Structural, Functional, and Genetic Changes Surrounding Electrodes Implanted in the Brain.

Implantable neurotechnology enables monitoring and stimulating of the brain signals responsible for performing cognitive, motor, and sensory tasks. Electrode arrays implanted in the brain are increasingly used in the clinic to treat a variety of sources of neurological diseases and injuries. However, the implantation of a foreign body typically initiates a tissue response characterized by physical disruption of vasculature and the neuropil as well as the initiation of inflammation and the induction of reactive glial states. Likewise, electrical stimulation can induce damage to the surrounding tissue depending on the intensity and waveform parameters of the applied stimulus. These phenomena, in turn, are likely influenced by the surface chemistry and characteristics of the materials employed, but further information is needed to effectively link the biological responses observed to specific aspects of device design. In order to inform improved design of implantable neurotechnology, we are investigating the basic science principles governing device-tissue integration. We are employing multiple techniques to characterize the structural, functional, and genetic changes that occur in the cells surrounding implanted electrodes. First, we have developed a new "device-in-slice" technique to capture chronically implanted electrodes within thick slices of live rat brain tissue for interrogation with single-cell electrophysiology and two-photon imaging techniques. Our data revealed several new observations of tissue remodeling surrounding devices: (a) there was significant disruption of dendritic arbors in neurons near implants, where losses were driven asymmetrically on the implant-facing side. (b) There was a significant loss of dendritic spine densities in neurons near implants, with a shift toward more immature (nonfunctional) morphologies. (c) There was a reduction in excitatory neurotransmission surrounding implants, as evidenced by a reduction in the frequency of excitatory postsynaptic currents (EPSCs). Lastly, (d) there were changes in the electrophysiological underpinnings of neuronal spiking regularity. In parallel, we initiated new studies to explore changes in gene expression surrounding devices through spatial transcriptomics, which we applied to both recording and stimulating arrays. We found that (a) device implantation is associated with the induction of hundreds of genes associated with neuroinflammation, glial reactivity, oligodendrocyte function, and cellular metabolism and (b) electrical stimulation induces gene expression associated with damage or plasticity in a manner dependent upon the intensity of the applied stimulus. We are currently developing computational analysis tools to distill biomarkers of device-tissue interactions from large transcriptomics data sets. These results improve the current understanding of the biological response to electrodes implanted in the brain while producing new biomarkers for benchmarking the effects of novel electrode designs on responses. As the next generation of neurotechnology is developed, it will be increasingly important to understand the influence of novel materials, surface chemistries, and implant architectures on device performance as well as the relationship with the induction of specific cellular signaling pathways.

A comparative study of key quality performance indicators in anesthesia and surgery in operation theatre at a tertiary care hospital in Rishikesh.

Background and Aims: A Key Performance Indicator (KPI) is a critical metric measuring organizational success or specific activities, reflecting the periodic achievement of operational goals aligned with strategic objectives. Material and Methods: A retrospective cross-sectional study of key quality performance indicators, (CQI-NABH) concerning anesthesia and surgical services was conducted at a tertiary care hospital after taking institutional ethical clearance (AIIMS/IEC/21/150). It was as per COP 13, COP 14, and COP 15 standards of NABH 4th edition published in 2015. The study was conducted at the department of anesthesiology at a tertiary care hospital, and data were retrospectively analyzed from 01 October 2019, till November 2020. All patients undergoing elective or emergency surgical procedures under monitored anesthesia care and regional or general anesthesia during the study period were considered.The primary objective was to analyze Continuous Quality Improvement (CQI) in perioperative services, with secondary goals including gap identification, suggesting corrective actions, and examining quality indicators during the COVID-19 pandemic in 2020. Results: Out of 8574 patients operated during the study, 6705 were in the four months before the pandemic, and 1869 were operated during the COVID-19 scenario. In the pre-COVID era, many of the cases were performed on an elective basis (71.23%), and emergencies constituted 16.9% of the total number of cases. In the COVID era, most of the cases were emergencies (45.4%) and semi-emergencies (40.25%), and elective cases were only 14.05% of the total cases performed. The percentage of modification of anaesthesia plans ranged from 0-3.34%. Adverse anaesthesia events were observed in 0-2.1%, primarily related to cardiovascular, respiratory, and airway issues. No anaesthesia-related mortality was reported. Prophylactic antibiotic administration within one hour of surgery ranged from 88-100%. Conclusions: Monitoring and evaluating healthcare performance, specifically through KPIs, is vital for optimizing care and resource utilization. These indicators provide an overview of hospital service efficiency, aiding in key areas such as patient treatment, satisfaction, healthcare quality improvement, cost reduction, and optimal resource utilization. Addressing identified issues ensures effective and sustainable quality improvement in anaesthesia services, emphasizing ongoing monitoring as a foundation for hospital quality assurance.

