread by direct contact with the stool or respiratory secretions and can also spread through contaminated sources like water. Neonates affected by enterovirus have effects ranging from asymptomatic to severe life-threatening diseases.

What Is Neonatal Enteroviral Infection?

Neonates (children less than one month of age) have an immature immune system and are more prone to complications of viral and bacterial infections like enterovirus. Enterovirus usually causes mild and self-limiting infections, but it affects neonates more severely than older children. Factors affecting the severity and outcome of the infection include the mode of transmission, virus serotype, and the presence or absence of passively acquired serotype-specific maternal antibodies.

How Is Neonatal Enteroviral Infection Transmitted?

Enterovirus infection is spread through oral-fecal routes or by contamination through respiratory routes. Sources of contamination include wading pools, contaminated hands, and swimming pools. The viral shedding (the virus is released from the infected host) through feces continues for several weeks after infection. In contrast, viral shedding through the respiratory tract lasts only up to one week. The incubation period is usually from about three to six days. The most commonly associated serotypes with severe neonatal infection are Coxsackievirus B and echovirus.

Neonatal enteroviral infection is transmitted through transplacental, intrapartum (period from onset of labor through delivery), and postnatal acquisition. Neonates can also be secondarily affected by infections from communities.

• Transplacental Transmission - Maternal factors like coexisting infection, advanced age, and compromised uteroplacental blood flow increase the risk of transplacental fetal infection. In neonates with an enteroviral infection, almost 65 % of their mothers had a symptomatic infection during their perinatal period. The intrauterine enterovirus infection causes transplacental transmission and possibly an active infection in the placenta. This transmission is spread through the bloodstream.

• Intrapartum Transmission - Infants with an enterovirus infection had mothers who were symptomatic one week before the delivery. These mothers had symptoms like fever, abdominal pain, and respiratory distress. In the mother, the virus was found and recovered from the common transmission routes, like the blood, vaginal secretions, oropharyngeal secretions, and feces. Vaginal delivery is another possible route of transmission of the disease to the newborn.

• Postnatal Transmission - Postnatal transmission can happen in various ways. An infected infant can infect the neonates in a newborn nursery. Enterovirus infections from healthcare workers can spread to neonates and infants. Infants requiring intensive nursing care like gavage feeds (tube feeding for intake of medicines and liquids) and mouth care are at the highest risk of secondary infections.

What Symptoms Are Seen in a Neonatal Enteroviral Infection?

Symptoms of neonatal enteroviral infections can range from asymptomatic nonspecific illness to a severe fatal disease called neonatal enteroviral sepsis. Some of the mild infections include:

• Fever.

• Rash.

• Poor feeding.

• Lethargy (lack of energy or enthusiasm).

• Hand-foot mouth disease.

• Conjunctivitis (infection or inflammation of a thin layer (conjunctiva) that covers the front of the eye).

• Pluerodynia (pain in the muscles between the ribs).

Severe symptoms include:

• Sepsis.

• Meningitis (swelling of the membrane covering the brain and the spinal cord).

• Encephalitis (inflammation of the brain).

• Myocarditis (inflammation of the heart).

• Pneumonia (infection of the lungs).

• Hepatitis (inflammation of the liver).

• Coagulopathy (bleeding disorder).

• Acute paralysis.

• Chronic infection in immunocompromised patients.

• Cardiac arrest.

How Is Neonatal Enteroviral Infection Diagnosed?

An awareness of clinical sciences, recognizing the risk factors, monitoring parameters associated with severe cases, and using rapid RT-PCR tests for viral load help physicians diagnose severe cases of neonatal enteroviral infections on time.

History - The clinician takes a detailed history which includes pregnancy-related questions like the history of abnormal ultrasounds, screening tests or pregnancy risks, maternal infections, or maternal illnesses before delivery. In addition, the history of the neonates should include the following:

• A family history of genetic diseases.

• Exposure to sick contacts.

• History of neonatal intensive care unit (NICU) stay.

• History of viral or blood cultures.

• History of sepsis evaluation.

Physical Examination - Signs and symptoms in neonates should be thoroughly evaluated. Symptoms to look out for include diarrhea, fever, cough, congestion, rash, irritability, and poor feeding. Vital signs like pulse, blood pressure, and respiration rate should be checked, and a physical examination of the body should also be done.

• Head, Ears, Eyes, Nose, and Throat - Fontanelle (a spot on the baby’s head where the skull bones have not fused completely) is examined, and mucous membranes are noted. The mouth should be checked for oropharyngeal lesions (lesions at the back of the mouth).

• Chest Area - It is checked for tachypnea (breathing that is abnormally rapid and shallow) is noted. Differentiate between the transmitted upper airway sounds and any actual respiratory findings.

• Heart - It is checked for tachycardia (faster than normal heartbeat) and auscultated (examination using a stethoscope) for any murmurs, gallop rhythm, or muffled heart sounds.

• Abdomen Area - The abdomen should be palpated to evaluate for any signs of hepatomegaly.

• Extremities - Checked for assessing symmetric and equal movements in all extremities.

• Skin - Examined for signs of jaundice; consider nonspecific rashes and assess perfusion (passage of blood through blood vessels or organs) and color.

• Neurological tests - Reflexes are examined, and any changes in a normal tone are considered.

Laboratory Tests - Complete blood count, blood culture, urine analysis, urine culture, and stool culture are done to rule out sepsis.

CSF Analysis - Cerebrospinal fluid (CSF) is collected through lumbar puncture for culture, glucose, protein, and cell count tests in order to diagnose the infection.

RT-PCR Test - The RT-PCR (reverse-transcriptase polymerase chain reaction) test can diagnose the infection rapidly , it has improved sensitivity, and results are obtained quickly.

Imaging Studies - Imaging studies like chest x-ray is also considered. Opacities are noted in the x-rays for diagnosing the infection.

How Is Neonatal Enteroviral Infection Managed?

Treating enteroviral infections in neonates depends on the presenting symptoms and signs. Since most enterovirus infections are self-limiting, no specific therapy is needed, and supportive therapy is provided.

• Clinicians who diagnose neonatal enteroviral infections mainly treat complications of enteroviral diseases like liver failure, heart failure, and encephalopathy (a disease that affects the brain).

• Even though neonates infected with enteroviral have a low risk of bacterial infections, starting them with antibiotics like Cefotaxime, Gentamicin, or Ampicillin along with Vancomycin is recommended.

• Similarly, infants suspected of herpes simplex virus are started on Acyclovir to protect against and treat herpes encephalitis.

How Can a Neonatal Enteroviral Infection Be Prevented?

• Recognizing the mode of transmission is essential in preventing an enterovirus infection. It also helps predict the outcomes and understand the disease’s severity.

• Neonatal protection is achieved through maternal immunoglobulin G (IgG), given transplacentally to the neonate, and immunoglobulin A (IgA), given through breast milk.

• Antimicrobial substances like lactoferrin in breast milk also protect neonates from infection.

• Studies show that a lack of breastfeeding leads to frequent enteroviral infections in neonates.

• It is recommended to delay delivery for at least five to seven days after the onset of symptoms suggesting a maternal enteroviral infection. This delay helps the fetus to acquire antibodies for protection passively.

Conclusion:

Neonatal enteroviral infection is an infection caused by the enterovirus to children aged less than one year. This infection is more likely to develop into complicated diseases like encephalitis, hepatitis, and myocarditis. Recognizing the route of transmission is important in the prevention of this infection. As this infection is life-threatening to a neonate, clinicians need to recognize the symptoms of this viral infection and treat it accordingly.