Prevalence of malaria and its risk factors in Lake Tana and surrounding areas, northwest Ethiopia.

BACKGROUND: In Ethiopia, malaria is a major concern to the health, and socio-economic development of the country because of its occurrence at the peak agricultural activities. Factors such as environmental, human host, parasite, and vector determine malaria transmission. Therefore, the present study was conducted to determine the prevalence and associated factors of malaria among febrile patients who visited selected health centres. METHODS: Institutional-based cross-sectional study was conducted between October 2020 to July 2021 in eight selected health centres located in Lake Tana and its surrounding areas. A simple random sampling technique was used to select febrile patients. Thick and thin blood films were prepared and processed according to the WHO guidelines. Socio-demographic and malaria risk factors were collected from study participants who could read and write using a self-administered questionnaire, whereas face-to-face interview was used to collect information from those participants who could not write and read. The strength of association between risk factors and malaria was assessed using univariate and multivariate logistic regression models. RESULTS: Of the total (531) febrile patients, 75.3% were malaria negative and 24.7% (overall prevalence) were malaria confirmed cases. Most of the infections were caused by Plasmodium falciparum (72.5%) followed by Plasmodium vivax (23.7%) and mixed-species (3.8%). The highest prevalence was recorded in Kidist Hana (51.5%) followed by Robit (34.8%), Gorgora (30.3%), and Wusha Tiris (25%) health centres. In terms of months, the highest prevalence (37.5%) was detected in October whereas the lowest (14%) was in March. Logistic regression analysis revealed that gender (p = 0.023), educational level (p = 0.025), study month (p = 0.036), presence of eave in the house (p = 0.002) and wall openings (p = 0.041), not using bed nets (p = 0.001), sleeping in the same house with cattle (p = 0.031) and the distance between mosquito-breeding site and living house (p = 0.020) were explanatory risk factors significantly associated with malaria among studied participants. CONCLUSIONS: In this study, we confirmed that the occurrence of malaria prevalence was high and continued against the Ethiopian malaria elimination plan of 2021-2025. Therefore, to meet the goals of this plan, the current prevention and control efforts should be stepped up even better in the coming years.

Alkyne modified purines for assessment of activation of Plasmodium vivax hypnozoites and growth of pre-erythrocytic and erythrocytic stages in Plasmodium spp.

Malaria is a major global health problem which predominantly afflicts developing countries. Although many antimalarial therapies are currently available, the protozoan parasite causing this disease, Plasmodium spp., continues to evade eradication efforts. One biological phenomenon hampering eradication efforts is the parasite's ability to arrest development, transform into a drug-insensitive form, and then resume growth post-therapy. Currently, the mechanisms by which the parasite enters arrested development, or dormancy, and later recrudesces or reactivates to continue development, are unknown and the malaria field lacks techniques to study these elusive mechanisms. Since Plasmodium spp. salvage purines for DNA synthesis, we hypothesised that alkyne-containing purine nucleosides could be used to develop a DNA synthesis marker which could be used to investigate mechanisms behind dormancy. Using copper-catalysed click chemistry methods, we observe incorporation of alkyne modified adenosine, inosine, and hypoxanthine in actively replicating asexual blood stages of Plasmodium falciparum and incorporation of modified adenosine in actively replicating liver stage schizonts of Plasmodium vivax. Notably, these modified purines were not incorporated in dormant liver stage hypnozoites, suggesting this marker could be used as a tool to differentiate replicating and non-replicating liver forms and, more broadly, as a tool for advancing our understanding of Plasmodium dormancy mechanisms.

Using observed incidence to calibrate the transmission level of a mathematical model for Plasmodium vivax dynamics including case management and importation.

In this work, we present a simple and flexible model for Plasmodium vivax dynamics which can be easily combined with routinely collected data on local and imported case counts to quantify transmission intensity and simulate control strategies. This model extends the model from White et al. (2016) by including case management interventions targeting liver-stage or blood-stage parasites, as well as imported infections. The endemic steady state of the model is used to derive a relationship between the observed incidence and the transmission rate in order to calculate reproduction numbers and simulate intervention scenarios. To illustrate its potential applications, the model is used to calculate local reproduction numbers in Panama and identify areas of sustained malaria transmission that should be targeted by control interventions.

