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IPs should enforce mask use during spinal shots
Fatal Ohio case underscores transmission risk
A fatal meningitis infection in a pregnant woman in Ohio has been linked to an anesthesiologist giving shots into the spine without wearing a surgical face mask, a breach of current infection prevention guidelines, the Centers for Disease Control and Prevention reports.1
Though transmission factors are not completely understood, the case appears to be another in which an asymptomatic health care worker transmits Streptococcus salivarius — a common oral bacterium — via droplets while administering an injection into the spine.
"This particular bacteria doesn't cause infections in the mouth — almost everyone carries it, and it doesn't cause us any problems," says Jonathan Duffy, MD, an investigator with the CDC's Epidemic Intelligence Service. "In that sense, the anesthesiologists are not infected, but [infection can occur] when it gets into some place where it is not supposed to be — like the spine."
The fatal infection in Ohio was actually part of a cluster, following close on the heels of another pregnant patient who survived an identical infection after being administered anesthesia by the same provider. The CDC also reported a cluster of three similar cases in New York in 2008, emphasizing that the reports indicate health care workers are not likely following current recommendations that include wearing face masks when performing such procedures.
Features common to all five cases included rapid onset (< 24 hours) of meningitis after anesthesia in previously healthy women and the association of each cluster with a single anesthesiologist who performed the procedures. In both clusters, S. salivarius most likely was transmitted directly from the anesthesiologist to the patients, either by droplet transmission directly from the oropharynx or contamination of sterile equipment, the CDC concluded. Droplet transmission of oral flora has been suggested as the most likely route of transmission in previous reports of clusters associated with a single health care provider.2,3 S. salivarius and other viridans group streptococci are the most commonly identified etiologies of meningitis after spinal procedures, accounting for 49% and 60% of cases in literature reviews.4
Although the occurrence of meningitis after spinal anesthesia is not new, the cases described occurred after the June 2007 release of recommendations for the prevention of such infections by the CDC's Healthcare Infection Control Practices Advisory Committee (HICPAC).5 In response to several reports of meningitis following myelography radiographic imaging procedures that involved injecting a contrast material into the spine, HICPAC recommended surgical masks for providers who were either placing a catheter or injecting material into the spinal canal or epidural space.
Facilities at which those procedures are performed should raise awareness of these recommendations among staff members and assess compliance with the recommendations by performing periodic audits, the CDC urged.
"This message is actually for any health care providers that are performing injections and procedures on the spine," Duffy says. "That includes people from other specialties such as neurology, radiology, surgeons, and internists — a whole spectrum of people who may be doing injection procedures. These [cases] were related to anesthesia for childbirth, but it could be anesthesia for surgical cases. These recommendations would apply to anyone who is inserting a needle into or near the spine."
Health care providers who perform spinal procedures should be familiar with and follow the recommendations for use of masks, proper aseptic technique, and safe injection practices. In addition to wearing masks, these practices include using new sterile needles and syringes when accessing multidose vials and using single-dose vials whenever possible. The current level of compliance with these recommendations is an open question.
"We don't have any national statistics or percentages of how many people wear masks when they do these procedures," Duffy concedes. "As these case reports highlight, in Ohio, the anesthesiologist was not wearing a mask for these procedures. Clearly, even though these guidelines are out there, some people may not be aware of them and, certainly, some people are not following the recommendations. People should be aware of and adhere to these recommendations."
No surveillance changes have been enacted, but the CDC emphasized that local and state health departments are in the best position to help health care facilities identify and investigate cases or clusters of health care-associated meningitis and ensure adherence to infection control recommendations.
"Our message to state health departments is that when they get reports of cases of meningitis with these organisms to be aware that it is a potential health care-associated infection and to pursue that line of investigation," Duffy says.
