Malaria is one of the world’s deadliest killers, causing debilitating illness and enormous human suffering and affecting some of the poorest, most marginalised populations on the planet.

The sheer numbers are almost incomprehensible. Every year, malaria claims about 655,000 lives, and there are an estimated 216 million cases of the disease.

In the Asia-Pacific region alone, more than 2.3 billion people are at risk of being infected with mal-aria parasites.

It is estimated that in 2010, more than 32 million malaria cases occurred across the region, leaving a crippling legacy of income loss, absenteeism, spiralling treatment costs - and, tragically, more than 42,000 people dead.

Yet malaria is entirely preventable and curable, thanks to several simple, low-cost solutions that have slashed infection rates over the past decade: long-lasting, insecticide-treated bed nets; indoor spraying; prevention and treatment of malaria during pregnancy; and early detection, diagnosis and treatment.

But a new threat has emerged in the Asia-Pacific that could undo all the recent, hard-won gains.

Evidence of rising resistance to the front-line treatment drug artemisinin in Cambodia and the nations of the Greater Mekong - Vietnam, Myanmar and Thailand - sounds a warning bell to the region and the rest of the world.

For years, artemisinin combin-ation therapy has been the most effective way to treat the most lethal species of malaria parasite, Plasmodium falciparum.

When administered correctly, it can protect the region for years to come. But for some time now, it hasn’t always been used as it should.

Fake or counterfeit drugs of poor quality, or people not completing a full course of treatment, have resul-ted in artemisinin-resistant strains.

There is now broad agreement that only aggressive, collective, long-term action and laser-sharp focus can prevent this scenario unfolding.

Australia views malaria as a pressing public-health issue for the region, and since 2003 has supp-orted programs to fight the disease.

It provides funding to the World Health Organisation and the Global Fund, both of which are big inter-national players in public health, and I was appointed last year as Australia’s new ambassador for HIV/AIDS, tuberculosis and malaria.

The role has been expanded to cover tuberculosis and malaria to reflect just how seriously Aust-ralia is taking the challenge of these diseases in the Asia-Pacific neighbourhood.

In further recognition that malaria is a priority issue, and to help drive regional co-operation, Australia hosted the Malaria 2012: Saving Lives in the Asia-Pacific conference in Sydney last year.

Cambodia’s Minister for Health, His Excellency Dr Mam Bunheng, and his team played an active part in this conference, drawing attention to the challenges of providing preventative and curative services for internal migrant workers and

for migrant workers who cross international borders.

Conference delegates from more than 30 countries acknowledged the impressive progress in the fight against malaria and committed to working together to achieve reg-ional and global malaria-reduction targets by 2015.

This commitment was reinforced at the East Asia Summit, held in Phnom Penh last November, where an Australian-initiated declaration was adopted by the region’s leaders, committing countries to working collaboratively to address malaria control and resistance to anti-malarial medicines.

To this end, I am pleased to announce that Cambodia has been chosen as the hub for the regional Emergency Response to Artemisinin Resistance Project, a joint initiative of AusAID, the World Health Organ-isation and the Bill and Melinda Gates Foundation.

This program is being launched today to mark World Malaria Day.

Different countries have different challenges, but what we do know is that only with sufficient funding, increased effort and capacity can the war against malaria be won.

We all need to be prepared and to join forces to face these challenges together. We are heartened by the willingness of Cambodia and other countries in the region to collabor-ate in tackling this foe.

James Gilling is AusAID‘s first assistant director-general for policy and sectors and ambassador for HIV/AIDS, TB and malaria.