scholarly journals Insecticide susceptibility status and knockdown resistance (kdr) mutation in Aedes albopictus in China

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yong Wei ◽  
Xueli Zheng ◽  
Song He ◽  
Xuli Xin ◽  
Jiachun Zhang ◽  
...  
Keyword(s):  
Mortality Rate ◽  
High Resistance ◽  
Pyrethroid Resistance ◽  
Management Strategies ◽  
Resistance Management ◽  
World Health ◽  
Knockdown Resistance ◽  
Phenotypic Resistance ◽  
Pcr Products ◽  
Health Organization

Abstract Background Aedes (Stegomyia) albopictus (Skuse, 1894) is the main vector of dengue virus in China. The resistance to insecticides is a huge obstacle for the control of this species, and determining its resistance status and mechanisms in China is essential for the implementation of vector management strategies. Methods We have investigated the larval and adult resistance status of Ae. albopictus to deltamethrin in eight field populations in China. Mutations at the voltage-gated sodium channel gene, related to the knockdown resistance (kdr) effect, were detected by sequencing of PCR products. The eight field populations were examined for pyrethroid resistance using the World Health Organization standard bioassays, and the association between the mutations and phenotypic resistance was tested. Results The eight field populations of larvae of Ae. albopictus in China exhibited high resistance to deltamethrin; the RR50 values ranged from 12 (ZJ) to 44 (GZ). Adult bioassay revealed that Ae. albopictus populations were resistant to deltamethrin (mortality rate < 90%), except ZJ population (probably resistant, mortality rate = 93.5%). Long knockdown time in the field populations was consistent with low mortality rates in adult bioassay. F1534S mutation showed increased protection against deltamethrin in all populations except BJ and SJZ populations, whereas I1532T mutation showed increased protection against deltamethrin in only BJ population. Conclusion There were different degrees of resistance to deltamethrin in field Ae. albopictus populations in China. The longest knockdown time and lowest mortality rate observed in Ae. albopictus population in Guangzhou indicate the severity of high resistance to deltamethrin. The patchy distribution of deltamethrin resistance and kdr mutations in Ae. albopictus mosquitoes suggests the necessity for resistance management and developing counter measures to mitigate the spread of resistance. Graphical Abstract

scholarly journals Pyrethroid Resistance Status of Aedes (Stegomyia) Aegypti (Linneaus) from Dengue Endemic Areas in Peninsular Malaysia

2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Rosilawati R ◽  
Lee HL ◽  
Nazni WA ◽  
Nurulhusna AH ◽  
Roziah A ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Mosquito Control ◽  
Pyrethroid Resistance ◽  
Resistance Management ◽  
Laboratory Strain ◽  
Control Agent ◽  
Peninsular Malaysia ◽  
World Health ◽  
Resistance Level ◽  
Health Organization

Vector control is still the principal method to control dengue and chemical insecticides, especially the pyrethroids such as permethrin are the forerunners of mosquito control agent. Intensive and extensive use of pyrethroids often result in resistance, thereby hampering control efforts. The present study was conducted to evaluate the susceptible status of Aedes aegypti, the primary vector of dengue against permethrin. A nationwide mosquito sampling via ovitrapping was conducted in 12 dengue hotspots across 5 states in Peninsular Malaysia. Field collected Aedes eggs were hatched and reared until L3 larval and further identified it species. Adult F0 Aedes aegypti were reared until F1 progeny and the female were used in adult assay, performed according to World Health Organization (WHO) protocol as to determine the resistance level. The laboratory strain maintained for more than 1000 generations that were susceptible to permethrin served as the control strain. Evaluation of resistance ratio was assessed by comparing the knockdown rate with laboratory susceptible strain. In this present study, 70% ofAe. aegypti population from dengue hotspots was highly resistance to permethrin. The study clearly demonstrated that widespread of permethrin resistant Ae. aegypti in Malaysian mosquito’s population, indicating the need of implementing an efficient pyrethroid resistance management.

scholarly journals Insecticide resistance status in Anopheles gambiae (s.l.) in coastal Kenya

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Daniel N. Munywoki ◽  
Elizabeth D. Kokwaro ◽  
Joseph M. Mwangangi ◽  
Ephantus J. Muturi ◽  
Charles M. Mbogo
Keyword(s):  
Insecticide Resistance ◽  
Anopheles Gambiae ◽  
Point Mutation ◽  
Management Strategies ◽  
Resistance Management ◽  
Pcr Amplification ◽  
Sub Saharan Africa ◽  
World Health ◽  
Phenotypic Resistance ◽  
Coastal Kenya

