ABSTRACT
Background: During September 2012, an increased number of fever cases was reported from Ramnagar-II block, Purba Medinipur district. This study investigated the outbreak, with the following objectives: to describe the distribution of fever cases, to determine the risk factors and to recommend preventive measures. Materials and Methods: The clinical features, date of onset and outcome of all cases of fever were listed. Blood specimens were collected from affected patients and sent for serological examination. An epidemic curve was plotted and environmental and entomological surveys were carried out. Results: There was a total of 100 cases, of which 56% (56/100) were men. Among the four villages studied, the highest number of cases was from Gopalpur 37% (37/100), followed by Badalpur 26% (26/100); 19% (19/100) of cases had a history of migration from dengue-endemic areas. The majority of cases were in age group 15–45 years – 52% (52/100), followed by the age group >45 years – 28% (28/100). All the cases had history of fever (100%), followed by myalgia – 82%, headache – 78%, and retro-orbital pain – 73%. The outbreak started on 7 September 2012, peaked on 18 September, then gradually declined and no further cases were noted after 28 September 2012. Seventy-nine per cent (79/100) of cases were NS1 test positive (non-structural antigen-1) and 72% (13/18) cases were positive on a dengue monoclonal antibody (IgM) capture enzyme-linked immunosorbent assay (MAC-ELISA) test. All recovered except one (case-fatality ratio: 1%). The values for Household Index, Container Index and Breteau Index of the four villages were: Badalpur, 3%, 10% and 5%; Gopalpur, 13%, 23% and 18%; Ramchandrapur, 9%, 11%, and 13%; and Tajpur, 2%, 2% and 2%. Conclusion: The outbreak was probably due to dengue fever. The study led to a recommendation to destroy water containers and use mosquito nets. The outbreak was controlled.
ABSTRACT
Background & objectives: An increased number of cases with influenza like illness (ILI) were reported in Greater Kolkata Metropolitan Area (GKMA) during July and August 2010. We investigated these cases to confirm the outbreak, describe the distribution of patients and propose control measures. Methods: A suspected case of influenza like illness (ILI) was defined as acute onset of fever (>38°C) with cough or sore throat and a confirmed case as ILI case with throat swab positive for influenza A (H1N1) on RT-PCR. The demographic and clinical details were collected from patients attending the swine flu OPD of Infectious Disease Hospital, Kolkata, during July 5 to August 16, 2010. Results: Overall 440 patients with ILI attended the swine flu OPD of Infectious Disease and Bengal General hospital during the study period, of which 129 were positive for influenza A (H1N1). Four patients died (case fatality ratio: 0.90%). Besides fever, common symptoms included cough (73%), running nose (54%), sore throat (43%), respiratory distress (25%) and diarrhoea (4%). Forty seven (11%) patients (including the four who died) had co-morbidities. The outbreak started on July 10, peaked on July 24 and subsided by August 14, 2010. A total of 372 (85%) patients were from GKMA. Majority (n=168, 45%) of the cases from GKMA were from 6 boroughs of Kolkata Municipal Areas. Interpretation & conclusions: An outbreak of influenza A (H1N1) occurred in Kolkata predominantly affecting young and middle aged population. State health authorities implemented several interventions to limit the outbreak including training of health care providers in case management and infection control, vaccination of health care workers, creation of isolation wards and administration of oseltamivir to ILI patients, and community health education about social distance and personal hygiene measures.