Table 2.
Investigations and laboratory results on diagnosis among children and adults with NJI in Iceland, 2003–2017
| Children <2 years | 2–18 years | Total | Adults 18–65 years | >65 years | Total | P value | |
| No of cases | 19 | 21 | 40 | 149 | 110 | 259 | |
| Admission data: | |||||||
| Temperature (median, °C) | 38 | 38 | 38 | 37.7 | 37.6 | 37.7 | 0.02 |
| WCC (median, x109/L) | 13.2 | 10.9 | 11.4 | 9.9 | 11.6 | 10.5 | 0.4 |
| ESR (median, mm/hour) | 34 | 35 | 35 | 54 | 71 | 57 | 0.006 |
| CRP (median, mg/L) | 49 | 48 | 49 | 123 | 180 | 148 | <0.001 |
| Synovial fluid WCC (median, x106)* | 86 675 | 31 075 | 31 075 | 50 400 | 69 000 | 58 794 | 0.3 |
| Positive blood culture† | 3/16 (19) | 7/15 (47) | 10/31 (32) | 32/100 (32) | 42/79 (53) | 74/179 (41) | 0.4 |
| Crystal arthropathy¶ | – | – | – | 5/60 (8) | 22/63 (35) | 27/123 (22) | – |
| Normal admission values:‡ | |||||||
| Temperature <37.8°C | 6/19 (32) | 8/21 (38) | 14/40 (35) | 78/141 (55) | 59/102 (58) | 137/246 (56) | 0.02 |
| WCC <10.5×109/L | 6/19 (32) | 10/21 (48) | 16/40 (40) | 84/143 (59) | 41/109 (38) | 125/252 (50) | 0.3 |
| CRP <10 mg/L | 2/19 (10.5) | 4/21 (19) | 6/40 (15) | 4/143 (3) | 6/107 (6) | 10/250 (4) | 0.01 |
| ESR <20 mm/hour | 1/10 (10) | 1/7 (14) | 2/17 (12) | 11/70 (16) | 7/49 (14) | 18/119 (15) | 1 |
| Other infective syndromes: | |||||||
| Adjacent osteomyelitis | 3/19 (16) | 9/21 (43) | 12/40 (30) | 16/149 (11) | 13/110 (12) | 29/259 (11) | 0.005 |
| Endocarditis | 0 | 0 | 0 | 3/149 (2) | 4/110 (4) | 7/259 (3) | – |
| Cellulitis | 0 | 0 | 0 | 3/149 (2) | 3/110 (3) | 6/259 (2) | – |
| Other§ | 0 | 0 | 0 | 3/149 (2) | 5/110 (5) | 8/259 (3) | – |
Data are no/no (%).
P value, children vs adults.
P values <0.05 are shown in bold.
*Information on number of WCC in the synovial fluid obtained was found in 171 adult cases and 12 paediatric cases.
†Information on blood culture (whether taken, positive or negative) was found in: all paediatric cases, 141 cases in age group 18–65 years and 103 cases >65 years. Blood culture was performed in 16/19 <2 years, 15/21 cases 2–18 years, 100/149 cases 18–65 years and 79/110 >65 years.
‡Information on (A) temperature was found in: all paediatric cases, 144/149 cases 18–65 years and 102/110 >65 years. (B) WCC: all paediatric cases, 143/149 cases 18–65 years and 109/110 >65 years. (C) CRP: all paediatric cases, 143/149 cases 18–65 years, 107/110 >65 years. (D) ESR: 10/19 cases <2 years, 7/21 cases 2–18 years, 70/149 cases 18–65 years and 49/110 >65 years.
§Pneumonia 5 (all patients were >65 years), urinary tract infection 2, streptococcal toxic shock syndrome one patient.
¶Information on concurrent crystal arthropathy in adults was found in: 60/149 cases 18–65 and 63/110 >65 years.
CRP, C reactive protein; ESR, erythrocyte sedimentation rate; NJI, native joint infection; WCC, white cell count.