Abstract Background The rapid and widespread evolution of insecticide resistance has emerged as one of the major challenges facing malaria control programs in sub-Saharan Africa. Understanding the insecticide resistance status of mosquito populations and the underlying mechanisms of insecticide resistance can inform the development of effective and site-specific strategies for resistance prevention and management. The aim of this study was to investigate the insecticide resistance status of Anopheles gambiae (s.l.) mosquitoes from coastal Kenya. Methods Anopheles gambiae (s.l.) larvae sampled from eight study sites were reared to adulthood in the insectary, and 3- to 5-day-old non-blood-fed females were tested for susceptibility to permethrin, deltamethrin, dichlorodiphenyltrichloroethane (DDT), fenitrothion and bendiocarb using the standard World Health Organization protocol. PCR amplification of rDNA intergenic spacers was used to identify sibling species of the An. gambiae complex. The An. gambiae (s.l.) females were further genotyped for the presence of the L1014S and L1014F knockdown resistance (kdr) mutations by real-time PCR. Results Anopheles arabiensis was the dominant species, accounting for 95.2% of the total collection, followed by An. gambiae (s.s.), accounting for 4.8%. Anopheles gambiae (s.l.) mosquitoes were resistant to deltamethrin, permethrin and fenitrothion but not to bendiocarb and DDT. The L1014S kdr point mutation was detected only in An. gambiae (s.s.), at a low allelic frequency of 3.33%, and the 1014F kdr mutation was not detected in either An. gambiae (s.s.) or An. arabiensis. Conclusion The findings of this study demonstrate phenotypic resistance to pyrethroids and organophosphates and a low level of the L1014S kdr point mutation that may partly be responsible for resistance to pyrethroids. This knowledge may inform the development of insecticide resistance management strategies along the Kenyan Coast.

scholarly journals Mapping insecticide resistance in mosquitoes to aid malaria control

2020 ◽  
Author(s):  
Catherine L. Moyes ◽  
Duncan Kobia Athinya ◽  
Tara Seethaler ◽  
Katherine Battle ◽  
Marianne Sinka ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Malaria Control ◽  
Pyrethroid Resistance ◽  
Resistance Management ◽  
Resistance Mechanisms ◽  
World Health ◽  
Malaria Vector Control ◽  
Metabolic Resistance ◽  
Insecticide Resistance Management ◽  
Health Organization

AbstractMalaria vector control may be compromised by resistance to insecticides in vector populations. Actions to mitigate against resistance rely on surveillance using standard susceptibility tests, but there are large gaps in the monitoring data. Using a published geostatistical ensemble model, we have generated maps that bridge these gaps and consider the likelihood that resistance exceeds recommended thresholds. Our results show that this model provides more accurate next-year predictions than two simpler approaches. We have used the model to generate district-level maps for the probability that pyrethroid resistance in Anopheles gambiae s.l. exceeds the World Health Organization (WHO) thresholds for susceptibility and confirmed resistance. In addition, we have mapped the three criteria for the deployment of piperonyl butoxide-treated nets that mitigate against the effects of metabolic resistance to pyrethroids. This includes a critical review of the evidence for presence of cytochrome P450-mediated metabolic resistance mechanisms across Africa. The maps for pyrethroid resistance are available on the IR Mapper website where they can be viewed alongside the latest survey data.Significance StatementMalaria control in Africa largely relies on the use of insecticides to prevent mosquitoes from transmitting the malaria parasite to humans, however, these mosquitoes have evolved resistance to these insecticides. To manage this threat to malaria control, it is vital that we map locations where the prevalence of resistance exceeds thresholds defined by insecticide resistance management plans. A geospatial model and data from Africa are used to predict locations where thresholds of resistance linked to specific recommended actions are exceeded. This model is shown to provide more accurate next-year predictions than two simpler approaches. The model is used to generate maps that aid insecticide resistance management planning and that allow targeted deployment of interventions that counter specific mechanisms of resistance.

scholarly journals Personal protection with PBO-pyrethroid synergist-treated nets after 2 years of household use against pyrethroid-resistant Anopheles in Tanzania

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jackline L. Martin ◽  
Franklin W. Mosha ◽  
Eliud Lukole ◽  
Mark Rowland ◽  
Jim Todd ◽  
...  
Keyword(s):  
Pyrethroid Resistance ◽  
Density Ratio ◽  
Household Survey ◽  
Sensu Stricto ◽  
World Health ◽  
Malaria Vectors ◽  
Personal Protection ◽  
North West ◽  
Hole Index ◽  
Health Organization

