Bulletin of the World Health Organization

Incidence of influenza-like illness and severe acute respiratory infection during three influenza seasons in Bangladesh, 2008–2010

Eduardo Azziz-Baumgartner, ASM Alamgir, Mustafizur Rahman, Nusrat Homaira, Badrul Munir Sohel, MA Yushuf Sharker, Rashid Uz Zaman, Jacob Dee, Emily S Gurley, Abdullah Al Mamun, Syeda Mah-E-Muneer, Alicia M Fry, Marc-Alain Widdowson, Joseph Bresee, Stephen Lindstrom, Tasnim Azim, Abdullah Brooks, Goutam Podder, M Jahangir Hossain, Mahmudur Rahman & Stephen P Luby

Volume 90, Number 1, January 2012, 12-19

Table 3. Incidence of influenza-associated influenza-like illness (ILI) per 100 person–years based on health care utilization survey data from hospital catchment areas and surveillance data for three influenza seasons, Bangladesh, 2008–2010

Parameter Kishorgonj Comilla Barisal Bogra Total seasonal influenza
Number of patients with ILI with samples that tested positive for influenza viruses during 2008 (numerator) 15 22 38 18 93
Census population in catchment area in 2008 (denominator) 407 276 680 113 513 894 770 318 2 371 601
Sampling fraction (i.e. surveillance 2 days per month) (denominator) 0.07 0.07 0.07 0.07 0.07
Patients with ILI who sought care at sentinel site during past 2 months (divided by 8 to extrapolate to 7 days)/Number with ILI during 7 days (denominator) 4/687 2/528 7/624 1/596 14/2435
Incidence of influenza-associated ILI (per 100 person–years) during 2008
10
13
10
21
10
Number of patients with ILI whose samples tested positive for influenza viruses during 2009 (numerator) 23 41 33 18 115
Census population in catchment area during 2009 (denominator) 413 386 690 315 521 602 781 873 2 407 175
Sampling fraction (i.e. surveillance 2 days per month) (denominator) 0.07 0.07 0.07 0.07 0.07
Number of patients with ILI who sought care at sentinel site during past 2 months (divided by 8 to extrapolate to 7 days)/Number with ILI during 7 days (denominator) 4/687 2/528 7/624 1/596 14/2435
Incidence of influenza-associated ILI (per 100 person–years) during 2009
15
24
9
21
13
Number of patients with ILI whose samples tested positive for influenza during 2010 (numerator) 26 55 46 31 158
Census population in catchment area in 2009 (denominator) 419 586 700 669 529 426 793 601 2 443 283
Sampling fraction (i.e. surveillance 2 days per month) (denominator) 0.07 0.07 0.07 0.07 0.07
Number of patients with ILI who sought care at sentinel site during past 2 months (divided by 8 to extrapolate to 7 days)/Number with ILI during 7 days (denominator) 4/687 2/528 7/624 1/596 14/2435
Incidence of influenza-associated ILI (per 100 person–years) in 2010 16 32 35 35 17