In silico identification, characterization, and expression analysis of RNA recognition motif (RRM) containing RNA-binding proteins in Aedes aegypti.

RNA-binding proteins (RBPs) are the proteins that bind RNAs and regulate their functioning. RBPs in mosquitoes are gaining attention due to their ability to bind flaviviruses and regulate their replication and transmission. Despite their relevance, RBPs in mosquitoes are not explored much. In this study, we screened the whole genome of Aedes aegypti, the primary vector of several pathogenic viruses, and identified the proteins containing RNA recognition motif (RRM), the most abundant protein domain in eukaryotes. Using several in silico strategies, a total of 135 RRM-containing RBPs were identified in Ae. aegypti. The proteins were characterized based on their available annotations and the sequence similarity with Drosophila melanogaster. Ae. aegypti RRM-containing RBPs included serine/arginine-rich (SR) proteins, polyadenylate-binding proteins (PABP), heteronuclear ribonucleoproteins (hnRNP), small nuclear ribonucleoproteins (snRNP), splicing factors, eukaryotic initiation factors, transformers, and nucleolysins. Phylogenetic analysis revealed that the proteins and the domain organization are conserved among Ae. aegypti, Bombyx mori, and Drosophila melanogaster. However, the gene length and the intron-exon organization varied across the insect species. Expression analysis of the genes encoding RBPs using publicly available RNA sequencing data for different developmental time points of the mosquito life cycle starting from the ovary and eggs up to the adults revealed stage-specific expression with several genes preferentially expressed in early embryonic stages and blood-fed female ovaries. This is the first database for the Ae. aegypti RBPs that can serve as the reference base for future investigations. Stage-specific genes can be further explored to determine their role in mosquito growth and development with a focus on developing novel mosquito control strategies.

Status of insecticide resistance in the dengue vector Aedes aegypti in India: A review.

The study aims to present an overview of the extent of insecticide resistance in the dengue vector Aedes aegypti in India. Published data on insecticide resistance in this species were systematically searched through online databases like PubMed, Google, and Google Scholar. From each study, data were extracted and analyzed to understand the spatial and temporal patterns. Particular emphasis was given to the commonly used insecticides for mosquito control. Forty-three studies met the inclusion criteria, of which 13 had adult bioassay data, 13 larval bioassay data and 17 contained both. Data demonstrated high resistance to DDT and resistance is also widespread against carbamates. There is mounting evidence of increased tolerance to pyrethroids and organophosphorus compounds, viz permethrin, deltamethrin, lambda-cyhalothrin, malathion, and temephos. The emergence of resistance to all the insecticide classes further justifies the need for annual resistance monitoring and to maintain a nationwide database that can provide a reference for formulating effective control strategies.

Role of Nebulized Heparin in Clinical Outcome of COVID-19 Patients with Respiratory Symptoms: A Systematic Review.

