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1.
PLoS Negl Trop Dis ; 17(5): e0011397, 2023 05.
Artículo en Inglés | MEDLINE | ID: covidwho-20232722

RESUMEN

BACKGROUND: The study assessed the risk of transmission of Aedes-borne arboviruses in a community at Cape Coast during the Covid-19 restriction period in 2020 based on entomological indices. The spatial distribution of insecticide resistance was also assessed in Ae. aegypti population from Cape Coast. METHODS: Three larval indices were calculated from a household larval survey in 100 randomly selected houses. WHO susceptibility bioassay was performed on female adult Ae. aegypti that were reared from the larvae collected from household containers and other receptacles located outside houses against four insecticides. The mosquitoes were also screened for F1534C, V1016I, and V410L kdr mutations. RESULTS: The estimated larval indices in the study community were House index- 34%, Container index- 22.35%, and Breteau index- 2.02. The mosquito population was resistant to Deltamethrin (0.05%), DDT (4%), Fenitrothion (1%), and Bendiocarb (0.1%). A triple kdr mutation, F1534C, V410L and V1016I were detected in the mosquito population. CONCLUSION: The study found the risk of an outbreak of Aedes-borne diseases lower in the covid-19 lockdown period than before the pandemic period. The low risk was related to frequent clean-up exercises in the community during the Covid-19 restriction period. Multiple insecticide resistance couple with three kdr mutations detected in the study population could affect the effectiveness of control measures, especially in emergency situations. The study supports sanitation improvement as a tool to control Ae. aegypti and could complement insecticide-based tools in controlling this vector.


Asunto(s)
Aedes , Arbovirus , COVID-19 , Insecticidas , Piretrinas , Animales , Humanos , Femenino , Resistencia a los Insecticidas/genética , Aedes/genética , Ghana , Control de Enfermedades Transmisibles , Insecticidas/farmacología , Mutación , Brotes de Enfermedades , Mosquitos Vectores/genética
2.
Trials ; 23(1): 640, 2022 Aug 09.
Artículo en Inglés | MEDLINE | ID: covidwho-2314290

RESUMEN

BACKGROUND: Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) target night-time indoor biting mosquitoes and effectively reduce malaria transmission in rural settings across Africa, but additional vector control tools are needed to interrupt transmission. Attractive targeted sugar baits (ATSBs) attract and kill mosquitoes, including those biting outdoors. Deployment of ATSBs incorporating the insecticide dinotefuran was associated with major reductions in mosquito density and longevity in Mali. The impact of this promising intervention on malaria transmission and morbidity now needs to be determined in a range of transmission settings. METHODS/DESIGN: We will conduct three similar stand-alone, open-label, two-arm, cluster-randomized, controlled trials (cRCTs) in Mali, Kenya, and Zambia to determine the impact of ATSB + universal vector control versus universal vector control alone on clinical malaria. The trials will use a "fried-egg" design, with primary outcomes measured in the core area of each cluster to reduce spill-over effects. All household structures in the ATSB clusters will receive two ATSBs, but the impact will be measured in the core of clusters. Restricted randomization will be used. The primary outcome is clinical malaria incidence among children aged 5-14 years in Mali and 1-14 years in Kenya and Zambia. A key secondary outcome is malaria parasite prevalence across all ages. The trials will include 76 clusters (38 per arm) in Mali and 70 (35 per arm) in each of Kenya and Zambia. The trials are powered to detect a 30% reduction in clinical malaria, requiring a total of 3850 person-years of follow-up in Mali, 1260 person-years in Kenya, and 1610 person-years in Zambia. These sample sizes will be ascertained using two seasonal 8-month cohorts in Mali and two 6-month seasonal cohorts in Zambia. In Kenya, which has year-round transmission, four 6-month cohorts will be used (total 24 months of follow-up). The design allows for one interim analysis in Mali and Zambia and two in Kenya. DISCUSSION: Strengths of the design include the use of multiple study sites with different transmission patterns and a range of vectors to improve external validity, a large number of clusters within each trial site, restricted randomization, between-cluster separation to minimize contamination between study arms, and an adaptive trial design. Noted threats to internal validity include open-label design, risk of contamination between study arms, risk of imbalance of covariates across study arms, variation in durability of ATSB stations, and potential disruption resulting from the COVID-19 pandemic. TRIAL REGISTRATION: Zambia: ClinicalTrials.gov NCT04800055 . Registered on March 15, 2021 Mali: ClinicalTrials.gov NCT04149119 . Registered on November 4, 2019 Kenya: ClinicalTrials.gov NCT05219565 . Registered on February 2, 2022.


