Malaria bigger killer than previously thought

Malaria is a killer, but a new study published in The Lancet has found that it’s a more profligate killer than previously thought and overturned a longstanding belief that it’s children under the age of 5 that are most at risk from the disease.

The study found that 1.2 million people died from malaria in 2010, which is nearly twice the number previously thought.

According to Dr Alan Lopez, the head of the University of Queensland’s School of Population Health, and a study co-author, the disparity comes from comes from re-examining the assumption that young children are most likely to succumb to the disease, while if they survive, then they develop immunity to the disease later in life.

“Despite assumptions that mainly young children die from malaria, our study identified that 42 per cent of malaria deaths occur in older children and adults,” Dr Lopez said.

The study found that more than 78,000 children aged 5 to 14, and more than 445,000 people ages 15 and older died from malaria in 2010, meaning that 42 per cent of all malaria deaths were in people aged 5 and older.

One positive note from the study is that malaria deaths are in decline, largely thanks to new anti-malarial drugs and insecticide-treated bed nets that have been rolled out in high risk areas in Africa.

Starting in 1985, malaria deaths grew every year before peaking in 2004 at 1.8 million deaths worldwide. Since then, the number of deaths has fallen annually and, between 2007 and 2010, the decline in deaths has been more than 7 per cent each year.

“We have seen a huge increase in both funding and in policy attention given to malaria over the past decade, and it’s having a real impact,” Dr Lopez said.

The study’s lead author and Director of the Institute for Health Metrics and Evaluation at the University of Washington in the US, Dr Christopher Murray, said the study’s finding that many more adults are dying from malaria is surprising.

“You learn in medical school that people exposed to malaria as children develop immunity and rarely die from malaria as adults,” said Dr Murray.

“What we have found in hospital records, death records, surveys and other sources shows that just is not the case.”

The study is published today in The Lancet 2012; 379: 413–31.