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Table 1 Bacterial co-infection among the fatal cases of A(H1N1)2009pdm (n = 11)

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

Author (year)
Study location/ period
Study type Study population N (%) autopsied N (%) hospitalised prior to death Requirement for Antiviralsa
n/N (%) any n/N (%) 48 h
Antibioticsb
n/N (%) pre n/N (%) on
n/N (%) during admission
Positive bacterial growth N (%) bacterial pneumonia N (%) with S.pneumoniae
Site of isolation
ICU Mechanical Ventilation
Fajardo-Dolci (2009) [14]
Mexico
16/3/09–16/5/09
Medical record review N = 100
Consecutive notified hospitalized fatal cases
0/100 (0) 100/100 (100) NR 84/100 (84.0) 56/100 (56)
NR
94/100 (94) 2/100 (2%)
(Site not mentioned)
77/82 (94.0)
CXR suggestive of pneumonia.
NR
Lee (2010) [1]
USA
4/09–7/09
Enhanced surveillance/confirmed cases in New York City. N = 47 31/47 (66) 47/47 (100.0) All 28 cases who died after > 24 in hospital were admitted to ICU 25/47 (80.6) 32/47 (68.0)
NR
NR NR 13/47 (27.6)
By immunohistochemical analysis or PCR
21/28 with abnormal CXR and multilobar infiltrates.
8/47 (17.0) Lung/airway tissue
By immunohistochemical analysis or PCR
Lucas (2010) [19]
UK
4/09–1/10
Case series.
15% of reported H1N1 deaths
N = 68
Autopsied fatal cases
68/68 (100) 68/68 (100) NR NR NR NR 20/68 (29.4)
(Culture of lung/ blood)
28/68 (41.2)
- Autopsy findings
- Culture and histopathology
7/68 (10.3)
(6 confirmed and 1 possible through histology) isolation site Lung/ and or blood
Gill (2010) [2]
USA
5/09–7/09
Case series.
Autopsy request New York City (NYC) Office of chief medical examiner (n = 32), family requests (n = 10), deaths outside of NYC (n = 2)
N = 34
Autopsied fatal cases
34/34 (100) 21/34 (61.8) NR 12/21 (57.1) NR NR 10/30 (33.3) Positive bacteria by culture, immunohistochemistry, and/or PCR 18/33 (54.4) have evidence of bacterial co-infection by tissue Gram stain. 6/30 (20) Positive for streptococcus by culture, immunohistochemistry, and/or PCR
16/33 (55) have evidence of bacterial co-infection by tissue Gram stain morphologically compatible with streptococcus.
CDC (2009) [15]
USA
4/09–8/09
Multicenter case series.
100% of reported deaths
N = 36
Pediatric (< 18 yrs).
Hospitalized fatal cases
NR 28/33 (84.8) 24/36 (66.7) NR 19/30 (63.3)
Status unknown for 6 cases
4/30 (13%)
NR NR 10/23 (43.5)
Based on culture and pathology results
3/23 (13) from multiple sites in px (BC, lung tissue, pleural fluid, CSF)
Shieh (2010) [18]
USA
5/09–10/09
Notified fatal case series/US CDC N = 100
Autopsied fatal cases
100/100 (100) 58/87 (66.7) NR 42/57 (73.7) 44/67 (65.7)
NR
NR NR 29/100 (29)
Bacterial co-infection positive through PCR and histopathology on lung tissue
38/64 (59) radiological diagnosis of pneumonia
10/100 (10)
Lung tissue through PCR
CDC (2009) [16]
USA
5/09–8/09
Case series (US CDC), multiple (8) states N = 77
Autopsied fatal cases
77/77 (100) 8/18 (44.0) NR 7/7 (100.0) NR 7/9 (77.8) NR 22/77 (28.6)
Histopathology and positive PCR for bacteria
10/77 (positive through immunohistochemical assays) respiratory tissue
Mauad (2010) [17]
Brazil
7/09–8/09
Case series N = 21
Autopsied fatal cases
21 (100) 21 (100.0) 16/21 (76.2) 21/21 (100.0) 16/21 (76.2)
NR
13/21 (61.9) 3/9 (33.3) 8/21 (38.1) 6/21 (28.6) diagnosed by culture of bronchial aspirate and/or tissue PCR
Kim (2011) [20]
Korea
8/09–11/09
Active mortality inpatient surveillance N = 115
Notified hospitalized fatal cases
0/115 (0) 115/115 (100%) 63/115 (54.8) NR 100/115 (87%)
41/115 (35.6)
NR 34/115 (29.6) positive on blood or sputum culture 34/115 (29.6) positive on blood or sputum culture
97/113 (85.8)
CXR suggestive of pneumonia
3/115 (2.6) bronchoalveolar lavage (BAL)
Streptococcus was also isolated from blood of one case
Nakajima (2012) [21]
Japan
8/09–2/10
Multicenter (15), case series, Tokyo. N = 20
Autopsied fatal cases
20/20 (100) 11/20 (55.0) NR 7/20 (35.0) 14/20 (70%)
13/20 (65%)
10/20 (50%) 4/11 (36.4%) 5/20 (25%) Based on histopathological finding (bacteria isolated in 4 of 5) 2/10 (20%)
sputum, blood cultures; lung tissue
Tamme (2012) [22]
Estonia
10/09–5/10
Case series N = 21
Autopsied fatal cases
19/21 (90) 17/21 (81.0) 15/21(71.4) NR 3/21 (14.3)
1/21 (4.8%)
16/21 (76.2) 8/21 (38.1)
(Culture performed on 14 samples)
9/21 (42.8)
Culture or Autopsy findings consistent with sepsis or bacterial infection
2/21 (9.5)
Blood and/or lung tissue culture
  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
  4. aNumber (percentage) of cases on antivirals; N (%) started within 48 h of symptom onset
  5. bNumber (percentage) of cases on antibiotics commencing pre-admission, on admission or during admission (if reported)