Asunto(s)
COVID-19 , Culicidae , Mosquiteros Tratados con Insecticida , Insecticidas , Malaria , Animales , Niño , Culicidae/parasitología , Humanos , Kenia/epidemiología , Malaria/epidemiología , Malí , Control de Mosquitos/métodos , Mosquitos Vectores , Pandemias , Azúcares/efectos adversos , Zambia/epidemiología
3.
J Agric Food Chem ; 71(8): 3620-3638, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: covidwho-2257654

RESUMEN

The world's hunger is continuously rising due to conflicts, climate change, pandemics (such as the recent COVID-19), and crop pests and diseases. It is widely accepted that zero hunger is impossible without using agrochemicals to control crop pests and diseases. Diamide insecticides are one of the widely used green insecticides developed in recent years and play important roles in controlling lepidopteran pests. Currently, eight diamine insecticides have been commercialized, which target the insect ryanodine receptors. This review summarizes the development and optimization processes of diamide derivatives acting as ryanodine receptor activators. The review also discusses pest resistance to diamide derivatives and possible solutions to overcome the limitations posed by the resistance. Thus, with reference to structural biology, this study provides an impetus for designing and developing diamide insecticides with improved insecticidal activities.


Asunto(s)
COVID-19 , Insecticidas , Mariposas Nocturnas , Animales , Insecticidas/farmacología , Insecticidas/química , Canal Liberador de Calcio Receptor de Rianodina/química , Diamida/farmacología , Diamida/química , ortoaminobenzoatos/química
4.
Viruses ; 14(10)2022 10 06.
Artículo en Inglés | MEDLINE | ID: covidwho-2066557

RESUMEN

INTRODUCTION: Aedes aegypti is the vector of several arboviruses such as dengue, Zika, and chikungunya. In 2015-16, Zika virus (ZIKV) had an outbreak in South America associated with prenatal microcephaly and Guillain-Barré syndrome. This mosquito's viral transmission is influenced by microbiota abundance and diversity and its interactions with the vector. The conditions of cocirculation of these three arboviruses, failure in vector control due to insecticide resistance, limitations in dengue management during the COVID-19 pandemic, and lack of effective treatment or vaccines make it necessary to identify changes in mosquito midgut bacterial composition and predict its functions through the infection. Its study is fundamental because it generates knowledge for surveillance of transmission and the risk of outbreaks of these diseases at the local level. METHODS: Midgut bacterial compositions of females of Colombian Ae. aegypti populations were analyzed using DADA2 Pipeline, and their functions were predicted with PICRUSt2 analysis. These analyses were done under the condition of natural ZIKV infection and resistance to lambda-cyhalothrin, alone and in combination. One-step RT-PCR determined the percentage of ZIKV-infected females. We also measured the susceptibility to the pyrethroid lambda-cyhalothrin and evaluated the presence of the V1016I mutation in the sodium channel gene. RESULTS: We found high ZIKV infection rates in Ae. aegypti females from Colombian rural municipalities with deficient water supply, such as Honda with 63.6%. In the face of natural infection with an arbovirus such as Zika, the diversity between an infective and non-infective form was significantly different. Bacteria associated with a state of infection with ZIKV and lambda-cyhalothrin resistance were detected, such as the genus Bacteroides, which was related to functions of pathogenicity, antimicrobial resistance, and bioremediation of insecticides. We hypothesize that it is a vehicle for virus entry, as it is in human intestinal infections. On the other hand, Bello, the only mosquito population classified as susceptible to lambda-cyhalothrin, was associated with bacteria related to mucin degradation functions in the intestine, belonging to the Lachnospiraceae family, with the genus Dorea being increased in ZIKV-infected females. The Serratia genus presented significantly decreased functions related to phenazine production, potentially associated with infection control, and control mechanism functions for host defense and quorum sensing. Additionally, Pseudomonas was the genus principally associated with functions of the degradation of insecticides related to tryptophan metabolism, ABC transporters with a two-component system, efflux pumps, and alginate synthesis. CONCLUSIONS: Microbiota composition may be modulated by ZIKV infection and insecticide resistance in Ae. aegypti Colombian populations. The condition of resistance to lambda-cyhalothrin could be inducing a phenome of dysbiosis in field Ae. aegypti affecting the transmission of arboviruses.


