Unexplained Critical Illnesses and Deaths of Possible Infectious Etiology (UNEX) and Medical Examiner Infectious Deaths Surveillance (MED-X), 2017
MDH conducts surveillance for unexplained deaths and critical illnesses in an effort to identify those that may have an infectious etiology. This surveillance is performed through two complementary surveillance systems, Unexplained Critical Illnesses and Deaths of Possible Infectious Etiology (known as UNEX), and Medical Examiner (ME) Infectious Deaths Surveillance (known as MED-X) which is not limited to deaths with infectious hallmarks. Focus is given to cases
<50 years of age with no significant underlying conditions; however, any case should be reported regardless of the patient’s age or underlying medical conditions to determine if further testing conducted or facilitated by MDH may be indicated. Testing of pre- mortem and post-mortem specimens is conducted at the PHL and the CDC Infectious Diseases Pathology Branch (IDPB).
In 2017, 80 cases met UNEX criteria (69 deaths, 11 critical illnesses), compared to 97 cases in 2016. Of the 80, 51 (64%) were reported by providers, 28 (35%) were found by death certificate review, and 1 (1%) was discovered by public health investigation. Forty- one (51%) cases presented with respiratory symptoms, 20 (25%) with sudden unexpected death, 8 (10%) with neurologic symptoms, 3 (4%) with shock/sepsis, 4 (5%) with cardiac symptoms, 1 (1%) with gastrointestinal illness, and 3 (4%) with multiple symptoms. The age of cases ranged from newborn to 70 years. The median age was 15 years among 52 reported cases, and 44.5 years among 28 non-reported cases found through active surveillance. Fifty-four percent resided in the metropolitan area and 50% were female.
There were 257 MED-X cases in 2016; 69 of these also met UNEX criteria. The median age of the cases was 48 years, and 55% were male. There were 180 (70%) cases found through death certificate review; MEs reported 75 (29%) cases. The most common syndrome was pneumonia/upper respiratory infection (106 [41%]).
There were 148 potential UNEX or MED-X cases that had specimens tested at the PHL and/or the IDPB. Thirty-three cases had pathogens identified as confirmed, probable, or possible cause of illness, including 29 UNEX deaths (Table 5). Thirty-four were determined to be non-infectious. Among 38 unexplained deaths occurring in those <50 years of age without any immunocompromising conditions, UNEX helped to identify the pathogen(s) involved in 13 (34%) cases. MED-X surveillance detected an additional 53 cases with pathogens identified by MEs as the cause of death (Table 5). Cases with pathogens of public health importance detected included a 59 year-old male who presented to the emergency room with acute respiratory distress syndrome and rhabdomyolysis. PHL testing detected Legionella spp. by PCR leading to a public health investigation. UNEX laboratory testing detected Capnocytophaga canimorsus infection in a whole blood sample from a 60 year-old male who had traveled to Minnesota for a conference, succumbed to sepsis-like syndrome, but the family declined autopsy.
Further investigation determined the man had a splenectomy from an earlier accident, and also was a dog owner. Finally, UNEX surveillance was able to diagnose a case of La Crosse encephalitis in a 14 year-old female. A public health investigation found that she lived near a private property with large numbers of used tires that were collecting rainwater.
- For up to date information see>> Unexplained Deaths and Critical Illnesses
- Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2017