Digitized smart surveillance and micromanagement using information technology for malaria elimination in Mangaluru, India: an analysis of five-year post-digitization data.

BACKGROUND: Malaria control system (MCS), an Information technology (IT)-driven surveillance and monitoring intervention is being adopted for elimination of malaria in Mangaluru city, Karnataka, India since October 2015. This has facilitated 'smart surveillance' followed by required field response within a timeline. The system facilitated data collection of individual case, data driven mapping and strategies for malaria elimination programme. This paper aims to present the analysis of post-digitization data of 5 years, discuss the current operational functionalities of MCS and its impact on the malaria incidence. METHODS: IT system developed for robust malaria surveillance and field response is being continued in the sixth year. Protocol for surveillance control was followed as per the national programme guidelines mentioned in an earlier publication. Secondary data from the malaria control system was collated and analysed. Incidence of malaria, active surveillance, malariogenic conditions and its management, malariometric indices, shrinking malaria maps were also analysed. RESULTS: Smart surveillance and subsequent response for control was sustained and performance improved in five years with participation of all stakeholders. Overall malaria incidence significantly reduced by 83% at the end of 5 years when compared with year of digitization (DY) (p < 0.001). Early reporting of new cases (within 48 h) was near total followed by complete treatment and vector control. Slide positivity rate (SPR) decreased from 10.36 (DY) to 6.5 (PDY 5). Annual parasite incidence (API) decreased from 16.17 (DY) to 2.64 (PDY 5). There was a negative correlation between contact smears and incidence of malaria. Five-year data analyses indicated declining trends in overall malaria incidence and correlation between closures by 14 days. The best impact on reduction in incidence of malaria was recorded in the pre-monsoon months (~ 85%) compared to lower impact in July-August months (~ 40%). CONCLUSION: MCS helped to micromanage control activities, such as robust reporting, incidence-centric active surveillance, early and complete treatment, documentation of full treatment of each malaria patient, targeted mosquito control measures in houses surrounding reported cases. The learnings and analytical output from the data helped to modify strategies for control of both disease and the vector, heralding the city into the elimination stage.

Plasmodium vivax liver stage assay platforms using Indian clinical isolates.

BACKGROUND: Vivax malaria is associated with significant morbidity and economic loss, and constitutes the bulk of malaria cases in large parts of Asia and South America as well as recent case reports in Africa. The widespread prevalence of vivax is a challenge to global malaria elimination programmes. Vivax malaria control is particularly challenged by existence of dormant liver stage forms that are difficult to treat and are responsible for multiple relapses, growing drug resistance to the asexual blood stages and host-genetic factors that preclude use of specific drugs like primaquine capable of targeting Plasmodium vivax liver stages. Despite an obligatory liver-stage in the Plasmodium life cycle, both the difficulty in obtaining P. vivax sporozoites and the limited availability of robust host cell models permissive to P. vivax infection are responsible for the limited knowledge of hypnozoite formation biology and relapse mechanisms, as well as the limited capability to do drug screening. Although India accounts for about half of vivax malaria cases world-wide, very little is known about the vivax liver stage forms in the context of Indian clinical isolates. METHODS: To address this, methods were established to obtain infective P. vivax sporozoites from an endemic region in India and multiple assay platforms set up to detect and characterize vivax liver stage forms. Different hepatoma cell lines, including the widely used HCO4 cells, primary human hepatocytes as well as hepatocytes obtained from iPSC's generated from vivax patients and healthy donors were tested for infectivity with P. vivax sporozoites. RESULTS: Both large and small forms of vivax liver stage are detected in these assays, although the infectivity obtained in these platforms are low. CONCLUSIONS: This study provides a proof of concept for detecting liver stage P. vivax and provide the first characterization of P. vivax liver stage forms from an endemic region in India.

Haplotype of RNASE 3 polymorphisms is associated with severe malaria in an Indian population.