Asunto(s)
Aedes , Antiinfecciosos , Arbovirus , COVID-19 , Dengue , Insecticidas , Piretrinas , Infección por el Virus Zika , Virus Zika , Animales , Femenino , Humanos , Virus Zika/genética , Resistencia a los Insecticidas , Insecticidas/farmacología , Colombia/epidemiología , Pandemias , Triptófano , Mosquitos Vectores , Piretrinas/farmacología , Bacterias , Redes y Vías Metabólicas , Fenazinas , Mucinas , Transportadoras de Casetes de Unión a ATP , Antiinfecciosos/farmacología , Alginatos
5.
Malar J ; 21(1): 253, 2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: covidwho-2009404

RESUMEN

BACKGROUND: The Democratic Republic of the Congo (DRC) organized a first mass distribution campaign of long-lasting insecticidal nets (LLINs) with digitalized data management with coordinated support from the Ministry of Health (MOH) and Santé Pour Tous En Milieu Rural-an 'Association sans but lucratif' (SANRU Asbl), in the context of the Covid-19 pandemic in Kongo Central province. This article describes the planning and implementation process of this campaign as well as the challenges and lessons learned. METHODS: The planning and implementation process was performed in line with the standard guidance issued by the National Malaria Control Programme (NMCP) following the start of Covid-19. The changes and adaptations put in place as well as the challenges encountered are described. RESULTS: A total of 5,629,211 people were registered (7.7% above projection) in 1,065,537 households (6.2% below projection) giving an average of 5.3 people per household. Of a total of 3,062,850 LLINs ordered, 2,886,096 were distributed to households (94%). Out of 11,070 villages and 3,947 teams planned, 91.7% of villages were reached and 93% of teams were established. CONCLUSION: The revision of standards of campaign implementation during Covid-19, as well as effective coordination supported by real-time decision-making through digital data management, have been factors in the success of this campaign. Maintaining this momentum is essential to ensure the continuity of malaria prevention services for the population.


Asunto(s)
COVID-19 , Mosquiteros Tratados con Insecticida , Insecticidas , Malaria , COVID-19/epidemiología , COVID-19/prevención & control , República Democrática del Congo/epidemiología , Humanos , Malaria/epidemiología , Malaria/prevención & control , Control de Mosquitos , Pandemias/prevención & control
6.
Pediatr Dermatol ; 39(5): 737-739, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: covidwho-1937986

RESUMEN

The influence of the nationwide lockdown orders during the COVID-19 pandemic on the transmission of scabies and lice remains unknown. We conducted a cross-sectional study utilizing UNC patient registry i2b2 to investigate monthly cases and prescriptions for scabies and lice in adult and pediatric patients in North Carolina. There were significant decreases in the cases and prescriptions for scabies and lice in the pediatric and adult populations. These results provide early insights on how COVID-19 pandemic lockdown orders affected the prevalence of these two conditions and suggest that physical distancing measures reduce transmission of these parasitic conditions.


