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Table 4 Reproduction numbers from the 2009 influenza A/H1N1 pandemic

From: Estimates of the reproduction number for seasonal, pandemic, and zoonotic influenza: a systematic review of the literature

Location

Wavea

Study population

Mean GT/SIb

Reproduction number (R)

95% CIc

Basic or effective

Case definition

Reference

Year published

Mexico

0

Community

1.91

1.25

0.76–1.74

Basic

Laboratory confirmed illness

[44]

2011

Australia

1st

Community

2.8

1.50

1.50–2.70

Effective

Laboratory confirmed illness

[45]

2010

Australia

1st

Community

2.8

1.20

1.0–1.4

Effective

Laboratory confirmed illness

[45]

2010

Australia

1st

Community

2.9

2.40

2.3–2.4

Effective

Laboratory confirmed illness

[46]

2009

Australia, rural

1st

Community

2.9

1.28

1.26–1.30

Effective

Laboratory confirmed illness

[47]

2011

Australia, urban

1st

Community

2.9

1.26

1.22–1.30

Effective

Laboratory confirmed illness

[47]

2011

Canada

1st

Community

1.91

1.30

1.12–1.47

Basic

Laboratory confirmed illness

[48]

2010

Canada

1st

Community

2.78

2.21

1.98–2.50

Basic

Laboratory confirmed illness

[49]

2012

Canada

1st

Community

3.6

1.63

1.31–1.96

Basic

Laboratory confirmed illness

[48]

2010

Canada

1st

Community

4.31

1.31

1.25–1.38

Basic

Laboratory confirmed illness

[50]

2010

Chile

1st

Community

2.5

1.80

1.6–2.0

Effective

Unconfirmed emergency room visits

[51]

2010

Chile, central

1st

Community

3

1.32

1.27–1.37

Effective

Unconfirmed hospitalizations

[52]

2012

Chile, northern

1st

Community

3

1.19

1.13–1.24

Effective

Unconfirmed hospitalizations

[52]

2012

Chile, southern

1st

Community

3

1.58

1.45–1.72

Effective

Unconfirmed hospitalizations

[52]

2012

China

1st

Community

2.6

1.25

1.22–1.28

Effective

Laboratory confirmed illness

[53]

2012

China

1st

Community

4.31

1.53

1.45–1.60

Basic

Laboratory confirmed illness

[54]

2012

China

1st

Community

NR

1.68

 

Basic

Laboratory confirmed illness

[55]

2011

Hong Kong

1st

Community

3

1.70

1.6–1.8

Effective

Laboratory confirmed illness

[56]

2010

Hong Kong

1st

Community

3.2

1.45

1.4–1.5

Effective

Laboratory confirmed illness

[57]

2010

Israel

1st

Community

2.92

1.06

0.97–1.16

Effective

Laboratory confirmed illness

[58]

2011

Italy

1st

Community

2.6

1.30

1.23–1.32

Effective

Unconfirmed illness

[59]

2012

Japan

1st

School

1.9

2.30

2.0–2.6

Effective

Laboratory confirmed illness

[60]

2009

Japan

1st

Community

2.7

1.28

1.23–1.33

Effective

Laboratory confirmed illness

[60]

2009

Mexico

1st

Community

1.91

1.58

1.34–2.04

Basic

Unconfirmed illness

[61]

2009

Mexico

1st

Community

1.96

1.42

 

Basic

Unconfirmed illness

[62]

2010

Mexico

1st

Community

2.6

1.40

1.2–1.9

Basic

Laboratory confirmed illness

[61]

2009

Mexico

1st

Community

2.6

1.22

1.05–1.60

Basic

Laboratory confirmed illness

[61]

2009

Mexico

1st

Community

3

1.80

1.78–1.81

Effective

Unconfirmed illness

[63]

2011

Mexico

1st

Community

3

1.43

1.29–1.57

Effective

Laboratory confirmed illness

[64]

2009

Mexico

1st

Community

3.1

2.20

2.1–2.4

Effective

Laboratory confirmed illness

[65]

2009

Mexico

1st

Community

3.5

2.30

2.1–2.5

Basic

Laboratory confirmed illness

[11]

2009

Mexico

1st

Community

3.6

1.75

1.6–1.9

Basic

Seeding from Mexico

[66]

2009

Mexico

1st

Community

4.1

3.10

2.9–3.5

Effective

Laboratory confirmed illness

[65]

2009

Mexico City

1st

Community

3

1.72

 

Basic

Laboratory confirmed illness

[67]

2009

Morocco

1st

Community

2.3

1.44

1.32–1.56

Basic

Laboratory confirmed illness

[68]

2012

Morocco

1st

Community

2.7

1.40

1.34–1.48

Basic

Laboratory confirmed illness

[68]

2012

Netherlands

1st

Community

3

0.50

 

Effective

Laboratory confirmed illness

[69]

2009

New Zealand

1st

Community

2.7

1.25

1.07–1.47

Effective

Laboratory confirmed illness

[70]

2011

New Zealand

1st

Community

2.8

1.96

1.80–2.15

Effective

Laboratory confirmed illness

[71]

2009

New Zealand

1st

Community

2.8

1.55

1.16–1.86

Effective

Laboratory confirmed illness; unconfirmed illness

[72]

2010

North America

1st

Community

2.7

1.3–2.1

 

