Vivax Working Group
Vivax Working Group Meeting, Cambodia
The APMEN Vivax Working Group met in Siem Reap, Cambodia over two-and-a-half days from 26-28 November 2014. The meeting closely followed the East Asia Summit’s commitment to a malaria-free Asia-Pacific region by 2030.
Participants welcomed the opportunity to review country achievements and challenges, to hear about current technical approaches and WHO recommendations in relation to P. vivax and for Country Partners and Partner Institutions to meet in small group settings that provided enough time for careful analysis and discussion of the persisting policy barriers and research needs in support of malaria elimination.
The key diagnostic challenges discussed include: methods for detection of individuals with very low (sub-patent) levels of parasitaemia; and development of a reliable, affordable point-of-care test for G6PD activity. Additional evidence gaps of relevance to national programs include: defining optimal cut-offs for quantitative G6PD tests.
Key therapeutic challenges include: supporting primaquine effectiveness through better support mechanisms for health workers and patients to ensure primaquine adherence; short-course alternatives to primaquine; and the ability to maintain therapeutic efficacy studies in an era of declining incidence, and to share results between countries with similar epidemiology and program stages. Additional evidence gaps of relevance to national programs include: effective protocols to identify and respond to 8-aminoquinolone failures; and quantification of morbidity (e.g. due to anaemia), all-cause mortality and lost productivity in vivax cases where no radical cure is given.
Health service decision-makers and donors need to be aware of the financial cost of acute and relapsing vivax infection to the individual and their family, and to the local economy.
Key surveillance challenges included: detection of individuals with asymptomatic P. vivax carriage; better understanding of the epidemiology of G6PD variants and deficiency, and their association with risk of haemolysis; and platforms for more efficient, effective sharing of information. Additional evidence gaps of relevance to national programs include: case and foci investigation (including genetic markers to distinguish local from imported cases); and the detection and management of asymptomatic carriers of P. vivax.
The APMEN VxWG held a workshop titled “Analysis and Interpretation of Vivax Antimalarial Efficacy Studies” on 24 and 25th November prior to the annual meeting in Siem Reap.
This workshop was attended by researchers involved in the APMEN technical grants - clinical research theme and other researchers involved in vivax clinical trials with the aim to exchange experiences and discuss approaches to data analysis of these trials. Participants had time to discuss specific issues and challenges in regards to study designs and conduct of the studies. The focus of the meeting was on technical aspects around data management and analysis. Group work was conducted using 4 different datasets from Bhutan, Malaysia, Vanuatu and Bangladesh. Participants also discussed the implication these preliminary results may have for further research and program managers in the respective countries.