Severe malaria (SM) caused by Plasmodium falciparum (Pf) infection has been associated with life-threatening anemia, metabolic acidosis, cerebral malaria and multiorgan dysfunction. It may lead to death if not treated promptly. RNASE 3 has been linked to Pf growth inhibition and its polymorphisms found associated with SM and cerebral malaria in African populations. This study aimed to assess the association of RNASE 3 polymorphisms with SM in an Indian population. RNASE 3 gene and flanking regions were amplified followed by direct DNA sequencing in 151 Indian patients who visited Wenlock District Government Hospital, Mangalore, Karnataka, India. Allele, genotype and haplotype frequencies were compared between patients with SM (n = 47) and uncomplicated malaria (UM; n = 104). Homozygous mutant genotype was only found for rs2233860 (+ 499G > C) polymorphism (< 1% frequency). No significant genetic associations were found for RNASE 3 polymorphism genotypes and alleles in Indian SM patients using the Fisher's exact test. C-G-G haplotype of rs2233859 (- 38C > A), rs2073342 (+ 371C > G) and rs2233860 (+ 499G > C) polymorphisms was correlated significantly with SM patients (OR = 3.03; p = 0.008) after Bonferroni correction. A haplotype of RNASE 3 gene was found associated with an increased risk of SM and confirming that RNASE 3 gene plays a role in susceptibility to SM.

Clinical features and haematological parameters among malaria patients in Mangaluru city area in the southwestern coastal region of India.

The aim of this study was to assess the clinical profile, severity and complications of patients suffering from malaria in Mangaluru, a southwestern coastal city in India. A total of 579 patients, who were treated at the District Wenlock Hospital, Mangaluru, and 168 healthy controls were recruited in this study. The clinical profile, haematological and biochemical parameters, and disease complications were assessed. The majority of patients were treated as outpatients and patients who had severe clinical conditions were admitted to the hospital for treatment and supportive care. Among the total 579 patients recruited in this study, the distribution of P. vivax, P. falciparum and mixed infections were 364 (62.9%), 150 (25.9%) and 65 (11.2%), respectively. Among these, 506 (87.4%) had mild malaria, whereas 73 (12.6%) had severe malaria. Overall, the clinical features and severity of malaria in P. vivax and mixed infection patients were comparable to P. falciparum patients, albeit with some significant differences. The clinical complications in severe malaria cases included thrombocytopenia (50.7%), metabolic acidosis (30.1%), severe anaemia (26.0%), jaundice (21.9%), hepatic dysfunction (15.1%), acute renal failure (6.8%), haematuria (8.2%), hypotension (9.6%), cerebral malaria (1.4%) and acute respiratory distress syndrome (1.4%). All the patients with severe malaria recruited in our study were successfully treated and discharged. Majority of patients had mild malaria, likely due to seeking treatment soon after experiencing symptoms and/or having preexisting immune protection. However, a significant number of patients had severe malaria and required hospital admission indicating that there is a substantial need for creating awareness among vulnerable immigrant population. Implementing effective surveillance and vector control measures in malaria hotspot locations in the city and educating people about preventive measures are likely to reduce the malaria burden in this endemic region.

Efficacy and safety of fixed dose combination of arterolane maleate and piperaquine phosphate in comparison with chloroquine phosphate in children with acute uncomplicated Plasmodium vivax malaria: A phase III, randomised, multicentric study.