Asunto(s)
COVID-19 , Insecticidas , Infestaciones por Piojos , Phthiraptera , Escabiosis , Adulto , Animales , COVID-19/epidemiología , COVID-19/prevención & control , Niño , Control de Enfermedades Transmisibles , Estudios Transversales , Humanos , Ivermectina , Infestaciones por Piojos/epidemiología , Infestaciones por Piojos/prevención & control , Pandemias , Permetrina , Escabiosis/epidemiología , Escabiosis/prevención & control
7.
New Microbiol ; 45(2): 83-98, 2022 04.
Artículo en Inglés | MEDLINE | ID: covidwho-1887519

RESUMEN

Malaria is long known as a deadly vector borne infection, caused by five parasite species of the coccidian genus Plasmodia that are present in as many as 85 countries. Despite significant progresses have been achieved to control the infection by early diagnosis and artemisinin combination treatment, insecticide-treated nets and indoor residual spraying, malaria still represents a major public health issue in many endemic low-income countries. New diagnostic tools of higher sensitivity and specificity are now available for use in endemic countries to better guide diagnosis and treatment. In particular, highly sensitive rapid antigenic tests are now available and the loop-mediated isothermal amplification is a very promising and highly sensitive diagnostic tool. After 2015, decreasing morbidity and mortality trends have been stagnating because of limited funding, emergence of parasite and vector resistance to drugs and insecticides respectively and, recently, by the disrupting effect of COVID-19 pandemic. The incomplete knowledge of the complex immunity of malaria infection has slowed the development of an effective vaccine. However, in 2021, the RTS-S vaccine, however of suboptimal protective efficacy, has been made available for routine use in children above 5 months of age. Population movements has increased the chance of observing imported malaria in non-endemic areas, where malaria competent vectors may still exist.


Asunto(s)
COVID-19 , Insecticidas , Malaria , COVID-19/prevención & control , Niño , Humanos , Insecticidas/uso terapéutico , Malaria/diagnóstico , Malaria/tratamiento farmacológico , Malaria/epidemiología , Control de Mosquitos , Pandemias
8.
Acta Trop ; 232: 106503, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: covidwho-1850533

RESUMEN

Head louse infestations caused by Pediculus humanus capitis (Phthiraptera: Pediculidae) are a public health problem in developing and developed countries worldwide. Head to head contact is by far the most common mode of lice transmission. In March 2020, WHO declared the COVID-19 outbreak as a pandemic. Starting from March 2020, the Israeli government established mandatory isolation for extensive periods including closure of school systems for very long time. The aim of the project was to compare the pediculicide sale numbers before the COVID-19 epidemic with those starting of the epidemic in 2020, as a possible marker for changing epidemiology of head lice during the COVID pandemic. Data were collected from a large pharmacy chain in Israel, which provided the actual sales of pediculicides during the years 2010-2020. During the period 2010-2019 a significant increase of pediculicide sales from 281,986 - 498,107 was observed, the highest number being from 2019. In 2020, this number dropped to 294,477, a significant drop compared to previous years and to 2019. The results of this study suggest that head louse infestations are increasing in the last years, while the extended isolation of children due to COVID-19 influenced significantly the infestation rate of children with head lice.


Asunto(s)
COVID-19 , Insecticidas , Infestaciones por Piojos , Pediculus , Animales , COVID-19/epidemiología , Niño , Humanos , Israel/epidemiología , Infestaciones por Piojos/epidemiología
9.
Environ Monit Assess ; 194(6): 416, 2022 May 10.
Artículo en Inglés | MEDLINE | ID: covidwho-1826650

