Association of climate factors with outbreak of Dengue Fever – An Eco-Epidemiological analysis
Dengue infection, which cause dengue fever (DF), dengue haemorrhagic fever (DHF) and shock syndrome (DSS) are currently endemic or intermittently epidemic in many tropical and sub-tropical regions of the world. According to the World Health Organization, dengue has recently become a major public health concern globally. It is generally found in tropical and sub-tropical regions, and more specifically in urban and semi-urban areas.
This study was conducted to find out the relationship of dengue fever with climate factors such as temperature, humidity and rainfall in the year 2010.
METHODS:
The confirmed dengue infections in hospital cases were detected through the hospital information system. Monthly data of total rainfall, temperature and relative humidity for the year 2010 was obtained from Meteorological department of Karachi.
RESULTS:
Overall, 576 cases were positive and hospitalized during 2010. The mean age was 30 ± 17.66 years and 391 (67.9%) were males. Out of 576 cases 476 (82.6%) belongs to adult’s age group. Dengue infection cases were reported during warmest weather with maximum number of cases 226 (39.2%) reported in the month of October 2010 followed by 135 (23.4%) in the month of September 2010. The difference between number of positive cases during different months was significant (p-value=0.03).
CONCLUSIONS:
These results suggest that climate factors such as temperature and rainfall collectively be responsible for an outbreak of dengue infection. Dengue viruses have a basically universal transmission cycle, but changes in temperature or rainfall may have varied local effects.