The global burden of Plasmodium vivax malaria is obscure and insidious.

J. Kevin Baird and colleagues, examine and discuss the estimated global burden of vivax malaria and it's biological, clinical, and public health complexity.

Recent Molecular Assessment of Plasmodium vivax and Plasmodium falciparum Asymptomatic Infections in Botswana.

In 2016, we reported the presence of Plasmodium vivax in Botswana through active case detection. A real-time PCR was used during a similar study in 10 districts to assess changes in the P. vivax prevalence. We assessed 1,614 children (2-13 years of age) for hemoglobin (Hb; g/dL) and Plasmodium parasites. The median age of all participants was 5.0 years (25th percentile, 3 years; 75th percentile, 8 years). The median Hb (g/dL) level was 12.1, but 18.3% of the participants had anemia (Hb < 11.0 g/dL); these participants were clustered in the younger than 5 years age group in all districts (P < 0.001). The risk of anemia decreased with age 5 years or older (odds ratio [OR], 0.26; 95% confidence interval [CI], 0.197-0.34; P < 0.001). The prevalence rates of Plasmodium parasites were as follows: P. vivax, 12.7%; P. falciparum, 12.7%; P. malariae, 0.74%; and P. ovale (P. ovale curtisi), 0.68%. Mixed infection rates were as follows: P. falciparum and P. vivax, 2.35%; P. falciparum and P. ovale curtisi, 0.56%; P. vivax and P. malariae, 0.06%; and P. falciparum and P. malariae, 0.68%. The infections were largely asymptomatic (99.6%). Using logistic regression, the risk of infection with P. vivax was highest in Kweneng East (OR, 6.2; 95% CI, 2.9-13.1), followed by South East (OR, 5.6; 95% CI, 2.5-12.3) and Ngami (OR, 5.1; 95% CI, 2.2-12.0). Compared to the risk of infection for children younger than 5 years, the risk of infection decreased for children 5 years or older in regions with high rates of P. vivax and P. falciparum infections. P. vivax and P. falciparum have expanded within the asymptomatic population in Botswana; therefore, careful attention is required for their elimination.

Socio-economic determinants of malaria in tribal dominated Mandla district enrolled in Malaria Elimination Demonstration Project in Madhya Pradesh.

BACKGROUND: Malaria is known as a disease of poverty because of its dominance in poverty-stricken areas. Madhya Pradesh state in central India is one of the most vulnerable states for malaria morbidity and mortality. Socio-economic, environmental and demographic factors present challenges in malaria control and elimination. As part of the Malaria Elimination Demonstration Project in the tribal district of Mandla in Madhya Pradesh, this study was undertaken to assess the role of different social-economic factors contributing to malaria incidence. METHODS: The study was conducted in the 1233 villages of district Mandla, where 87% population resides in rural areas. The data was collected using the android based mobile application-SOCH for a period of 2 years (September 2017 to August 2019). A wealth index was computed along with analysis of the socio-economic characteristics of houses with malaria cases. Variables with significant variation in malaria cases were used in logistic regression. RESULTS: More than 70% of houses in Mandla are Kuccha (made of thatched roof or mud), 20% do not have any toilet facilities, and only 11% had an annual income of more than 50,000 INR, which converts to about $700 per year. Households with younger heads, male heads, more number of family members were more likely to have malaria cases. Kuccha construction, improper water supply, low household income houses were also more likely to have a malaria case and the odds doubled in houses with no toilet facilities. CONCLUSION: Based on the results of the study, it has been found that there is an association between the odds of having malaria cases and different household variables such as age, gender, number of members, number of rooms, caste, type of house, toilet facilities, water supply, cattle sheds, agricultural land, income, and vector control interventions. Therefore, a better understanding of the association of various risk factors that influence the incidence of malaria is required to design and/or deploy effective policies and strategies for malaria elimination. The results of this study suggest that appropriate economic and environmental interventions even in low-income and poverty-stricken tribal areas could have huge impact on the success of the national malaria elimination goals.

