Exploring new tools for P. vivax elimination in Brazil
On 26th April 2022, Medicines for Malaria Venture (MMV) and PATH hosted the PAVE Symposium as part of the largest malaria congress in Brazil to discuss evidence generation efforts and potential implications for managing Plasmodium vivax (P. vivax) malaria. The symposium featured representatives from the Brazilian Ministry of Health (MoH), the Pan American Health Organization (PAHO), and local malaria researchers who presented and discussed the recent and ongoing efforts to control and eliminate malaria in Brazil focusing on the role of new technologies and approaches. Brazil leads the way with evidence generation on radical cure innovation through a real-world study known as TRuST. TRuST, the Tafenoquine Roll-out STudy, is looking at the introduction of a point-of-care quantitative G6PD test and appropriate treatment with either primaquine or single-dose tafenoquine (TQ) in the municipalities of Manaus (AM) and Porto Velho (RO). Cost-effectiveness and budget impact analyses are also being performed to support this evidence generation effort. The symposium was an important opportunity to take stock of these research efforts and to start to consider the potential role of new tools in eliminating malaria in Brazil.
The first topic of the symposium was a preview of the new Brazilian Malaria Elimination Plan, subsequently launched on May 11th, which aims to eliminate Plasmodium falciparum (P. falciparum) by 2030 and P. vivax malaria by 2035. The plan includes three pillars of action: prompt diagnosis and treatment, promotion of activities related to malaria prevention and control, and transforming malaria surveillance into a core intervention. Following these three pillars, the MoH aims to reduce malaria cases to fewer than 68,000 by 2025 and achieve 0 malaria cases by 2035.
“There are some challenges we need to face, such as the low diagnostic coverage in remote areas and among indigenous populations as well as ensuring health professionals are trained in the use of new tools. The new Brazilian Malaria Elimination Plan covers the period 2022 to 2025 and aims to strengthen local malaria elimination efforts via a range of investments, including hiring and training municipal health professionals, improving local epidemiological capacity, developing local malaria elimination plans, and publishing community education guides,” explained Cassia Rangel, Director of the Department of Immunization and Communicable Diseases (DEIDT) of the MoH.
Francisco Edilson de Lima, Deputy Coordinator of the General Coordination of Zoonosis and Vector Transmissible Diseases (CGZV) of the MoH, shared a country perspective of future achievements and challenges for new tools to optimize radical cure for P. vivax malaria. Edilson highlighted the need for further discussion on TQ administration in children and adolescents under 16, an age group with a high incidence of P. vivax cases. He also highlighted the need to improve information systems and increase health care worker participation in trainings on new tools and strategies. Brazil has made significant progress, and Edilson underlined the need to recognize the work of local institutions on treatment surveillance and to concentrate efforts in areas with the highest burden of relapsing cases. He concluded by reaffirming the country’s commitment to promoting research and technical discussions on the evidence generated to optimize radical cure through innovation.
One recent, key milestone in innovation for vivax malaria was the start of the TRuST study. Dr. Marcus Lacerda, a physician at the Tropical Medicine Foundation (FMT) and the study’s Principal Investigator, explained that TRuST seeks to understand the feasibility of providing radical cure treatment based on the results of G6PD testing to malaria patients in the municipalities of Manaus and Porto Velho. “The TRuST study is a way of tracking the malaria treatment with TQ that is being carried out temporarily by the national and local health care authorities in the field. This single dose of TQ can be very beneficial to patients, as it provides radical cure in a shorter time,” said Dr. Lacerda. In February 2022, after a successful first phase in high- and medium-level facilities, the study moved to its second phase, expanding the study’s sites to include lower-level facilities. The analysis of the study’s second phase will begin during the third quarter of 2022. The TRuST study’s final goal is to provide critical evidence to guide the MoH on the optimal deployment of TQ and G6PD testing in the Brazilian Unified Health System (SUS).
The researchers Daniel Villela and Marcia Pinto from Fiocruz presented on the work they are doing to investigate the potential public health and budget impact of introducing TQ and G6PD testing to SUS. According to a study co-authored by Villela, malaria treatment with TQ could increase the rate of radical cure by up to 20% , leading to a predicted 38% reduction in P. vivax transmission, averting more than 214,000 cases over a five-year period. Dr. Pinto's budget impact analysis is currently undergoing validation of the model and parameters with the MoH, a key step to ensure the results reflect the reality of malaria management.
Sheila Rodovalho, Malaria and Neglected Infectious Diseases National Consultant at PAHO’s Brazilian office, concluded the symposium by sharing priorities for the American region to reach malaria elimination, “PAHO proposes that each country must develop mechanisms to assess relapses, address gaps in evidence, and implement strategic policies. We encourage the sharing of experiences, south to south cooperation and working with international organizations to reach this goal.”
The Partnership for Vivax Elimination (PAVE) is led by Medicines for Malaria Venture (MMV) and PATH bringing together National Malaria Programmes, researchers, funders, and other organizations to eliminate P. vivax malaria. PAVE supports countries in achieving their elimination goals through: working with National Malaria Programmes to identify optimal radical cure tool options and strategies for their given contexts to achieve higher patient coverage; generating and making available high-quality evidence on P. vivax case management that can be considered by national governments in making policy decisions and guiding implementation; and advancing the development and deployment of quality-assured medicines and diagnostics for P. vivax.