Abstract Background The spread of pyrethroid resistance in malaria vectors threatens the effectiveness of standard long-lasting insecticidal nets (LLIN). Synergist nets combine pyrethroid (Py) and piperonyl-butoxide (PBO) to enhance potency against resistance mediated by mono-oxygenase mechanisms. Our project assessed personal protection of the World Health Organization first-in-class PBO-Py LLIN (Olyset Plus) versus the standard LLIN (Olyset net) against pyrethroid-resistant Anopheles gambiae sensu lato (s.l.) and An. funestus in North-West Tanzania after 20 months of household use. Methods From a household survey, 39 standard Olyset net and 39 Olyset Plus houses were selected. The physical integrity and hole index (HI) of the nets were assessed, and resting mosquitoes were collected from inside nets and from room walls. The indoor abundance was estimated using CDC light traps and species identified using PCR. The bioefficacy of PBO and standard LLINs against wild Anopheles was assessed using 30-minute cylinder bioassays. Results Of 2397 Anopheles collected, 8.9% (n = 213) were resting inside standard Olyset nets, while none were found inside Olyset Plus nets (PBO-Py LLINs) of any HI category. Resting density of blood-fed mosquitoes was higher on walls of sleeping rooms with Olyset nets compared to Olyset Plus (0.62 vs 0.10, density ratio [DR]: 0.03, 95% CI 0.01–0.13, p < 0.001). Mosquitoes were found inside Olyset nets of all WHO HI categories, but more were collected inside the more damaged nets (HI ≥ 643) than in less damaged (HI 0–64) nets (DR: 6.4, 95% CI 1.1–36.0, p = 0.037). In bioassay, mortality of An. gambiae s.l. was higher with Olyset Plus than with Olyset nets for new nets (76.8% vs 27.5%) and nets used for 20 months (56.8% vs 12.8%); similar trends were observed with An. funestus. Conclusion The PBO-Py LLINs provided improved protection after 20 months of household use, as demonstrated by the higher bioassay mortality and absence of pyrethroid-resistant An. gambiae sensu stricto (s.s.) and An. funestus collected from inside Olyset Plus nets, irrespective of HI category, as compared to Olyset nets.

scholarly journals Molluscicidal activity of crown of Christ (Euphorbia splendens var. hislopii) (Euphorbiaceae) latex submitted to pH variation

2003 ◽  
Vol 46 (3) ◽  
pp. 415-420 ◽  
Author(s):  
Maurício Carvalho Vasconcellos ◽  
José Augusto Albuquerque dos Santos ◽  
Ivonise Paz da Silva ◽  
Fátima Eliana Ferreira Lopes ◽  
Virgínia Torres Schall
Keyword(s):  
Mortality Rate ◽  
Aqueous Solutions ◽  
Schistosoma Mansoni ◽  
World Health Organization ◽  
Biomphalaria Glabrata ◽  
World Health ◽  
Ph Variation ◽  
Health Organization ◽  
Minor Concentration ◽  
Molluscicidal Activity

Laboratory and field bioassays have confirmed the specificity of the molluscicidal activity of the Euphorbia splendens var. hislopii latex (crown of Christ) (Euphorbiaceae) over snails of the species Biomphalaria glabrata, B. tenagophila, B. straminea, B. pfeifferi and Bulinus sp. in the control of Schistosoma mansoni. In the present study, the effect of the pH variation on lethal concentration (LC90) over B. tenagophila was evaluated. Bioassays with the aqueous solutions of the latex ranging from 0.4 to 12 µl/l were adjusted for pH of 5.0; 6.0; 7.0 and 8.0, and tested in accordance with methods standardized by World Health Organization. The results obtained indicated that the minor concentration of the latex occurred at pH 6.0 (LC90 = 3.2 µl/l) and the maximum at pH 8.0 (LC90 = 10.3 µl/l). Lethal concentrations adjusted for pH 5.0 and 7.0 were 3.4 µl/l and 4,7µl/l, respectively. From the results it could be concluded that the molluscicidal toxicity was not altered when the concentrations were adjusted for pH 5.0 and 6.0, as we observed that mortality rate was 100% starting at a concentration of 2.0 µl/l, not the same for the concentrations with adjustment for pH 7.0 and 8.0.

scholarly journals Literature Review The Relationship Of Antenatal Class Towards Mothers’ Knowledge Of DangerousSign During Pregnancy

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Ayu Kurniati ◽  
Enny Fitriahadi
Keyword(s):  
Developing Countries ◽  
Mortality Rate ◽  
Literature Review ◽  
World Health ◽  
Live Births ◽  
Complication Risk ◽  
The World ◽  
Health Organization ◽  
Relationship Of ◽  
The Relationship

