Neonatal Meningitis - Types, Symptoms, Diagnosis, and Treatment

Introduction

Meningitis is inflammation of the membranes surrounding the brain and spinal cord, including the dura mater, arachnoid, and pia mater. It can occur at almost all ages but is more common in infancy. Meningococcal meningitis and pneumococcal meningitis can occur at any age, whereas Haemophilus influenza is common in children from three months to five years. It is more common in males than females. It is a serious medical condition in neonates. Viruses, bacteria, fungi, or protozoa may cause it.

What Is the Pathophysiology of Neonatal Meningitis?

The bacteria is transmitted through droplets of respiratory secretions. The progression of neonatal meningitis begins with bacteria colonizing the gastrointestinal tract. The bacteria then invade the intestinal mucosal layer into the bloodstream, causing bacteremia and invasion of the cerebrospinal fluid. The neonates' less efficient immune system cannot prevent the invading bacteria. Therefore, colonization of the mother plays an important role in transmission to the neonate, causing early-onset meningitis. The incubation period is between two to ten days.

What Are the Signs and Symptoms of Neonatal Meningitis?

The symptoms seen in neonatal meningitis are often non-specific that may indicate several other conditions, such as sepsis. These may include fever, dyspnea, and irritability. Signs and symptoms include

• Flu-like symptoms.

• Fever.

• Altered consciousness.

• Lethargy.

• Irritability.

• Headache.

• Photophobia.

• Stiff neck.

• Brudzinski sign or passive neck flexion causes the hips and knees to flexion.

• Kernig sign or extension at the knee with the hip joint flexed causes spasms in the hamstring muscles.

• Seizure.

• Skin rashes.

• Poor appetite.

Other symptoms of meningitis in neonates or infants include

• Apnea.

• Jaundice.

• Neck rigidity.

• Hypothermia or hyperthermia.

• Poor feeding.

• High-pitched cry.

• Bulged fontanelles.

• Poor reflexes.

• Abdominal distension.

• Anorexia.

• Jitteriness.

• Sunset eyes.

What Are the Types of Neonatal Meningitis?

The types of meningitis in neonates:

Bacterial Meningitis:

• Brucella.

Viral Meningitis:

• Enteroviruses.

• Ebstein-Barr virus.

• Human immunodeficiency virus (HIV).

• Mumps.

• Influenza.

• Herpes simplex virus.

• Varicella zoster.

• Lymphocytic choriomeningitis.

Fungal Meningitis:

• Cryptococcus neoformans.

• Candida.

• Histoplasma.

• Blastomyces.

• Coccidioides.

Protozoa and Parasites Meningitis:

• Toxoplasma.

• Amoeba.

• Cysticercus.

Non-infectious Meningitis:

Malignant Disease:

• Breast cancer.

• Bronchial cancer.

• Leukemia.

• Lymphoma.

Inflammatory Disease:

• Sarcoidosis.

• Behcet's disease.

• Systemic lupus erythematosus (SLE).

What Are the Laboratory Diagnostic Tests to Be Carried Out?

The diagnosis is based on clinical manifestation and cerebrospinal fluid examination. The cerebrospinal fluid is obtained by lumbar puncture under aseptic conditions. A lumbar puncture is necessary until and unless there are contraindications such as increased intracranial pressure, unstable patient, skin infection at the site of lumbar puncture, thrombocytopenia, and papilloedema. It is always recommended to obtain a computed tomography (CT) to exclude a mass lesion such as a cerebral abscess before lumbar puncture because of the risk of conning. It is collected in three sterile containers for cell count, biochemical analysis, and bacterial examination. The sample should be examined immediately after collection or placed in the incubator at thirty-seven-degree centigrade.

• In bacterial meningitis, the CSF (cerebrospinal fluid) is usually cloudy or turbid due to more than 1000 x 106 cells per liter of neutrophils.

• The total protein content is usually significantly elevated, and glucose levels are markedly diminished or absent.

• Gram film and culture may allow the identification of the organism.

• Blood cultures may be positive.

• Polymerase chain reaction (PCR) techniques can be used on blood and CSF to identify bacterial deoxyribose nucleic acid (DNA).

What Is the Management of Neonatal Meningitis?

The treatment protocol aims to sterilize the cerebrospinal fluid of any meningitis-causing pathogens. A repeated lumbar puncture is recommended twenty-four to forty-eight hours after the initial treatment to declare sterilization. It is important to start the treatment as soon as possible. Delayed treatment may lead to cerebral palsy, blindness, and deafness.

Drugs such as antimicrobial agents are recommended that act upon bacterial infections. A combination of Ampicillin, with an aminoglycoside Gentamicin, and third generation Cephalosporin such as Cefotaxime is recommended for early onset meningitis. A regimen of antistaphylococcal antibiotics such as Nafcillin or Vancomycin, with Cefotaxime, Ceftriaxone, or Ceftaxidime with or without an aminoglycoside is usually recommended for late-onset neonatal meningitis.

In the case of herpes simplex virus-derived meningitis, antiviral therapy such as Acyclovir or Vidarabine is used. Depending upon the severity of the disease, the infant may require other therapies, such as

• Anticonvulsant Drugs: If the infant undergoes seizures.

• Intracranial pressure should be monitored using an intracranial pressure monitoring device.

• It may also require evaluation for cerebral abscess.

• It may also require evaluation for hydrocephalus.

• Supportive therapy includes: Maintaining fluid and electrolyte balance and maintaining temperature.

There are various vaccines available to prevent bacterial meningitis. However, vaccines are not hundred percent effective against these bacteria. They also do not protect against all strains of bacteria. The prognosis of the disease depends on the patient's age, the illness's duration, complications, pathogens involved, and the individual's immune status. Patients with viral meningitis usually have an excellent prognosis. The prognosis is worse for patients at extremes of ages, such as children under two years or adults over sixty years. Patients with impaired levels of consciousness are at higher risk for developing neurologic sequelae.

What Are the Complications of Neonatal Meningitis?

The complications of neonatal meningitis include

• Obstructive hydrocephalus:

• Hemorrhage.

• Cerebral infarction.

• Formation of brain abscess.

• Increased intracranial pressure.

• Subdural effusion or empyema or collection of pus in the brain.

• Cerebral edema for which intravenous mannitol is given six to eight hours for the first few days.

• Convulsions for which intravenous Diazepam can be given.

• Ventriculitis is the inflammation of the ventricles in the brain, especially in bacterial infections.

• Ataxia.

• Stroke.

• Shock, which is treated with intravenous fluid and maintenance of blood pressure.

Conclusion

Acute bacterial meningitis in neonates is a medical emergency, and any delay in instituting effective antimicrobial therapy may lead to increased morbidity and mortality. Therefore, it is important to start the treatment as soon as possible. Delayed treatment may lead to cerebral palsy, blindness, and deafness. The prognosis of the disease depends on the patient's age, the illness's duration, complications, pathogens involved, and the individual's immune status. Early intervention and treatment are highly beneficial for the patient to improve the conditions.