BACKGROUND & OBJECTIVES: In India, the burden of Plasmodium vivax malaria has been projected to be highest in some areas. This study investigated the efficacy and safety of fixed dose combination (FDC) of arterolane maleate (AM) 37.5 mg and piperaquine phosphate 187.5 mg (PQP) dispersible tablets and (not with) chloroquine in the treatment of uncomplicated vivax malaria in pediatric patients. METHODS: This multicentric, open-label trial was carried out at 12 sites in India. A total of 164 patients aged 6 months to 12 years with P. vivax malaria were randomized in a ratio of 2:1 to AM-PQP (111 patients) or chloroquine (53 patients) arms. The duration of follow up was 42 days. RESULTS: At 72 hours, the proportion of a parasitaemic and afebrile patients was 100% in both treatment arms in per protocol (PP) population, and 98.2% and 100% [95% CI: -1.8 (-6.33 to 5.08)] in AM-PQP and chloroquine arms, respectively, in intent to treat (ITT) population. The efficacy and safety of AM-PQP was found to be comparable to chloroquine in the treatment of uncomplicated P. vivax malaria in pediatric patients. Overall, the cure rate at Day 28 and 42 was >95% for both AM-PQP or CQ. The commonly reported clinical adverse event was vomiting. No patient was discontinued for any QTc abnormality. INTERPRETATION & CONCLUSION: The efficacy and safety of FDC of arterolane maleate and piperaquine phosphate was found to be comparable to chloroquine for treatment of uncomplicated P. vivax malaria in pediatric patients.

Indigenously developed digital handheld Android-based Geographic Information System (GIS)-tagged tablets (TABs) in malaria elimination programme in Mangaluru city, Karnataka, India.

BACKGROUND: Under-reporting, delayed diagnosis, incomplete treatment and inadequate vector management are few among many factors responsible for uninterrupted transmission of malaria in India. Information technology (IT) and mobile apps can be utilized effectively to overcome these hurdles. Indigenously developed digital handheld geographic information system (GIS)-tagged Android-based tablets (TABs) has been designed especially for implementation of digitization protocol. This has changed the effectiveness of malaria surveillance and intervention strategies in a malaria endemic area of Mangaluru city, Karnataka, India. METHODS: A software was developed and implemented for control measures to create a digital database of each malaria case. Secondary data analyses were carried out to determine and compare differences in malariometric indices between pre- and post-digitization years. With the introduction of this software active surveillance, information education and communication (IEC), and anti-vector measures were made 'incidence-centric'. This means that the entire control measures were carried out in the houses where the malaria cases (index cases) were reported and also in surrounding houses. RESULTS: Annual blood examination rate (ABER) increased from 13.82 to 32.8%. Prompt reporting of new cases had improved (36% within 24 h and 80% within 72 h). Complete treatment and parasite clearance time were documented in 98% of cases. In the second post-digitization year untraceable cases reduced from 11.3 to 2.7%; contact blood smears collection also increased significantly (p < 0.001); Slide Positivity Rate (SPR) decreased from 15.5 to 10.48%; malaria cases reduced by 30%. CONCLUSIONS: IT is very useful in translation of digitized surveillance to core interventions thereby effectively reduce incidence of malaria. This technology can be used effectively to translate smart surveillance to core interventions following the '1-3-7-14' strategy.

Malaria elimination in India-The way forward.

The World Malaria Report 2018 published by the World Health Organization highlights that no significant progress in reducing global malaria cases was achieved for the period 2015-2017. India carries 4% of the global malaria burden and contributes 87% of the total malaria cases in South-East Asia. India is in malaria elimination mode, and set targets for malaria-free status by 2030. Diagnosis and treatment of asymptomatic falciparum malaria cases continues to be a challenge for health care providers. To overcome these hurdles innovative solutions along with the existing tools and strategies involving vector control, mass drug administration, disease surveillance hold the key to solve this gigantic health problem.

A study on bionomics of malaria vectors in three different eco-epidemiological settings in Upper Krishna Project catchment area of Karnataka state, India: Implications for malaria vector control.

