Meningitis in Children: Bacterial vs. Viral, Suspected Bacterial

00:00 So sometimes though patients come in and they have signs of meningitis and they get a tap and they have white blood cells but they actually just have a virus. This is really common in the fall and winter months when we see outbreaks of enterovirus throughout the United States. So in Boston, a doctor named Lise Nigrovic put together a set of rules that are very effective at allowing us to rule out meningitis immediately when we first evaluate the child. This is fantastic because it means in most children we can send them home from the emergency room with a bad headache knowing it's just viral disease and it will get better rather than needing to admit these patients to the wards and give them antibiotics. Let me specify, this rule does not apply to your neonates. To those kids under 8 weeks of age we should not be using these rules. These rules are really for older children. So what are they? If all of these are true, you do not have bacterial meningitis. I, you should not have seized. No seizures allowed. II, your CSF protein should be less than 80. III, your CSF absolute neutrophil count should be less than 1000. Your CSF absolute neutrophil count is calculated just like your serum neutrophil count. It's the number of cells times the percentage of bands plus segs. Your total blood neutrophil count should be less than 10,000 and your gram stain should be negative. If all of these things are true, you may presume that this patient has viral meningitis and not bacterial meningitis and the prognosis is outstanding without any treatment. There is one other thing or a few other things that we want to consider. The first is Lyme disease. There are some areas in the United States like the northeast and the east coast really that are more endemic to Lyme disease. In patients with Lyme disease that absolutely presents with headache and those patients absolutely get meningitis particularly in the early stages of disease. If a patient has had 7 days of headache or their 7th cranial nerve is abnormal or they have more than 70% monos in their spinal fluid, that's a sign this is probably Lyme disease not another cause and you should treat them accordingly. If the enterovirus PCR is positive especially in the fall and winter months, you really don't need to worry about bacterial disease and you can stop the antibiotics. Keep in mind while enterovirus is a benign illness in most people, in small babies they can be very sick and they may even die.

02:57 We've seen that before. Keep in mind for patients with tuberculosis that you may need to do extra testing. I've seen a few cases of TB meningitis and these kids can be particularly sick and very challenging to treat. If you suspect TB meningitis, we'll usually get an acid-fast bacilli stain on the CSF and we may test them with an interferon gold test. In patients who might have HSV in their early childhood for example or in older children with oral lesions, we will suspect they might have encephalitis. This is not just a pure meningitis. The infants are usually sick, they might have seizures and hypothermia and irritability and older patients will generally manifest with full-fledged encephalitis. They may have a meningitis component but think about HSV in patients with encephalitis. It may be you need more testing in immunocompromised children or in patients where there are signs of encephalitis or signs of focal disease. These are exceptions that we have to consider when we might have to ramp up our testing. If you suspect bacterial disease, you want to admit infants who you believe might have bacterial meningitis. If you've proven that it's not bacterial meningitis, you can presume it's viral and send them home. We're going to _____ this differently depending on the age of the child and we discussed this a little bit in our febrile infant talk as well. In neonates, we're going to treat with ampicillin and either gentamicin or ceftazidime and we're going to sometimes give them acyclovir if we're concerned about HSV meningitis.

04:45 We'll do a rule out sepsis for 24 to 36 hours and once they're negative they can probably go home we'll presume it's viral. If a patient has evidence of meningitis on exam and has CSF pleocytosis between 4 and 8 weeks of age, we're going to start ampicillin and ceftriaxone and we're going to rule that patient out by watching them until the CSF culture is negative. In older children, we'll often use vancomycin and ceftriaxone. The reason for this is Strep pneumoniae becomes slightly more common and because these children are so remarkably sick, we have to make sure we're treating every path of possible bacteria and so those few Streptococcus that are resistant to ampicillin will be treated effectively with vancomycin.

05:32 Some recommend vancomycin even earlier than 8 weeks in some patients, especially if resistant pneumococcus is prevalent in the community.

05:41 Another trick about treating patients with meningitis is they may have SIADH, so they may develop hyponatremia and we need to be careful with their hydration status. Additionally, there is some evidence that patients with Neisseria meningitidis may respond to steroids. That evidence hasn't held out for other infections like Strep pneumo and so it's somewhat controversial whether to give steroids or not. That's something you should discuss with your infectious disease's team.

06:13 Generally, the way we're going to treat bacterial meningitis in children is we're going to provide IV antibiotics until the lumbar puncture repeat culture is negative. This usually requires multiple weeks of antibiotics. For Strep pneumoniae we'll treat for 2 weeks, for Neisseria meningitidis we can treat for 1 week and for HIB we treat for 10 days. So it varies depending on the nature of the illness. Little infants often get 2 to 3 weeks of therapy. After therapy is done, it's indicated to check for hearing in infants. This is because deafness is strongly associated with infectious meningitis. Early intervention is indicated after treatment because even in children who are effectively treated, they may result in some learning deficits or cerebral palsy or a long-term problem and that may not be noted immediately after therapy, it may show up over time. So early intervention is key. We have to get them plugged in and followed and intervened with early so they can have a better outcome. These patients in general with bacterial meningitis have a variable prognosis, from a normal outcome to severe MR or possibly even death in 5 to 10%.

07:29 Remember, sensorineural hearing loss is common, happens in almost a third of patients. Likewise, another potential side effects is hydrocephalus. These patients may have a problem with drainage of the CSF out of their ventricular collecting system and they may end up needing a VP shunt.

07:47 Patients may develop vascular infarcts of the brain and have deficits as a result. For example, they may present with hemiparesis afterwards. This isn't that uncommon. So in summary, we're going to treat this disease effectively and quickly and as rapidly as we can and as thorough as we can but then we need long term to be watching out for the development, their healing and they need to get the intervention that will help them develop and grow. So that's my summary of Meningitis in Children. Thanks for your time.