Table 3.

Summary of previous rickettsial infection cases, Ontario, Canada (2013–2018)

Variable	Spotted fever group rickettsiae	Typhus group rickettsiae	Unspecified Rickettsia infection
Total cases, n	183	89	308
Female, n (%)	93 (50.8)	47 (52.8)	157 (50.9)
Age, mean ± SE (range)	41.3 ± 1.37 (3–87)	44.9 ± 2.11 (2–85)	43.8 ± 1.08 (<  1–89)
IFA IgG titer, n
1:64	154	75	n/a
1:128	22	6	n/a
1:256	7	8	n/a
IFA SFGR/TGR IgG titers (URI)
1:64/1:64	n/a	n/a	154
1:64/1:128	n/a	n/a	9
1:64/1:256	n/a	n/a	1
1:128/1:64	n/a	n/a	42
1:128/1:128	n/a	n/a	50
1:128/1:256	n/a	n/a	8
1:256/1:64	n/a	n/a	6
1:256/1:128	n/a	n/a	12
1:256/1:256	n/a	n/a	25
1:512/1:512	n/a	n/a	1
Year of onset, n
2013	9	12	19
2014	6	19	22
2015	10	20	33
2016	12	20	36
2017	45	14	92
2018	101	4	106
Signs and symptoms, n (%)a
None reported	123 (65.1)	65 (73.0)	199 (64.6)
Headache	30 (46.2)	5 (20.8)	53 (39.8)
Fatigue	19 (29.2)	4 (16.7)	33 (24.8)
Arthralgia/arthritis	8 (12.3)	1 (4.2)	7 (5.3)
Fever	7 (10.8)	6 (25.0)	16 (12.0)
Gastrointestinal complaints	6 (9.2)	2 (8.3)	5 (3.8)
Tick bite	4 (6.2)	1 (4.2)	5 (3.8)
Rash (not described)	2 (3.1)	1 (4.2)	6 (4.5)
Respiratory complaints	1 (1.5)	5 (20.8)	8 (6.0)
Elevated liver enzymes	1 (1.5)	0 (0.0)	0 (0.0)
Dizziness	1 (1.5)	0 (0.0)	0 (0.0)
Anemia	1 (1.5)	0 (0.0)	0 (0.0)
Anxiety	1 (1.5)	0 (0.0)	0 (0.0)
Encephalitis/meningitis	1 (1.5)	2 (8.3)	2 (1.5)
Myalgia/body aches	1 (1.5)	0 (0.0)	3 (2.3)
Rash (vesicular)	1 (1.5)	1 (4.2)	2 (1.5)
Rash (maculopapular)	1 (1.5)	3 (12.5)	2 (1.5)
Jaundice	1 (1.5)	0 (0.0)	1 (0.8)
Malaise/unwell	0 (0.0)	0 (0.0)	4 (3.0)
Chills	0 (0.0)	0 (0.0)	1 (0.8)

Abbreviations: IFA immunofluorescent assay, n/a not applicable, SFGR spotted fever group rickettsiae, TGR typhus group rickettsiae

^a Cases reporting at least one sign or symptom: SFGR, n = 60; TGR, n = 24; URI, n = 109. Some cases have > 1 sign or symptom. Denominator is based on number of cases with at least one sign or symptom reported on the requisition