The World Health Organization is defending its numbers on global malaria deaths and disputes a new study claiming that nearly twice as many people die of malaria than previously believed.

The study, which appears in the British health journal, The Lancet, reports that more than 1.2 million people died of malaria in 2010, compared to WHO estimates of 655,000 deaths.

The World Health Organization also disputes the study's claim that adults are as susceptible to malaria deaths as children under five.

WHO spokesman Gregory Hartl told VOA Friday that there is a notable statistical difference in regard to children over five and adults in Africa. He said the study published in The Lancet used a different methodology and less reliable sources of data in arriving at its conclusions.

“The Lancet used in its study verbal autopsies… basically, there is no diagnosis done in laboratory or after death of how a person actually died. You rely on the verbal record of a friend or relative saying that X person died of fever, for example. However, we know that there are many different diseases which cause fever.”

Hartl says it is believed that most people who survive malaria in the first five years of life have a much higher immunity to this mosquito-borne disease later in life. He says in most cases, diseases other than malaria are the most likely causes of death among adults.

But the WHO spokesman agreed with the assessment by researchers at the University of Washington in Seattle, who conducted the new study, that deaths linked to malaria have been declining.

He said that an early diagnosis and treatment can prevent malaria deaths.

WHO says that the distribution of hundreds of millions of insecticide-treated bed nets to those at risk of malaria has prevented many people from contracting the deadly disease.