An Activation-Clearance Model for Plasmodium vivax Malaria.

Malaria is an infectious disease with an immense global health burden. Plasmodium vivax is the most geographically widespread species of malaria. Relapsing infections, caused by the activation of liver-stage parasites known as hypnozoites, are a critical feature of the epidemiology of Plasmodium vivax. Hypnozoites remain dormant in the liver for weeks or months after inoculation, but cause relapsing infections upon activation. Here, we introduce a dynamic probability model of the activation-clearance process governing both potential relapses and the size of the hypnozoite reservoir. We begin by modelling activation-clearance dynamics for a single hypnozoite using a continuous-time Markov chain. We then extend our analysis to consider activation-clearance dynamics for a single mosquito bite, which can simultaneously establish multiple hypnozoites, under the assumption of independent hypnozoite behaviour. We derive analytic expressions for the time to first relapse and the time to hypnozoite clearance for mosquito bites establishing variable numbers of hypnozoites, both of which are quantities of epidemiological significance. Our results extend those in the literature, which were limited due to an assumption of collective dormancy. Our within-host model can be embedded readily in multiscale models and epidemiological frameworks, with analytic solutions increasing the tractability of statistical inference and analysis. Our work therefore provides a foundation for further work on immune development and epidemiological-scale analysis, both of which are important for achieving the goal of malaria elimination.

Malaria radical cure opportunity assessment in India: Discussing opportunities through stakeholder convening workshop and recommendation for improved access to malaria treatment.

India contributes to over 40% of the global Plasmodium vivax disease burden, and P. vivax contributes to approximately one-third of all malaria in India. Government of India has set goals to eliminate malaria by 2030. Doing so will require scaling up existing and new strategies, treatments and diagnostic tools. Access to appropriate diagnosis and treatment for P. vivax malaria is currently limited, and it is unclear how new tools will be rolled out. To support the government in its malaria elimination efforts, the current challenges associated with access to best clinical management of vivax malaria must be understood and mitigated to effectively deploy new tools and scale up existing solutions. The recent Food and Drug Administration (US-FDA) as well as Therapeutics Goods Administration (Australian TGA) approval of tafenoquine, developed by GSK GlaxoSmithKline and Medicines for Malaria Venture (MMV) as a new single-dose radical cure treatment for P. vivax malaria, and the commercial availability of new point-of-care glucose-6-phosphate dehydrogenase (G6PD) tests provide new opportunities to improve clinical management of vivax malaria in India. This report discusses the background, objectives, implementation strategies, and next steps that came out of the Stakeholder Workshop on Malaria Radical Cure in New Delhi, India on 4 February 2019. The focus was to understand the risks and opportunities associated with access to best clinical practices for managing vivax malaria in India. A key outcome was to propose a framework for articulating and segmenting important investment opportunities for improving access to best clinical practices for P. vivax radical cure in India.

Assessment of community knowledge, practice, and determinants of malaria case households in the rural area of Raya Azebo district, Northern Ethiopia, 2017.

BACKGROUND: In Ethiopia malaria is one of the leading causes of outpatient visits and admission. Still, it remains a major cause of morbidity and mortality in the study area. Therefore, this study was aimed to assess the knowledge, practice, and determinant of malaria case households in rural areas of Raya Azebo district, Northern Ethiopia. METHOD: A community-based cross-sectional survey was conducted in the selected villages of Raya Azebo district from January to June 2017. A multi-stage random sampling method was employed to select a total of 422 study households. Data was collected using a semi-structured questionnaire. The household head was interviewed face to face. Logistic regression analysis was used to determine the determinant of malaria cases households. RESULT: A total of 412 (97.6) of the respondents had ever heard about malaria. About 63% of households recognized the causes of malaria to be a mosquito bite. Around 173 (41%) of the study households had been treated for malaria within a year of data collection. This study also revealed that the presence of mosquito breeding sites near to home, bed bug infestation, outdoor sleep due to bed bugs and household with poor bed net practicing were significantly associated with malaria case households. CONCLUSION: Although the overall knowledge on malaria transmission, symptoms, and the preventive measure was relatively good, the rate of household insecticide-treated net coverage and utilization were reported low in the area. Therefore, the distribution of adequate bed net with community-based education is a key intervention to promote household insecticide-treated net utilization. In addition, an effective bed bug management strategy is necessary to overcome the outdoor sleeping habit of the community in the area.