RESUMEN

The use of imidacloprid and, to a lesser degree, other neonicotinoid insecticides is widespread in FL (and globally). The moderate to high water solubility and environmental persistence of neonicotinoids allows these compounds to readily enter, and be retained in, water resources where they may harm nontarget organisms and impact biological communities and associated trophic structures negatively. To better understand imidacloprid's chronic long-term exposure potential to aquatic invertebrate communities in FL, grab water samples were collected monthly in 2015 at 77 monitoring stations statewide. Fifty-eight stations (75%), representing 24 of the 25 drainage basins sampled, had detectable concentrations of imidacloprid, with concentrations ranging from 2 to 660 nanograms per liter [ng/L]. Imidacloprid basin medians were found to be correlated with two of six land use categories (urban, transportation, agriculture, and three crop classes) examined; urban (rho = 0.43, p-value = 0.03), and orchards and vineyards (rho 0.49, p-value = 0.01). The resampling of 12 select stations, representing eight basins, between August 2019 and July 2020, for the neonicotinoids acetamiprid, clothianidin, dinotefuran, imidacloprid, and thiamethoxam, showed that (1) median values of imidacloprid continued to exceed the US EPA chronic freshwater Invertebrate Aquatic Life Benchmark (IALB) (10 ng/L), (2) imidacloprid concentration was directly correlated with flow measurements, and (3) while median imidacloprid concentration decreased between the two sampling events (48.5 vs. 34.5 ng/L, p-value = 0.01) differences in event 1 and 2 streamflow regimes and disruptions due to the COVID-19 pandemic likely affected this outcome. Clothianidin was the only other neonicotinoid found to have values greater than a US EPA IALB, with detections at three stations exceeding the chronic IALB (50 ng/L). This study highlights the challenges associated with limiting neonicotinoids from entering water resources and identifies means to reduce their entry into and persistence within FL water resources.


Asunto(s)
COVID-19 , Insecticidas , Contaminantes Químicos del Agua , Animales , Monitoreo del Ambiente , Florida , Humanos , Insecticidas/análisis , Invertebrados , Neonicotinoides/análisis , Nitrocompuestos , Pandemias , Agua
10.
J Med Entomol ; 59(1): 301-307, 2022 01 12.
Artículo en Inglés | MEDLINE | ID: covidwho-1784366

RESUMEN

The efficacy of three groups of insect growth regulators, namely juvenile hormone mimics (methoprene and pyriproxyfen), chitin synthesis inhibitors (diflubenzuron and novaluron), and molting disruptor (cyromazine) was evaluated for the first time, against Aedes albopictus Skuse (Diptera: Culicidae) larvae from 14 districts in Sabah, Malaysia. The results showed that all field populations of Ae. albopictus were susceptible towards methoprene, pyriproxyfen, diflubenzuron, novaluron, and cyromazine, with resistance ratio values ranging from 0.50-0.90, 0.60-1.00, 0.67-1.17, 0.71-1.29, and 0.74-1.07, respectively. Overall, the efficacy assessment of insect growth regulators in this study showed promising outcomes and they could be further explored as an alternative to conventional insecticides.


Asunto(s)
Aedes , Hormonas Juveniles/farmacología , Control de Mosquitos/métodos , Aedes/efectos de los fármacos , Aedes/crecimiento & desarrollo , Animales , Diflubenzurón/farmacología , Insectos Vectores/efectos de los fármacos , Insectos Vectores/crecimiento & desarrollo , Insecticidas/farmacología , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Malasia , Metopreno/farmacología , Compuestos de Fenilurea/farmacología , Piridinas/farmacología
11.
Ann Parasitol ; 68(1): 35-38, 2022.
Artículo en Inglés | MEDLINE | ID: covidwho-1771929

RESUMEN

Scabies is a highly contagious, parasitic infestation caused by Sarcoptes scabiei var. hominis. There are some reports which claim the incidence of scabies has increased during COVID-19 lockdown. In this study, we aimed to compare the prevalence of scabies between March to September 2020 - the first six months of the COVID-19 outbreak in Turkey - and March to September 2019 - the same period in the previous year. Case number percentages were compared month-over-month and by total numbers for each specified period. Pearson's chi-squared test was the comparison tool used. We checked the records of 36,469 patients who were admitted to Bezmialem Vakif University, Faculty of Medicine, Dermatology Department, a tertiary healthcare center, between March and September 2019, and out of this number, 258 patients had been diagnosed with scabies. The overall scabies case percentage was 0.71% and the range of monthly prevalence was 0.57%-0.83%. During the corresponding period in 2020, 26,219 dermatology patients were admitted, and 465 of those patients were diagnosed with scabies. The overall scabies case percentage was 1.77% and the range of monthly prevalence was 1.37%-3.46%. Scabies prevalence percentages were statistically significantly higher in all months and in the overall total in 2020 (P<0.001). Our nine patients, who admitted in 2020, did not respond to permethrin treatment but responded well to an ivermectin and permethrin combination. Scabies incidence has increased during the COVID-19 pandemic according to our study. We believe there may be an underreported resistance to permethrin and that starting treatment with oral ivermectin in combination with topical permethrin in extraordinary times, such as a pandemic, may help to control outbreaks.