Basic

Laboratory confirmed illness

[73]

2010

Peru

1st

Community

2.8

1.37

1.33–1.41

Effective

Laboratory confirmed illness

[74]

2009

Peru

1st

Community

3

1.30

1.3–1.3

Effective

Unconfirmed illness

[75]

2011

Peru, Lima

1st

Community

3

1.70

1.6–1.7

Effective

Unconfirmed illness

[75]

2011

Singapore

1st

Dance club

1.91

1.9–2.1

 

Basic

Laboratory confirmed illness

[76]

2010

Singapore

1st

Military

NR

1.91

1.50–2.36

Effective

Laboratory confirmed and unconfirmed illness

[77]

2010

South Africa

1st

Community

2.3

1.43

1.38–1.49

Effective

Laboratory confirmed illness

[78]

2012

South Africa

1st

Community

2.78

1.47

1.30–1.72

Effective

Laboratory confirmed illness

[78]

2012

South Africa

1st

Community

2.78

1.42

1.20–1.71

Effective

Laboratory confirmed illness

[78]

2012

Southern Hemisphere

1st

Community

1.9

1.16–1.53

 

Effective

Laboratory confirmed illness

[79]

2010

Southern Hemisphere

1st

Community

2.60

1.33

1.28–1.45

Basic

Laboratory confirmed and unconfirmed illness

[80]

2011

Taiwan

1st

Community

1.91

1.14

1.04–1.25

Effective

Laboratory confirmed illness

[81]

2011

Taiwan

1st

Community

NR

1.16

0.98–1.34

Effective

Serology confirmed infection

[82]

2011

Thailand

1st

Community

1.9

1.78

1.67–1.89

Basic

Laboratory confirmed illness

[83]

2009

Thailand

1st

Community

2.6

2.07

1.92–2.22

Basic

Laboratory confirmed illness

[83]

2009

United Kingdom

1st

School

2.2

1.33

1.11–1.56

Effective

Laboratory confirmed illness

[84]

2012

United Kingdom

1st

Community

2.5

1.44

1.27–1.63

Effective

Laboratory confirmed illness

[85]

2009

USA

1st

Community

2.2

1.70

1.4–2.1

Basic

Laboratory confirmed illness

[86]

2009

USA

1st

Community

2.6

2.20

1.4–2.5

Basic

Laboratory confirmed illness

[86]

2009

USA

1st

School

2.7

3.30

3.0–3.6

Effective

Unconfirmed illness

[87]

2009

USA

1st

Community

3.5

1.3–2.0

1.0–2.2

Basic

Laboratory confirmed illness

[11]

2009

USA

1st

Camp attendees

7

2.20

1.4–3.3

Effective

Unconfirmed illness

[88]

2011

Vietnam

1st

Community

1.9

1.50

1.5–1.6

Basic

Laboratory confirmed illness

[89]

2010

Vietnam

1st

Community

3.6

2.00

1.9–2.2

Basic

Laboratory confirmed illness

[89]

2010

worldwide

1st

Community

2.67

1–2

 

Effective

Laboratory confirmed illness

[90]

2011

China

2nd

Community

4

1.66

1.27–2.05

Effective

confirmed hospitalizations

[91]

2012

China

2nd

Community

4.3

1.70

1.4–1.9

Effective

Laboratory confirmed illness

[92]

2010

France

2nd

Military

2.9

1.5–1.6

 

Effective

Unconfirmed illness

[93]

2012

Iran

2nd

school

NR

1.28

1.05–1.54

Basic

Unconfirmed illness

[94]

2012

Italy

2nd

Community

2.5

1.33

 

Effective

Unconfirmed illness

[95]

2011

Japan

2nd

Community

3

1.48

1.41–1.56

Effective

Unconfirmed illness

[96]

2012

Mexico

2nd

Community

3

1.62

1.61–1.63

Effective

Unconfirmed illness

[63]

2011

Reunion Island

2nd

Community

2.8

1.26

1.08–1.49

Effective

Unconfirmed illness

[97]

2010

Taiwan

2nd

Community

1.91

1.02

1.01–1.02

Effective

Laboratory confirmed illness

[81]

2011

Taiwan

2nd

Community

NR

1.87

1.68–2.06

Effective

Serology confirmed infection

[82]

2011

United Kingdom

2nd

Community

2.5

1.30

1.2–1.5

Effective

Laboratory confirmed illness

[98]

2010

Mexico

3rd

Community

3

1.24

1.23–1.24

Effective

Unconfirmed illness

[63]

2011

various

 

Community

NR

1.30

1.1–1.4

Effective

Serology confirmed infection

[99]

2012

Median reproduction number for the 2009 pandemic: 1.46; Interquartile range 1.30–1.70

  1. aThe 2009 influenza A/H1N1 pandemic began in Mexico in the late winter or early spring of 2009 [44]. The United States and the United Kingdom experienced a first wave of illnesses in the Spring of 2009 followed by a second wave during the Fall of 2009 [4]. However, unlike these three countries, a number of countries, especially in the Southern Hemisphere, only experienced a single wave of illnesses [100].
  2. bThe generation time (GT) or serial interval (SI) assumed in the reproduction number estimation.
  3. cConfidence interval.
  4. NR = Not reported.
  5. This table is also available as a .csv file as Additional file 4.
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BMC Infectious Diseases

ISSN: 1471-2334

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