Epidemiologic profile of health care workers (HCW) with pandemic influenza A H1N1 infection

Background: As of October, 9, 17.219 cases of laboratory-confirmed H1N1 infection (2009-flu), with 1.369 deaths were reported in Brazil and our hospital was reference for severe cases.
Objective: Compare characteristics of HCW with confirmed 2009-flu with those of influenza-like illness by other causes.

Methods: We performed interviewed HCW who had influenza-like symptoms and were tested for 2009-flu infection, from July through September.
Influenza-like illness was defined as ≥ 38°C or cough or sore throat. Confirmed 2009-flu cases were defined as a HCW with influenza-like illness and who had a laboratory-confirmed pandemic H1N1 virus infection by RT-PCR.We described clinical findings, potential exposures at work, in the community and outcomes. We compared cases in which 2009-flu was confirmed with those negative.

Results: 916 HWC received sick-leave due to flu-like illness; 249 were tested, of which 84 (34%) were interviewed. Their characteristics are in Table.
Four of 34 2009- flu cases were hospitalized and 2 died. Among 50 negative cases, 2 were hospitalized and none died.
Conclusions: Fever was more frequent among 2009-flu infected HCW.
Sore throat and coryza were more frequent in 2009 flu-negative HCW.
Activities and profession were not associated with 2009-flu.
Seasonal flu vaccination coverage was low (55%) and was not protective.
Nosocomial and community contact with 2009-flu cases was frequent but not associated with 2009-flu.

	2009 flu (n=34)		2009 flu negative (n=50)	RR (95%IC)	p
Median Age  (range)	39 (24-57)		32 (21-67)		.15
Male	12		12	1.37 (.81-2.30)	.26
Profession
Physician	12		10		.30
Nurse	2		8
Assistant Nurse	12		20
Others	8		12
Workplace
Emergency Room	7		13	.79 (.35-1.78)	.57
ICU	4		12	.42 (.10-1.62)	.16
Ward	12		9	1.96 (.93-4.41)	.07
Other	11		16	1.01 (.54-1.90)	.97
Activities
Patient assistance	28		41	1 (.82-1.23)	.97
Administrative	3		6	.74 (.20-2.74)	.64
Other	3		3	1.52 (.22-1.25)	.69
Clinical Characteristics of disease
Cough	31	42		1.56 (.58-4.24)	.34
Fever	29	31		2.13 (.97-4.80)	.04
Myalgia	24	33		1.13 (.64-2.02)	.66
Coryza	19	42		.48 (.30-.77)	.004
Dyspnea	16	21		1.13 (.67-1.90)	.65
Arthralgia	13	19		1 (.59-1.71)	.98
Headache	11	23		.70 (.39-1.24)	.21
Sore throat	15	37		.49 (.29-.81)	.005
Diarrhea	10	12		1.17 (.67-2.1)	.58
Conjunctivitis	3	1		1.94 (1.03-3.63)	.15
Others	0	4
Underlying medical conditions-any	14	28		.74 (.46-1.18)	.18
Heart failure	2	3		1.33 (.25-7.08)	.74
Hemoglobinopathy	0	1
Smoke	3	1		9 (.68-52.57)	.06
Pulmonary disease	1	5		.40 (.05-3.1)	.35
Diabetes mellitus	0	1
Pregnancy	0	2
Arterial hypertension	3	5		1.20 (.33-4.31)	.78
Obesity	3	4		1.50 (.39-5.8)	.56
Others	2	6		.67 (.15-2.89)	.58
Use of oseltamivir	27/32(84)	40/49		1.13 (.53-2.41)	.75
2008 flu vaccine	19/32	26/50		1.20 (.69-2.09)	.51
Contact with H1N1-suspected case	18/34	30/50		.84 (.5-1.14)	.52
Contact with 2009flu  case	20/34	30/50		.75 (.45-1.26)	.29
Contact with 2009flu at home	11/33	13/50		1.23 (.71-2.12)	.47
Contact with 2009-flu in the community	15/33	26/50		.85 (.50-1.46)	.56