IHI scientist: Reform global policy on malaria urgently

A screen grab of a Lancet article by Prof. Gerry Killeen.
April 17, 2020
IHI scientist: Reform global policy on malaria urgently

The world's attention has been focused on COVID-19, but the World Health Organization [WHO] needs to take urgent action to accelerate the market entry of next-generation insecticide-treated nets, warns Professor Gerry Killeen, the newly appointed AXA Chair in University College Cork.

Professor Killeen’s warning has been published on April 16 this week in the prestigious Lancet medical journal in his paper bearing the title, “Control of malaria vectors and management of insecticide resistance through universal coverage with next-generation insecticide-treated nets.”

Prof Killeen, an expert on disease control has received an AXA Research Chair award to UCC worth €1m to bring the fight against malaria one step closer to eradication, while, at the same time, fostering improved management of wildlife areas in Africa.

Malaria still infects hundreds of millions of people each year, transmitted through the bites of mosquitoes. Currently, the most effective way to prevent it is with insecticide-treated nets (ITNs) placed over all beds and other sleeping spaces, to not only protect the human users but also kill mosquitoes attempting to attack them.

While increasingly widespread use of ITNs has achieved great reductions of malaria burden since the turn of the century, a recent WHO report has found the fight against this mosquito-borne disease stalled from 2014 onwards.

“Since the turn of the century, over 4 million malaria-related deaths have been averted in Africa, mostly through vector control using bed nets treated with exceptionally safe and affordable pyrethroid insecticides,” said Prof Killeen, an applied pathogen ecologist.

“However, progress has stalled for two major reasons: because resistance of mosquitoes to insecticides has eroded the impact of insecticide-treated nets, and because mosquitoes can avoid them by feeding upon animals, feeding outdoors or resting outdoors.”

As explained by Prof Killeen in the Lancet today, a novel range of new ITN products, treated with two or more complementary insecticides from different chemical classes, offer exciting options for tackling insecticide resistant malaria mosquitoes now and in the future.

But a delay in approving these next-generation ITNs could cost lives.

“Urgent corrective action is required to reform global policy regarding where, when and how new insecticides and new next generation ITNs are used,” Prof Killeen warns in the Lancet.

“Literally millions of lives will depend on whether we decide to use emerging new next generation ITN technologies for pre-emptive insecticide resistance management now, or in a biologically unsustainable reactive fashion later,” he writes.

His AXA-funded research at UCC will recognize the fact that not all mosquitos act the same, and can adapt to their environments.

“Not only can next-generation ITNs be used reactively now to kill the insecticide resistant mosquitoes we face to today, they can also be used to prevent mosquitoes with further forms of resistance against new insecticides from evolving over the decades ahead,” he said.

“Some feed on humans outdoors, while others exploit cattle or their wild relatives as alternative sources of blood, thereby evading interventions targeted to humans or livestock. These behaviours may make it particularly difficult to eliminate malaria from many parts of Africa where humans and wildlife co-exist”.

Prof Killeen is leading a research program to characterize the opportunities and obstacles that arise notably from biodiversity conservation efforts in Africa.

Through ground-breaking research, he aims to prove that malaria elimination will require interventions that target all the different blood-feeding behaviors mosquitoes can exhibit, including feeding upon wild animals, and that an opportunity may exist to preserve and restore insecticide susceptibility in vector populations if they can be found persisting in conversation areas where pesticides are absent.

Prof Killeen is particularly interested in Wildlife Management Areas (WMAs) in Tanzania, where he has been based at the Ifakara Health Institute (IHI) for the last 17 years.

“These transitional conservation areas are grossly understudied and their potential is far from fully exploited. Simply by doing research there, we hope to both enhance the protection and utility of these areas, while also protecting humans from the pathogens and vectors that live there. The project relates primarily to health, but it also pertains substantially to biodiversity and the environment”, he said.

By committing to share two thirds of the funds provided by AXA with IHI and a local WMA in Tanzania and supplementing that with postgraduate degree scholarships for local scientists, UCC is investing in strengthening resilience of the country at institutional level.

One reviewer of Prof Killeen’s application to the AXA Research Fund described UCC as “an outward-looking institution with a broad, interdisciplinary research interest”.

“I could not have asked for greater commitment by UCC to the principles of benefit sharing with partner institutions in low and middle-income countries,” Prof Killeen said. #