The most likely diagnosis is Meningitis. ✔Causes: Group B Streptococcus Listeria monocytogenes Neisseria meningitidis H influenza Strep. pneumonia Coxsackievirus Fungi(immunocompromised individuals) ✔Signs and symptoms: It presents with: Headache Nuchal rigidity Fever Photophobia Vomiting Altered mental status Convulsions ✔Diagnosis: Lumbar puncture(CSF Sampling) ✔Complications: Death Hydrocephalus Hearing loss Seizures.