Differential Diagnosis for a 3-day-old Boy with Seizure and Meningitis
- Single most likely diagnosis:
- E) Streptococcus agalactiae (group B): This is the most likely causal organism given the patient's age, symptoms, and laboratory results. Group B streptococcus is a common cause of neonatal meningitis, particularly in the first week of life. The presence of gram-positive cocci in the cerebrospinal fluid (CSF) and the clinical presentation of seizures, lethargy, and poor feeding are consistent with this diagnosis.
- Other Likely diagnoses:
- D) Neisseria meningitidis: Although less common in neonates, Neisseria meningitidis can cause meningitis in this age group. However, the gram stain showing gram-positive cocci makes this diagnosis less likely.
- C) Haemophilus influenzae: This organism can cause meningitis in young children, but it is typically seen in older infants and children, and the gram stain would show gram-negative coccobacilli.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- D) Neisseria meningitidis: As mentioned earlier, although less likely, Neisseria meningitidis can cause severe and rapidly progressive meningitis, making it a "do not miss" diagnosis.
- C) Haemophilus influenzae: Similarly, Haemophilus influenzae type b (Hib) can cause severe meningitis, and although the age and gram stain make it less likely, it should not be entirely ruled out without further testing.
- Rare diagnoses:
- A) Borrelia burgdorferi: This is the causative agent of Lyme disease, which is unlikely to cause meningitis in a 3-day-old neonate.
- B) Cytomegalovirus: Although CMV can cause congenital infection, it typically presents with different symptoms, such as hepatosplenomegaly, jaundice, and petechiae, rather than acute meningitis.
- F) Streptococcus pneumoniae: This organism can cause meningitis, but it is less common in neonates, and the clinical presentation and gram stain would be more consistent with other diagnoses.
- G) Varicella-zoster virus: This virus can cause congenital varicella syndrome, but it is rare and would not typically present with acute meningitis in the first week of life.