An outbreak of dengue fever in periurban slums of Chandigarh, India, with special reference to entomological and climatic factors
Ratho, R.K.; Mishra, B.; Kaur, J.; Kakkar, N.; Sharma, K.
Indian Journal of Medical Sciences 59(12): 518-526
2005
ISSN/ISBN: 0019-5359 PMID: 16385170 Document Number: 260368
Aim: An outbreak of dengue fever was investigated in a periurban slum area of Chandigarh, India, during September-December 2002. Materials and Methods: Blood samples from 218 patients and 30 apparently healthy contacts were tested for dengue-specific IgM and IgG antibodies. All acute samples (n=80) collected within 5 days of illness were subjected to virus isolation in newborn mice. The average temperature, rainfall and humidity during the epidemic year were compared with the number of dengue cases. Statistical Analysis: Statistical significance was determined using the c2-test. Results: 76 cases were positive by either dengue IgM capture assay (n=57) or virus isolation (n=17) or both (n=2). 15 of 19 viral isolates subjected for typing using a type-specific multiplex reverse transcription-polymerase chain reaction were dengue virus. High rainfall and humidity with the temperature range of 21-33 degrees C during August-September might have favoured the breeding of mosquitoes (3 of 10 mosquito pools examined were positive for dengue antigen), thus leading to an increase in the number of dengue cases in October and November 2002. Conclusion: The present outbreak emphasizes the need for continuous seroepidemiological and entomological surveillance for the timely implementation of effective dengue control programmes.