Table 2 Clinical description and antibiotic therapy of B. pertussis positive and negative index cases
From: Hospital-based prospective study of pertussis in infants and close contacts in Tehran, Iran
| Â | Â | N available | Total | B. pertussis cases | Negative cases | P valuea |
|---|---|---|---|---|---|---|
N = 199 | N = 40 | N = 159 | ||||
Cough duration at inclusion (days) | ||||||
| Â | median (IQR) | 199 | 8 (6-11) | 10 (7.5-19.5) | 8 (6-10) | 0.004 |
 ≥ 14 days | n (%) | 199 | 34 (17.1) | 15 (37.5) | 19 (12.0) | <0.001 |
Pertussis-like symptoms | ||||||
 Nocturnal cough | n (%) | 199 | 104 (52.3) | 22 (55.0) | 82 (51.6) | 0.698 |
 Coughing spells | n (%) | 199 | 163 (81.9) | 34 (85.0) | 129 (81.1) | 0.570 |
 Apnea | n (%) | 199 | 31 (15.6) | 9 (22.5) | 22 (13.8) | 0.177 |
 Cyanosis | n (%) | 199 | 130 (65.3) | 31 (77.5) | 99 (62.3) | 0.070 |
 Inspiratory whoop | n (%) | 199 | 32 (16.1) | 9 (22.5) | 23 (14.5) | 0.216 |
 Difficult breathing in | n (%) | 199 | 83 (41.7) | 17 (42.5) | 66 (41.5) | 0.910 |
 Vomiting | n (%) | 199 | 49 (24.6) | 10 (25.0) | 39 (24.5) | 0.951 |
 Post tussif vomiting | n (%) | 199 | 57 (28.6) | 16 (40.0) | 41 (25.8) | 0.076 |
 Good conditions btw cough | n (%) | 197 | 139 (70.6) | 24 (60.0) | 115 (73.3) | 0.101 |
 Abnormal pulm auscultation | n (%) | 193 | 26 (13.5) | 8 (21.1) | 18 (11.6) | 0.127 |
 >> sign of upper infection | n (%) | 23 | 14 (60.9) | 4 (50.0) | 10 (66.7) | 0.435 |
 >> sign of lower infection | n (%) | 9 (39.1) | 4 (50.0) | 5 (33.3) | ||
Temperature | ||||||
 ≤ 37.5 | n (%) | 199 | 190 (95.5) | 38 (95.0) | 152 (95.6) | 0.871 |
 37.5-38.5 | n (%) | 9 (4.5) | 2 (5.0) | 7 (4.4) | ||
Biological data | ||||||
 Leukocytes (/mm3) | median (IQR) | 191 | 10600 (8200-13200) | 12900 (10100-17300) | 9950 (7800-12400) | <0.001 |
 Lymphocytes (/mm3) | median (IQR) | 179 | 6640 (5150-9265) | 10080 (6020-14245) | 6438 (5073-8421) | <0.001 |
 Hyperlymphocytosis (> 9000/μl) | n (%) | 179 | 46 (25.7) | 19 (54.3) | 27 (18.8) | <0.001 |
 Neutrophiles (/mm3) | median (IQR) | 179 | 2772 (1900-4350) | 3290 (1800-4862) | 2662 (1944-4047) | 0.495 |
 Platelets (x103/mm3) | median (IQR) | 193 | 407 (304-506) | 474 (320-605) | 392 (297-485) | 0.040 |
 Hemoglobin (g/dl) | median (IQR) | 195 | 10.5 (9.8-11.5) | 11 (9.9-11.6) | 10.5 (9.7-11.5) | 0.415 |
 Mean corpuscular volume (MCV) (μ3) | median (IQR) | 194 | 87 (82-93) | 87 (81-93) | 87 (82.5-93) | 0.567 |
 SpO2 | median (IQR) | 196 | 95 (95-96) | 95 (95-96) | 95 (95-96) | 0.856 |
Birth and weight | ||||||
 Premature birth (< 37 weeks) | n (%) | 197 | 22 (11.2) | 2 (5.0) | 20 (12.7) | 0.165 |
 Low birth weight (< 2.5 kg) | n (%) | 198 | 22 (11.1) | 2 (5.0) | 20 (12.7) | 0.169 |
 Wasting | n (%) | 188 | 54 (28.7) | 13 (34.2) | 41 (27.3) | 0.403 |
 Stunting | n (%) | 196 | 23 (11.7) | 6 (15.0) | 17 (10.9) | 0.472 |
Antibiotic therapy before enrollment | ||||||
 Yes | n (%) | 188 | 120 (63.8) | 24 (63.2) | 96 (64.0) | 0.923 |
 Macrolides | n (%) |  | 82 (43.6) | 16 (42.1) | 66 (44.0) | 0.833 |
 >> for > 48h before sampling | n (%) | 82 | 37 (45.1) | 10 (62.5) | 27 (40.9) | 0.119 |
Last clinical evaluation | ||||||
 Time after inclusion (days) | median (IQR) | 195 | 14 (13-14) | 14 (13-14) | 14 (13-14) | 0.933 |
 Full recovery | n (%) | 195 | 164 (84.1) | 27 (67.5) | 137 (88.4) | 0.002 |
 Healing with persistent cough | n (%) | 195 | 27 (13.9) | 10 (25.0) | 17 (11.0) | - |
 No improvement | n (%) | 195 | 2 (1.0) | 2 (5.0) | 0 (0 | - |
Death | n (%) | 195 | 2 (1.0) | 1 (2.5) | 1 (0.7) | - |
Hospitalization | ||||||
 Yes | n (%) | 199 | 192 (96.5) | 39 (97.5) | 153 (96.2) | 0.696 |