Which condition is characterized by fever, headache, stiff neck and is diagnosed by Gram stain and latex agglutination?

• A. Bacterial meningitis
• B. Viral meningitis
• C. Encephalitis
• D. Meningoencephalitis

Answer: (A)

Fever, headache, and neck stiffness are classic signs of meningitis, an inflammation of the protective membranes around the brain and spinal cord. When this clinical picture is confirmed with Gram stain showing bacteria in the cerebrospinal fluid and a positive latex agglutination test detecting bacterial antigens, it points to bacterial meningitis. The Gram stain provides a direct look at the bacteria present, while latex agglutination rapidly identifies common bacterial culprits (like Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae) by their capsule antigens, guiding urgent treatment. Viral meningitis typically lacks bacteria on Gram stain and would not rely on latex agglutination for diagnosis, and encephalitis or meningoencephalitis involve brain tissue differently and are not diagnosed primarily by these tests.