Drug resistance puts Africa’s malaria success in peril

[NAIROBI] Resistance to the world’s most powerful malaria drug could emerge in Africa, a genetic study has shown.

Malaria deaths in Africa were approximately halved between 2000 and 2015, but progress has stalled in the past few years, according to the WHO.

The study, by the network of African scientists, the Plasmodium Diversity Network Africa, published in Science last month (23 August), looked at samples of Plasmodium falciparum collected from 15 African countries including Cameroon, Ethiopia, Ghana, Malawi, Mali and Senegal to analyse genetic variations.

Of the five parasites that cause malaria, P. falciparum accounts for most of the malaria cases, contributing to 99.7 per cent of Africa’s almost 200 million malaria cases in 2017, the WHO says.

“This is crucial information for understanding how resistance to malaria drugs is developing in Africa.”

Abdoulaye Djimdé, Wellcome Trust Sanger Institute

According to the researchers, populations of P. falciparum in different regions of Sub-Saharan Africa are sharing genetic materials in ways that could make the fight against resistance to antimalarials challenging.

“Genetic material originating from all directions was shared by all populations, indicating that the flow of genes is multi-directional, as opposed to unidirectional from east to west as previously thought,” says Abdoulaye Djimdé, a co-author of the study, in a statement released last month (22 August) by the UK-based Wellcome Sanger Institute, where he is an international fellow.

“This is crucial information for understanding how resistance to malaria drugs is developing in Africa."

They found the parasite sharing genes that can confer resistance to artemisinin, which is used as the basis for the most powerful malaria treatments.

Southeast Asia is already dealing with artemisinin-resistant P. falciparum, and this study suggests that artemisinin resistance may also emerge independently in Sub-Saharan Africa.

Alfred Amambua-Ngwa, the study’s lead author and an assistant professor at the Medical Research Council Unit in The Gambia, London School of Hygiene and Tropical Medicine, said policymakers should be aware that if resistance were to emerge or spread in Africa, this will reverse the gains made in malaria trends over the last two decades.

The WHO and national malaria programmes should be more vigilant in observing and documenting any changes in treatment response for prompt action, he tells SciDev.Net.

Gunturu Revathi, head of microbiology at the Aga Khan University Hospital, Kenya, says that “malaria is the queen of infectious diseases”.

“The implications of malaria are very clear: loss of life, loss of productivity and   increased burden on the already crumbling healthcare system,” Revathi says.

She commends the researchers for using genome sequencing to identify the spread of P. falciparum across different geographic locations in Africa over time.

But she adds that interpreting data from genome sequencing could be challenging. “We need more well trained and experienced scientists in interpretation of sequencing data”.

Building competent scientists in interpretation of sequencing data, according Revathi,  is more than short, superficial training as assumed in places such as Kenya. It takes at least five-eight years in bioinformatics training with well-grounded faculty. 
 
This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk.