Plasmodium vivax is an important cause of malaria, associated with a significant public health burden. Whilst enhanced malaria-control activities have successfully reduced the incidence of Plasmodium ...falciparum malaria in many areas, there has been a consistent increase in the proportion of malaria due to P. vivax in regions where both parasites coexist. This article reviews the epidemiology and biology of P. vivax, how the parasite differs from P. falciparum, and the key features that render it more difficult to control and eliminate. Since transmission of the parasite is driven largely by relapses from dormant liver stages, its timely elimination will require widespread access to safe and effective radical cure.
Plasmodium vivax infection is present across most of the malaria-endemic world.P. vivax relapses, arising from dormant liver stages, cause recurrent episodes of malaria that are the main determinant of significant morbidity, mortality, and ongoing transmission.In coendemic areas, where intense malaria-control activities have reduced the burden of P. falciparum, there has been a rise in the proportion of malaria attributable to P. vivax.There is an increased risk of P. vivax after the treatment of P. falciparum in coendemic regions, suggesting potential benefit of universal radical cure for both parasites in some areas.Novel host and parasite diagnostics, single-dose tafenoquine, and short-course primaquine regimens offer hope for safer and more effective radical cure to eliminate the parasite.
Antibiotic resistance (ABR) particularly hits resource poor countries, and is fuelled by irrational antibiotic (AB) prescribing. We surveyed knowledge, attitudes and practices of AB prescribing among ...medical students and doctors in Kisangani, DR Congo.
Self-administered questionnaires.
A total of 184 questionnaires were completed (response rate 94.4%). Knowledge about AB was low (mean score 4.9/8 points), as was the estimation of local resistance rates of S. Typhi and Klebsiella spp.(correct by 42.5% and 6.9% of respondents respectively). ABR was recognized as a problem though less in their own practice (67.4%) than nation- or worldwide (92.9% and 85.5%, p<.0001). Confidence in AB prescribing was high (88.6%) and students consulted more frequently colleagues than medical doctors when prescribing (25.4% versus 11.6%, p= 0.19). Sources of AB prescribing included pharmaceutical companies (73.9%), antibiotic guidelines (66.3%), university courses (63.6%), internet-sites (45.7%) and WHO guidelines (26.6%). Only 30.4% and 16.3% respondents perceived AB procured through the central procurement and local pharmacies as of good quality. Local AB guidelines and courses about AB prescribing are welcomed (73.4% and 98.8% respectively).
This data shows the need for interventions that support rational AB prescribing.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The WHO recommends routine testing of G6PD activity to guide radical cure in patients with Plasmodium vivax malaria. Females may have intermediate G6PD enzyme activity and to date, only complex ...diagnostics are able to reliably identify them. The semi-quantitative G6PD diagnostic "One Step G6PD Test" (Humasis, RoK; "RDT") is a lateral flow assay that can distinguish deficient, intermediate, and normal G6PD status and offers a simpler diagnostic alternative.
G6PD status of participants enrolled in Malinau and Nunukan Regencies and the capital Jakarta was assessed with the RDT, and G6PD activity was measured in duplicate by reference spectrophotometry. The adjusted male median (AMM) of the spectrophotometry measurements was defined as 100% activity; 70% and 30% of the AMM were defined as thresholds for intermediate and deficient G6PD status, respectively. Results were compared to those derived from spectrophotometry at the clinically relevant G6PD activity thresholds of 30% and 70%.
Of the 161 participants enrolled, 10 (6.2%) were G6PD deficient and 12 (7.5%) had intermediate G6PD activity by spectrophotometry. At the 30% threshold, the sensitivity of the RDT was 10.0% (95%CI: 0.3-44.5%) with a specificity of 99.3% (95%CI: 96.4-100.0%); the positive predictive value was 50.0% (95%CI: 1.3-98.7%) and the negative predictive value 94.3% (95%CI: 89.5-97.4%). The corresponding figures at the 70% threshold were 22.7% (95%CI: 7.8-45.4%), 100.0% (95%CI: 97.4-100.0%), 100.0% (95%CI: 47.8-100.0%) and 89.1% (95%CI: 83.1-93.5%), respectively.