BACKGROUND & OBJECTIVES: Understanding of malaria vector distribution and influence of climatic environments is essential for devising control strategies. The aim of the study was to study the bionomics of prevalent malaria vectors in three different settings for development of evidence-based sustainable malaria control strategy with special reference to vector control. METHODS: Three villages with different eco-epidemiological settings like riverine-low malarious, riverine-high malarious and non-riverine high malarious villages were selected after baseline studies. Entomological aspects such as man hour density, per structure density, mosquito landing collections, sibling species identification, insecticide susceptibility status, parity rate, etc. were studied in these three villages following standard methods and techniques. The effect of these variables was analysed statistically. RESULTS: Mosquito collections revealed the presence of three malaria vectors in the study villages, namely Anopheles culicifacies s.l., An. fluviatilis s.l. and An. stephensi (Diptera: Culicidae) with varying proportions and seasonal abundance. Densities of the principal malaria vector, An. culicifacies varied seasonally. Anopheles culicifacies was found resistant to DDT (4%), malathion (5%), lambda-cyhalothrin (0.05%) and alpha-cypermethrin (0.1%). Peak density of An. culicifacies was found during post-monsoon months starting from August-September to December in the high malarious villages. INTERPRETATION & CONCLUSION: The main vector control interventions should be planned in the post-monsoon months in these villages and suitable insecticide resistance management strategy should be followed as An. culicifacies was found resistant to DDT, malathion, alpha-cypermethrin and lambda-cyhalothrin in the study area.

Presence of novel triple mutations in the pvdhfr from Plasmodium vivax in Mangaluru city area in the southwestern coastal region of India.

BACKGROUND: Genes encoding dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) are the targets of sulfadoxine-pyrimethamine (SP) present in artemisinin based combination therapy (ACT; artesunate + sulfadoxine pyrimethamine) for Plasmodium falciparum. Although SP is generally not used to treat vivax infection, mutations in dhfr and dhps that confer antifolate resistance in Plasmodium vivax are common; which may be attributed to its sympatric existence with P. falciparum. Current study was aimed to determine the pattern of mutations in dhfr and dhps in P. vivax isolates from Mangaluru region. METHODS: A total of 140 blood samples were collected from P. vivax-infected people attending Wenlock Hospital Mangaluru during July 2014 to January 2016. Out of 140 isolates, 25 (18%) and 50 (36%) isolates were selected randomly for sequence analysis of pvdhfr and pvdhps genes respectively. Fragment of pvdhps and full length pvdhfr were amplified, sequenced and analysed for single nucleotide polymorphisms. dhps was analysed by PCR-RFLP also, to detect the two specific mutations (A383G and A553G). RESULTS: Analysis of pvdhps sequences from 50 isolates revealed single and double mutants at 38 and 46% respectively. Three non-synonymous mutations (K55R, S58R and S117N) were identified for pvdhfr. Among these, K55R was detected for the first time. CONCLUSIONS: The current study indicates that P. vivax dhps and dhfr mutant alleles are prevalent in this area, suggesting significant SP pressure.

Drug resistance genes: pvcrt-o and pvmdr-1 polymorphism in patients from malaria endemic South Western Coastal Region of India.

BACKGROUND: Malaria is highly prevalent in many parts of India and is mostly caused by the parasite species Plasmodium vivax followed by Plasmodium falciparum. Chloroquine (CQ) is the first-line treatment for blood stage P. vivax parasites, but cases of drug resistance to CQ have been reported from India. One of the surveillance strategies which is used to monitor CQ drug resistance, is the analysis of single nucleotide polymorphisms (SNPs) of the associated gene markers. Susceptibility to CQ can also be determined by copy number assessment of multidrug resistant gene (mdr-1). The current study has examined the prevalence of SNPs in P. vivax orthologs of P. falciparum chloroquine resistant and multi-drug resistant genes (pvcrt-o and pvmdr-1, respectively) and pvmdr-1 copy number variations in isolates from the highly endemic Mangaluru city near the South Western Coastal region of India. METHODS: A total of 140 blood samples were collected from P. vivax infected patients attending Wenlock Hospital Mangaluru during July 2014 to January 2016. Out of these 140 samples, sequencing was carried out for 54 (38.5%) and 85 (60.7%) isolates for pvcrt-o and pvmdr-1, respectively. Single nucleotide polymorphisms (SNPs) in the pvcrt-o and pvmdr-1 genes were analysed by direct sequencing method, while copy number variations of 60 isolates (42. 8%) were determined by real time PCR. RESULTS: Out of 54 clinical isolates analysed for pvcrt-o, three (5.6%) showed K10 insertion and the rest had wild type sequence. This is the first report to show K10 insertion in P. vivax isolates from India. Further, out of 85 clinical isolates of P. vivax analysed for mutations in pvmdr-1 gene, only one isolate had wild type sequence (~ 1%) while the remaining (99%) carried mutant alleles. Seven non-synonymous mutations with two novel mutations (I946V and Y1028C) were observed. Of all the observed mutations in pvmdr-1 gene, T958M was most highly prevalent (present in 90% of samples) followed by F1076L (76%), and Y976F (7%). Amplification of pvmdr-1 gene was observed in 31.6% of the isolates, out of 60 amplified. CONCLUSION: The observed variations both in pvmdr-1 and pvcrt-o genes indicate a trend towards parasite acquiring CQ resistance in this endemic area.

