'We can defeat malaria': Chief of Asia-Pacific alliance on mosquito-borne disease

SINGAPORE: Africa is often in the spotlight for carrying most of the global burden of malaria, but the chief of an alliance that focuses on the Asia Pacific said more can be done to eliminate the mosquito-borne disease in this region.

There were about 12,000 deaths from the disease in the Asia Pacific last year, according to a recent report released by the World Health Organization (WHO), noted Dr Sarthak Das, chief executive of the Asia Pacific Leaders Malaria Alliance.

That translates into three deaths every two hours, Dr Das told CNA’s Asia Now on Friday (Dec 9), days after the release of this year’s world malaria report.

But with a 70 per cent drop in malaria deaths in the past 20 years and given the elimination of the disease in countries like China and Sri Lanka, there is hope for the region to be rid of it, he said.

“There is no reason, as we head into 2023, why this is a disease that we should still be dealing with a decade from now,” he said.

“We do have the tools; we do have the wherewithal in terms of programmatic knowledge and what we need is political commitment … and sufficient resources to finish the job.”

MALARIA-FREE FUTURE

Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes.

According to the WHO report, there were an estimated 619,000 malaria deaths globally in 2021 compared to 625,000 in 2020, the first year of the pandemic. In 2019, before the COVID-19 pandemic struck, the number of deaths stood at 568,000.

WHO director-general Tedros Adhanom Ghebreyesus noted that following a marked increase in malaria cases and deaths in the first year of the COVID-19 pandemic, malaria-affected countries redoubled their efforts and were able to mitigate the worst impacts of COVID-related disruptions to malaria services.

“We face many challenges, but there are many reasons for hope. By strengthening the response, understanding, and mitigating the risks, building resilience, and accelerating research, there is every reason to dream of a malaria-free future,” he said.

TOOLS TO ELIMINATE DISEASE

While there are interesting developments like new generations of insecticide-treated nets - typically used as a key line of defence against malaria - and genetically modified mosquitoes, Dr Das turned the focus on traditional methods in the fight against it.

“I think the really important thing for us as a community in public health focused on malaria, but also as a global community is to recognise there are bread and butter tools that we've been using to eliminate this disease and that with really sound operational controls … we can defeat malaria,” he said.

While newer tools can accelerate progress towards getting rid of the disease, and the science should move forward, “we mustn't sit back and wait and think that there's a magic bullet”, he said.

He noted that the first vaccine against malaria approved by the WHO prevents infection caused by one type of parasite and there are none currently for the type of parasite seen a lot in the Asia Pacific, the Plasmodium vivax.

“This is the oldest pandemic that we know. We choose to not call it a pandemic because it's happening mostly in poor countries, but it is a pandemic,” said Dr Das.

PROBLEMS WITH EXISING TOOLS

Another expert, Professor James Beeson, stressed the importance of new tools and strategies, given the waning effectiveness of commonly used methods to prevent malaria.

Using bed nets treated with insecticides, and to some extent, spraying of insecticides indoors, has been an important strategy in preventing malaria because the disease is transmitted through the bite of mosquitoes, said Prof Beeson, who is head of Malaria Immunity and Vaccines Laboratory at the Burnet Institute, an independent medical research organisation.

But he said that such strategies are becoming less effective due to several factors, including mosquitoes becoming resistant to the insecticides and changing their behaviour - biting people when they are not protected by mosquito nets.

“We've also seen changes in the distribution of mosquitoes. There are concerns about mosquitoes transmitting malaria in urban or … semi-urban areas, which generally hasn't happened a lot over the years,” he told CNA's Asia First.

He said that historically, malaria has been a problem for rural communities, mainly because the mosquitoes that transmit malaria do not like urban environments, partly because of pollution. If malaria starts becoming more established in urban areas, that could lead to “very major increases in malaria burden”, he cautioned.

“We definitely need new tools or new strategies, such as highly effective vaccines,” he said.

COMPLEXITY OF MALARIA VACCINE

The WHO-approved vaccine against the disease is starting to roll out in areas with high transmission of malaria and has been implemented for young children and infants, Prof Beeson said. WHO said the vaccine, which requires four doses, has a 30 per cent reduction in deadly severe malaria.

On why the vaccine is not as effective as the one against the COVID-19 virus, Prof Beeson said that the development of a malaria vaccine is not as straightforward.

“For malaria, there are … hundreds of different proteins, or what we call targets. It’s a much much more complicated organism many, many times more complicated than a virus like COVID,” he said.

“This complexity means that it's been really a much bigger task to understand how to effectively make a vaccine that is highly protective.”

He added that there has not been enough investment to bring in the best technology and develop highly protective vaccines.