While there is a dire need for an easy-to-use, economical, semi-quantitative diagnostic for the point of care, the observed performance of the "One Step G6PD Test" in its current form was insufficient to guide antimalarial treatment.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Glucose-6-Phosphate dehydrogenase (G6PD) deficiency is the most common enzymopathy worldwide, no reliable bedside diagnostic tests to quantify G6PD activity exist. This study evaluated two novel ...quantitative G6PD diagnostics.
Participants with known G6PD activity were enrolled in Bangladesh. G6PD activity was measured by spectrophotometry, Biosensor (BS; AccessBio/CareStart, USA) and STANDARD G6PD (SG; SDBiosensor, ROK). G6PD activity was measured repeatedly in a subset of samples stored at room temperature and 4°C.
158 participants were enrolled, 152 samples tested by BS, 108 samples by SG and 102 samples were tested by all three methods. In comparison to spectrophotometry BS had sensitivity and specificity of 72% (95%CI: 53-86) and 100% (95%CI: 97-100) at 30% cut off respectively, while SG had a sensitivity of 100% (95%CI: 88-100) and specificity of 97% (95%CI: 91-99) at the same cut off. The sensitivity and specificity at 70% cut off activity were 71% (95%CI: 59-82) and 98% (95%CI, 92-100) respectively for BS and 89% (95%CI: 77-96) and 93% (95%CI: 83-98) respectively for SG. When an optimal cut-off was applied the sensitivity of the BS at 70 cut off rose to 91% 95%CI: 80-96 and specificity to 82% 95%CI: 83-89; a diagnostic accuracy comparable to that of the SG (p = 0.879). G6PD activity dropped significantly (-0.31U/gHb, 95%CI: -0.61 to -0.01, p = 0.022) within 24 hours in samples stored at room temperature, but did not fall below 90% of baseline activity until day 13 (-0.87U/gHb, 95%CI: (-1.11 to -0.62), p<0.001).
BS and SG are the first quantitative diagnostics to measure G6PD activity reliably at the bedside and represent suitable alternatives to spectrophotometry in resource poor settings. If samples are stored at 4°C, G6PD activity can be measured reliably for at least 7 days after sample collection.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In remote communities, diagnosis of G6PD deficiency is challenging. We assessed the impact of modified test procedures and delayed testing for the point-of-care diagnostic STANDARD G6PD (SDBiosensor, ...RoK), and evaluated recommended cut-offs. We tested capillary blood from fingerpricks (Standard Method) and a microtainer (BD, USA; Method 1), venous blood from a vacutainer (BD, USA; Method 2), varied sample application methods (Methods 3), and used micropipettes rather than the test's single-use pipette (Method 4). Repeatability was assessed by comparing median differences between paired measurements. All methods were tested 20 times under laboratory conditions on three volunteers. The Standard Method and the method with best repeatability were tested in Indonesia and Nepal. In Indonesia 60 participants were tested in duplicate by both methods, in Nepal 120 participants were tested in duplicate by either method. The adjusted male median (AMM) of the Biosensor Standard Method readings was defined as 100% activity. In Indonesia, the difference between paired readings of the Standard and modified methods was compared to assess the impact of delayed testing. In the pilot study repeatability didn't differ significantly (p = 0.381); Method 3 showed lowest variability. One Nepalese participant had <30% activity, one Indonesian and 10 Nepalese participants had intermediate activity (≥30% to <70% activity). Repeatability didn't differ significantly in Indonesia (Standard: 0.2U/gHb IQR: 0.1-0.4; Method 3: 0.3U/gHb IQR: 0.1-0.5; p = 0.425) or Nepal (Standard: 0.4U/gHb IQR: 0.2-0.6; Method 3: 0.3U/gHb IQR: 0.1-0.6; p = 0.330). Median G6PD measurements by Method 3 were 0.4U/gHb (IQR: -0.2 to 0.7, p = 0.005) higher after a 5-hour delay compared to the Standard Method. The definition of 100% activity by the Standard Method matched the manufacturer-recommended cut-off for 70% activity. We couldn't improve repeatability. Delays of up to 5 hours didn't result in a clinically relevant difference in measured G6PD activity. The manufacturer's recommended cut-off for intermediate deficiency is conservative.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Recent advances in G6PD deficiency screening and treatment are rapidly changing the landscape of radical cure of vivax malaria available for National Malaria Programs (NMPs). While NMPs await the ...WHO's global policy guidance on these advances, they will also need to consider different contextual factors related to the vivax burden, health system capacity, and resources available to support changes to their policies and practices. Therefore, we aim to develop an Options Assessment Toolkit (OAT) that enables NMPs to systematically determine optimal radical cure options for their given environments and potentially reduce decision-making delays. This protocol outlines the OAT development process.
