Malaria Epidemiology and COVID-19 Pandemic: Are They Interrelated?

Coronavirus disease 2019 (COVID-19) is a systemic disease, impacting multiple organs in the human body. But COVID-19 also impacts other diseases of relevance to public and planetary health. To understand and respond to the COVID-19 pandemic, we need an intersectional conceptual lens and systems thinking. For example, the strain on health care systems due to COVID-19 has adversely impacted global malaria elimination programs. With many epidemiological, clinical, and biological parallels documented, we examined in this study the scenario of malaria and COVID-19 syndemic in India. The disruptive influence of COVID-19 on the National Framework for Malaria Elimination (NFME), impact of unintended chemoprophylaxis, population genetic influences, and the shifting patterns of epidemiology are compared. Importantly, a time series analysis forecasted the burden of malaria increasing in the upcoming years. Although reported malaria cases showed a decline in 2020 compared to the previous years, an increase in cases was documented in 2021, with nine states reporting an increase up to July 2021. Pandemics often cause crosscutting disruptions in health care. Reshaping the priorities of the malaria elimination program and a diligent implementation of the priorities in the NFME would, therefore, be well-advised: (1) vector control, (2) antimalarial therapy recommendations, (3) monitoring drug resistance, (4) prevention of the spread of asymptomatic disease-causing low-density transmission, and (5) large-scale testing measures. In conclusion, the findings from the present study inform future comparative studies in other world regions to better understand the broader, systemic, temporal, and spatial impacts of the COVID-19 pandemic on existing and future diseases across public health systems and services.

The genome trilogy of Anopheles stephensi, an urban malaria vector, reveals structure of a locus associated with adaptation to environmental heterogeneity.

Anopheles stephensi is the most menacing malaria vector to watch for in newly urbanising parts of the world. Its fitness is reported to be a direct consequence of the vector adapting to laying eggs in over-head water tanks with street-side water puddles polluted by oil and sewage. Large frequent inversions in the genome of malaria vectors are implicated in adaptation. We report the genome assembly of a strain of An. stephensi of the type-form, collected from a construction site from Chennai (IndCh) in 2016. The genome reported here with a L50 of 4, completes the trilogy of high-resolution genomes of strains with respect to a 16.5 Mbp 2Rb genotype in An. stephensi known to be associated with adaptation to environmental heterogeneity. Unlike the reported genomes of two other strains, STE2 (2R+b/2Rb) and UCI (2Rb/2Rb), IndCh is found to be homozygous for the standard form (2R+b/2R+b). Comparative genome analysis revealed base-level details of the breakpoints and allowed extraction of 22,650 segregating SNPs for typing this inversion in populations. Whole genome sequencing of 82 individual mosquitoes from diverse geographical locations reveal that one third of both wild and laboratory populations maintain the heterozygous genotype of 2Rb. The large number of SNPs can be tailored to 1740 exonic SNPs enabling genotyping directly from transcriptome sequencing. The genome trilogy approach accelerated the study of fine structure and typing of an important inversion in An. stephensi, putting the genome resources for this understudied species on par with the extensively studied malaria vector, Anopheles gambiae. We argue that the IndCh genome is relevant for field translation work compared to those reported earlier by showing that individuals from diverse geographical locations cluster with IndCh, pointing to significant convergence resulting from travel and commerce between cities, perhaps, contributing to the survival of the fittest strain.

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.

Acquired antibody responses against merozoite surface protein-119 antigen during Plasmodium falciparum and P.vivax infections in South Indian city of Mangaluru.

