Table 2.

Clinical Characteristics and Symptoms of Illness Among Cases and Controls, Multistate Investigation of Influenza-Associated Parotitis, United States, 1 October 2014–31 March 2015

Characteristic	Cases (n = 50)		Controls (n = 124)		Odds Ratio [95% Confidence Interval]a	P Valuea
	Respondents	n (%)	Respondents	n (%)
Influenza-like illnessb	49	25 (51)	122	109 (89)	0.15 [0.06, 0.35]	<.001
Self-report of testing for influenza	45	30 (67)	124	123 (99)	0.003 [<0.001, 0.05]	<.001
Self-report of testing for strep throat	43	18 (42)	113	50 (44)	0.8 [0.3, 1.7]	.53
Self-reported symptoms
Fever/feverishc	49	32 (65)	122	115 (94)	0.1 [0.05, 0.4]	<.001
Chills	49	24 (49)	115	87 (76)	0.3 [0.2, 0.7]	.002
Muscle ache	47	18 (38)	119	83 (70)	0.3 [0.1, 0.6]	<.001
Headache	48	30 (63)	119	86 (72)	0.6 [0.3, 1.3]	.23
Cough	50	32 (64)	122	106 (87)	0.2 [0.1, 0.6]	.001
Wheezing	49	5 (10)	121	36 (30)	0.2 [0.07, 0.6]	.004
Shortness of breath	49	4 (8)	120	33 (28)	0.2 [0.05, 0.6]	.007
Sore throat/difficulty swallowing	49	27 (55)	121	79 (65)	0.6 [0.3, 1.2]	.17
Runny nose	46	23 (50)	121	75 (62)	0.6 [0.2, 1.2]	.12
Ear pain	48	19 (40)	119	26 (22)	2.3 [1.1, 4.8]	.03
Rash	49	5 (10)	122	10 (8)	0.9 [0.2, 3.4]	.87
Facial swelling	50	34 (68)	122	2 (2)	41.7 [10.0, 174.6]	<.001
Gland swelling	50	36 (72)	113	29 (26)	5.9 [2.7, 13.0]	<.001
Tongue swellingd	47	1 (2)	121	4 (3)	…	…
Discomfort with acidic foods	40	4 (10)	92	8 (9)	1.1 [0.2, 4.7]	.95

^aOdds ratios (ORs), 95% confidence intervals, and P values from conditional logistic regression. Reference group for OR is absence of symptom or condition.

^bInfluenza-like illness defined as fever (≥100^oF) or feeling feverish and cough and/or sore throat.

^cTemperature ≥100^oF or self-report of feeling feverish.

^dOR for frequency of tongue swelling in cases compared with controls could not be estimated from the model.