Berries of a common weed found in India may be effective in fighting mosquitoes that spread dengue fever, a study has found.
Synthetic insecticides are increasingly useless in fighting disease-spreading mosquitoes, such as the Stegomyia aegypti that can spread dengue and yellow fever viruses.
In the online open-access journal BMC Complementary and Alternative Medicine, scientists in India described how they used juice and extracts from the Solanum villosum weed and found it was particularly effective in eliminating S. aegypti larvae.
"The extract ... from the plant could be used in stagnant water bodies which are known to be the breeding grounds for mosquitoes," Nandita Chowdhury, Anupam Ghosh and Goutam Chandra from Burdwan University in West Bengal wrote.
They went on to discover the juices contained certain chemical compounds.
"These act as a repellent which protect(s) against the lethal effects of the larval mosquitoes," they added.
From Africa to Asia to Latin America, around 2.5 billion people live in areas where they are at risk of dengue fever. There is no vaccine or drugs to treat the illness, which killed an estimated 22,000 people last year, most of them children.
Due to international travel and climate change, the aegypti mosquito's habitat is spreading.
In January, health officials warned that the disease was poised to move across the United States. It has been spreading aggressively in Latin America and the Caribbean, reaching epidemic levels last year.
Of the 50 million people who contract the disease every year, about one percent get potentially deadly severe dengue haemorrhagic fever (DHF), which requires hospitalisation.