Unexplained Critical Illnesses and Deaths of Possible Infectious Etiology, 2002
Surveillance for unexplained critical illnesses and deaths of possible infectious etiology in Minnesota began in September 1995 as part of the EIP. MDH requests that any case of unexplained critical illness or death that appears to have a possibly infectious cause be reported, regardless of the patient's age or underlying medical conditions. A subset of reported cases (i.e., persons 6 months to 49 years of age with no serious underlying medical conditions who died of apparent non-nosocomial infectious processes) are eligible for testing performed at CDC as part of the core surveillance project. For cases who are not eligible for enrollment in the CDC project, some testing may be available at CDC and MDH, at the physician's request.
Forty possible cases were reported to MDH in 2002, compared to 35 cases in 2001. The cause(s) of illness subsequently were determined for 14 cases. One death remains unexplained, but there was no clear evidence to suggest an infectious cause. Among the remaining 25 cases, eight case patients presented with respiratory symptoms, eight with neurologic symptoms, five with shock/sepsis, and two each with cardiac symptoms and sudden unexpected death. The respiratory cases ranged from 2 to 51 years of age; the neurologic cases were 7 to 57 years of age; the sepsis cases were 8 to 53 years of age; the cardiac cases were 16 and 42 years of age; and the sudden unexpected deaths occurred in a 2-year-old and a 20-year-old. Four patients with respiratory symptoms and two patients with neurologic syndromes died. Four patients with sepsis and both cardiac case-patients died. Five each of the respiratory case-patients and neurologic case-patients, four sepsis case patients, and both cardiac case patients resided in the seven-county Twin Cities metropolitan area. The remaining case-patients resided in Greater Minnesota, except for two neurologic cases, who were out-of-state residents hospitalized in Minnesota.
Three sepsis cases, three respiratory cases, one neurologic case, one cardiac case, and both sudden unexpected deaths were eligible for inclusion in the CDC project. Specimens have been sent to CDC for testing for all cases, except for the cardiac case and one of the sudden unexpected deaths, which still are under investigation. An etiology was identified for all three respiratory cases and one sudden unexpected death based on the finding of Streptococcus pneumoniae in lung tissue from each of the case-patients by using immunohistochemical methods. Preliminary tests have not revealed an etiology for the remaining unexplained cases.