Genome of Chagas disease vector decoded

[MONTEVIDEO] An international team of scientists has decoded the genome of one of the main vectors of Chagas disease, paving the way for more targeted vector control and new ways to prevent disease transmission.  

Chagas disease is transmitted via a parasite that lives on different species of the blood-sucking triatomine bugs, also known as 'assassin' or 'kissing' bugs, that live in the crevices of poor-quality houses, particularly in rural areas.

In Central America the most common species of the bug is Rhodnius prolixus. The first draft of its genome was announced at the 3rd International Workshop for Genomic and Triatomine Biology, held in La Plata, Argentina, last month (17 May).

An estimated 11 million people are infected with Chagas disease in Latin America. It starts with fever and tiredness, and later leads to weakened heart and internal organs. Globally, it affects 14 million and kills about 15,000 per year.

Until now, scientists had only decoded the genome of the Chagas parasite Trypanosoma cruzi, but lacked genome information about the insect vectors.

"We chose R. prolixus because it has the smallest genome among all bugs from the triatomine family," said Pedro Oliveira, of the Federal University of Rio de Janeiro, Brazil, who led the research, which will be finalised and published within a year.

Oliveira told SciDev.Net that the team plans to sequence several insects of this sub-family, if more funding can be secured.  

The work took almost a decade and involved 30 researchers from Argentina, Brazil, Canada, the United States and Uruguay, and was funded by the US National Institutes of Health.

"The sequencing of this genome represents the start of the most interesting part of the research," said Rolando Rivera-Pomar, from the Regional Center for Genomic Studies at the National University of La Plata, who worked on the genome.

"If we discover why the kissing bug — and not other insects — transmits the parasite we could study the mechanism to inhibit this transmission," he said.

Ricardo Gürtler, of the University of Buenos Aires, Argentina, told SciDev.Net that knowing the insect vector genomes should, in theory, improve control strategies through the development of traps, inhibitors of the Chagas parasite growth, and detection of insecticide resistance, among others.

Oliveira added that such control technologies are "well advanced both for malaria and dengue mosquitoes", whose genomes have already been decoded.