Influence of midgut microbiota in Anopheles stephensi on Plasmodium berghei infections.

BACKGROUND: The native gut microbiota of Anopheles mosquitoes is known to play a key role in the physiological function of its host. Interestingly, this microbiota can also influence the development of Plasmodium in its host mosquitoes. In recent years, much interest has been shown in the employment of gut symbionts derived from vectors in the control of vector-borne disease transmission. In this study, the midgut microbial diversity has been characterized among laboratory-reared adult Anopheles stephensi mosquitoes, from the colony created by rearing progeny of wild-caught mosquitoes (obtained from three different locations in southern India) for multiple generations, using 16S ribosomal RNA (rRNA) gene sequencing approach. Further, the influence of native midgut microbiota of mosquitoes on the development of rodent malaria parasite Plasmodium berghei in its host has been studied. METHODS: The microbial diversity associated with the midgut of An. stephensi mosquitoes was studied by sequencing V3 region of 16S ribosomal RNA (rRNA) gene. The influence of native midgut microbiota of An. stephensi mosquitoes on the susceptibility of the mosquitoes to rodent malaria parasite P. berghei was studied by comparing the intensity and prevalence of P. berghei infection among the antibiotic treated and untreated cohorts of mosquitoes. RESULTS: The analysis of bacterial diversity from the midguts of An. stephensi showed Proteobacteria as the most dominant population among the three laboratory-reared strains of An. stephensi studied. Major genera identified among these mosquito strains were Acinetobacter, Pseudomonas, Prevotella, Corynebacterium, Veillonella, and Bacillus. The mosquito infectivity studies carried out to determine the implication of total midgut microbiota on P. berghei infection showed that mosquitoes whose native microbiota cleared with antibiotics had increased susceptibility to P. berghei infection compared to the antibiotic untreated mosquitoes with its natural native microbiota. CONCLUSIONS: The use of microbial symbiont to reduce the competence of vectors involved in disease transmission has gained much importance in recent years as an emerging alternative approach towards disease control. In this context, the present study was aimed to identify the midgut microbiota composition of An. stephensi, and its effect on the development of P. berghei. Interestingly, the analysis of midgut microbiota from An. stephensi revealed the presence of genus Veillonella in Anopheles species for the first time. Importantly, the study also revealed the negative influence of total midgut microbiota on the development of P. berghei in three laboratory strains of An. stephensi, emphasizing the importance of understanding the gut microbiota in malaria vectors, and its relationship with parasite development in designing strategies to control malaria transmission.

Field testing & evaluation of the efficacy & duration of effectiveness of a biolarvicide, Bactivec® SC (Bacillus thuringiensis var. israelensis SH-14) in Bengaluru, India.

