San Francisco Lab Worker Dies of Lab-acquired Meningococcus

There is a very sad report in today's San Jose Mercury News concerning a 25-year old associate at the San Francisco VA Medical Center's Northern California Institute for Research and Education (NCIRE) who'd been working on a vaccine for Neisseria meningitidis, serogroup B. The lab work is very important, since vaccines for most of the other major disease-causing serogroups (C, Y, W135, and A) have been developed and licensed in the US.

He apparently left work Friday evening without symptoms but two hours later felt feverish with a headache. By Saturday morning he had a rash and arrested in the car ride to the hospital. California-OSHA and CDC are investigating the case and have already confirmed that the strain he was infected with was the same serogroup B strain that the lab was studying.

Unfortunately, lab-acquired infections do occur with some frequency. The most memorable case for me was the report of a grad student in Singapore that was working on West Nile Virus yet became infected with SARS-CoV that had somehow contaminated his West Nile samples.

A few years ago (2009), Kamaljit Singh published a very nice review in CID covering microbiology lab-acquired infections.  Most of the data included in the review are old, with the included frequency data from 1976 and 1978.  However, I've pasted table 2 below, which highlights the relative risk of specific infections in lab workers compared to the general public.  After Brucella, N. meningitidis appears to be the second highest risk with a RR=40.8. The review also discusses the 16 cases reported between 1985 and 2001 and highlights the importance of tetravalent vaccine for all laboratory microbiologists. Sadly, that wouldn't have helped in this case.

Addendum: Updated report from SF Chronicle this morning (May 3) and local ABC affiliate report.  Name released and investigation uncovers lack of vaccination among workers (KQED). note: vaccination would have been ineffective in this case.

Occupational transmission of meningococcal disease

This week's MMWR has a report on transmission of meningococcal disease from an infected patient to a police officer who responded to the patient's home and a respiratory therapist who cared for the patient in the Emergency Department. Neither of the secondary cases were offered postexposure prophylaxis. CDC recommends prophylaxis for HCWs with direct exposure to the patient's oral secretions (e.g., performacne of endotracheal intubation). In this case the police officer was not evaluated for prophylaxis because of a delay in contact tracing. However, the MMWR report admits that if the CDC recommendations were followed the police officer may have not been offerred prophylaxis. What's surprising is that CDC didn't revise the recommendation. Given the severity of meningococcal disease I think we need to be more flexible than CDC's recommendation. We offer prophylaxis to any unprotected HCW within 3 feet of the patient.

Wear a mask when performing lumbar punctures!

An Ohio newspaper reports that two women developed meningitis recently due to Streptococcus salivarius after undergoing spinal anesthesia by the same anesthesiologist. It was noted that the anesthesiologist did not wear a mask during the procedures. One of the women died. Such cases have been increasingly recognized over the last several years, and occur when the saliva of a healthcare worker performing a lumbar puncture for diagnostic or therapeutic purposes contaminates the spinal needle which is in direct communication with the CSF. This can easily occur if the operator is talking when performing the procedure. For this reason, CDC specifically recommended that masks be worn during such procedures in its latest guideline on isolation precautions (p. 69 of this document).