Merozoite surface protein-1 (MSP-1) of malaria parasites has been extensively studied as a malaria vaccine candidate and the antibody response to this protein is an important indicator of protective immunity to malaria. Mangaluru city and its surrounding areas in southwestern India are endemic to malaria with Plasmodium vivax being the most widespread and prevalent species although P. falciparum also frequently infects. However, no information is available on the level of protective immunity in this population. In this regard, a prospective hospital-based study was performed in malarial patients to assess antibody responses against the 19-kDa C-terminal portion of P. vivax and P. falciparum MSP-1 (MSP-119). Serum samples from 51 healthy endemic controls and 267 infected individuals were collected and anti-MSP-119 antibody levels were analyzed by ELISA. The possible association between the antibody responses and morbidity parameters such as malarial anemia and thrombocytopenia was investigated. Among the 267 infected cases, 144 had P. vivax and 123 had P. falciparum infections. Significant levels of anti-MSP-119 antibody were observed both in P. vivax (123/144; 85.4%) and P. falciparum (108/123; 87.9%) infected individuals. In both type of infections, the major antibody isotypes were IgG1 and IgG3. The IgG levels were found to be increased in patients with severe anemia and thrombocytopenia. The antibody levels were also higher in infected individuals who had several previous infections, although antibodies produced during previous infections were short lived. The predominance of cytophilic anti-MSP-119 IgG1 and IgG3 antibodies suggests the possibility of a dual role of Pv MSP-119 and Pf MSP-119 during malarial immunity and pathogenesis.

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.

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.

Association between inflammatory cytokine levels and anemia during Plasmodium falciparum and Plasmodium vivax infections in Mangaluru: A Southwestern Coastal Region of India.

BACKGROUND AND OBJECTIVES: Dysregulated production of inflammatory cytokines might play important role in anemia during malaria infection. The objective of this study was to assess the extent of anemia due to malaria, associated complications, and inflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin [IL]-6, and IL-10) across varying anemic intensity during malaria infections. MATERIALS AND METHODS: A hospital-based cross-sectional study was conducted at District Wenlock hospital in Mangaluru city. Samples from 627 patients and 168 healthy controls (HC) were analyzed for level of hemoglobin (Hb), red blood cells (RBCs), and inflammatory cytokines. The blood cell parameters and inflammatory cytokines levels across varying intensity of anemia were analyzed using Kruskal-Wallis test and pair-wise comparison between two groups were by Mann-Whitney U-test. Correlations were calculated by Pearson's and Spearman rank correlations. RESULTS: Compared to HC, Hb, and RBC levels were significantly lower in infected patients. On comparison with mild anemia patients (Hb 8-10.9 g/dL), the levels of TNF-α and IL-6 were significantly elevated, whereas IL-10 levels were lower during severe anemia (SA) (Hb <5 g/dL). In this endemic setting, we found a strong negative association between Hb levels and parasitemia, Hb and TNF-α, and positive relationship with IL-10; anemic patients also had significantly high TNF-α/IL-10 ratios. SA was associated with complications such as acute renal failure (16.0%), jaundice (16.0%), metabolic acidosis (24.0%), hypoglycemia (12.0%), hyperparasitemia (4.0%), and hepatic dysfunction (16.0%). CONCLUSIONS: Contrary to its benign reputation, Plasmodium vivax (Pv) infections can also result in severe malarial anemia (SMA) and its associated severe complications similar to Plasmodium falciparum infections. Dysregulated inflammatory cytokine responses play an important role in the pathogenesis of SMA, especially during Pv infections.

Genome Mining-Based Identification of Identical Multirepeat Sequences in Plasmodium falciparum Genome for Highly Sensitive Real-Time Quantitative PCR Assay and Its Application in Malaria Diagnosis.

Developing ultrasensitive methods capable of detecting submicroscopic parasitemia-a challenge that persists in low transmission areas, asymptomatic carriers, and patients showing recrudescence-is vital to achieving malaria eradication. Nucleic acid amplification techniques offer improved analytical sensitivity but are limited by the number of copies of the amplification targets. Herein, we perform a novel genome mining approach to identify a pair of identical multirepeat sequences (IMRSs) that constitute 170 and 123 copies in the Plasmodium falciparum genome and explore their potential as primers for PCR. Real-time quantitative PCR analyses have shown the ability of P. falciparum IMRSs to amplify as low as 2.54 fg of P. falciparum genomic DNA (approximately 0.1 parasite), with a striking 100-fold increase in detection limit when compared with P. falciparum 18S rRNA (251.4 fg; approximately 10 parasites). Validation with clinical samples from malaria-endemic regions has shown 6.70 ± 1.66 cycle better detection threshold in terms of Ct value for P. falciparum IMRSs, with approximately 100% sensitivity and specificity. Plasmodium falciparum IMRS assays are also capable of detecting submicroscopic infections in asymptomatic samples. To summarize, this approach of initiating amplification at multiple loci across the genome and generating more products with increased analytical sensitivity is different from classic approaches amplifying multicopy genes or tandem repeats. This can serve as a platform technology to develop advanced diagnostics for various pathogens.

