This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Trauma, Subject name: Surgery
Which of the following bacterial meningitis is associated with sudural effusion? 
Select and explain. 
A. H. influenza, B. Neisseria meningitits, C. Streptococcus pneumonia, D. Enterococcus
A: H. influenza
Answer: A: H. influenza 
Explanation: Chronic Subdural Empyema It may be primary infection of subdural space from sinusitis focus causing suppuration and pus formation. It can be complication of the chronic subdural haematoma. It is due to secondary bacterial infection of collected clot/fluid. Infection is from sinusitis scalp (common)/through earlier trauma wound/haematogenous. Commonly Gram positive organisms cause empyema like streptococci (viridans/milleri) but other virulent organisms like Gram negative bacteria (H.influenzae) occasionally can cause. There is coical venous thrombophlebitis and coical infarction. Headache, fever, meningism and convulsions are the features. MRI is ideal than CT to diagnose. Treatment: Antibiotics, craniotomy and drainage; anticonvulsants, ICU care, proper monitoring, regular follow up. Condition has got 10% moality. Ref: SRB's Manual of Surgery 5th edition Pgno : 1097