Dengue fever in a municipality of West Bengal, India, 2015: An outbreak investigation

• Main Authors: Falguni Debnath, Manickam Ponnaiah, Pralay Acharya
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2017-01-01
• Series: Indian Journal of Public Health
• Subjects: Dengue; monoclonal IgM antibody capture-ELISA; NS1 ELISA; outbreak; West Bengal
• Online Access: http://www.ijph.in/article.asp?issn=0019-557X;year=2017;volume=61;issue=4;spage=239;epage=242;aulast=Debnath

Background: In November 2015, death due to fever and increased number of fever cases were reported from Baranagar Municipality of North 24 Parganas district of West Bengal. Objectives: The episode was investigated with the objective to (1) confirm the existence of an outbreak, (2) describe it in terms of time, place, and person, (3) determine the cause of outbreak, and (4) recommend control measures. Methods: Monthly incidence of dengue from 2012 to 2014 was calculated and compared with 2015 to confirm the outbreak. We used Integrated Disease Surveillance Programme definition and searched for suspect dengue cases going door-to-door in ward number one of Baranagar Municipality. Active case search was done in health facilities also. Information on date of onset, symptoms, sociodemographic, serological reports, and clinical outcome for suspected and confirmed dengue cases was collected. Blood specimens were collected for NS1 ELISA/monoclonal IgM antibody capture-ELISA test. Environmental and entomological surveys were done. Results: Six hundred and seventy-one dengue cases (Overall attack rate = 3/1000), two deaths (Case fatality = 3/1000) were reported during September 14, 2015, till December 12, 2015. Out of 34 wards, attack rate was highest in ward number 1 (0.7%) and was 3 per 1000 among females. All age groups were affected. Thirty-two percent required hospitalization. NS1 ELISA was positive for 612 cases. Out of interviewed 31 dengue cases, 94% had headache, 90% had myalgia, followed by arthralgia, rash, and retro-orbital pain. Only in ward number 1, house index was >5%. Conclusion: We confirmed dengue outbreak. All age groups got affected. Deaths occurred in this outbreak. Potential breeding sources were present in ward number 1.