An outbreak of dengue fever in Peri Urban slums of Chandigarh, India, with special reference to entomological and climatic factors
ABSTRACT Dengue viral infection is one of the most important public health problem in tropical countries.
An outbreak of dengue fever was investigated in a periurban slum area of Chandigarh, India, during September to December, 2002.
Blood samples from 218 patients and 30 apparently healthy contacts were tested for dengue-specific immunoglobulin M (IgM) and IgG antibodies including 80 acute samples collected within 5 days of illness were subjected for virus isolation in newborn mice. The average temperature, rainfall, and humidity of the epidemic year were compared with the number of dengue cases.
statistical significance was found out using c2-test.
A total of 76 cases were positive by either dengue IgM capture assay (n = 57) or virus isolation (n = 17) or both (n = 2). Fifteen of nineteen viral isolates subjected for typing by type-specific multiplex reverse transcription-polymerase chain reaction were found to be of dengue virus. High rainfall and humidity with the temperature range from 21 degrees C to 33 degrees C during the months of August and September might have favored the breeding of mosquitoes, thus leading to an increase in the number of dengue cases in October and November, 2002.
The present outbreak thus emphasizes the need for continuous sero epidemiological and entomological surveillance for the timely implementation of effective dengue control programme.
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- "Several studies have linked poverty or wealth to dengue (Lifson, 1996; Ratho et al., 2005; Flauzino et al., 2009; Mena et al., 2011), while others have found only transitory associations (Heukelbach et al., 2001; Mondini and Chiaravalloti Neto, 2007), highlighting the complexity of this relationship. It is possible that using relative poverty instead of absolute poverty might better discriminate between levels of economic disadvantage and detect disparities not only between urban and rural environments, but also within them. "
Chapter: Mapping the epidemiology of dengueDengue and dengue hemorrhagic fever, 2nd edited by Gubler DJ, Ooi EE, Vasudevan S, Farrar J, 08/2014: chapter 2: pages 30-49; CABI, Wallingford, U.K..
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- "The extracted viral RNA was reverse transcribed to cDNA using murine Moloney leukemia virus reverse transcriptase (MBI Fermentas, USA) following the manufacturer's instructions and stored at −20 °C. The cDNA of all the cases and controls was subjected to dengue nested RT-PCR and chikungunya RT-PCR using DENV-and CHIKV-specific primers, respectively (Lanciotti et al., 1992; Naresh et al., 2007; Ratho et al., 2005). "
ABSTRACT: The reemergence of chikungunya virus (CHIKV) has compounded the already existing dengue problem because of clinical similarities and common vector, demanding the need for a rapid and specific diagnosis. Thus, dengue chikungunya multiplex reverse transcriptase-polymerase chain reaction (DCmRT-PCR) was developed and validated for simultaneous detection of dengue and chikungunya viral infections and its utility in virus serotyping. Blood samples from 97 suspected dengue and chikungunya cases and 10 healthy controls were subjected to dengue and chikungunya conventional RT-PCR and DCmRT-PCR. Thirty-one of 97 samples were positive for dengue or chikungunya viral RNA by RT-PCR and DCmRT-PCR with 100% concordance. DCmRT-PCR products were cycle sequenced. Seven dengue virus strains were clustered within genotype III of DENV-3 and 4 within genotype III of DENV-1, whereas chikungunya sequences were clustered within the Central/East African genotype. DCmRT-PCR was found to be a potential rapid test for simultaneous detection of dengue and CHIKV in clinical samples along with dengue serotyping.Diagnostic microbiology and infectious disease 08/2011; 71(2):118-25. DOI:10.1016/j.diagmicrobio.2011.06.020 · 2.57 Impact Factor
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- "The lower temperature threshold for larval development is approximately 15°C (Rueda et al., 1990); however, different strains of Ae. aegypti may exhibit slightly different adaptations to temperature (Mattingly, 1957). By influencing human and vector behavior (Peterson et al., 2005; Chakravarti and Kumaria, 2002), climatic factors strongly affect not only the development and survival of the mosquito (Alto and Juliano, 2001; Nagao et al., 2003) but also the transmission dynamics of diseases, such as dengue (Colwell et al., 1998; Patz et al., 2000; Bartley et al., 2002; Ratho et al., 2005; Thammapalo et al., 2005). Little information is available, however, about Ae. aegypti at the northern margins of its distribution, particularly in a desert environment. "
ABSTRACT: This study examined the association of human and environmental factors with the presence of Aedes aegypti, the vector for dengue fever and yellow fever viruses, in a desert region in the southwest United States and northwest Mexico. Sixty-eight sites were longitudinally surveyed along the United States-Mexico border in Tucson, AZ, Nogales, AZ, and Nogales, Sonora during a 3-year period. Aedes aegypti presence or absence at each site was measured three times per year using standard oviposition traps. Maximum and minimum temperature and relative humidity were measured hourly at each site. Field inventories were conducted to measure human housing factors potentially affecting mosquito presence, such as the use of air-conditioning and evaporative coolers, outdoor vegetation cover, and access to piped water. The results showed that Ae. aegypti presence was highly variable across space and time. Aedes aegypti presence was positively associated with highly vegetated areas. Other significant variables included microclimatic differences and access to piped water. This study demonstrates the importance of microclimate and human factors in predicting Ae. aegypti distribution in an arid environment.EcoHealth 03/2010; 7(1):64-77. DOI:10.1007/s10393-010-0288-z · 2.27 Impact Factor