Many types of bacteria can cause purulent meningitis, with meningococcus being the most common, followed by pneumococcus and Haemophilus influenzae. Meningitis caused by these two bacteria is most frequently seen in infancy. Staphylococcus aureus-induced meningitis can occur at any age, often preceded by sepsis or a purulent focus before meningitis develops. Meningitis caused by Escherichia coli and Paracolobacterum is more common in newborns. Other less virulent bacteria, such as Proteus, Alcaligenes, Enterococcus, Listeria, Moraxella catarrhalis, and Streptococcus viridans, may occasionally cause meningitis in the neonatal period. Salmonella typhi can rarely cause meningitis during the septicemic phase, while Pseudomonas aeruginosa often infects through open craniocerebral trauma. Mixed infections caused by two different pathogens are more commonly observed in infants.

bubble_chart Clinical Manifestations

The onset is acute, occasionally with mild initial symptoms that develop into typical manifestations within 1–3 days. Symptoms include fever, vomiting, drowsiness, delirium, convulsions, unconsciousness, grayish complexion, fixed and vacant stare, hyperesthesia, dysphoria, restlessness, screaming, neck stiffness, head retraction, bulging or tense anterior fontanelle, and positive Kernig's and Brudzinski's signs. Children over 2 years old often complain of headaches, with more pronounced disturbances of consciousness. Dehydration and acidosis may also accompany the condition. During physical examination, attention should be paid to identifying potential sources of infection, such as pneumonia, otitis media, sinusitis, head trauma, skin abscesses, and septicemia.

1. Cerebrospinal fluid (CSF) examination: Lumbar puncture is of decisive significance for diagnosis (however, it is contraindicated if there is significantly increased intracranial pressure or abnormalities at the puncture site. In such cases, an intravenous dehydrating agent should first be administered once, followed by puncture with a finer needle without measuring pressure, and slowly releasing 1–2 ml of CSF). CSF smear for bacteria should be performed routinely, along with bacterial culture and drug sensitivity testing. In treated patients, cultures may be negative, but smears often still detect pathogens. The CSF appears turbid, with cell counts ranging from hundreds to tens of thousands, negative for sugar in the five-tube test, and strongly positive for protein. Rapid diagnostic methods for specific antigens can also be performed using CSF, such as counterimmunoelectrophoresis, latex agglutination tests, and immunofluorescence. CSF lactate dehydrogenase (LDH) and its isoenzymes are elevated; lactate >3.9 mmol/L, and C-reactive protein is positive.
2. Blood picture: Leukocytosis with increased neutrophils and a left shift.
3. Head CT scan: Acute patients do not require CT examination, but children suspected of complications such as subdural effusion or ventriculitis should undergo CT for timely management and follow-up.

bubble_chart Diagnosis

Early recognition of the symptoms and signs of purulent meningitis is crucial. When in doubt, a timely lumbar puncture should be performed for diagnosis to avoid delaying treatment, which could increase mortality or the risk of complications.

bubble_chart Treatment Measures

In addition to symptomatic treatment, active pathogen treatment should be carried out.

1. High-dose penicillin at 400,000–800,000 U/(kg·d), administered intravenously in 4–6 divided doses, with a total treatment course of 3–4 weeks.
2. Ampicillin at 150–300 mg/(kg·d), administered intravenously in 4–6 divided doses daily, with a total treatment course of 3–4 weeks.
3. Chloramphenicol at 60–100 mg/(kg·d), with a total dose not exceeding 2 g, administered intravenously in 3–4 divided doses daily, with a treatment course of 3–4 weeks.
4. Cephalosporins: cefuroxime or cefotaxime at 100–200 mg/(kg·d), administered intravenously in 2–4 divided doses daily; or ceftriaxone at 80 mg/(kg·d), administered intravenously once daily. The treatment course is 3–4 weeks.
5. Other options include methicillin at 150–300 mg/(kg·d), nafcillin at 100 mg/(kg·d), cephalosporin II at 50 mg/(kg·d), vancomycin at 40 mg/(kg·d), erythromycin at 30–50 mg/(kg·d), carbenicillin at 150–300 mg/(kg·d), and piperacillin at 100–200 mg/(kg·d), all administered intravenously. The treatment course is 3–4 weeks.

Treatment of complications:

1. For subdural effusion, perform daily or every-other-day punctures, with each local aspiration not exceeding 10–15 ml. If the effusion does not decrease after 2 weeks, perform subdural air contrast imaging and continuous drainage. If there is still no improvement, consider cyst stripping surgery.
2. For ventriculitis, administer antibacterial drugs via intraventricular injection. For patients with significantly increased intracranial pressure, controlled drainage of the lateral ventricle via ventricular puncture may be used.