Coronavirus disease-2019 (COVID-19) is an extremely contagious illness caused by the SARS-CoV-2 virus and has been declared a pandemic by the World Health Organization (WHO). There are currently no particular treatments, however, nebulized heparin has been offered as a viable therapy. The purpose of this systematic review is to assess the efficacy of nebulized heparin in COVID-19 patients with respiratory symptoms. Methods: Relevant studies were identified through a systematic search of the PubMed, Medline, Embase, Cochrane Library and Web of Science, and Scopus databases. The search terms included "nebulized heparin," "COVID-19," and "SARS-CoV-2." Studies that evaluated the use of nebulized heparin in COVID-19 patients with respiratory symptoms were included. The rest of the studies along with those that were not published in English were excluded. The systematic review was registered under PROSPERO-CRD42023413927. Observations: Five studies have been included in this systematic review. Case reports, case series, observational studies, and randomized controlled trial (RCT) comprised the studies. The patient sample sizes ranged from 2 to 98. The studies assessed the efficacy of nebulized heparin in COVID-19 patients with variable disease severity. The evaluated outcomes included mortality, hospital stay duration, oxygen requirements, and laboratory parameters. Conclusion: Based on the clinical studies included in this systematic review, nebulized heparin may be useful in the management of COVID-19. Oxygen saturation was greater, inflammatory indicators were lower, and hospital stays were shorter in these patients. However, the studies had limitations, including inconsistent sample sizes, varying dosages of nebulized heparin, and no control groups. Nebulized heparin in patients with COVID-19 needs to be studied further to determine its safety and effectiveness. How to cite this article: Gupta B, Ahluwalia P, Gupta N, Gupta A. Role of Nebulized Heparin in Clinical Outcome of COVID-19 Patients with Respiratory Symptoms: A Systematic Review. Indian J Crit Care Med 2023;27(8):572-579.

Nebulized Heparin to Reduce COVID-19-induced Acute Lung Injury: A Prospective Observational Study.

Background: High mortality due to COVID-19 disease has been a serious concern, a few of the causes being disseminated intravascular coagulation (DIC) and venous thromboembolism. Considering this, some experts have used heparin. However, its role still needs to be validated. Materials and methods: This study predicts the role of nebulized heparin in decreasing the severity of lung injury caused by COVID-19. Thirty patients admitted with COVID-19 acute respiratory distress syndrome (ARDS) in the intensive care unit (ICU) of All India Institute of Medical Sciences, Rishikesh, were included in this study, which was conducted over a period of 3 months. Patients were nebulized with 2 mL of heparin 5,000 units/mL IV formulation diluted with 3 mL of 0.9% sodium chloride, every 6 hours for a total duration of 7 days. Improvement in oxygenation (ratio of partial pressure of oxygen in blood and fraction of inspired oxygen delivered, pO2/FiO2 ratio) was calculated as the primary outcome. Other parameters like effect on inflammatory markers (neutrophil-lymphocyte ratio, total leukocyte count, interleukin (IL-6), and D-dimer values), time to liberate from mechanical ventilation, and hospital stay were calculated as secondary outcomes. Results: In our study population, the mean age was 54.5 years and the majority of patients were males (79.0%). All patients received prone ventilation and none of them required tracheostomy. However, 5 patients (16.6%) succumbed to illness. After nebulization with unfractionated heparin, no statistically significant difference was seen in the neutrophil-lymphocyte ratio (mean = 6.87, p = 0.318) and interleukin (IL-6) levels (mean = 62.85, p = 0.6) over 7 days. Similarly, the D-dimer level also had no statistically significant change (mean = 1853.73 p = 0.570). However, there was a statistically significant improvement in oxygenation (pO2/FiO2 ratio) over 7 days (mean = 184.96, p = 0.00). Similarly, there was a significant improvement in PaO2 (84.17 ± 33.82) and SO2 (92.30 ± 3.49). Although, no significant changes were seen in the partial pressure of carbon dioxide on nebulized heparin administration. Conclusion: Administration of nebulized heparin in COVID-19 pneumonia with mild ARDS may improve oxygenation and result in the improvement of inflammatory markers with variable sensitivity and specificity. How to cite this article: Gupta B, Chandrakar S, Gupta N, Jain G. Nebulized Heparin to Reduce COVID-19-induced Acute Lung Injury: A Prospective Observational Study. Indian J Crit Care Med 2023;27(3): 222-224.

Integrating the Various 'M' Principles of Management into the Establishment of a Palliative Care Service.

