Time to share: DNA-based tools for malaria control worldwide

Researchers contributing to large-scale genetic studies have to overcome some unique and often site-specific challenges: evading marauding elephants, using folklore to explain research aims to communities, or in the case of Dr Muminatou Jallow, a paediatrician in The Gambia, obtaining permission from labouring mothers to sample blood from their babies’ umbilical cords after birth.

These are just some of the many stories that have emerged from the Malaria Genomic Epidemiology Network (MalariaGEN), an extensive collaboration of researchers in 30 countries led by Oxford professor Dominic Kwiatkowski, since it was launched in 2005 with funding from the Gates Foundation’s Grand Challenges in Global Health.

Dr Jallow had found that asking for permission to collect blood samples from umbilical cords during antenatal clinics was ineffective, as many women give birth at home, so she asked before birth – often once women had gone into labour.

Through MalariaGEN, Dr Jallow, like all collaborators in this data-sharing community, was able to enrich her studies with genetic data for her samples. And through this process, MalariaGEN and its partners are building a huge database of DNA sequences covering all three parties in the malaria triangle: humans, mosquitoes and parasites, along with the necessary skills and technical infrastructure to support complex genetic analyses.

'It’s very important to bring out all the tools we can to work out how the parasite and mosquito populations are changing, and to provide new tools to track the spread of drug resistance,' says Professor Kwiatkowski.

A crucial advance has been learning to sequence the parasite genome directly from patient blood samples, providing a quick and powerful means to measure diversity in the parasite genome and detect changes in parasite populations.

'We can now investigate the characteristics of parasite populations to reveal patterns of emerging drug resistance,' explains Professor Kwiatkowski. An initial comparison of parasites from various locations in Africa, Asia and South America has already yielded insight into parasite populations. 'In Western Cambodia, a global epicentre of drug resistance, we found that the pattern of parasite population diversity is quite distinct from the other parts of South East Asia and elsewhere in the world'.

Underpinning these genetic advances are strong relationships carefully cultivated thorough years of collaboration. From the outset, MalariaGEN recognised the importance of building a sustainable network and addressing the ethical aspects of its research, such as those pertaining to community engagement, data-sharing and obtaining informed consent. This approach is reflected in the ethical framework they have developed in collaboration with Professor Michael Parker, Director of the Ethox Centre in Oxford’s Department of Public Health.

In this way, the network helps researchers to enrich their studies with critical genetic data and to receive recognition for their contributions to networked science – while building the global resources that are increasingly important for understanding disease. 'It’s very important to bring out all the tools we can to work out how the parasite and mosquito populations are changing, and to provide new tools to track the spread of drug resistance,' says Professor Kwiatkowski.