Assessment of glucose-6-phosphate dehydrogenase activity using CareStart G6PD rapid diagnostic test and associated genetic variants in Plasmodium vivax malaria endemic setting in Mauritania.

BACKGROUND: Primaquine is recommended by the World Health Organization (WHO) for radical treatment of Plasmodium vivax malaria. This drug is known to provoke acute hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Due to lack of data on G6PD deficiency, the use of primaquine has been limited in Africa. In the present study, G6PD deficiency was investigated in blood donors of various ethnic groups living in Nouakchott, a P. vivax endemic area in Mauritania. METHODOLOGY/PRINCIPAL FINDINGS: Venous blood samples from 443 healthy blood donors recruited at the National Transfusion Center in Nouakchott were screened for G6PD activity using the CareStart G6PD deficiency rapid diagnostic test. G6PD allelic variants were investigated using DiaPlexC G6PD genotyping kit that detects African (A-) and Mediterranean (B-) variants. Overall, 50 of 443 (11.3%) individuals (49 [11.8%] men and 1 [3.7%] woman) were phenotypically deficient. Amongst men, Black Africans had the highest prevalence of G6PD deficiency (15 of 100 [15%]) and White Moors the lowest (10 of 168, [5.9%]). The most commonly observed G6PD allelic variants among 44 tested G6PD-deficient men were the African variant A- (202A/376G) in 14 (31.8%), the Mediterranean variant B- (563T) in 13 (29.5%), and the Betica-Selma A- (376G/968C) allelic variant in 6 (13.6%). The Santamaria A- variant (376G/542T) and A variant (376G) were observed in only one and two individuals, respectively. None of the expected variants was observed in 8 (18.2%) of the tested phenotypically G6PD-deficient men. CONCLUSION: This is the first published data on G6PD deficiency in Mauritanians. The prevalence of phenotypic G6PD deficiency was relatively high (11.3%). It was mostly associated with either African or Mediterranean variants, in agreement with diverse Arab and Black African origins of the Mauritanian population.

Comparative ophthalmic assessment of patients receiving tafenoquine or chloroquine/primaquine in a randomized clinical trial for Plasmodium vivax malaria radical cure.

PURPOSE: Ophthalmic safety observations are reported from a clinical trial comparing tafenoquine (TQ) efficacy and safety versus sequential chloroquine (CQ)/primaquine (PQ) for acute Plasmodium vivax malaria. METHODS: In an active-control, double-blind study, 70 adult subjects with microscopically confirmed P. vivax malaria were randomized (2:1) to receive 400 mg TQ × 3 days or 1500 mg CQ × 3 days then 15 mg PQ × 14 days. MAIN OUTCOME MEASURES: clinically relevant changes at Day 28 and Day 90 versus baseline in the ocular examination, color vision evaluation, and corneal and retinal digital photography. RESULTS: Post-baseline keratopathy occurred in 14/44 (31.8%) patients with TQ and 0/24 with CQ/PQ (P = 0.002). Mild post-baseline retinal findings were reported in 10/44 (22.7%) patients receiving TQ and 2/24 (8.3%) receiving CQ/PQ (P = 0.15; treatment difference 14.4%, 95% CI - 5.7, 30.8). Masked evaluation of retinal photographs identified a retinal hemorrhage in one TQ patient (Day 90) and a slight increase in atrophy from baseline in one TQ and one CQ/PQ patient. Visual field sensitivity (Humphrey™ 10-2 test) was decreased in 7/44 (15.9%) patients receiving TQ and 3/24 (12.5%) receiving CQ/PQ; all cases were < 5 dB. There were no clinically relevant changes in visual acuity or macular function tests. CONCLUSIONS: There was no evidence of clinically relevant ocular toxicity with either treatment. Mild keratopathy was observed with TQ, without conclusive evidence of early retinal changes. Eye safety monitoring continues in therapeutic studies of low-dose tafenoquine (300 mg single dose). CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT01290601.

