Eight cases of meningitis after myelography were most likely explained by which route?

1. Blood or cerebrospinal fluid from all eight cases grew streptococcal species consistent with mouth and throat flora. 2. Equipment and products used during the procedures, including contrast media, were excluded as probable sources. 3. In the seven cases with procedural detail, antiseptic skin preparation and sterile gloves had been used. 4. Sterile gloves rule out the ungloved hands explanation. 5. None of the clinicians wore a face mask, which raised droplet spread of mouth and throat flora as the most likely explanation. 6. Nothing points to fungal spores from building work, which is a hazard for severely immunocompromised patients instead. _Source: CDC Guideline for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings (2007), Part III, section III.A.1.c. Infection Control Practices for Special Lumbar Puncture Procedures_