Serum levels of IFN-β are associated with days of evolution but not with severity of dengue.

The serum levels of beta interferon (IFN-β) were evaluated in clinical samples taken in the acute phase of dengue fever for 107 patients during the 2011 dengue outbreak in Yucatán, México. Dengue diagnoses were confirmed by NS1 or IgM/IgG serology in all patients. Average serum IFN-β levels in patients with dengue fever without warning signs (n = 53) were 140 pg/ml, and 105 pg/ml for patients with warning signs (n = 54).