Asunto(s)
COVID-19 , Insecticidas , Escabiosis , COVID-19/epidemiología , Control de Enfermedades Transmisibles , Humanos , Insecticidas/uso terapéutico , Ivermectina/uso terapéutico , Pandemias , Permetrina/uso terapéutico , Escabiosis/tratamiento farmacológico , Escabiosis/epidemiología
12.
Molecules ; 27(5)2022 Feb 28.
Artículo en Inglés | MEDLINE | ID: covidwho-1760782

RESUMEN

Dengue is a neglected disease, present mainly in tropical countries, with more than 5.2 million cases reported in 2019. Vector control remains the most effective protective measure against dengue and other arboviruses. Synthetic insecticides based on organophosphates, pyrethroids, carbamates, neonicotinoids and oxadiazines are unattractive due to their high degree of toxicity to humans, animals and the environment. Conversely, natural-product-based larvicides/insecticides, such as essential oils, present high efficiency, low environmental toxicity and can be easily scaled up for industrial processes. However, essential oils are highly complex and require modern analytical and computational approaches to streamline the identification of bioactive substances. This study combined the GC-MS spectral similarity network approach with larvicidal assays as a new strategy for the discovery of potential bioactive substances in complex biological samples, enabling the systematic and simultaneous annotation of substances in 20 essential oils through LC50 larvicidal assays. This strategy allowed rapid intuitive discovery of distribution patterns between families and metabolic classes in clusters, and the prediction of larvicidal properties of acyclic monoterpene derivatives, including citral, neral, citronellal and citronellol, and their acetate forms (LC50 < 50 µg/mL).


Asunto(s)
Aedes , Insecticidas , Aceites Volátiles , Animales , Cromatografía de Gases y Espectrometría de Masas , Humanos , Insecticidas/farmacología , Larva , Mosquitos Vectores , Aceites Volátiles/farmacología
13.
Lancet ; 399(10331): 1202-1203, 2022 03 26.
Artículo en Inglés | MEDLINE | ID: covidwho-1757953
15.
PLoS One ; 16(11): e0260281, 2021.
Artículo en Inglés | MEDLINE | ID: covidwho-1546951

RESUMEN

BACKGROUND: There is a growing need to use green alternative larvicidal control for Aedes larvae compared to chemical insecticides. Substantial reliance on chemical insecticides caused insecticide resistance in mosquito populations. Thus, research for alternate chemical compounds from natural products is necessary to control Aedes larvae. This study explores the analysis of chemical compositions from Areca catechu nut as a potential larvicide for Aedes (Diptera: Culicidae). METHODS: The Areca catechu nut collected from Ipoh, Perak, Malaysia was grounded into powder and used for Soxhlet extraction. The chemical analysis of the extracts and their structures were identified using the GCMS-QP2010 Ultra (Shimadzu) system. National Institute of Standards and Technology (NIST) Chemistry WebBook, Standard Reference Database 69 (https://webbook.nist.gov/chemistry/) and PubChem (https://pubchem.ncbi.nlm.nih.gov/), the two databases used to retrieve the synonyms, molecular formula, molecular weight, and 2-dimensional (2D) structure of chemical compounds. Next, following WHO procedures for larval bioassays, the extracts were used to asses larvicidal activity against early 4th instar larvae of Aedes aegypti and Aedes albopictus. RESULTS: The larvicidal activities were observed against early 4th stage larvae with different concentrations in the range from 200 mg/L to 1600 mg/L. The LC50 and LC95 of Aedes aegypti were 621 mg/L and 2264 mg/L respectively; whereas the LC50 and LC95 of Aedes albopictus were 636 mg/L and 2268 mg/L respectively. Mortality was not observed in the non-target organism test. The analysis using gas chromatography and mass spectrometer recovered several chemical compounds such as Arecaidine, Dodecanoic acid, Methyl tetradecanoate, Tetradecanoic acid , and n-Hexadecanoic acid bioactive components. These chemical constituents were used as additive formulations in pesticides, pest control, insect repellent, and insecticidal agents. CONCLUSIONS: Our study showed significant outcomes from the extract of Areca catechu nut and it deserves further investigation in relation to chemical components and larvicidal actions between different species of Aedes mosquitoes. Even though all these findings are fundamental, it may have some interesting potentials to be developed as natural bio-larvicidal products.


