Involvement of dual serotypes during a severe dengue outbreak in Wadi area, Nagpur district, Maharashtra 2017.

BACKGROUND & OBJECTIVES: An outbreak of dengue-like illness was reported from Wadi area within the Nagpur Municipal Corporation during September-October 2017 with five deaths. Major symptoms reported were high fever (103-106 F), acute joint pains, myalgia, drowsiness, breathlessness, etc. An investigation was conducted to confirm the etiological agent, its characterization and the vectors involved in the outbreak.

METHODS

Serological analysis was conducted to detect dengue (DEN)/chikungunya IgM antibodies in 158 sera samples. Nested-PCR was carried out to serotype eight ELISA positive samples. Adult and larval mosquito collections were conducted in the affected areas to determine species composition and mosquito density.

RESULTS

Dengue IgM antibodies were detected in 44 sera samples. Molecular typing revealed involvement of DEN-2 and DEN-3 serotypes. Dengue hemorrhagic fever symptoms were observed in two patients. Aedes aegypti breeding was found rampant with Breteu index and house index ranging from 23 to 70 and 17 to 56, respectively. Major breeding habitats encountered were, used tyres, cement tanks and refrigerator trays.

INTERPRETATION & CONCLUSION: Clinical symptoms, detection of anti-DEN IgM antibodies in high number of samples and heavy breeding of Ae. aegypti confirmed it was a dengue outbreak.