Kolkata has recorded three times more dengue cases than Mumbai and Chennai.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/kolkata-1st-delhi-close-2nd-dengue-cases
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/times-india-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/kolkata
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/west-bengal
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dengue
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/diseases
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vector-borne-diseases
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/mumbai
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/chennai-d