London: Malaria is tens of thousands of
years older than previously thought -- in fact, it is as old
as humanity, a new study has claimed.
An international team, led by Imperial College
London, has found that the potentially deadly tropical disease
evolved alongside anatomically modern humans and even migrated
alongside them out of Africa some 60,000 to 80,000 years ago,
the `Current Biology` journal reported.
"Most recent work to understand how malaria has spread
across the tropics has worked on the premise that the disease
arose alongside the development of agriculture around 10,000
"Our research shows that the malaria parasite has
evolved and spread alongside humans and is at least as old as
the event of the human expansion out of Africa 60-80,000 years
ago," Dr Francois Balloux, who led the team, said.
Researchers worked on the largest collection of
malaria parasites ever assembled. By characterising them by
DNA sequencing they were able to track the progress of malaria
across the tropics and to calculate the age of the parasite.
They discovered clear correlation of decreasing
genetic diversity with distance from sub-Saharan Africa. This
accurately mirrored the same data for humans suggesting strong
evidence of co-evolution and migration.
Dr Balloux said: "The genetic sequencing of malaria
parasite shows a geographic spread pattern with striking
similarities to studies on humans. This points to a shared
geographic origin, age and route of spread around the world.
"This understanding is important because despite the
prevalence and deadly impact of malaria little research has
previously been done to understand the genetic variation of
"The genetic diversity of malaria parasites is central
to their threat as it helps them to overcome the immune system
and to develop drug resistance, making this research vital in
informing new and more effective control strategies."
There are an estimated 230 million cases of malaria
worldwide each year, causing between 1 and 3 million deaths,
and 1.4 billion people are said to be at risk of infection.