| Viruses | Other |
| Herpes simplex virus 1,2 | Mycobacteria |
| Enteroviruses | Listeria |
| Varicella Zoster | Syphilis |
| Arboviruses | Leptospira |
| HIV | Toxoplasma |
| Epstein–Barr Virus | Fungi for example, Cryptococcus |
| Mumps | Carcinomatosis |
| Measles | |
| Lymphocytic choriomeningitis virus | |
| Adenovirus | Partially treated bacterial meningitis |
| Cytomegalovirus | |
| Influenza A,B | |
| Parainfluenza | |
| Rubella |