Asunto(s)
Aedes/efectos de los fármacos , Areca/química , Insecticidas/toxicidad , Nueces/química , Extractos Vegetales/toxicidad , Aedes/fisiología , Animales , Control de Insectos , Repelentes de Insectos/química , Repelentes de Insectos/aislamiento & purificación , Repelentes de Insectos/toxicidad , Insecticidas/química , Insecticidas/aislamiento & purificación , Larva/efectos de los fármacos , Larva/fisiología , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación
16.
PLoS One ; 16(11): e0257736, 2021.
Artículo en Inglés | MEDLINE | ID: covidwho-1511815

RESUMEN

Since 2016, fall armyworm (FAW) has threatened sub-Saharan 'Africa's fragile food systems and economic performance. Yet, there is limited evidence on this transboundary pest's economic and food security impacts in the region. Additionally, the health and environmental consequences of the insecticides being used to control FAW have not been studied. This paper presents evidence on the impacts of FAW on maize production, food security, and human and environmental health. We use a combination of an agroecology-based community survey and nationally representative data from an agricultural household survey to achieve our objectives. The results indicate that the pest causes an average annual loss of 36% in maize production, reducing 0.67 million tonnes of maize (0.225 million tonnes per year) between 2017 and 2019. The total economic loss is US$ 200 million, or 0.08% of the gross domestic product. The lost production could have met the per capita maize consumption of 4 million people. We also find that insecticides to control FAW have more significant toxic effects on the environment than on humans. This paper highlights governments and development partners need to invest in sustainable FAW control strategies to reduce maize production loss, improve food security, and protect human and environmental health.


Asunto(s)
Agricultura/economía , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Spodoptera/patogenicidad , África del Norte , Animales , Etiopía , Humanos , Insecticidas/economía , Larva/genética , Larva/parasitología , Factores Socioeconómicos , Spodoptera/efectos de los fármacos , Zea mays/crecimiento & desarrollo , Zea mays/parasitología
17.
Elife ; 102021 08 06.
Artículo en Inglés | MEDLINE | ID: covidwho-1513052

RESUMEN

Monitoring local mosquito populations for insecticide resistance is critical for effective vector-borne disease control. However, widely used phenotypic assays, which are designed to monitor the emergence and spread of insecticide resistance (technical resistance), do not translate well to the efficacy of vector control products to suppress mosquito numbers in the field (practical resistance). This is because standard testing conditions such as environmental conditions, exposure dose, and type of substrate differ dramatically from those experienced by mosquitoes under field conditions. In addition, field mosquitoes have considerably different physiological characteristics such as age and blood-feeding status. Beyond this, indirect impacts of insecticide resistance and/or exposure on mosquito longevity, pathogen development, host-seeking behavior, and blood-feeding success impact disease transmission. Given the limited number of active ingredients currently available and the observed discordance between resistance and disease transmission, we conclude that additional testing guidelines are needed to determine practical resistance-the efficacy of vector control tools under relevant local conditions- in order to obtain programmatic impact.