Background & objectives: Different formulations of Bacillus thuringiensis var. israelensis (Bti) have been tested against different mosquito vectors and other insects for their residual activity. In the present study, the efficacy and residual activity of a new formulation of Bti (Bactivec Suspension Concentrate) were evaluated against immature stages of Anopheles stephensi Liston (Diptera: Culicidae), Aedes aegypti Linnaeus (Diptera: Culicidae) and Culex quinquefasciatus Say (Diptera: Culicidae), in natural habitats in Phase II and Phase III in Bengaluru, India. Methods: Preferential breeding habitats of the mosquito species were selected and four dosages (0.25, 0.5, 1 and 2 ml/50 l) were tested in Phase II trial. Two most effective dosages, 0.5 and 1 ml/50 l were selected for Phase III trial. The evaluation was carried out essentially following the guidelines of the World Health Organization Pesticide Evaluation Scheme. Pre-treatment and post-treatment densities were recorded at regular intervals, and >80 per cent reduction in pupae was taken as the duration of effectiveness. Results: Bactivec SC treated at the dosage of 1 ml/50 l could produce 10-17 days efficacy (>80% reduction in pupae) in clean water habitats tested, whereas 0.5 ml/50 l dosage showed residual activity from 7 to 14 days against Ae. aegypti and An. stephensi in Phase III studies. In polluted water habitats, 4-7 days efficacy could be recorded against Cx. quinquefasciatus in Phase III. Interpretation & conclusions: The Bactivec SC formulation was operationally feasible and easy to handle. For the control of Anopheles and Aedes mosquitoes in freshwater habitats, 1 ml/50 l dosage was found effective, whereas in polluted water habitats against Cx. quinquefasciatus 5 ml/m2 was found effective.

Malaria prevalence in Mangaluru city area in the southwestern coastal region of India.

BACKGROUND: Malaria is highly prevalent in many parts of India and the Indian subcontinent. Mangaluru, a city in the southwest coastal region of Karnataka state in India, and surrounding areas are malaria endemic with 10-12 annual parasite index. Despite high endemicity, to-date, very little has been reported on the epidemiology and burden of malaria in this area. METHODS: A cross-sectional surveillance of malaria cases was performed among 900 febrile symptomatic native people (long-time residents) and immigrant labourers (temporary residents) living in Mangaluru city area. During each of dry, rainy, and end of rainy season, blood samples from a group of 300 randomly selected symptomatic people were screened for malaria infection. Data on socio-demographic, literacy, knowledge of malaria, and treatment-seeking behaviour were collected to understand the socio-demographic contributions to malaria menace in this region. RESULTS: Malaria is prevalent in Mangaluru region throughout the year and Plasmodium vivax is predominant species compared to Plasmodium falciparum. The infection frequency was found to be high during rainy season. Infections were markedly higher in males than females, and in adults aged 16-45 years than both younger and older age groups. Also, malaria incidence was high among immigrants compared to native population. In both groups, infection rate was directly correlated with their literacy level, knowledge on malaria, dwelling environment, and protective measures used. There was also a significant difference in treatment-seeking behaviour between these two groups. CONCLUSIONS: Malaria incidences in Mangaluru region are predominantly localized to certain hotspot areas within the city, where socioeconomically underprivileged and immigrant labourers are densely populated. These areas have inadequate sanitation and constant water stagnation, harbouring high vector density and contributing to high infection incidences. Additionally, people in these areas seldom practice preventive measures such as using bed nets. The high incidences of malaria in adults are due to minimal cloth wearing, and long working hours stretching to late evenings in places with high vector density. Instituting heightened preventive public measures by governments and creating awareness on using preventive protective and environmental hygienic measures through educational programmes may substantially reduce the risk of contracting infections in these areas and spreading to other areas.

Modified error in constitutive equations (MECE) approach for ultrasound elastography.

A partial differential equation-constrained optimization approach is presented for reconstructing mechanical properties (e.g., elastic moduli). The proposed method is based on the minimization of an error in constitutive equations functional augmented with a least squares data misfit term referred to as MECE for "modified error in constitutive equations." The main theme of this paper is to demonstrate several key strengths of the proposed method on experimental data. In addition, some illustrative examples are provided where the proposed method is compared with a common shear wave elastography (SWE) approach. To this end, both synthetic data, generated with transient finite element simulations, as well as ultrasonically tracked displacement data from an acoustic radiation force (ARF) experiment are used in a standard elasticity phantom. The results indicate that the MECE approach can produce accurate shear modulus reconstructions with significantly less bias than SWE.

