Introduction

Definition of neonatal meningitis

Neonatal meningitis is a severe medical condition affecting newborns and if not treated promptly, may be fatal. Meningitis is an infection and inflammation of the protective membrane of the central nervous system, also known as the meninges. Neonatal meningitis is more common in newborns of less than 44 days old.¹

Early onset meningitis is commonly caused by bacteria contracted by the baby from the mother during birth. The bacteria may be harmless to the mother but pose a risk to the newborn.

On the other hand, late-onset meningitis occurs when the baby contracts the bacteria from their environment. This is likely to happen to premature babies. 

Whichever meningitis the newborn may contract, early or late, if symptoms are not recognised early enough, this can be very serious so, it is important to ensure that the newborn receives efficient and prompt management.^1,2

Causes of neonatal meningitis 

Meningitis is commonly caused by either a bacterial or viral infection, nonetheless, in rare cases, it can be caused by a fungal or parasitic infection. 

Bacterial causes

During the first 28 days of a newborn, bacterial meningitis is usually caused by bacteria such as;

• Group B Streptococcus (GBS) - which is commonly spread from the mother to the baby at birth
• Gram-negative bacilli (E.coli) - which is spread from contaminated food. E.g. individuals who have not washed their hands after using the bathroom
• Listeria monocytogenes - neonates can contract this from their mother in utero ( inside their mother’s womb)

Viral causes

Viral meningitis is not as serious as bacterial or fungal meningitis, nonetheless, it is still important to be aware about. Common viruses causing mild meningitis include:

• Influenza - the flu-causing virus. It is spread through contact with respiratory droplets- e.g. coughing, sneezing etc.
• Measles and mumps viruses - It is spread through contact with infected secretions through respiratory droplets
• Non-polio enteroviruses 

Viruses causing more severe types of meningitis include: 

• Varicella - chickenpox-causing virus
• Herpes simplex virus - spreads through the mother in utero or during birth
• West Nile Virus - transmitted through a mosquito bite

Fungal causes

Fungal meningitis is rare. It mostly only affects those who are immunocompromised or have a weak immune system. It is possible to contract fungal meningitis from fungi that live in soil, bird droppings or around bats. These fungi can enter the newborn’s body by being breathed in.^1,3,4

Common Symptoms 

Early symptoms

• Fever
• Irritability
• Lethargy

Progression of symptoms

• High-pitched cry
• Bulging fontanelle
• Seizures
• Difficulty breathing
• Hypotonia - low muscle tone^1,3,4,5

Differential diagnosis 

Differential diagnosis includes non-infectious causes with similar signs and symptoms to neonatal meningitis. Non-infectious conditions include:

• Neonatal seizure disorders
• Intracranial haemorrhage 
• Inborn dysfunction of the metabolism 
• Central venous thrombosis
• Sepsis
• Cerebral aneurysm^3,4

Diagnostic evaluation 

Physical examination

In the cases of late-onset meningitis, the doctor would assess the baby for any signs indicating meningitis. Convulsions, bulging anterior fontanelle and neck stiffness are some signs that may be present in a newborn with meningitis y. 

Laboratory tests

• Lumbar puncture - also known as a spinal tap. The fluid surrounding your baby’s brain and the spinal cord is taken out and tested for signs of infection
• Blood cultures - a blood sample is taken and tested in the laboratory to check for the infectious agent causing the meningitis
• Imaging studies - CT scans are also carried out to check the brain for any abscesses (built-up pus from the infection)^1,3,4,5,6

Management of neonatal meningitis

Meningitis management depends on the infectious agent and thus, treated accordingly: 

Medical treatment

• Antibiotics - are used to treat bacterial meningitis and are usually given intravenously (IV) 
• Antivirals - viral meningitis is often managed conservatively, by watching and waiting until symptoms subsided but, if symptoms and infection persist for more than 10 days, further treatment can be initiated through antivirals. Meningitis caused by varicella, West Nile or Herpes Simplex virus can be more severe so, antiviral medication would be initiated intravenously
• Antifungals - fungal meningitis is also treated intravenously and would require your baby to be admitted to the hospital for a period of time, due to the more severe effects and the underlying issues of fungal infections

Prognosis 

Complications

Meningitis is uncommon but can be severe, especially in newborns. Nonetheless, when treated early and efficiently, a baby can recover fully when treated.

Delaying treatment, although recovery is still possible, it may still cause some long-term complications. This includes: 

• Brain damage
• Blindness
• Hearing problems
• Fluid around the brain
• Learning difficulties
• Seizures^1,4,5,6

Prevention 

Maternal interventions

At birth, antibiotics can be given to the newborn to prevent group B Streptococcus infection. Furthermore, pregnant women are advised to avoid cheese and unpasteurised milk, to prevent Listeria. 

Normal hygiene, including handwashing and covering the mouth when coughing or sneezing, is important to prevent bacterial and viral spread. 

Vaccination strategies

Vaccination against influenza, varicella, measles, mumps and rubella is now available to prevent you from contracting these viral infections.^4,5,6

Summary

Neonatal meningitis is a condition that causes the newborn to develop meningitis, an infection of the meningeal layer protecting the brain. If not treated promptly, it can quickly become severe. This can cause long-term complications for your newborn. Meningitis can be treated accordingly depending on the infectious agent. Prevention techniques, such as washing hands regularly and covering the mouth when coughing and sneezing, can easily prevent the spread of such infections.