When it comes to medical caregiving, palliative care (PC) is a multidisciplinary strategy that has the goal of improving quality of life while also alleviating suffering. The doctrine of care for persons with life threatening or debilitating illnesses, as well as bereavement assistance for their families, is based on an organised, highly structured system of providing care to people with life-threatening or debilitating illnesses for the course of their lives. A coordinated continuum of care must be guaranteed throughout multiple healthcare settings, including the hospital, the patient's home, the hospice and long-term care institutions. It is essential for patients and clinicians to communicate and make decisions jointly. It is the goal of PC to provide pain relief and emotional and spiritual support to patients and the people who care for them. The best way to ensure the plan's success is to have an interdisciplinary multidimensional team of medical professionals, nurses, counsellors, social workers and volunteers coordinate it. Due to the alarming projections of cancer incidence over the next few years, a lack of hospices in developing countries, inadequate inclusion of PC, high out-of-pocket expenses for cancer treatment and the resulting financial burden on families, there is a critical need for PC and cancer hospices. To establish PC services, we stress the importance of the various M principles of management, which are divided into the following categories: Mission, Medium (setting), Men, Material including medications and Machines, Methods, Money and Management. These principles are discussed in greater detail later in this short communication. We believe that if we follow these principles, we will be able to establish PC services ranging from home-based care to the provision of care in tertiary care centres.

Morphological and molecular characterization of Aedes aegypti variant collected from Tamil Nadu, India.

BACKGROUND & OBJECTIVES: Accurate mosquito species identification is the basis of entomological surveys and effective vector control. Mosquito identification is either done morphologically using diagnostic features mentioned in taxonomic keys or by molecular methods using cytochrome oxidase subunit 1 (coxI) and Internal transcribed spacer 2 (ITS2). METHODS: We performed a larval survey for Aedes mosquitoes from eight different geographical regions in Tamil Nadu, India. The mosquitoes collected during the survey were characterized using both morphological and molecular markers. RESULTS: During an entomological survey from eight different geographical regions in Southern India, a morphological variety named Aedes aegypti var. luciensis was observed. The variant mosquitoes were characterized using both morphological and molecular markers. The variant mosquitoes differed only in the dark scaling of 5th segment of hind-tarsi. Around one third to two third of the 5th segment in variant mosquitoes was dark which has been described as white in identification keys. No other significant difference was observed in adults or immature stages. The variation was heritable and coexisting in the field with the type form mosquitoes. Comparison of the genetic profile of coxI and ITS2 were similar in variant and the type form indicating both of them to be conspecific. INTERPRETATION & CONCLUSION: The morphological variant mosquitoes were found genetically similar to the Ae. aegypti type form. However, considering its high prevalence and coexistence with Ae. aegypti type form in different geographical regions, detailed studies on bionomics, ecology, genetics, behavior as well as its plausible role in disease transmission are warranted.

Prediction of endotracheal tube size in the pediatric age group by ultrasound: A systematic review and meta-analysis.

Anatomical differences in the airway in pediatric patients, compared to adults pose many challenges during endotracheal intubation, such as selecting the proper sized endotracheal tube (ETT) during intubation. Our primary objective was to assess how accurate is ultrasound (US) co-relation in comparison to standard age-based formulas in pediatric patients. Meta-analysis was registered in PROSPERO 2020, CRD42020220041. Online literature available in PubMed, Cochrane, and Embase, Goggle scholar was searched from year 2000 till November 30, 2020, using relevant Mesh terms, ('airway US' OR (('airway'/exp OR airway) AND ('US'/exp OR US))) AND ('endotracheal intubation'/exp OR 'endotracheal intubation') AND ('pediatric'/exp OR pediatric)" to Predict endotracheal tube size/placement in pediatric age (neonate till 18 years) by the US. Bibliographic cross-references of selected publications were further manually screened. The full texts of each article were studied, once the abstract was found appropriate independently by two reviewers. A total of 48 papers published between 2010 and 2020 were identified as relevant and read in detail. Average numbers of patients were 86 and total numbers of patients were 1978. Most of the studies included pediatric patients posted for elective surgeries under general anesthesia and excluded emergency procedures, known laryngeal or tracheal pathology, high-risk patients, recent upper respiratory tract infections or allergy to ultrasound gel. A total of 18 independent correlations were analyzed. Final combined r value calculated from all the included articles was 0.824 (95% CI 0.677, 0.908) with a P < 0.00001 {strong co-relation (r > 0.80)}. Q statistic of 756.484, and I2 statistics of 97.53% showed a large degree of heterogeneity in the effect size across the studies. Use of US for upper airway in pediatric patients is an effective modality and can effectively predict endotracheal tube size estimations in comparison to standard age-based or height-based formulae in the pediatric age group. US is a non-invasive, cost-effective, portable, and reproducible technique as compared to CT and MRI. It also takes less time with increasing expertise and experience.

