There is a paucity of data regarding the incidence of MDROs in bloodstream infections (BSIs) among spinal-cord injury (SCI) patients. People with SCI have an increased risk of infection and BSIs are more common in this population than non-SCI patients. They are frequently colonized with MDROS, which may be due to the large amounts of antibiotics they receive, as well as their prolonged hospitalizations.
Dinh et al,1 published the results of a 16-year retrospective study which examined the prevalence of MDRO BSIs in the SCI population, while comparing the characteristics of the MDRO population and the non-MDRO patients. The duration of the study was divided into 4-year periods: 1998-2001; 2002-2005; 2006-2009; and 2010-2013. The percentages of MDROs for each period were collected and compared with each other.
Demographics of the patients include:
- Median age = 50.84
- Sex ratio = 0.73 (male)
- 61% paraplegic and 39% tetraplegic
- Mean duration of SCI = 11.6 years
- Most common cause of SCI was mainly post-traumatic, including motor vehicle accidents, acts of violence, falls, and sporting accidents; multiple sclerosis, and infection
The study found 318 episodes of positive blood cultures among 256 patients; 78 instances were determined to be contaminants (single isolates of coagulase-negative Staphylococci, Corynebacteria, etc.) and not included. The primary sites of infection were due to UTI (34%) and pressure sores (25%), followed by catheter line-associated BSI, pulmonary infection, and osteoarticular infection. 351 organisms were isolated from the 318 positive blood cultures with Enterobacteriaceae being the most common pathogen, followed by S. aureus, P. aeruginosa, Streptococcus spp., and Enterococcus spp.
MDROs were isolated in 40.5% of BSIs but the striking result is that the proportion of MDROs over time was stable. Even though the MDROs over the 4 four-year groups were high, the incidence of non-MDRO, ESBL (Extended-spectrum Beta-lactamase) producers, MDRO, and MRSA (Methicillin-resistant Staph aureus) did not statistically change in 16 years.
The authors looked for a connection between the characteristics of infection and the presence of BSIs due to MDROs but no associated risk related to age, gender, duration of SCI, primary site of infection, or bacterial species was identified. This is one of the largest cohorts of SCI patients studied to date and the authors would like their findings confirmed by future prospective studies.
Are you surprised by the results? Did you think the incidence would likely increase in the later study years? Does your facility take care of chronic SCI patients, and have you had same experience? Has your MDRO BSI rates remained stable or deceased over time in this subset of chronically ill patients?
- A Dinh, M Saliba, D Saadeh, F Bouchand, A Descatha, A L Roux, B Davido, B Clair, P Denys, D Annane, C Perronne and L Bernard. Blood stream infections due to multidrug-resistant organisms among spinal cord-injured patients, epidemiology over 16 years and associated risks: a comparative study. Spinal Cord , (16 February 2016).