Knockdown Resistance (kdr) Mutations in Indian Anopheles stephensi (Diptera: Culicidae) Populations.

Knockdown resistance (kdr) in insects resulting from mutation(s) in the voltage-gated sodium channel (VGSC) gene is one of the mechanisms of resistance against DDT and the pyrethroid group of insecticides. Earlier, we reported the presence of two classic kdr mutations, i.e., L1014F and L1014S in Anopheles stephensi Liston, a major Indian malaria vector affecting mainly urban areas. This report presents the distribution of these alleles in different An. stephensi populations. Seven populations of An. stephensi from six states of India were screened for the presence of two alternative kdr mutations L1014F and L1014S using allele-specific polymerase chain reaction assays. We recorded the presence of both kdr mutations in northern Indian populations (Alwar and Gurgaon), with the preponderance of L1014S, whereas only L1014F was present in Raipur (central India) and Chennai (southern India). None of the kdr mutations were found in Ranchi in eastern India and in Mangaluru and Mysuru in southern India. This study provides evidence for a focal pattern of distribution of kdr alleles in India.

Monitoring the efficacy of antimalarial medicines in India via sentinel sites: Outcomes and risk factors for treatment failure.

BACKGROUND & OBJECTIVES: To combat the problem of antimalarial drug resistance, monitoring the changes in drug efficacy over time through periodic surveillance is essential. Since 2009, systematic and continuous monitoring is being done through nationwide sentinel site system. Potential early warning signs like partner drug resistance markers were also monitored in the clinical samples from the study areas. METHODS: A total of 1864 patients with acute uncomplicated malaria were enrolled in therapeutic efficacy studies of artesunate plus sulphadoxine-pyrimethamine (AS+SP) for Plasmodium falciparum; those infected with P. vivax were given chloroquine (CQ). Polymerase chain reaction (PCR) was used to distinguish post-treatment reinfection from treatment failures. Isolates of P. falciparum were also analysed for dihydropteroate synthase (dhps) and dihydrofolate reductase (dhfr) gene mutations. RESULTS: Overall, 1687 (91.7%) patients completed the follow-up. In most of the falciparum patients the parasitaemia was cleared within 24 h of treatment, except 12 patients who remained parasite positive after 72 h. Presence of dhfr and dhps quintuple mutation was observed predominantly in treatment failure samples. A daily dose of artesunate of < 3 mg/kg of body weight, age of <5 yr, and fever at enrolment were associated with an increased risk of treatment failure. The AS+SP in P. falciparum was effective in > 95% cases in all the sentinel sites except in Northeastern region (NE). Chloroquine remained 100% efficacious in case of P. vivax infections. INTERPRETATION & CONCLUSION: Till 2012, India's national antimalarial drug resistance monitoring system proved highly efficacious and safe towards first-line antimalarials used in the country, except in Northeastern region where a decline in efficacy of AS+SP has been observed. This led to change in first-line treatment for P. falciparum to artemether-lumefantrine in Northeastern region.

Malaria parasite-synthesized heme is essential in the mosquito and liver stages and complements host heme in the blood stages of infection.

Heme metabolism is central to malaria parasite biology. The parasite acquires heme from host hemoglobin in the intraerythrocytic stages and stores it as hemozoin to prevent free heme toxicity. The parasite can also synthesize heme de novo, and all the enzymes in the pathway are characterized. To study the role of the dual heme sources in malaria parasite growth and development, we knocked out the first enzyme, δ-aminolevulinate synthase (ALAS), and the last enzyme, ferrochelatase (FC), in the heme-biosynthetic pathway of Plasmodium berghei (Pb). The wild-type and knockout (KO) parasites had similar intraerythrocytic growth patterns in mice. We carried out in vitro radiolabeling of heme in Pb-infected mouse reticulocytes and Plasmodium falciparum-infected human RBCs using [4-(14)C] aminolevulinic acid (ALA). We found that the parasites incorporated both host hemoglobin-heme and parasite-synthesized heme into hemozoin and mitochondrial cytochromes. The similar fates of the two heme sources suggest that they may serve as backup mechanisms to provide heme in the intraerythrocytic stages. Nevertheless, the de novo pathway is absolutely essential for parasite development in the mosquito and liver stages. PbKO parasites formed drastically reduced oocysts and did not form sporozoites in the salivary glands. Oocyst production in PbALASKO parasites recovered when mosquitoes received an ALA supplement. PbALASKO sporozoites could infect mice only when the mice received an ALA supplement. Our results indicate the potential for new therapeutic interventions targeting the heme-biosynthetic pathway in the parasite during the mosquito and liver stages.

