A baby’s body is usually well equipped to adjust to its new environment immediately after birth. This new environment is a space teeming with bacteria, viruses and fungi. The bugs are invisible, and they are present on many surfaces including human skin and mucous membranes. Hence, a newborn is at risk of acquiring infection very easily, not only because of the ubiquitous presence of the organisms, but also due to their inability to produce an adequate immune response to an invasion by the organisms. This capacity is hampered further if a baby is born prematurely. Sepsis is the body’s extreme response to an infection.
Meningitis is a complication of sepsis. It is the inflammation of the layers of tissue that cover the brain and spinal cord, and of the fluid-filled space between the layers.
Although meningitis can affect people of any age, babies under 2 are at the highest risk of getting meningitis. A baby can get meningitis when bacteria, viruses, or a fungus infecting another part of their body travels in the bloodstream to reach their brain and spinal cord.
It is extremely important to discuss about meningitis because of the high rate of mortality and morbidity associated with it. Meningitis is associated with the same germs that cause bacterial sepsis, with Group B Streptococcus and E. coli accounting for approximately 70% of all cases in the first week of life.
The symptoms of meningitis in a neonate are usually not related to the nervous system/brain, and they frequently present with fever or low body temperature, apneas (stopping their breathing) , breathing difficulty, low blood pressure, difficulty in feeding or skin rash (bleeding spots underneath the skin called petechiae or viral exanthem). Occasionally a focus of infection like a furuncle or redness of the umbilical cord can be seen.
The most alarming symptoms related to brain in a newborn are again nonspecific, and can be manifested in the form of lethargy and irritability or excessive crying. Abnormal body posture like arching of the neck, deviation of the head towards one side, stiffness of limbs can be seen. Seizures develop at some time in nearly 50% of cases. But unlike in adults, babies might have subtle seizures manifested in the form of repetitive blinking of eyes, lip smacking, sucking movements, cycling like movement of limbs or staring episodes. Some normal newborn activities like jitteriness can be stopped after restraining the jittery limb, whereas, a seizure cannot be restrained and will be rhythmic in nature. Any abnormal activity associated with a change in baby’s colour to pale, blue or mottled, is most likely to be a seizure. A bulging or full anterior fontanelle (the soft yielding spot on the top of the head) is seen later in the course of the disease.
The gold standard for diagnosis of meningitis is the analysis of the fluid which circulates around the brain and spinal cord, called as the Cerebrospinal fluid (CSF). Examination of CSF is necessary to determine the infecting organism and the duration of antibiotic therapy. CSF is obtained by a procedure called as Lumbar Puncture(LP). In this procedure a specialised needle is inserted into the space created between the vertebral bones. The sample of CSF is obtained for investigation and the needle is withdrawn after that. Baby may need sedation during the procedure and it is always performed under cardio-respiratory monitoring. Along with blood investigations namely, the white blood cell (WBC) count and markers of infection like the C reactive protein (CRP) or the procalcitonin, a diagnosis of sepsis with meningitis is usually evident. In a few cases, a repeat CSF examination is done after initiation of antibiotic therapy, especially if the baby has not responded clinically and is experiencing seizures or continued fever.
Infants with bacterial meningitis are usually very sick and should be monitored in neonatal intensive care units. Accurate fluid management with necessary respiratory and hemodynamic support can be provided in the NICU. In general, approximately 2-3 days are required for an antibiotic therapy to clear the CSF in infants with meningitis. It is therefore essential to obtain a CSF sample ideally before starting the baby on antibiotics. Occasionally a peripherally inserted central venous catheter (PICC) is inserted if a prolonged antibiotic therapy is expected. Ultrasound of the brain and frequently an MRI should be considered to exclude the complications of meningitis.
Complications from neonatal meningitis include brain abscess (localised collection of pus), hydrocephalus (excessive collection of CSF under pressure), subdural effusions (collection of fluid-frequently infected, in between the meninges), ventriculitis (infection of the CSF filled cavities of brain), visual and hearing impairment. Head circumference is measured weekly to identify rapid enlargement of ventricles in hydrocephalus. Severe cases of meningitis can also result in decrease in the volume of brain tissue (cerebral atrophy). The best way to avoid complications is a complete and effective antibiotic therapy.
Meningitis due to viruses are caused by herpes simplex, varicella, mumps and non-polio enteroviruses. Herpes simplex is also associated with encephalitis (inflammation of brain tissue). It is treated with an antiviral agent called Acyclovir, and the duration of therapy is 14 days. Viral meningitis are usually self-resolving in 7-10 days, but may still make the baby very sick, requiring intensive care. Meningitis due to fungal invasion is usually an extension of a soft tissue fungal infection in the head and neck area, and is less common compared to bacterial meningitis.
In general, the severity of complications is related to the severity of the disease. Regular follow up for neurodevelopment, language, hearing and visual assessment is essential. Approximately 40%–50% of survivors have some evidence of neurologic damage. Early initiation of physiotherapy, speech therapy and occupational therapy with devices to aid vision and hearing help improve overall neurodevelopmental outcome.
Meningitis may not be entirely preventable in the neonatal population. But, early diagnosis and prompt treatment results in near normal outcome.
Best practices in neonatal care and evidence based medicine is our best bet!
Namrata Todurkar, MBBS, MD (Pediatrics), DNB (Pediatrics). Fellowship in Neonatology from National Neonatology Forum India. Fellow in Neonatal-Perinatal Medicine in University of British Columbia. Areas of interest: Neonatal nutrition, Fluid and Electrolyte Management, Inborn Errors, Neurodevelopmental followup of preterm infants. Dr. Todurkar is a volunteer blogger at CPBF.