The intersection of the national opioid epidemic and infection control has reached some strange and critical crossroads, from drug-diverting healthcare workers infecting patients to addicted admissions infecting themselves by injecting through their IV lines. Now, we have another twist: the distinct possibility that infectious diseases could be masking some of the national death toll of opioids.
Victoria Hall, MD, a CDC epidemic intelligence officer at the Minnesota Department of Health, described her findings recently in Atlanta at the annual EIS conference.
“In early spring, we were notified of an unexplained death — a middle-aged man who died suddenly at home,” she says. “Two days prior, he had seemed ill to his family, but he didn’t want to go to the hospital. He was also slurring his words some. He was on long-term opioid therapy for some back pain and his family was a little bit concerned that he was abusing his medication.”
On autopsy, however, the medical examiner listed the cause of death as pneumonia, and it was subsequently referred to the health department’s unexplained deaths group.
“Further testing diagnosed an influenza pneumonia, but also detected a toxic level of opioids in his system,” Hall says. “[Again], on the death certificate, it only listed pneumonia and listed no mention of opioids. So this death wasn’t counted in the state opioid surveillance death system.”
The case was detected because of the Minnesota Department of Health’s Unexplained Deaths and Critical Illness of Possible Infectious Etiology (UNEX), which has conducted surveillance since 1995.
“This was started by CDC in many states,” she says. “Today, Minnesota is the only state that has maintained the program. It was developed to constantly be on the lookout for these new and emerging health threats, particularly infectious diseases. It takes cases that have no clear explanation for deaths and looks further into it. It helps facilitate more testing to try to find answers, and try to find any new diseases that might be emerging.”
What also is emerging is a national opioid epidemic that the CDC estimates causes some 90 overdoses every day. It turns out, that may be an underestimate.
The Nexus
“[UNEX] has also allowed us to look into the opioid epidemic from an infectious disease standpoint,” Hall says. “We know that deaths involving infectious diseases like pneumonia or endocarditis can be complicated if there are opioids in the system. Opioids at therapeutic or higher than therapeutic levels could impact the immune system. It actually makes your immune cells less effective at fighting off illness. They are also sedatives, so they have side effects such as a decrease in your breathing. [That] makes you less prone to cough, makes your breathing more shallow, and makes it easier for something like a pneumonia to really set in.”
Hall and co-investigators reviewed deaths detected through UNEX as well as opioid use during 2006–2015.1 Fifty-nine (3.5%) of 1,676 UNEX deaths had evidence of opioid use. Twenty-two deaths involved toxic opioid levels, but lacked correct ICD-10 codes to be reported by statewide opioid death surveillance. Thirty-two of 59 UNEX deaths with opioid use had pneumonia. A pathogen was identified in 20 (63%) pneumonia cases, including Streptococcus pneumoniae and Haemophilus influenza A. “There’s no national standardization for how to fill out a death certificate,” she says. “We found that if you have a really profound infectious disease, like really bad pneumonia, that may be the only thing written on the death certificate. It’s not going to be picked up in opioid surveillance, which is quite concerning because it means that the epidemic, which is already quite severe, could potentially be even worse.” Beyond the numbers, there may be other aspects of both opioids and infectious diseases that can be revealed by studying their nexus.
“We found a lot of suggestions of interactions between the two. Opioids may make you more prone to get infectious diseases, but if you have a really severe infectious disease, you are [also] more prone to opioid-related illness or deaths,” Hall says. “This is especially true in pneumonia cases where even at normally prescribed and at overdosed levels, opioids seem to be playing a big role in illness. Understanding how opioid use and the infectious diseases like pneumonia interact with each other might better inform our future guidance for clinicians. So we can handle these cases while people are still alive and not catch them through a system like ours.”
REFERENCE
- Hall V, Lynfield R, Wright N, et al. Deaths Associated with Opioid Use and Possible Infectious Disease Etiologies Among Persons in the Unexplained Death (UNEX) Surveillance System — Minnesota, 2006–2015. CDC EIS Conference. Atlanta, April 24-27, 2017.