Association between Inflammatory Cytokine Levels and Thrombocytopenia during Plasmodium falciparum and P. vivax Infections in South-Western Coastal Region of India.

BACKGROUND: Thrombocytopenia is a most commonly observed complication during malaria infections. Inflammatory cytokines such as IL-1, IL-6, and IL-10 have been documented in malaria induced thrombocytopaenia. This study was aimed to understand the possible relationship between inflammatory cytokines across varying degrees of thrombocytopenia during P. vivax, P. falciparum, and mixed infections. METHODS: A hospital-based cross sectional study was conducted at District Wenlock Hospital in Mangaluru, a city situated along the south-western coastal region of Arabian Sea in India. In this study, blood samples from 627 malaria patients were analyzed for infected parasite species, clinical conditions, platelet levels, and key cytokines that are produced in response to infection; samples from 176 uninfected healthy individuals were used as controls. RESULTS: The results of our study showed a high prevalence of malarial thrombocytopenia (platelets <150 ×103/µl) in this endemic settings. About 62.7% patients had mild-to-moderate levels of thrombocytopenia and 16% patients had severe thrombocytopenia (platelets <50 × 103/µl). Upon comparison of cytokines across varying degrees of thrombocytopenia, irrespective of infecting species, the levels of TNF-α and IL-10 were significantly higher during thrombocytopenia, whereas IL-6 levels were considerably lower in severe thrombocytopenia patients suffering from P. vivax or P. falciparum infections. The severe clinical complications observed in patients with malarial thrombocytopenia included severe anemia (17.5%), acute renal failure (12.7%), jaundice (27.0%), metabolic acidosis (36.5%), spontaneous bleeding (3.2%), hypoglycemia (25.4%), hyperparasitemia (4.8%), acute respiratory distress syndrome (1.6%), pulmonary edema (19.0%), and cerebral malaria (1.6%) in various combinations. CONCLUSION: Overall, the results of our study suggest that inflammatory cytokines influence the transformation of mild forms of thrombocytopenia into severe forms during malarial infections. Further studies are needed to understand the association of inflammatory cytokine responses with severe malaria complications and thrombocytopenia.

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.

Malaria Severity in Mangaluru City in the Southwestern Coastal Region of India.

Dakshina Kannada district in the Southwestern region of Karnataka state, India, including Mangaluru city is endemic to malaria. About 80% of malaria infections in Mangaluru and its surrounding areas are caused by Plasmodium vivax and the remainder is due to Plasmodium falciparum. Malaria-associated clinical complications significantly occur in this region. Here, we report the pathological conditions of 41 cases of fatal severe malaria, admitted to the district government hospital in Mangaluru city during January 2013 through December 2016. The results of clinical, hematological, and biochemical analyses showed that most of these severe malaria cases were associated with thrombocytopenia, anemia, metabolic acidosis, acute respiratory distress, and single or multi-organ dysfunction involving liver, kidney, and brain. Of the 41 fatal malaria cases, 24, 10, and seven patients had P. vivax, P. falciparum, and P. vivax and P. falciparum mixed infections, respectively. These data suggest that besides P. falciparum that is known to extensively cause severe and fatal malaria illnesses, P. vivax causes fatal illnesses substantially in this region, an observation that is consistent with recent findings in other regions.

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.

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.

Epidemiology of Plasmodium vivax Malaria in India.