Use of anthropophilic culicid-based xenosurveillance as a proxy for Plasmodium vivax malaria burden and transmission hotspots identification.

Vector-borne diseases account for more than 17% of all infectious diseases, causing more than one million deaths annually. Malaria remains one of the most important public health problems worldwide. These vectors are bloodsucking insects, which can transmit disease-producing microorganisms during a blood meal. The contact of culicids with human populations living in malaria-endemic areas suggests that the identification of Plasmodium genetic material in the blood present in the gut of these mosquitoes may be possible. The process of assessing the blood meal for the presence of pathogens is termed 'xenosurveillance'. In view of this, the present work investigated the relationship between the frequency with which Plasmodium DNA is found in culicids and the frequency with which individuals are found to be carrying malaria parasites. A cross-sectional study was performed in a peri-urban area of Manaus, in the Western Brazilian Amazon, by simultaneously collecting human blood samples and trapping culicids from households. A total of 875 individuals were included in the study and a total of 13,374mosquito specimens were captured. Malaria prevalence in the study area was 7.7%. The frequency of households with at least one culicid specimen carrying Plasmodium DNA was 6.4%. Plasmodium infection incidence was significantly related to whether any Plasmodium positive blood-fed culicid was found in the same household [IRR 3.49 (CI95% 1.38-8.84); p = 0.008] and for indoor-collected culicids [IRR 4.07 (CI95%1.25-13.24); p = 0.020]. Furthermore, the number of infected people in the house at the time of mosquito collection was related to whether there were any positive blood-fed culicid mosquitoes in that household for collection methods combined [IRR 4.48 (CI95%2.22-9.05); p<0.001] or only for indoor-collected culicids [IRR 4.88 (CI95%2.01-11.82); p<0.001]. Our results suggest that xenosurveillance can be used in endemic tropical regions in order to estimate the malaria burden and identify transmission foci in areas where Plasmodium vivax is predominant.

Assessment of drug resistance associated genetic diversity in Mauritanian isolates of Plasmodium vivax reveals limited polymorphism.

BACKGROUND: Plasmodium vivax is the predominant malaria species in northern Mauritania. Molecular data on P. vivax isolates circulating in West Africa are scarce. The present study analysed molecular markers associated with resistance to antifolates (Pvdhfr and Pvdhps), chloroquine (Pvmdr1), and artemisinin (Pvk12) in P. vivax isolates collected in two cities located in the Saharan zone of Mauritania. METHODS: Blood samples were obtained from P. vivax-infected patients recruited for chloroquine therapeutic efficacy study in 2013 and febrile patients spontaneously consulting health facilities in Nouakchott and Atar in 2015-2016. Fragments of Pvdhfr (codons 13, 33, 57, 58, 61, 117, and 174), Pvdhps (codons 382, 383, 512, 553, and 585), Pvmdr1 (codons 976 and 1076) and Pvk12 (codon 552) genes were amplified by PCR and sequenced. RESULTS: Most of the isolates in Nouakchott (126/154, 81.8%) and Atar (44/45, 97.8%) carried the wild-type Pvdhfr allelic variant (IPFSTSI). In Nouakchott, all mutants (28/154; 18.2%) had double Pvdhfr mutations in positions 58 and 61 (allelic variant IPFRMSI), whereas in Atar only 1 isolate was mutant (S117N, allelic variant IPFSTNI). The wild-type Pvdhps allelic variant (SAKAV) was found in all tested isolates (Nouakchott, n = 93; Atar, n = 37). Few isolates in Nouakchott (5/115, 4.3%) and Atar (3/79, 3.8%) had the mutant Pvmdr1 allele 976F or 1076L, but not both, including in pre-treatment isolates obtained from patients treated successfully with chloroquine. All isolates (59 in Nouakchott and 48 in Atar) carried the wild-type V552 allele in Pvk12. CONCLUSIONS: Polymorphisms in Pvdhfr, Pvdhps, Pvmdr1, and Pvk12 were limited in P. vivax isolates collected recently in Nouakchott and Atar. Compared to the isolates collected in Nouakchott in 2007-2009, there was no evidence for selection of mutants. The presence of one, but not both, of the two potential markers of chloroquine resistance in Pvmdr1 in pre-treatment isolates did not influence the clinical outcome, putting into question the role of Pvmdr1 mutant alleles 976F and 1076L in treatment failure. Molecular surveillance is an important component of P. vivax malaria control programme in the Saharan zone of Mauritania to predict possible emergence of drug-resistant parasites.