Arterial Blood Gas as a Predictor of Mortality in COVID Pneumonia Patients Initiated on Noninvasive Mechanical Ventilation: A Retrospective Analysis.

Background: The alveolar-arterial oxygen (A-a) gradient measures the difference between the oxygen concentration in alveoli and the arterial system, which has considerable clinical utility. Materials and methods: It was a retrospective, observational cohort study involving the analysis of patients diagnosed with acute COVID pneumonia and required noninvasive mechanical ventilation (NIV) over a period of 3 months. The primary objective was to investigate the utility of the A-a gradient (pre-NIV) as a predictor of 28-day mortality in COVID pneumonia. The secondary objective included the utility of other arterial blood gas (ABG) parameters (pre-NIV) as a predictor of 28-day mortality. The outcome was also compared between survivors and nonsurvivors. The outcome variables were analyzed by receiver-operating characteristic (ROC) curve, Youden index, and regression analysis. Results: The optimal criterion for A-a gradient to predict 28-day mortality was calculated as ≤430.43 at a Youden index of 0.5029, with the highest area under the curve (AUC) of 0.755 (p <0.0001). On regression analysis, the odds ratio for the A-a gradient was 0.99. A significant difference was observed in ABG predictors, including PaO2, PaCO2, A-a gradient, AO2, and arterial-alveolar (a-A) (%) among nonsurvivors vs survivors (p-value <0.001). The vasopressor requirement, need for renal replacement therapy, total parenteral requirement, and blood transfusion were higher among nonsurvivors; however, a significant difference was achieved with the vasopressor need (p <0.001). Conclusion: This study demonstrated that the A-a gradient is a significant predictor of mortality in patients initiated on NIV for worsening respiratory distress in COVID pneumonia. All other ABG parameters also showed a significant AUC for predicting 28-day mortality, although with variable sensitivity and specificity. Key messages: COVID-19 pneumonia shows an initial presentation with type 1 respiratory failure with increased A-a gradient, while a subsequent impending type 2 respiratory failure requires invasive ventilation. A significant difference was observed in ABG predictors, including PaO2, PaCO2, A-a gradient, AO2, and a-A (%) among nonsurvivors vs survivors. (p-value <0.001). The vasopressor requirement, need for renal replacement therapy, total parenteral requirement, and blood transfusion need were higher among nonsurvivors than survivors; however, a significant difference was achieved with the vasopressor need (p <0.001). How to cite this article: Gupta B, Jain G, Chandrakar S, Gupta N, Agarwal A. Arterial Blood Gas as a Predictor of Mortality in COVID Pneumonia Patients Initiated on Noninvasive Mechanical Ventilation: A Retrospective Analysis. Indian J Crit Care Med 2021;25(8):866-871.

Mucormycosis in COVID Diabetic Patients: A Horrifying Triad!

Infectious diseases with the coronavirus disease-2019 (COVID-19) can be linked to various microbial and fungal coinfections. Mucormycosis is an invasive opportunistic infection that enters as inhalation of fungal spores through the nose or paranasal sinuses in diabetic and immunocompromised patients. We present our experience of managing seven cases of recent COVID-19 infection with uncontrolled diabetes who developed rhino-orbital mucormycosis. All patients were diagnosed by clinical examination and imaging and managed by emergency surgical debridement and liposomal amphotericin-B. A lethal triad of impaired immunity due to COVID-19 infection, state of hyperglycemia, increased use of steroids, or rampant broad-spectrum antimicrobials works as fertile soil and may assist in the growth or alleviation of a fungal infection. Healthcare professionals must be aware of the potential of secondary invasive fungal infections in diabetic patients with moderate to severe category of COVID-19 infectious disease, especially on steroid therapy. HOW TO CITE THIS ARTICLE: Panwar P, Gupta A, Kumar A, Gupta B, Navriya SC. Mucormycosis in COVID Diabetic Patients: A Horrifying Triad! Indian J Crit Care Med 2021;25(11):1314-1317.

Anesthetic considerations in patients with cystic pulmonary adenomatoid malformations.

