Unexplained Critical Illnesses and Deaths of Possible Infectious Etiology, 2016: DCN - Minnesota Dept. of Health

Unexplained Critical Illnesses and Deaths of Possible Infectious Etiology (UNEX) and Medical Examiner Infectious Deaths Surveillance (MED-X), 2016

Surveillance for unexplained critical illnesses and deaths of possible infectious etiology (UNEX) began September 1995. 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. In addition to provider reporting, death certificates are reviewed for any deaths in persons <50 years of age with no apparent significant underlying conditions for possible unexplained infectious syndromes.

In 2006, MDH began Medical Examiner (ME) Infectious Deaths Surveillance (known as MED-X) to evaluate all ME cases for infectious-related deaths. MEs report explained and unexplained cases. Unexplained deaths in previously healthy individuals <50 years of age are included regardless of infectious hallmarks; this is predominantly represented by Sudden Unexplained Infant Deaths. In addition, MDH reviews death certificates, in which an autopsy was performed by an ME, with a potential infectious cause of death listed. Cases found through death certificate review are also considered for UNEX surveillance if they are <50 years of age and have no immunocompromising conditions. Testing of pre-mortem and postmortem specimens is conducted at the PHL and the CDC Infectious Diseases Pathology Branch (IDPB). Cases are excluded from UNEX if they are determined to be explained by providers, are not critically ill, or have no infectious disease hallmarks.

In 2016, 97 cases met UNEX criteria (73 deaths, 24 critical illnesses), compared to 87 cases in 2015. Of the 97, 73 (75%) were reported by providers, 23 (24%) were found by death certificate review, and 1 (1%) was discovered by public health investigation of a related UNEX case. Thirty-nine (40%) cases presented with respiratory symptoms, 25 (26%) with sudden unexpected death, 19 (20%) with neurologic symptoms, 6 (6%) with shock/sepsis, 4 (4%) with cardiac symptoms, 2 (2%) with gastrointestinal illness, and 2 (2%) with multiple symptoms. The age of cases ranged from newborn to 73 years. The median age was 12 years among 73 reported cases, and 50 years among 23 non-reported cases found through active surveillance. Sixty-one percent resided in the metropolitan area, and 52% were female.

There were 218 MED-X cases in 2016; 73 of these also met UNEX criteria. The median age of the cases was 47.5 years, and 56% were male. There were 137 (63%) cases found through death certificate review; MEs reported 81 (37%) cases. The most common syndrome was pneumonia/upper respiratory infection (n=87 [40%]). Of the 218 cases, 68 (31%) were confirmed to have had an infectious cause, 143 (66%) had possible infectious causes, and 7 (3%) were non-infectious or unknown cause.

There were 163 cases that had specimens tested at PHL and/or IDPB. Forty-three cases had pathogens identified as confirmed, probable, or possible cause of illness, including 41 UNEX cases (Table 5). Among 47 unexplained deaths occurring in those <50 years of age without any immunocompromising conditions, UNEX helped to identify the pathogen(s) involved in 20 (43%) cases. ME surveillance detected an additional 39 cases with pathogens identified by MEs as the cause of death (Table 5). Cases with pathogens of public health importance detected included a 32-week gestation female who died hours after birth. The neonate was noted to have hydrops fetalis at birth, and placental pathology revealed acute chorioamnionitis and funisitis. CDC laboratory testing detected Treponema pallidum subsp. Pallidum from multiple tissues collected at autopsy. This case represents the first congenital syphilis death in Minnesota in over 25 years. UNEX laboratory testing detected Leptospira spp. infection in a 12 year-old male who presented with Bell’s palsy. A public health investigation was initiated, and the family dog was found to be recently infected with Leptospira spp. Finally, UNEX surveillance was able to diagnose a case of influenza A H1N1 in an 18 year-old female whose family refused autopsy based on religious grounds. Based on this diagnosis, the UNEX team was able to assist diagnosing a hospitalized family member with an influenza A H1N1/ MSSA coinfection.

UNEX/MEDX Pathogens Identified as confirmed, probable, or possible cause of illness

Updated Tuesday, 28-May-2019 08:26:39 CDT