Â鶹ӰÊÓ

As the world marks World Malaria Day to commemorate the global effort to control the disease, experts note that with more than 250 million new malaria infections each year, there is still much work to be done.

Governments, aid agencies and the private sector have spent billions of dollars fighting malaria over the past decade, sending medicines and supplies to countries hit hard by the deadly infection.

While there has been progress in containing the disease, it continues to kill as many as 850,000, according to figures from the World Health Organization.

Before 2008, the WHO estimated there were nearly 500 million malaria cases and one million deaths. A report issued last week on the status of malaria in Africa, where 90 per cent of the world's cases are contracted, noted that $1.8 billion was spent fighting the disease last year, a 10-fold jump since 2004.

The report, produced by UNICEF and the UN-led partnership Roll Back Malaria, said that countries where the disease is most prevalent have produced more than 150 million insecticide-treated bed nets to protect against the mosquitoes that spread the disease and that donors have purchased 160 million badly-needed drug treatments.

But Dr. Timothy Geary, the director of McGill University's Institute of Parasitology, says the international community still has a long way to go in cutting the disease down to size.

"The most hopeful sign is that we're taking it seriously again," he told CTV.ca in a phone interview from Montreal. "We're making progress in rolling it back, but the situation is unstable."

"A lot of the drugs we have been using have lost their efficacy and there's real concern about drug resistant strains of the disease developing."

There is little data to indicate if the bed nets are reaching the people most at risk of contracting malaria. According to UNICEF and its partners, the percentage of children sleeping under bed nets ranges from four per cent in Cameroon, Swaziland and Guinea to 62 per cent in Zambia. In some countries like Tanzania and Malawi, more bed nets go to the rich than the poor, though the poor are most at risk.

There is also little evidence sick kids are getting the donated drugs. "The proportion of African children receiving (malaria medicine) is still very low," the report said.

Still the UN insists its initiatives are saving lives. "We cannot afford to relax our efforts," Dr. Coll Seck, executive director of the Roll Back Malaria Partnership, said in a statement.

"Investment in malaria control is saving lives and reaping far-reaching benefits for countries," he added. "Today, with approximately one third of the global investment needed, country programmes are saving a child's life every three minutes. This is very positive. We cannot afford to relax our efforts."

The UN said based on mathematical modeling, more than 10 million children were saved from malaria thanks to bed nets. But the study acknowledged that external aid in malaria funding "still falls short of the estimated $6 billion needed in 2010 alone for global implementation of malaria interventions."

"With strong collaboration, great progress has been made in the battle against malaria," said UNICEF Executive Director Ann M. Veneman. "But more remains to be done as children and pregnant women are still dying of this preventable and treatable disease, especially in Africa."

The greatest risk in the poorest countries

About 3.3 billion people -- nearly half of the world's population -- are at risk of malaria, and those living in the poorest countries are the most vulnerable.

Sub-Saharan African is the world's malaria hot zone. One in five of all childhood deaths in Africa are due to malaria and aid agencies have calculated that malaria kills an African child every 30 seconds. The disease also afflicts Asia, Latin America, the Middle East and even parts of Europe.

It contributes to the deaths of an estimated 10,000 pregnant women and up to 200,000 infants each year in Africa alone.

Malaria has been blamed for an average loss of 1.3 per cent of annual economic growth in countries with severe infection rates. It traps families and communities in a downward spiral of disease and poverty and impaired learning through lower attendance at schools and workplaces.

Malaria is caused by a parasite called Plasmodium falciparum, which is transmitted by mosquito bites.

Symptoms include fever, headache, and vomiting. If untreated, the disease can quickly become life-threatening by disrupting the blood supply to vital organs.

There is little likelihood of new drugs or a vaccine being developed in the short term Geary said, making eradicating the disease nearly impossible.

"The problem is this: we're never going to get rid of the mosquitoes," he said. "There's always going to be a small group of infected mosquitoes out there somewhere … waiting to spread once we drop our guard."

This has already happened, Geary said. In the 1960s, malaria was beaten back around the world by new drugs and the powerful pesticide DDT. But when DDT was banned in North America and aid groups focused their attention on other problems, malaria "came storming back," he said.

In many parts of the world, the parasites have developed resistance to malaria medicines and newer, more effective drugs are likely years away.

That has led many experts to conclude that efforts to reduce – and eventually eliminate – the disease should focus on "vector control," or preventing malaria-bearing mosquitoes from spreading it in the first place.

Measures as simple and relatively cheap as providing insecticide-laden mosquito nets can dramatically reduce the infection rate among high-risk groups, especially young children and pregnant women.

Spraying pesticides in homes and public buildings near high concentrations of mosquitoes is perhaps the most effective means of rapidly reducing rates of malarial infection.

The UN report said several African countries that have scaled up their prevention programs, including Eritrea, Ethiopia, Equatorial Guinea, Gambia, Ghana, Zambia, and Zanzibar have seen "marked reduction (30-95 per cent) in morbidity and mortality indicators."

But Geary said malaria will remain a scourge on the poorest citizens of the world's poorest nations for a long time to come.

"It's a huge challenge (and) an unfathomably massive burden on these countries economies. And it's going to be a burden for a long time."