Despite numerous initiatives aimed at eradicating malaria in Kenya, the disease still remains a leading cause of death, claiming thousands of lives each year. The most affected are children below five years and pregnant women.
For those diagnosed with the disease, treatment using recommended drugs known as Artemisinin Combination Therapies (ACTs) is their best bet at saving their lives.
Yet, the future of these drugs appears bleak in the face of emerging threat of resistant malaria parasites in South East Asia.
Just as was the case with previous malaria drugs, history shows that resistance usually begins in the Asian continent before moving gradually, and eventually spreading to Sub-Saharan Africa.
As such, researchers keen on tracking the performance of malaria drugs and detecting resistance as soon as it begins, have always focused on the Asian continent.
Over the years, scientists have conducted numerous studies in South East Asia aimed at understanding triggers for resistant parasites as well as mitigating factors to forestall or delay their spread to other countries.
A new study casts doubt on the effectiveness of this ‘looking outward’ approach and the assumption that resistant parasites flow from Asia to Africa.
The study, which was recently published in the Science Journal, revealed that malaria parasites in most African countries, including Kenya, have inherent features or characteristics that can enable them to develop resistance ACTs.
This means that resistance may develop locally, even as malaria experts continue to ‘point fingers’ at Asia that has over the years been viewed as the culprit.
The first of its kind, the study which was conducted by a team of African researchers known as the Plasmodium Diversity Network Africa (PDNA), looked at the genetic variety of malaria parasites across the continent.
Researchers collected samples of malaria parasite known as plasmodium falciparum (major cause of the disease in Africa) from 15 countries including Kenya, Ghana, Malawi, Mali, Senegal and Cameroon.
Results showed that the flow of different malaria parasite genes is happening in all directions and not just from South East Asia to Sub-Saharan Africa.
Indeed, the researchers noted that parasites in Africa were sharing genetic material with each other- including genes that can confer resistance to antimalarial drugs — from all directions within the continent.
This was an indication that drug resistant malaria parasites could also emerge independently in Africa, just as South East Asia, and spread rapidly from one country to another.
“Genetic material originating from all directions was shared by all malaria parasite populations, indicating that the flow of genes is multidirectional, as opposed to unidirectional — from East to West — as previously thought. This is crucial information for understanding how resistance to malaria drugs is developing in Africa,” said Professor Abdoulaye Djimdé, an International Fellow at the Welcome Sanger Institute and Chief of the Molecular Epidemiology and Drug Resistance Unit at the University of Bamako who participated in the study.
“Whatever the historic factors affecting the flow of genes, the multidirectional flow we’ve identified raises the prospect of continental spread of resistance to ACTs, which could arise from anywhere in Africa,” said Dr Alfred Amambua-Ngwa, the first author of the study and Assistant Professor in the MRC Unit of The Gambia at the London School of Hygiene and Tropical Medicine
He noted that continued large-scale surveillance of malaria parasite genes in Africa is vital to track the emergence and spread of drug resistance.
Even though Africa is not yet affected by the problem, the researchers stated that the emergence of malaria parasites that are resistant to ACTs would spell doom to the continent and reverse gains already made in the fight.
As a safeguard, they called for the development of new forms of treatment to tackle the disease, should the current ones become ineffective due to the looming resistance threat.
Under the Malaria Research for Capacity Development in West and Central Africa (MARCAD), the institution is also conducting research aimed at determining how long insecticide resistant malaria mosquitoes live in the wild.
The findings will be useful to Kenya and other African countries, which are currently grappling with the resistance of malaria mosquitoes to insecticides in bed nets and indoor residual sprays used to kill them.
“Normal malaria mosquitoes will be killed by insecticides. But the resistant ones won’t die. So our focus is on them. We want to know how long they can live so we can determine the number of malaria cases they are likely to transmit. This will help us know how long it will takes us to eliminate malaria,” said Dr Kevin Opondo, a researcher, during the recent 2019 DELTAS Africa Scientific conference that was convened by the African Academy of Sciences.
According to Dr Opondo, who is conducting the research using genetic tools, the findings will enable countries to identify appropriate and effective strategies for malaria prevention, treatment and elimination.
“The goal here is to promote evidence-based decision making,” he said.