Table 1. The main characteristics of the study groups.

	Community-acquired pneumonia		Severe acute symptoms		Patients with underlying conditions for severe influenza		P
	n = 240		n = 647		n = 352
	moy±DS		moy±DS		moy±DS
	n	%	n	%	n	%
Risk factors for severe influenza infection
Age	68.5±18.7		70.6±18.5		55±21.1		0.002
Age ≥65 years	153	63.8	444	68.6	127	36.1	0.00001
Asthma	44	18.7	259	40.6	38	11.2	0.00001
Bronchopulmonary dysplasia	5	2.1	20	3.1	1	0.3	0.01
Cystic fibrosis	23	9.8	34	5.3	13	3.9	0.009
Chronic respiratory failure	19	8.1	94	14.8	10	3	0.000001
Cardiac failure	27	11.5	126	19.8	20	5.9	0.000001
Cardiac valvulopathy	9	3.8	31	4.9	4	1.2	0.01
Congenital heart disease	3	1.3	14	2.2	4	1.2	0.4
Cardiovascular disease	14	6	57	9	10	3	0.002
Renal failure	21	8.9	68	10.7	19	5.6	0.03
Nephrotic syndrome	1	0.4	1	0.2	4	1.2	0.09%
Sickle-cell anemia	0	0	1	0.2	3	0,9	0.1
Hepatic failure	1	0.4	3	0.5	0	0	0.5
Diabetes	37	15.7	123	19.3	43	12.7	0.03
Systemic corticosteroid therapy	14	6	43	6.8	18	5.3	0.7
Leukemia or Lymphoma	6	2.6	5	0.8	2	0.6	0.05
Immunosuppression	14	6	24	3.8	18	5.3	0.3
Cancer	11	4.7	31	4.9	11	3.3	0.5
HIV infection	10	4.3	14	2.2	11	3.3	0.2
CD4 count	196±347		145±174		15–19		0.4
Obesity	11	4.70%	44	6.9	9	2.7	0.02
Pregnancy	1	0.4	6	0,9	4	1.2	0.6
At least one of the above	177	75.3	640	52.7	339	27.9	0.00001
Signs of severity
Polypnea	34	14.17%	124	12.41%	0	0	0.5
Cyanosis	5	2.08%	28	2.80%	0	0	0.0002
Oxygen saturation Spa02 < 95%	108	45.00%	416	41.64%	0	0	0.00001
Pneumonia	118	49.2	167	25.8	0	0	0.00001
Wheeze	52	21.67%	259	25,93%	0	0	0.0001
Tachycardia	35	14.58%	120	12.01%	0	0	0.000001
Hypotension	17	7.08%	45	4.50%	0	0	0.000001
Areas of mottled skin	9	3.75%	42	4.20%	0	0	0.000001
Discomfort	10	4.17%	39	3.90%	0	0	0.00002
Changes in mental status	12	5%	37	3.70%	0	0	0.00004
Oliguria	2	0.83%	5	0.50%	0	0	0.2
At least one of the above	177	73.8%	591	59.2%	0	0	0.00001