Computer-vision-based technology for fast, accurate and cost effective diagnosis of malaria.

BACKGROUND: Microscopy has long been considered to be the gold standard for diagnosis of malaria despite the introduction of newer assays. However, it has many challenges like requirement of trained microscopists and logistic issues. A vision based device that can diagnose malaria, provide speciation and estimate parasitaemia was evaluated. METHODS: The device was evaluated using samples from 431 consented patients, 361 of which were initially screened by RDT and microscopy and later analysed by PCR. It was a prospective, non-randomized, blinded trial. Quantification of parasitaemia was performed by two experienced technicians. Samples were subjected to diagnosis by Sight Dx digital imaging scanning. RESULTS: The sensitivity and specificity of the SightDx P1 device for analysed samples were found to be 97.05 and 96.33%, respectively, when compared to PCR. When compared to microscopy, sensitivity and specificity were found to be 94.4 and 95.6%, respectively. The device was able to speciate 73.3% of the PCR Plasmodium falciparum positive samples and 91.4% of PCR Plasmodium vivax positive samples. CONCLUSION: The ability of the device to detect parasitaemia as compared with microscopy, was within 50% in 71.3% of cases and demonstrated a correlation coefficient of 0.89.

Purification of a recombinant histidine-tagged lactate dehydrogenase from the malaria parasite, Plasmodium vivax, and characterization of its properties.

Lactate dehydrogenase (LDH) of the malaria parasite, Plasmodium vivax (Pv), serves as a drug target and immunodiagnostic marker. The LDH cDNA generated from total RNA of a clinical isolate of the parasite was cloned into pRSETA plasmid. Recombinant his-tagged PvLDH was over-expressed in E. coli Rosetta2DE3pLysS and purified using Ni(2+)-NTA resin giving a yield of 25-30 mg/litre bacterial culture. The recombinant protein was enzymatically active and its catalytic efficiency for pyruvate was 5.4 × 10(8) min(-1) M(-1), 14.5 fold higher than a low yield preparation reported earlier to obtain PvLDH crystal structure. The enzyme activity was inhibited by gossypol and sodium oxamate. The recombinant PvLDH was reactive in lateral flow immunochromatographic assays detecting pan- and vivax-specific LDH. The soluble recombinant PvLDH purified using heterologous expression system can facilitate the generation of vivax LDH-specific monoclonals and the screening of chemical compound libraries for PvLDH inhibitors.

Unusual multiple magnetic transitions and anomalous Hall effect observed in antiferromagnetic Weyl semimetal, Mn2.94Ge (Ge-rich).

We report on the magnetic and Hall effect measurements of the magnetic Weyl semimetal, Mn2.94Ge (Ge-rich) single crystal. From the magnetic properties study, we identify unusual multiple magnetic transitions below the Ne'el temperature of 353 K, such as the spin-reorientation (TSR) and ferromagnetic-like transitions. Consistent with the magnetic properties, the Hall effect study shows unusual behavior around the spin-reorientation transition. Specifically, the anomalous Hall conductivity increases with increasing temperature, reaching a maximum atTSR, which then gradually decreases with increasing temperature. This observation is quite in contrast to the Mn3+δGe (Mn-rich) system, though both compositions share the same hexagonal crystal symmetry. This study unravels the sensitivity of magnetic and topological properties on the Mn concentration.