A comparative study of clinical features between monotypic and dual infection cases with Chikungunya virus and dengue virus in West Bengal, India.

Chikungunya virus (CHIKV) and dengue virus (DENV) are circulating individually in the state of West Bengal, India. However, after 1965 the dual-infection caused by both viruses had not been recorded until 2010. In 2010, an investigation of the febrile cases was carried out to confirm the involvement of both viruses simultaneously. A total of 550 blood samples were tested for the detection of immunoglobulin M (IgM) antibody against both CHIKV and DENV. Serology by the enzyme-linked immunosorbent assay method confirmed that 131 (23.8%) and 104 (18.9%) patients had IgM antibody against CHIKV and DENV, respectively, whereas 68 (12.4%) had IgM antibodies against both CHIKV and DENV. Fever, joint pain, rashes, headache, myalgia, and nausea/vomiting are the common features in the case of both monotypic and dual-infection. Severe arthralgia and swelling of joints were common only in CHIKV-positive cases and abdominal pain was mainly associated with DENV infection. Diarrhea was reported only by the dual-infected patients (16.2%).