Based on the symptoms, doctors recommend a blood test. The samples are sent to NIV Pune, which confirms the presence or absence of the Chandipura virus.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/one-case-chandipura-virus-infection-detected-gujarat-all-you-need-know-about-virus-affects
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/indian-express-ahmedabad
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/gujarat
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health-care
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/children
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health