Malaria control and chemoprophylaxis policy in the Republic of Korea Armed Forces for the previous 20 years (1997-2016).

BACKGROUND: Vivax malaria reemerged along the Demilitarized Zone (DMZ), Republic of Korea (ROK), in 1993. While it was hypothesized that vivax malaria would spread throughout the peninsula, nearly all cases were due to exposure near the DMZ. To reduce spillover of vivax malaria to the civilian community, the ROK Ministry of National Defense (MND) initiated malaria prevention policies including a large-scale chemoprophylaxis programme in malaria high-risk areas in 1997. The present study investigated the overall changes in the incidence of malaria among ROK soldiers and the mass chemoprophylaxis program from 1997 to 2016. RESULTS: Peak numbers of vivax malaria were reported in 2000, with most cases reported near the DMZ, before declining to the current levels. To combat the rapid increase in the number of malaria cases and its expansion throughout the ROK, the MND implemented mosquito control and personal protection programmes. The MND also implemented a large-scale vivax malaria chemoprophylaxis programme using hydroxychloroquine (400 mg weekly) in 1997, and primaquine (15 mg × 14 days) as terminal chemoprophylaxis in 2001. Additionally, an improved medical system enabled the rapid detection and treatment of malaria to reduce morbidity and decrease transmission of malaria from humans to mosquitoes. Following the full implementation of these programmes, the incidence of vivax malaria declined in both ROK Armed Forces and civilian populations. Subsequently, several changes in the ROK Armed Forces chemoprophylaxis programme were implemented, including the reduction of the period of hydroxychloroquine prophylaxis by 2 months (2008) and other changes in the chemoprophylaxis policy, e.g., only ROK Armed Forces personnel in moderate risk groups received terminal primaquine chemoprophylaxis (2011), and in 2016, the discontinuation of terminal primaquine chemoprophylaxis in moderate-risk area. CONCLUSIONS: The resurgence of vivax malaria in the ROK Armed Forces personnel near the DMZ was successfully suppressed through the implementation of a mass malaria chemoprophylaxis programme initiated by the MND in 1997, as well as several other factors that may have contributed to the reduction of malaria transmission since 2000. Given the current malaria situation in the ROK and North Korea, it is necessary to reevaluate the ROK Armed Forces and civilian malaria control policies.

Genetic diversity of the Plasmodium vivax multidrug resistance 1 gene in Thai parasite populations.

Plasmodium vivax resistance to chloroquine (CQ) was first reported over 60 years ago. Here we analyzed sequence variations in the multidrug resistance 1 gene (Pvmdr1), a putative molecular marker for P. vivax CQ resistance, in field isolates collected from three sites in Thailand during 2013-2016. Several single nucleotide polymorphisms previously implicated in reduced CQ sensitivity were found. These genetic variations encode amino acids in the two nucleotide-binding domains as well as the transmembrane domains of the protein. The high level of genetic diversity of Pvmdr1 provides insights into the evolutionary history of this gene. Specifically, there was little evidence of positive selection at amino acid F1076L in global isolates to be promoted as a possible marker for CQ resistance. Population genetic analysis clearly divided the parasites into eastern and western populations, which is consistent with their geographical separation by the central malaria-free area of Thailand. With CQ-primaquine remaining as the frontline treatment for vivax malaria in all regions of Thailand, such a population subdivision could be shaped and affected by the current drugs for P. falciparum since mixed P. falciparum/P. vivax infections often occur in this region.

A Malaria Case Followed By Relapse.