Congenital pulmonary adenomatoid malformation (CPAM) is a rare entity. The authors searched the US National Library of Medicine Database, EMBASE, Google Scholar, PubMed Central for anesthetic management in CPAM. The search was performed using the terms: congenital cystic adenomatoid malformation, congenital pulmonary adenomatoid malformation, CCAM, CPAM, anesthetic management. The prognosis of CPAM depends on timely diagnosis, presence of hydrops, degree of hypoplasia of remaining lung, and the size of the lesion. Symptomatic patients must be treated surgically and lobectomy is considered the gold standard. Anesthetic management of such cases is challenging as it involves thoracotomy or thoracoscopic lobectomy or cystectomy and can lead to sudden hemodynamic Collapse. Early extubation should be considered to avoid iatrogenic ventilator-induced bronchial stump dehiscence resulting from positive pressure ventilation.

Anesthetic considerations and goals in robotic pediatric surgery: a narrative review.

The morphosis from open surgeries to minimally invasive procedures is in greater part owing to the development of robotics. There has been a hiking popularity of robotic assistance for surgeries in recent years. Though a minimally invasive approach for surgery, it poses major challenges for an anesthesiologist that compound further for pediatric patients. The need of the hour for an anesthesiologist is to have a scrupulous knowledge and understanding of the associated anatomical and physiological considerations in case of pediatric patients. Major anesthetic concerns include restricted patient access, physiologic changes of pneumoperitoneum and different operative positions, risk of hypothermia, efficient fluid and peri-operative pain management. Timely anticipation, cautious observation for peri-operative complications and quick intervention to manage the same are warranted to provide high-quality anesthetic care. This simply implies that as robotic surgery plans to stretch up-to zenith, anesthesiologists shall strive to ace their part in robotic pediatric anesthesia as well. With an efficient and dynamic teamwork, robotic-assisted surgeries hold the potential to turn wonders for the future of surgery.

Role of High-flow Nasal Oxygen Therapy in Cases with Pulmonary Hypertension in an Intensive Care Unit Setting.

High-flow nasal oxygen therapy warms and humidifies gases, allows better clearance of secretions, along with providing added benefits like preventing dehydration of airway surface, while decreasing atelectasis and thereby, offering comfort to the patient. While its effect on critically ill patients is still in its pioneering phase, there is lack of substantial evidence on the use of high-flow nasal cannula in cardiac patients with type I respiratory failure. We found it worthwhile to share our experience of its use in elderly and postpartum patients with moderate-to-severe pulmonary hypertension, with associated comorbidities and type I respiratory failure, with do-not-intubate or defer intubation status. In patients with pulmonary hypertension (PHT) and respiratory failure, endotracheal intubation followed by initiation of mechanical ventilation may have detrimental hemodynamic effects. Increase in lung volumes and decrease in functional residual capacity lead to increase in pulmonary hypertension and right ventricle afterload. If a patient has right heart failure, lung hyperinflation can fatally reduce cardiac output. High-flow nasal oxygen therapy may be of an advantage in these scenarios. How to cite this article: Gupta B, Kerai S, Kakkar K, Gupta L. Role of High-flow Nasal Oxygen Therapy in Cases with Pulmonary Hypertension in an Intensive Care Unit Setting. Indian J Crit Care Med 2019;23(10):458-461.

Artemisinin resistance at the China-Myanmar border and association with mutations in the K13 propeller gene.

Artemisinin resistance in Plasmodium falciparum parasites in Southeast Asia is a major concern for malaria control. Its emergence at the China-Myanmar border, where there have been more than 3 decades of artemisinin use, has yet to be investigated. Here, we comprehensively evaluated the potential emergence of artemisinin resistance and antimalarial drug resistance status in P. falciparum using data and parasites from three previous efficacy studies in this region. These efficacy studies of dihydroartemisinin-piperaquine combination and artesunate monotherapy of uncomplicated falciparum malaria in 248 P. falciparum patients showed an overall 28-day adequate clinical and parasitological response of >95% and day 3 parasite-positive rates of 6.3 to 23.1%. Comparison of the 57 K13 sequences (24 and 33 from day 3 parasite-positive and -negative cases, respectively) identified nine point mutations in 38 (66.7%) samples, of which F446I (49.1%) and an N-terminal NN insertion (86.0%) were predominant. K13 propeller mutations collectively, the F446I mutation alone, and the NN insertion all were significantly associated with day 3 parasite positivity. Increased ring-stage survival determined using the ring-stage survival assay (RSA) was highly associated with the K13 mutant genotype. Day 3 parasite-positive isolates had ∼10 times higher ring survival rates than day 3 parasite-negative isolates. Divergent K13 mutations suggested independent evolution of artemisinin resistance. Taken together, this study confirmed multidrug resistance and emergence of artemisinin resistance in P. falciparum at the China-Myanmar border. RSA and K13 mutations are useful phenotypic and molecular markers for monitoring artemisinin resistance.

