Meningitis Year 4 Paediatrics Notes OmpathStudy

Meningitis Year 4 · Paediatrics Collection: 4TH YEAR ALL NOTES / PAEDS / PAEDS 4.3 / Munge / CNS -- Slide 1 Meningitis Dr Rose Munge Slide 2 Introduction Infection of the central nervous system (CNS) is a significant cause of morbidity and mortality in children.\nIdentification of CNS infections can be problematic for clinicians because symptoms can be nonspecific in younger infants, and a delayed or missed diagnosis contributes to the morbidity and mortality rates associated with these diseases.\nImplementation of multiple conjugate vaccines has greatly reduced the incidence of bacterial infection of the CNS.\nViral infections remain a significant cause of CNS disease, with atypical bacterial, fungal, and parasitic pathogens also contributing to a smaller number of pediatric CNS infections. Slide 3 Patients with CNS infection have similar clinical manifestations.\nCommon symptoms include headache, nausea, vomiting, anorexia, photophobia, restlessness, altered state of consciousness, and irritability.\nCommon signs of CNS infection include fever, neck pain and rigidity, focal neurologic deficits, seizures, obtundation, and coma. Historically, infection of the CNS has been classified according to the affected tissue.\nMeningitis describes primary involvement of the meninges, whereas encephalitis indicates brain parenchymal involvement. These anatomic boundaries may be indistinct during infection, and patients may have evidence of both meningeal and parenchymal involvement. The diagnosis of CNS infection depends on a combination of imaging of the brain and testing the cerebrospinal fluid (CSF) by culture, PCR, and serologic methods. Slide 4 Acute Bacterial Meningitis Beyond the Neonatal Period Bacterial meningitis is one of the most serious pediatric infections and is associated with a high rate of acute complications and a risk of long-term morbidity and mortality.\nUse of antibiotics and vaccines against the most common causes of meningitis has significantly altered the spectrum of disease that clinicians observe today.\nThe most common causes of bacterial meningitis in children older than 1 mo of age are Haemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis.\nThe incidence of meningitis caused by all three organisms has been significantly reduced in countries that have introduced universal immunization against these pathogens. Slide 5 Epidemiology A major risk factor for bacterial meningitis is the lack of preexisting immunity to specific pathogens and serotypes.\nAdditional risk factors include recent colonization with pathogenic bacteria, close contact (household, daycare centers, college dormitories, military barracks) with individuals having invasive disease caused by N. meningitidis or H. influenzae type b, crowding, poverty, black or Native American race, and male sex.\nThe mode of transmission is through contact with respiratory tract secretions or droplets.\nThe risk of meningitis is increased among infants and young children with occult bacteremia. Slide 6 Defects of the complement system (C5-C8) are associated with recurrent meningococcal infection, and defects of the properdin system are associated with a significant risk of lethal meningococcal disease.\n Splenic dysfunction (e.g., in sickle cell anemia) or asplenia (caused by trauma or a congenital defect) is associated with an increased risk of pneumococcal, H. influenzae type b, and meningococcal sepsis and meningitis.\n T-lymphocyte defects (congenital or acquired by chemotherapy, AIDS, or malignancy) are associated with an increased risk of Listeria monocytogenes infections of the CNS. Slide 7 The risk of pneumococcal meningitis is increased in children with congenital or acquired CSF leak across a mucocutaneous barrier, such as a lumbar dural sinus, cranial or midline facial defects (cribriform plate), fistulas of the middle ear (stapedial foot plate) or inner ear (oval window, internal auditory canal, cochlear aqueduct), or CSF leakage as a result of basilar or other skull fracture. Lumbosacral dermal sinus and myelomeningocele are associated with staphylococcal, anaerobic, and Gram negative enteric bacterial meningitis.\n CSF shunt infections increase the risk of meningitis caused by Pseudomonas aeruginosa, Staphylococcus spp. (Staphylococcus aureus and coagulase-negative species), Propionibacterium spp., and other lower-virulence bacteria that typically colonize the skin. Slide 8 Streptococcus pneumoniae S. pneumoniae remains the most frequently identified pathogen of bacterial meningitis. A dramatic decrease in the rate of pneumococcal meningitis followed introduction of the 7 valent pneumococcal conjugate vaccine in the US and other countries that introduced this vaccine in 2000. However, an increased incidence of invasive disease caused by serotypes not contained in the original vaccine was observed, known as serotype replacement.\nAs a result, a 13-valent pneumococcal conjugate vaccine (PCV13) was intr