In Ohio in May 2009, a healthy woman, aged 26 (Patient D), was admitted to a hospital in active labor, the CDC reported. She received spinal anesthesia from Anesthesiologist B and delivered a healthy baby. Approximately 15 hours after receiving the spinal injection, Patient D experienced fever, nausea, and severe headache; a blood culture and diagnostic lumbar puncture were performed. The patient became lethargic and unresponsive and was airlifted to a tertiary care hospital approximately six hours after symptom onset. She subsequently recovered.
A second healthy woman aged 30 years (Patient E) was admitted to the same hospital in active labor three hours after Patient D. Patient E also received spinal anesthesia from Anesthesiologist B and delivered a healthy baby. Approximately 13 hours after receiving the spinal injection, Patient E experienced a severe headache, fever, confusion, and lethargy, and later became unresponsive. Blood cultures were drawn. Approximately six hours after symptom onset, she was airlifted to the same tertiary care hospital as Patient D; she died seven hours later. The cause of death was determined by autopsy to be suppurative meningoencephalitis caused by S. salivarius. Cerebrospinal fluid (CSF) was collected on autopsy. Blood and CSF cultures collected from both Patient D and Patient E revealed S. salivarius. Isolates from patients D and E were indistinguishable by pulsed-field gel electrophoresis (PFGE).
On the day after symptom onset in the two Ohio patients, the hospital, the local health department, the Ohio Department of Health, and the CDC initiated an investigation. Investigators cultured one opened anesthetic medication vial and three unopened vials, interviewed the hospital infection preventionist and medical director, and reviewed hospital intrapartum spinal anesthesia procedure protocols. Anesthesiologist B was found to be the only health care provider involved in the spinal procedures for both patients D and E. Because of initial concern that patients D and E potentially had meningococcal meningitis, Anesthesiologist B had been given ciprofloxacin as post-exposure prophylaxis approximately 12 hours after the patients' symptom onset. Cultures performed on swabs subsequently obtained from the oropharynx, buccal mucosa, and tongue of Anesthesiologist B resulted in no growth, but S. salivarius was identified using polymerase chain reaction (PCR) methods. However, a PFGE pattern could not be determined for the S. salivarius carried by the Ohio anesthesiologist because the bacteria were identified by PCR instead of culture.
Culture and PCR of the medication vials revealed no evidence of contamination. Interviews with staff members revealed that anesthesiologists at the hospital did not typically wear masks while performing bedside spinal procedures, despite a hospital policy requiring masks. In particular, Anesthesiologist B did not wear a mask while administering spinal anesthesia to patients D and E. With droplet transmission the most likely source, the hospital reinforced its policy requiring all staff members to use surgical masks when performing spinal anesthesia procedures. The clusters in Ohio in New York raise the question as to whether some providers are more likely than others to transmit infection.
"In these two clusters, there was a single health care provider that was associated with all of the different cases," Duffy says. "That leads us to believe that there is something that they do differently than their colleagues at the same institutions that may contribute to the infections. Some of these things might be 'operator-dependent,' in that some people work closer or farther way. Some people may talk more during the procedure. It has been noticed in previous reports that maybe someone who talks more is more likely to spread droplets during the procedures. There are all kinds of subtle factors."
The intrathecal space is entered during several diagnostic and therapeutic spinal procedures, including lumbar puncture, myelography, and spinal anesthesia, and can occur inadvertently during epidural anesthesia. Cases of meningitis have been reported after all of these procedures, although most published cases have involved spinal anesthesia. The actual incidence of meningitis after these procedures is not known.
"Meningitis cases that are due to these bacteria in our normal flora are not [routinely] reported to CDC, so CDC doesn't have specific numbers on how many cases might be occurring," Duffy says. "State health departments know more than we do; but as with any infections — as far as reporting goes — in general, we think that there fewer cases reported than actually occur."
In Sweden, one case of purulent meningitis occurred per 53,000 episodes of spinal anesthesia during 1990-1999.6 Post-spinal procedure meningitis causes serious infections; in one case series, one third of cases resulted in death.4