Therapeutic responses of Plasmodium vivax malaria to chloroquine and primaquine treatment in northeastern Myanmar.

Chloroquine-primaquine (CQ-PQ) continues to be the frontline therapy for radical cure of Plasmodium vivax malaria. Emergence of CQ-resistant (CQR) P. vivax parasites requires a shift to artemisinin combination therapies (ACTs), which imposes a significant financial, logistical, and safety burden. Monitoring the therapeutic efficacy of CQ is thus important. Here, we evaluated the therapeutic efficacy of CQ-PQ for P. vivax malaria in northeast Myanmar. We recruited 587 patients with P. vivax monoinfection attending local malaria clinics during 2012 to 2013. These patients received three daily doses of CQ at a total dose of 24 mg of base/kg of body weight and an 8-day PQ treatment (0.375 mg/kg/day) commencing at the same time as the first CQ dose. Of the 401 patients who finished the 28-day follow-up, the cumulative incidence of recurrent parasitemia was 5.20% (95% confidence interval [CI], 3.04% to 7.36%). Among 361 (61%) patients finishing a 42-day follow-up, the cumulative incidence of recurrent blood-stage infection reached 7.98% (95% CI, 5.20% to 10.76%). The cumulative risk of gametocyte carriage at days 28 and 42 was 2.21% (95% CI, 0.78% to 3.64%) and 3.93% (95% CI, 1.94% to 5.92%), respectively. Interestingly, for all 15 patients with recurrent gametocytemia, this was associated with concurrent asexual stages. Genotyping of recurrent parasites at the merozoite surface protein 3α gene locus from 12 patients with recurrent parasitemia within 28 days revealed that 10 of these were the same genotype as at day 0, suggesting recrudescence or relapse. Similar studies in 70 patients in the same area in 2007 showed no recurrent parasitemias within 28 days. The sensitivity to chloroquine of P. vivax in northeastern Myanmar may be deteriorating.

Plasmodium falciparum multidrug resistance protein 1 (pfmrp1) gene and its association with in vitro drug susceptibility of parasite isolates from north-east Myanmar.

OBJECTIVES: Plasmodium falciparum multidrug resistance protein 1 (pfmrp1) has recently emerged as an important determinant of drug resistance and mutations in the gene have been associated with several drugs. The aim of this study was to understand the level of genetic diversity in pfmrp1 and to determine the association of different mutations with altered drug susceptibilities of P. falciparum. METHODS: We analysed 193 sequences of pfmrp1 from South-East Asia, west Asia, Africa, Oceania and South America. We measured the level of genetic diversity and determined signatures of selection on the gene. In vitro susceptibilities of 28 P. falciparum isolates from north-east Myanmar to a panel of seven commonly used antimalarials were determined. Statistical analysis was performed to determine the association of different mutations with in vitro drug susceptibilities. RESULTS: A total of 28 single nucleotide polymorphisms were identified in 193 sequences, of which 22 were non-synonymous. Whereas mutations in the pfmrp1 gene were conserved among different countries within a continent, they were different between continents. Seven non-synonymous mutations were identified in the north-east Myanmar isolates; all were relatively frequent in this region as well as in other neighbouring countries. Molecular evolutionary analysis detected signatures of positive selection on the gene. Moreover, some mutations in this gene were found to be associated with reduced susceptibilities to chloroquine, mefloquine, pyronaridine and lumefantrine. CONCLUSIONS: Evidence of the positive selection of pmfrp1 and its association with the susceptibilities of parasites to multiple drugs signifies its potential as an important candidate for monitoring drug resistance.