Dental student are at a much greater risk of being exposed to methicillin-resistant Staphylococcus aureus (MRSA), the potentially lethal bacteria often found in hospitals and now increasingly in the general community. Known as one of the superbugs due to its ability to resist multiple antibiotics, the mortality rate for a MRSA bloodstream infection is about 20-30%.1 The findings of a recently published study in The Journal of Hospital Infection entitled “Higher prevalence of methicillin-resistant Staphylococcus aureus among dental students” http://www.journalofhospitalinfection.com/article/S0195-6701(14)00009-7/abstract lead to the inevitable conclusion that greater consideration for infection control and prevention is needed for both dental clinicians and their patients.
The study undertaken in Mexico City comparing 100 dental students (exposed to patients for 5-6 years) with 81 non-dental students found that the dental students had a significantly higher rate of carriage of MRSA. The study found that 20% of the dental students versus 6% of non-dental students were colonized with MRSA (odds ratio: 4.04; 95% confidence interval: 1.6–12.6; P = 0.0033). The conclusion of the study is that the dental students were occupationally threatened by exposure to this highly antibiotic resistant pathogen with implications that greater steps are needed to try to address this potential risk to their health. The other worrisome implication of this study is that these dental clinicians are also likely to be vectors for MRSA transmission to their patients if the proper precautions are not undertaken.
A key observation from this Mexican study underscores how widespread MRSA is in Mexico. If our data is to be trusted, North American and UK rates of MRSA colonization are significantly lower than in Mexico…. 2-3% versus the 6% found in the study’s non-dental student population. People colonized with MRSA are at a greater risk of self-infection, especially when immunocompromised as in the case of a surgery or major illness. 20-60% of patients identified as being colonized with MRSA in hospital subsequently develop an MRSA infection 2
Until recently, most antibiotics in Mexico were available over the counter and not by prescription. The ability of patients to self-prescribe (not matching the appropriate antibiotic to the prevailing infection) combined with standard non-compliance practices (taking sub-lethal doses) led to the emergence of high antibiotic resistance rates as evidenced by the finding of this study. Fortunately, there are greater controls over how antibiotics are now dispensed in Mexico which should help to lower antibiotic resistance rates in the Mexican public in the future. A reduction of the overuse and abuse of antibiotics in Mexico should, in the future, contribute to lowering the risk of MRSA colonization in the dental clinician population. In the meantime, however, the results of this study are shocking and must be taken as sign that more must be done to protect the dental clinician and their patients from this potentially deadly superbug.