The transmission of dengue is not very widespread and occurs only within a radius of 200 metres, acoording to a new research study published in the peer-reviewed journal Science.
Dengue is transmitted by the Aedes aegypti mosquito that also transmits chikungunya. More than 1.1 lakh dengue cases were reported in India last year and more than 227 deaths were recorded, as per the data from the National Vector Borne Disease Control Programme.
The new dengue study conducted at the Johns Hopkins Bloomberg School of Public Health in collaboration with researchers from the University of Florida and the Walter Reed Army Institute of Research in the United States, the Ministry of Public Health of Thailand and the Queen Sirikit National Institute of Child Health in Thailand.
The researchers genetically sequenced viruses that caused 640 dengue infections that occurred between 1994 and 2010 in Thailand’s densely populated capital Bangkok and less-densely populated surrounding regions. This led them to analyse 160 seperate chains of transmission circulating in Bangkok within one season.
They found that 60% of cases among people living in the same neighbourhood less than 200 metres apart came from the same transmission chain. This means that these patients were infected by the same virus. Only three percent of people people separated by between one and five kilometres had been infected by the same same transmission virus.
This study provides empirical evidence of the importance of location when it comes to assessing the risk of dengue infection and supports the role of targeted mosquito control around the residences of infected people, the researchers said.