Malaria is an infectious disease caused by an intracellular parasite, Plasmodium, which is transmitted to humans after the bite of an Anopheles mosquito. This disease has been prevalent for decades. It has caused great epidemics in history and has also delayed social and economic development. It is endemic in the Eastern Mediterranean and Southeastern Anatolia regions of our country. The most common plasmodium in our country is P. vivax. In P. vivax infections, patients should be treated with primaquine to eradicate hypnozoites. Here, we present a case of relapse with P. vivax, and we emphasize the importance of primaquine in the treatment.

Sample-to-answer palm-sized nucleic acid testing device towards low-cost malaria mass screening.

The effectiveness of malaria screening and treatment highly depends on the low-cost access to the highly sensitive and specific malaria test. We report a real-time fluorescence nucleic acid testing device for malaria field detection with automated and scalable sample preparation capability. The device consists a compact analyzer and a disposable microfluidic reagent compact disc. The parasite DNA sample preparation and subsequent real-time LAMP detection were seamlessly integrated on a single microfluidic compact disc, driven by energy efficient non-centrifuge based magnetic field interactions. Each disc contains four parallel testing units which could be configured either as four identical tests or as four species-specific tests. When configured as species-specific tests, it could identify two of the most life-threatening malaria species (P. falciparum and P. vivax). The NAT device is capable of processing four samples simultaneously within 50 min turnaround time. It achieves a detection limit of ~0.5 parasites/µl for whole blood, sufficient for detecting asymptomatic parasite carriers. The combination of the sensitivity, specificity, cost, and scalable sample preparation suggests the real-time fluorescence LAMP device could be particularly useful for malaria screening in the field settings.

A comprehensive model for assessment of liver stage therapies targeting Plasmodium vivax and Plasmodium falciparum.

Malaria liver stages represent an ideal therapeutic target with a bottleneck in parasite load and reduced clinical symptoms; however, current in vitro pre-erythrocytic (PE) models for Plasmodium vivax and P. falciparum lack the efficiency necessary for rapid identification and effective evaluation of new vaccines and drugs, especially targeting late liver-stage development and hypnozoites. Herein we report the development of a 384-well plate culture system using commercially available materials, including cryopreserved primary human hepatocytes. Hepatocyte physiology is maintained for at least 30 days and supports development of P. vivax hypnozoites and complete maturation of P. vivax and P. falciparum schizonts. Our multimodal analysis in antimalarial therapeutic research identifies important PE inhibition mechanisms: immune antibodies against sporozoite surface proteins functionally inhibit liver stage development and ion homeostasis is essential for schizont and hypnozoite viability. This model can be implemented in laboratories in disease-endemic areas to accelerate vaccine and drug discovery research.

Malaria Elimination: Time to Target All Species.

Important strides have been made within the past decade toward malaria elimination in many regions, and with this progress, the feasibility of eradication is once again under discussion. If the ambitious goal of eradication is to be achieved by 2040, all species of Plasmodium infecting humans will need to be targeted with evidence-based and concerted interventions. In this perspective, the potential barriers to achieving global malaria elimination are discussed with respect to the related diversities in host, parasite, and vector populations. We argue that control strategies need to be reorientated from a sequential attack on each species, dominated by Plasmodium falciparum to one that targets all species in parallel. A set of research themes is proposed to mitigate the potential setbacks on the pathway to a malaria-free world.

External quality assessment of malaria microscopy diagnosis among public health facilities in West Amhara Region, Ethiopia.

OBJECTIVE: To evaluate the importance of external quality assessment program on malaria microscopic diagnosis. RESULTS: A total of 3148 slides were collected in 4 consecutive external quality assessment rounds and blindly rechecked at Amhara Public Health Institute. The average agreement between health facility and APHI slide readers was 96.6%. The percent agreement for parasite detection and species identification for P. falciparum became improved in four consecutive EQA rounds from 93.88 to 99.24% and 92.67 to 97.35% respectively. The rates of false positive and false negative were also dramatically decreased in each round from 10.5 to 0.79% and 2.14 to 0.74% respectively. Therefore, we recommend that malaria EQA program should maintain and expand in all malaria diagnostic health facilities in the region to provide accurate and reliable malaria microscopic service.