In June 2007, the Healthcare Infection Control Practices Advisory Committee (HICPAC) recommended for the first time that surgical masks be worn by spinal procedure operators to prevent infections associated with these procedures. HICPAC made the recommendation in response to several reports of meningitis following myelography procedures. In September 2008, three bacterial meningitis cases in postpartum women were reported to the New York State Department of Health (NYSDOH); in May 2009, two similar cases were reported to the Ohio Department of Health. All five women had received intrapartum spinal anesthesia. Four were confirmed to have Streptococcus salivarius meningitis, and one woman subsequently died. This report summarizes the investigations of these five cases, which determined that the New York cases were associated with one anesthesiologist and the Ohio cases were associated with a second anesthesiologist. In Ohio, the anesthesiologist did not wear a mask; wearing a mask might have prevented the infections. The findings underscore the need to follow established infection-control recommendations during spinal procedures, including the use of a mask and adherence to aseptic technique.