Emerging Infectious Disease ISSN: 1080-6059

Increased Mortality Rate Associated with Chikungunya Epidemic, Ahmedabad, India

Dileep Mavalankar*

, Priya Shastri*, Tathagata Bandyopadhyay*, Jeram Parmar*, and Karaikurichi V. Ramani*

Author affiliations: *Indian Institute of Management, Ahmedabad, India;

Monthly chikungunya cases, deaths, and mortality rates, Ahmedabad, India, 2002–2005 and 2006*

Month	Chikungunya cases, 2006	Mortality rate/10,000 (99% CI), 2002–2005	Expected deaths, 2006 (99% CI)	Actual deaths, 2006	Excess deaths, 2006	Mortality rate/10,000, 2006	% Change in mortality rate
Jan	ND	6.19 (6.00–6.41)	2,422 (2,342–2502)	2,559	137	6.54	+5.66
Feb	ND	5.56 (5.37–5.76)	2,180 (2,105–2255)	2,227	47	5.68	+2.14
Mar	ND	5.76 (5.56–5.95)	2,264 (2,187–2,341)	2,337	73	5.95	+3.24
Apr	434	5.75 (5.53–5.92)	2,260 (2,183–2,337)	2,150	−110	5.47	−4.89
May	141	6.16 (5.93–6.33)	2,428 (2,349–2,507)	2,510	82	6.37	+3.37
Jun	31	5.80 (5.56–5.95)	2,290 (2,213–2,367)	2,156	−134	5.46	−5.86
Jul	184	5.50 (5.27–5.65)	2,177 (2,102–2,252)	2,270	93	5.73	+4.27
Aug	28,233	6.08 (5.82–6.21)	2,410 (2,331–2,489)	2,942	532	7.42	+22.09
Sep	27,360	6.40 (6.12–6.52)	2,541 (2,460–2,622)	3,989	1,448	10.05	+56.96
Oct	3,555	5.92 (5.64–6.03)	2,355 (2,277–2,433)	3,121	766	7.85	+32.51
Nov	539	6.27 (5.97–6.38)	2,500 (2,420–2,580)	2,698	198	6.77	+7.90
Dec	300	6.54 (6.22–6.63)	2,613 (2,531–2,695)	2,537	−76	6.35	−2.90
Total	60,777		28,440 (27,500–29,380)	31,496	3,056

*CI, confidence interval; ND, no data available.