Utilizing participatory research methods, the OAT will be developed in four phases where the NMPs and experts will have active roles in designing the research process and the toolkit. In the first phase, an essential list of epidemiological, health system, and political & economic factors will be identified. In the second phase, 2-3 NMPs will be consulted to determine the relative priority and measurability of these factors. These factors and their threshold criteria will be validated with experts using a modified e-Delphi approach. In addition, 4-5 scenarios representing country contexts in the Asia Pacific region will be developed to obtain the expert-recommended radical cure options for each scenario. In the third phase, additional components of OAT, such as policy evaluation criteria, latest information on new radical cure options, and others, will be finalized. The OAT will be pilot-tested with other Asia Pacific NMPs in the final phase.
Human Research Ethics Committee approval has been received from the Northern Territory, Department of Health, and Menzies School of Health Research (HREC Reference Number: 2022-4245). The OAT will be made available for the NMPs, introduced at the APMEN Vivax Working Group annual meeting, and reported in international journals.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Results-sharing with participants or their communities after the completion of research is an essential element of ethical research. The main objective of this study was to identify and document ...current practice of trial result dissemination, to explore attitudes among trialists towards result dissemination and to better understand previous experiences and barriers to returning results to participants. This mixed-methods study used a sequential exploratory design with two phases: i) an initial qualitative phase to explore the topic and to inform the quantitative data collection, ii) a quantitative survey. Findings from the survey and interviews were triangulated and presented to a network of clinical malaria researchers for validation. A total of 11 semi-structured interviews (SSIs) were conducted using an interview guide. The quantitative survey had a response rate of 19.9% (42/211). Disseminating results to participants after clinical trials was deemed critical for ethical malaria related research, with 38.1% indicating it as extremely important and 45.2% rating it as mostly important. Most respondents referred to the dissemination of results to policymakers and wider stakeholders as important aspects of research translation. The practice of patient or community engagement was prioritized in the pre-trial period and during the trial for obvious instrumental goals of improving retention, coverage and adherence, but much less priority was given to the post-trial period. The main reason for poor dissemination practice was the notion that the time lag between study participation and the availability of results was too long (42.4%). Other reasons included the assumption that the community was not interested (36.4%), and financial restraints (9.1%). The rich qualitative data revealed detailed accounts of operational, cultural, educational and economic aspects that pose further barriers to results-sharing, including limited knowledge about best practice. Better planning which includes adequate financial resourcing is required for meaningful dissemination of results to study participants. Improved institutional guidance and more stringent requirements by funders could support researchers who are generally interested and willing to complete the process. Best practice methods to conduct such dissemination remains to be explored.
The changing global health landscape has highlighted the need for more proactive, efficient and transparent health policy-making. After more than 60 years of limited development, novel tools for ...vivax malaria are finally available, but need to be integrated into national policies. This paper maps the malaria policy-making processes in seven endemic countries, to identify areas where it can be improved to align with best practices and optimal efficiency.
Data were collected during a workshop, convened by the Asia Pacific Malaria Elimination Network's Vivax Working Group in 2019, and subsequent interviews with key stakeholders from Cambodia, Ethiopia, Indonesia, Pakistan, Papua New Guinea (PNG), Sri Lanka and Vietnam. Documentation of policy processes provided by respondents was reviewed. Data analysis was guided by an analytic framework focused on three a priori defined domains: "context," "actors" and "processes".
The context of policy-making varied with available funding for malaria, population size, socio-economic status, and governance systems. There was limited documentation of the process itself or terms of reference for involved actors. In all countries, the NMP plays a critical role in initiating and informing policy change, but the involvement of other actors varied considerably. Available evidence was described as a key influencer of policy change; however, the importance of local evidence and the World Health Organization's endorsement of new treatments and diagnostics varied. The policy process itself and its complexity varied but was mostly semi-siloed from other disease specific policy processes in the wider Ministry of Health. Time taken to change and introduce a new policy guideline previously varied from 3 months to 3 years.
In the medium to long term, a better alignment of anti-malarial policy-making processes with the overall health policy-making would strengthen health governance. In the immediate term, shortening the timelines for policy change will be pivotal to meet proposed malaria elimination milestones.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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