A Retrospective Forensic Review of Unexpected Infectious Deaths

Abstract

Background: There exists a knowledge gap in identifying the spectrum of infectious pathogens and syndromes that lead to fulminant decline and death. The aim of this study was to better characterize patient-, pathogen-, and disease-related factors in the phenomenon of unexpected infectious deaths.

Methods: We conducted a population-based, retrospective cohort study of all community-based, unexpected infectious deaths in Ontario, Canada between January 2016 and December 2017. Patient-related information, infection-related information, and circumstances around the death were extracted for each case to facilitate descriptive analyses.

Results: Of the 7506 unexpected deaths over the study period, 418 (6%) were due to infectious diseases. Bacterial pneumonia (43%) was the most common infectious syndrome, followed by disseminated infection with no clear focus (12%), peritonitis (10%), myocarditis (6%), and pyelonephritis (5%). A pathogen was identified in 210 cases (50%), with the most common being Staphylococcus aureus (n = 35), Streptococcus pneumoniae (n = 30), Streptococcus pyogenes (n = 25), Klebsiella spp. (n = 23), and Escherichia coli (n = 19). Prodromal symptoms were present in 68% of persons before death, with a median (interquartile range) duration of only 1.0 (0.0-4.0) days; just 30% of those who died had had recent healthcare contact before their death.

Conclusion: Infectious diseases have the capacity to cause fulminant decline and death. The most common cause of unexpected infectious death is bacterial pneumonia, with a predominance of gram-positive bacteria. Given the rapidity of these deaths, preventing a majority of them would require upstream strategies to reduce infection susceptibility and transmission.

Keywords: epidemiology; forensic; infectious diseases; sepsis; unexpected death.

Figure 1.

Cause of death by clinical syndrome and stratified by age group. Sample sizes for age groups are as follows: 0–20 years, n = 32; 21–40 years, n = 57; 41–60 years, n = 190; 61–80 years, n = 112; and ≥81 years, n = 27. Abbreviations: HIV, human immunodeficiency virus; SSTI, skin and soft-tissue infection.

Figure 2.

Prodrome length associated with 352 unexpected infectious deaths (length unknown in 66 deaths). Bar graphs represent number of deaths by length of prodrome; line graph, cumulative number of deaths.

Figure 3.

Time from the most recent healthcare contact, in days (n = 114, with the time frame unknown for 10 persons). The majority of deaths (291 of 418 [70%]) occurred in persons with no recent healthcare contact. (For the remaining 3 persons, it was unknown whether there was any healthcare contact, and they were excluded from this analysis.)