On June 8, 2018, the CDC published a report that found that people who inject drugs were more than 16 times more likely to develop invasive methicillin-resistant Staphylococcus aureus (MRSA) infections than others. Between 2011 and 2016, the proportion of invasive MRSA cases that occurred among people who inject drugs increased from 4.1 percent to 9.2 percent.
MRSA is a bacteria that is resistant to many antibiotics. MRSA can cause a variety of problems including skin infections, sepsis, pneumonia, and bloodstream infections. While primarily diagnosed in healthcare settings, community-acquired MRSA has increased, in part, due to the increase in IV drug use.
Scientists have found that the opioid epidemic has had significant effects on health in the United States. In the United States, age-adjusted opioid overdose death rates increased by more than 200 percent between 1999 and 2015. Heroin overdose death rates increased nearly 300 percent between 2011 and 2015. In the two years between 2011 and 2013, the rate of heroin use within the past year among U.S. residents 12 years old and older increased 62.5 percent overall and 114.3 percent among non-Hispanic whites, compared with the two years between 2002 and 2004. Increases in human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections related to increases in injection drug use have been recently highlighted. Likewise, invasive bacterial infections, including endocarditis, osteomyelitis, and skin and soft tissue infections, have increased in areas where the opioid epidemic is expanding.
To assess the effects of the opioid epidemic on invasive MRSA infections, CDC investigators analyzed surveillance data. Their analysis found that people who inject drugs were estimated to be 16.3 times more likely to develop invasive MRSA infections than others. Infection types were frequently those associated with nonsterile injection drug use. Continued increases in nonsterile injection drug use are likely to result in increases in invasive MRSA infections, underscoring the importance of public health measures to curb the opioid epidemic.
In the six sites assessed, invasive MRSA infections disproportionately affected people who inject drugs. Among 39,050 invasive MRSA cases reported from six sites between 2005 and 2016, a total of 2,093 (5.4 percent) occurred in people who injected drugs. The estimated rate of invasive MRSA among people 13 years old and older who injected drugs in the previous year was 472.2 per 100,000 in 2011, and the estimated rate among people 13 years old and older who did not inject drugs in the previous year was 29.0 per 100,000. Clinical diagnoses frequently associated with injection drug use were more common among patients with invasive MRSA who injected drugs than among those who did not, including septic embolism, endocarditis, abscess (skin and internal), cellulitis, and osteomyelitis.
A decline and subsequent rise in the proportion of invasive MRSA cases among people who inject drugs was observed in the six-site catchment area between 2005 and 2016 and in two additional sites for which data were available through 2014. The proportion of invasive MRSA cases that occurred among people who inject drugs approximately doubled in some sites (counties in Connecticut, Georgia, Minnesota, and Tennessee) after 2011. In the six-site catchment area, the percentage of invasive MRSA cases among people who inject drugs declined from 6.4 percent in 2005 to 3.5 percent in 2010, but subsequently increased steadily to 9.2 percent in 2016. In two of three sites (Colorado and Oregon) that reported data from 2005 to 2014 only, similar increases in the proportion of invasive MRSA cases that occurred among people who inject drugs after an initial decrease (2005: 11.1 percent of cases; 2011: 10.6 percent; 2014: 15.2 percent) were observed. Similar patterns were seen in the incidence of acute HCV and in the rate of drug overdose deaths involving heroin, with notable increases in both beginning around 2010.
Demographic shifts in the population of invasive MRSA infections among injection drug users mirror those observed in the ongoing opioid epidemic, such as the increased proportion of cases among whites. Among invasive MRSA cases that occurred among people who inject drugs, cases between 2011 and 2016 were more likely to occur in people who were white and be community-associated than were cases between 2005 and 2010. Overall, cases of invasive MRSA among people who inject drugs were more likely to occur than cases among people who did not inject drugs in people who were younger and to be community-associated infections.
Although much attention has focused on the transmission of blood-borne pathogens such as HIV and hepatitis B and C viruses related to injection drug use, infections from skin flora such as Staphylococcus aureus are also important and might not be prevented solely by programs focused on preventing blood-borne pathogen transmission. Increases in nonsterile injection drug use are likely to result in increases in the occurrence of invasive MRSA infections among people who inject drugs, underscoring the importance of public health measures to curb the opioid epidemic. Effective interventions include primary prevention of opioid misuse through guideline-concordant opioid prescribing; treatment of opioid use disorder with medication-assisted therapies; community-based comprehensive syringe services programs that provide access to sterile equipment used to inject drugs and its safe disposal; and education on safer injection practices, wound care, and early warning signs of serious infections associated with injection drug use.
See the CDC Report
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See also Medical Risk Law Report: How Risky Is Going to the Hospital? The Dangers and Liabilities of Healthcare-Associated Infections
See also Medical Risk Law Report: Drugs, Dosage, and Damage: Physician Liability for Prescribing or Administering Medication
See the Medical Risk Law Blog: Pharmacy Owes Duty To Patient Not To Fill Excessive Prescriptions for Opioids