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Table 2 Bacterial co-infection among hospitalised cases of A(H1N1)2009pdm with confirmed pneumonia (n = 11)

From: The role of pneumonia and secondary bacterial infection in fatal and serious outcomes of pandemic influenza a(H1N1)pdm09

Author and year Study type Study population Case severity Antivirals*
n/N (%) any
n/N (%) 48 h
Antibiotics†
n/N (%) pre
n/N (%) on
n/N (%) during admission
Any positive bacterial growth n/N (%) S.pneumoniae
[Site of isolation]
N (%)pneumonia
Method
Diff/no diff
ICU Mechanical Ventilation Deaths
Perez-Padilla (2009) [23]
Mexico
3/09–4/09
Single-centre case series (retrospective medical record review) of patients admitted to hospital with pneumonia and A(H1N1)pdm09 (N = 18) N = 18 12/18 (66.7) 12/18 (66.7) 7/18 (38.9) 14/18 (77.7) 12/18 pre (66.7)
17/18 post (94.4)
0/6 (0) BC
0/2 (0) BA
0/1 (0) pleural fluid
4/18 (22.2) Ventilator Associated pneumonia
0/18 [NR]
NP swab and bronchial aspirates
18 (100)
CXR
No diff
Chien (2010) [3]
Taiwan
07/09–8/09
Nation-wide notified cases (retrospective medical record review)
New pulmonary infiltrates consistent with pneumonia, compatible clinical presentations.
Identification of clinicalyl significant bacteria in respiratory secretion or specimens from sterile compartments was recorded as secondary bacterial infection.
N = 96 35/96 (36.5) NR 10/96 (10.4) 96/96 (100.0)
- NR
NR 13/96 (13.2) pulmonary NFI (13.5) 2/99 (2) [Respiratory secretions] 13 (13.5)
CXR positive
Champunot (2010) [53]
Thailand
7/09–10/09
Single-centre case series (prospective);
Community acquired, new pulmonary infiltrate (CXR) within 24 h of admission, clinical symptoms
N = 24 13/24 (54.2) 11/24 (45.8) 5/24 (8.3) 24/24 (100%)
- NR
21/24 (87.5)
- Pre = 6
Blood culture 0/24 (0)
Sputum culture 2/24(8.3)
1/24 (4.2) [urine pneumococcal Ag
TOTAL 3/24 (12.5)
1/24 (4.2) [urine pneumococcal Ag] 24 (100.0)
CXR
No diff
Cui (2010) [24]
China
11/09–12/09
Single-centre case series (retrospective medical record review) of patients admitted to a tertiary hospital with pneumonia and H1N1(N = 68)
Blood cultures (BC) - Any patient with high fever > 38.0 °C for ≥3 days or repeated fever.
Sputum cultures (SC) - patients with symptoms of expectoration especially with yellowish/purulent sputum.
N = 68 30/68 (44) 13/68 (19.1) 10/68 (14.7) 68/68 (100.0)
50/68 (74%)
All received antibiotics
65/68 (95.6) received preadmission antibiotics
5/11 (45.5) [BC]
9/29 (31.0) [SC]
Total 11/29 (37.9)
0/11 (0.0) [BC]
0/29 (0.0) [SC]
68/68 (100.0)
CXR
No diff
Cuquemelle [54]
(2011)
France
11/09–4/10
Multicenter (24) case series (retrospective)/ not having received prior antibiotics (N = 103)
Microbiological investigations and biomarker levels were obtained as part of the routine clinical management of patients, at the discretion of the treating physician
N = 103 103/103 (100) 62/103 (60.2) 18/103 (17.5) NR 0/103 (0) 48/103 (46.6)
Isolation of bacteria
26/103 (25.2) [NS] Infiltrates on all CXR
Choi [55] Definition: the presence of an infiltrate on plain chest radiograph. N = 17 17/17 (100)
All in acute care unit
1/17 (5.9) 1/17 (5.9) 17/17 (100) 17/17 (100) 0/17 (0) BC
0/17 (0) SC
2/17 (11.8) urine Ag test (Legionella)
1/17 (5.9) PCR (TB)
0/17 (100)
Testing for S. pneumo
16/17 (94.1)
CXR
No diff
Viasus [56] Pneumonia was defined as the presence of a new infiltrate on a chest radiograph plus fever (temperature 38.0-C) and/or respiratory symptoms N = 234 (210 tested for microbiologic studies) 53/234 (22.6) 42/234 (17.9) 12/234 (5.1) 229/234 (97.9)
50/234 (22.4)
228/234 (97.9) 36/210 (17.1)
Specimens included: culture of blood, normally sterile fluids, or sputum and/or a positive urinary antigen test
26/210 (12.4) All CXR positive
Piacentini [57] Compares H1N1 with pneumonia in ICU and community acquired N = 10 10/10 (100) 5/10 (50) 0/10 (0) 10/10 (100) 10/10 (100) 2/10 (20.0)
Pre-treatment BC, SC, and urinary Ag for S. pneumoniae and Legionella sp.
2/10 (20)
Specimen type NR
CXR positive (multilobar infiltrates) all except 2 (single lobe infiltrates)
Mulrennan [58] New pulmonary infiltrates on imaging + clinical symptoms
Compared with non-pneumonia H1N1
N = 35 11/35 (31.4) 10/35 (28.6) 2/35 (5.7) 35/35 (100) NR 5/35 (14.3)
NP, lower resp. tarct
NR 35/35 (100)
CXR
no diff
Ugarte (2010) [25]
Chile
5/09–9/09
Adults
Multicenter (11) case series (retrospective) / adult ICU admissions
Definition: positive culture from a sterile site (e.g. blood) and/or lower respiratory tract specimens, or seroconversion to atypical bacterial pathogens. LRT specimens included expectorated sputum, ET aspirated sputum and BAL
N = 75 75/75 (100.0)) 56/75 (74.7)
-
19/75 (25.3) NR NR 7/75 (9.3)
Specimens NR
4/75 (5.3) on admission. Site NR
1/5 (20) empyema patients BC
74 (98.7)
CXR
No diff
Busi [4]   N = 40 NR NR 1/40 (2.5) NR NR 0/40 (0) Specimen NR   40/40 (100) 40 had findings consistent with pneumonia. These 28/40 (70 bilaterial) Non-Diff
  1. Antibiotics: time started – “Pre” = started prior admission, “On” = started on admission, “During” = started during admission
  2. Diff Differentiated between bacterial pneumonia, viral pneumonia and ARDS;
  3. No diff Did not differentiate between aetiology of abnormal chest imaging, NR not reported