WHO is launching today a new strategy to respond to the urgent problem of antimalarial drug resistance in Africa. The strategy is launched during Global Antimicrobial Awareness Week, an annual global campaign to raise awareness of the growing threat of resistance to antibiotics and other drugs.
In recent years, there have been reports from Africa of emerging parasite resistance to artemisinin, the central compound of the best available drugs to treat malaria. There are also worrying signs that parasites in some areas may be resistant to drugs commonly combined with artemisinin. Strong measures are needed to protect its effectiveness.
“Although resistance to antimalarial drugs is a serious concern, artemisinin-based combination therapies (ACTs) remain the best available treatment for treatment without complications. P falciparum malaria,” says Dr Pascal Ringwald, lead author of the new strategy and coordinator of WHO’s Global Malaria Programme. “Health care providers should continue to prescribe and use ACT to treat confirmed malaria.”
ACT at a glance
The WHO currently recommends 6 different artemisinin-based combination therapies (ACT) as first-line and second-line treatment for uncomplicated treatment. P falciparum malaria. plant isolated Artemisia annuaartemisinin and its derivatives are powerful drugs known for their ability to rapidly reduce the number of plasmodium parasites in the blood of malaria patients. ACTs combine an artemisinin derivative (artesunate, artemether, or dihydroartemisinin) with a partner drug. The function of the artemisinin compound is to reduce the number of parasites during the first 3 days of treatment, while the function of the associated drug is to eliminate the remaining parasites and cure the infection.
Increased resistance to antimalarial drug regimens
On a global scale, parasite resistance to artemisinin has been identified in the Greater Mekong subregion and in several areas of Africa, notably Eritrea, Rwanda, and Uganda. While artemisinin resistance alone rarely leads to treatment failure, resistance to both artemisinin and the partner drug within ACT drug regimens can lead to high rates of treatment failure, as seen in studies. recent years in parts of the Greater Mekong subregion.
To date, resistance to drugs associated with ACT has not been confirmed in Africa, and treatment remains highly effective. However, there are some worrying signs: data are lacking for several countries, and conflicting findings about the efficacy of ACT need to be further evaluated.
Given the heavy reliance on ACTs in Africa, total treatment failure could have very serious consequences. “We don’t have as many options for malaria drugs,” says Dr. Dorothy Achu, WHO’s new team leader for tropical and vector-borne diseases for the WHO African region. As it stands, we only have artemisinin-based combination therapies for uncomplicated malaria. So any threat to these drugs could lead to a lot of cases and deaths, which we obviously want to avoid,” she added.
In 2016, researchers at Imperial College London modeled the potential impact of widespread resistance to both artemisinin and an associated drug in Africa. Under this scenario, there would be approximately 16 million more malaria cases each year, and around 360,000 more severe cases requiring hospitalization, which in turn would lead to almost 80,000 additional malaria deaths per year. Under this same scenario, the annual economic impact on the entire African continent was estimated at US$1 billion.
WHO’s new strategy builds on lessons learned from previous global plans and complements existing strategies, including broader efforts to respond to antimicrobial resistance. Its goal is to minimize the threat and impact of antimalarial drug resistance in Africa through 4 pillars:
- strengthen surveillance of the efficacy and resistance of antimalarial drugs;
- better optimize and regulate the use of diagnostics and therapies to limit drug pressure through preventive measures;
- respond to resistance by limiting the spread of parasites resistant to antimalarial drugs;
- stimulate research and innovation to make better use of existing tools and develop new tools against antimalarial drug resistance.
The strategy’s 20 recommended interventions include, for example, generating standardized data on drug efficacy, promoting equitable access to quality diagnostics and drugs, ensuring optimal vector control coverage in priority areas, and developing innovative tools to limit malaria infection and transmission. Interventions need to be tailored to the local context, with the support of global and regional stakeholders.
All of these interventions require strong health systems and investments in primary health care, which are the backbone of any successful response to malaria.
Twenty interventions grouped into the four pillars of the Strategy to address resistance
Africa, the most affected by malaria
Sub-Saharan Africa bears almost the entire global malaria burden, accounting for approximately 96% of malaria cases and deaths in 2020; approximately 4 out of 5 of these deaths occurred among children under the age of five.
Despite considerable efforts to address malaria in Africa over the past 2 decades, progress has stalled in recent years, and in many countries with a high burden of disease, cases are on the rise. Emerging threats, such as resistance to antimalarial drugs, could further derail progress.