Historically, malaria in India was predominantly caused by Plasmodium vivax, accounting for 53% of the estimated cases. After the spread of drug-resistant Plasmodium falciparum in the 1990s, the prevalence of the two species remained equivalent at the national level for a decade. By 2014, the proportion of P. vivax has decreased to 34% nationally, but with high regional variation. In 2014, P. vivax accounted for around 380,000 malaria cases in India; almost a sixth of all P. vivax cases reported globally. Plasmodium vivax has remained resistant to control measures, particularly in urban areas. Urban malaria is predominantly caused by P. vivax and is subject to outbreaks, often associated with increased mortality, and triggered by bursts of migration and construction. The epidemiology of P. vivax varies substantially within India, including multiple relapse phenotypes with varying latencies between primary infection and relapse. Moreover, the hypnozoite reservoir maintains transmission potential and enables reestablishment of the parasite in areas in which it was thought eradicated. The burden of malaria in India is complex because of the highly variable malaria eco-epidemiological profiles, transmission factors, and the presence of multiple Plasmodium species and Anopheles vectors. This review of P. vivax malaria in India describes epidemiological trends with particular attention to four states: Gujarat, Karnataka, Haryana, and Odisha.

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 Transmission Under an Unusual Circumstance Causing Death in Two Siblings.

Two school-going siblings from a family residing in a presumed malaria non-endemic locality ∼90 km from Mangalore city in southwestern India contracted Plasmodium falciparum infection. In both cases, misunderstanding of initial clinical symptoms as due to viral hepatitis resulted in progression to severe malaria before malaria treatment was initiated. Despite treatment at a tertiary hospital, the children died of cerebral malaria and multi-organ dysfunction. Active case detection in the affected locality suggested that the infection was transmitted from infected individuals who worked in nearby malaria-endemic areas and periodically visited their families. A lesson from this study is that lethal falciparum malaria can be transmitted in regions of India, believed to be non-endemic for the disease, resulting in fatal outcomes if diagnosis is missed or delayed. Implementation of effective surveillance and control measures as well as preparedness for malaria detection and diagnosis are necessary in areas that are potentially disposed to malaria transmission even though they are presumed to be non-endemic.

Differential Diagnosis of Malaria on Truelab Uno®, a Portable, Real-Time, MicroPCR Device for Point-Of-Care Applications.

BACKGROUND: Sensitive and specific detection of malarial parasites is crucial in controlling the significant malaria burden in the developing world. Also important is being able to identify life threatening Plasmodium falciparum malaria quickly and accurately to reduce malaria related mortality. Existing methods such as microscopy and rapid diagnostic tests (RDTs) have major shortcomings. Here, we describe a new real-time PCR-based diagnostic test device at point-of-care service for resource-limited settings. METHODS: Truenat® Malaria, a chip-based microPCR test, was developed by bigtec Labs, Bangalore, India, for differential identification of Plasmodium falciparum and Plasmodium vivax parasites. The Truenat Malaria tests runs on bigtec's Truelab Uno® microPCR device, a handheld, battery operated, and easy-to-use real-time microPCR device. The performance of Truenat® Malaria was evaluated versus the WHO nested PCR protocol. The Truenat® Malaria was further evaluated in a triple-blinded study design using a sample panel of 281 specimens created from the clinical samples characterized by expert microscopy and a rapid diagnostic test kit by the National Institute of Malaria Research (NIMR). A comparative evaluation was done on the Truelab Uno® and a commercial real-time PCR system. RESULTS: The limit of detection of the Truenat Malaria assay was found to be <5 parasites/µl for both P. falciparum and P. vivax. The Truenat® Malaria test was found to have sensitivity and specificity of 100% each, compared to the WHO nested PCR protocol based on the evaluation of 100 samples. The sensitivity using expert microscopy as the reference standard was determined to be around 99.3% (95% CI: 95.5-99.9) at the species level. Mixed infections were identified more accurately by Truenat Malaria (32 samples identified as mixed) versus expert microscopy and RDTs which detected 4 and 5 mixed samples, respectively. CONCLUSION: The Truenat® Malaria microPCR test is a valuable diagnostic tool and implementation should be considered not only for malaria diagnosis but also for active surveillance and epidemiological intervention.

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.