Tularemia, 2017

Tularemia is an acute illness caused by Francisella tularensis subspecies tularensis (type A) or holarctica (type B). Routes of transmission include arthropod bites (particularly ticks and deer flies), contact with infected animals, and exposure to contaminated water or soil. There are six main clinical forms of disease and all include fever: ulceroglandular, glandular, pneumonic, oropharyngeal, oculoglandular, and typhoidal.

In 2017, 6 tularemia cases were reported; 4 were culture-confirmed cases, 2 were probable cases. Four cases had ulceroglandular, 1 had glandular, and 1 case had pneumonic tularemia. Two cases had type B tularemia, 2 had type A tularemia, and 2 were diagnosed by serology only and had an unidentified subtype. The median age of cases was 37.5 years (range, 6 to 79); 4 were female. Five cases were hospitalized, and all survived. Four cases likely acquired tularemia from a tick or deerfly bite, 1 from a cat bite, and 1 acquired tularemia by inhaling the bacteria, likely while mowing his lawn. This is the greatest number cases reported in one year since 1953 when there were also 6 cases reported.

From 2007 to 2017, 16 tularemia cases were reported, with a range of 0 to 6 cases annually. Ten cases had ulceroglandular, 3 had glandular, 2 had typhoidal, and 1 had pneumonic tularemia. Eight of 12 cases with a known tularemia subtype had type B, and 4 had type A. The median age of cases was 42.5 years (range, 2 to 87). Ten cases were most likely exposed through a tick or biting fly bite, 2 cases through water exposures, 2 cases through a cat scratch or bite, 1 case was exposed by inhaling the bacteria, and 1 case’s exposure could not be determined. Twelve of 14 cases for which race was known were white, 1 was black, and 1 was American Indian/ Alaska Native.

• For up to date information see>> Tularemia
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2017