IN 2013, the World Health Organization, released data in the form of Maternal Mortality Rate (MMR) worldwide, and the number reached 289,000 per 100, 000 live births, which 99% of cases occurred in developing countries. Research aims to discover the relationship of antenatal class towards mothers’ knowledge of the dangerous sign during pregnancy. The result showed that there is a relationship of antenatal class towards mothers’ knowledge of dangerous sign during pregnancy, From this result, the researcher concludes that antenatal class could increase mothers’ knowledge of dangerous sign during pregnancy and may decrease the complication risk during the childbirth.

scholarly journals Preliminary study of coronavirus disease 2019 on pets in pandemic in Denpasar, Bali, Indonesia

2021 ◽  
pp. 2979-2983
Author(s):  
Hamong Suharsono ◽  
Ali Ghufron Mukti ◽  
Ketut Suryana ◽  
I. Wayan Masa Tenaya ◽  
Dilasdita Kartika Pradana ◽  
...  
Keyword(s):  
Close Contact ◽  
Genetic Material ◽  
Rna Isolation ◽  
World Health ◽  
Intermediate Hosts ◽  
Rt Pcr ◽  
Pcr Products ◽  
Preliminary Study ◽  
Health Organization ◽  
Respiratory Droplets

Background and Aim: Coronavirus disease 2019 (COVID-19) is an acute infectious respiratory disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and has spread rapidly globally, resulting in a pandemic. In humans, the main routes of transmission are respiratory droplets and close contact with infected individuals or through contact with an object infected with the virus, followed by touching mouth, nose, or eyes. It is assumed that SARS-CoV-2 was originated in wild animals and was then transmitted to humans. Although some wildlife and domestic animals can be naturally or experimentally infected with the virus, the intermediate hosts that transmitted it to humans are still unknown. Understanding the dynamics of SARS-CoV-2 associated with possible zoonotic transmission of intermediate hosts is considered critical. Reportedly, cats or dogs living with COVID-19-positive humans tested positive for the disease, suggesting that the virus was transmitted to the animals from humans. Information regarding the epidemiological investigation and comprehensive studies is limited. Therefore, it is still unclear how high is the correlation of infection in humans and pet animals, especially those living together. The aim of this study was to investigate the possibility of SARS-CoV-2 infection in the pets of patients with COVID-19 who were hospitalized at the Wangaya hospital, Denpasar, Bali, Indonesia. Materials and Methods: A total of seven clinically asymptomatic pets (six dogs of different races and sexes and a cat [age, 360-2920 days]) were included in this study. These animals belonged to patients with confirmed SARS-CoV-2 infection from August to November 2020. Nasal swab and nasopharyngeal samples were collected from the pets individually under anesthetic condition and were collected 6-12 days after confirmed SARS-CoV-2 infection in owners and hospitalization at the Wangaya Hospital. The swab samples were then processed for RNA isolation and tested using reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2, in accordance with the World Health Organization manual 2020. Results: RT-PCR results for all seven RNA samples, prepared from the swab samples, were negative. For the samples, all PCR products were below the threshold limit, suggesting no genetic material belonging to the samples tested. Conclusion: This was the first preliminary study of COVID-19 on pets in pandemic using RT-PCR. The study tested a very limited quantity of samples, and all of them were negative. However, the way in which the samples were prepared was considered appropriate. Therefore, in further studies, testing of more samples of pets of more individuals with confirmed SARS-CoV-2 infection is required.

Machine Learning-Based Approach for Predictive Analytics in Healthcare

2022 ◽  
pp. 182-206
Author(s):  
Sandeep Kumar Hegde ◽  
Monica R. Mundada
Keyword(s):  
Machine Learning ◽  
Mortality Rate ◽  
Chronic Diseases ◽  
Domain Knowledge ◽  
Predictive Analytics ◽  
Future Trend ◽  
Medical Data ◽  
World Health ◽  
Premature Deaths ◽  
Health Organization

In this internet era, due to digitization in every application, a huge amount of data is produced digitally from the healthcare sectors. As per the World Health Organization (WHO), the mortality rate due to the various chronic diseases is increasing each day. Every year these diseases are taking lives of at least 50 million people globally, which includes even premature deaths. These days, machine learning (ML)-based predictive analytics are turning out as effective tools in the healthcare sectors. These techniques can extract meaningful insights from the medical data to analyze the future trend. By predicting the risk of diseases at the preliminary stage, the mortality rate can be reduced, and at the same time, the expensive healthcare cost can be eliminated. The chapter aims to briefly provide the domain knowledge on chronic diseases, the biological correlation between theses disease, and more importantly, to explain the application of ML algorithm-based predictive analytics in the healthcare sectors for the early prediction of chronic diseases.

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