Asunto(s)
Culicidae , Resistencia a los Insecticidas , Insecticidas , Control de Mosquitos , Mosquitos Vectores , Enfermedades Transmitidas por Vectores/prevención & control , Animales , Guías como Asunto
18.
PLoS Negl Trop Dis ; 15(8): e0009101, 2021 08.
Artículo en Inglés | MEDLINE | ID: covidwho-1416858

RESUMEN

BACKGROUND: In 2005, Bangladesh, India and Nepal agreed to eliminate visceral leishmaniasis (VL) as a public health problem. The approach to this was through improved case detection and treatment, and controlling transmission by the sand fly vector Phlebotomus argentipes, with indoor residual spraying (IRS) of insecticide. Initially, India applied DDT with stirrup pumps for IRS, however, this did not reduce transmission. After 2015 onwards, the pyrethroid alpha-cypermethrin was applied with compression pumps, and entomological surveillance was initiated in 2016. METHODS: Eight sentinel sites were established in the Indian states of Bihar, Jharkhand and West Bengal. IRS coverage was monitored by household survey, quality of insecticide application was measured by HPLC, presence and abundance of the VL vector was monitored by CDC light traps, insecticide resistance was measured with WHO diagnostic assays and case incidence was determined from the VL case register KAMIS. RESULTS: Complete treatment of houses with IRS increased across all sites from 57% in 2016 to 70% of houses in 2019, rising to >80% if partial house IRS coverage is included (except West Bengal). The quality of insecticide application has improved compared to previous studies, average doses of insecticide on filters papers ranged from 1.52 times the target dose of 25mg/m2 alpha-cypermethrin in 2019 to 1.67 times in 2018. Resistance to DDT has continued to increase, but the vector was not resistant to carbamates, organophosphates or pyrethroids. The annual and seasonal abundance of P. argentipes declined between 2016 to 2019 with an overall infection rate of 0.03%. This was associated with a decline in VL incidence for the blocks represented by the sentinel sites from 1.16 per 10,000 population in 2016 to 0.51 per 10,000 in 2019. CONCLUSION: Through effective case detection and management reducing the infection reservoirs for P. argentipes in the human population combined with IRS keeping P. argentipes abundance and infectivity low has reduced VL transmission. This combination of effective case management and vector control has now brought India within reach of the VL elimination targets.


Asunto(s)
Control de Insectos/normas , Insectos Vectores/parasitología , Insecticidas/administración & dosificación , Leishmaniasis Visceral/prevención & control , Phlebotomus/parasitología , Animales , Bioensayo , Femenino , Humanos , India/epidemiología , Control de Insectos/métodos , Resistencia a los Insecticidas , Leishmaniasis Visceral/epidemiología , Psychodidae/efectos de los fármacos , Piretrinas/administración & dosificación
19.
Parasit Vectors ; 14(1): 410, 2021 Aug 18.
Artículo en Inglés | MEDLINE | ID: covidwho-1371978

RESUMEN

BACKGROUND: Riverine species of tsetse (Glossina) transmit Trypanosoma brucei gambiense, which causes Gambian human African trypanosomiasis (gHAT), a neglected tropical disease. Uganda aims to eliminate gHAT as a public health problem through detection and treatment of human cases and vector control. The latter is being achieved through the deployment of 'Tiny Targets', insecticide-impregnated panels of material which attract and kill tsetse. We analysed the spatial and temporal distribution of cases of gHAT in Uganda during the period 2010-2019 to assess whether Tiny Targets have had an impact on disease incidence. METHODS: To quantify the deployment of Tiny Targets, we mapped the rivers and their associated watersheds in the intervention area. We then categorised each of these on a scale of 0-3 according to whether Tiny Targets were absent (0), present only in neighbouring watersheds (1), present in the watersheds but not all neighbours (2), or present in the watershed and all neighbours (3). We overlaid all cases that were diagnosed between 2000 and 2020 and assessed whether the probability of finding cases in a watershed changed following the deployment of targets. We also estimated the number of cases averted through tsetse control. RESULTS: We found that following the deployment of Tiny Targets in a watershed, there were fewer cases of HAT, with a sampled error probability of 0.007. We estimate that during the intervention period 2012-2019 we should have expected 48 cases (95% confidence intervals = 40-57) compared to the 36 cases observed. The results are robust to a range of sensitivity analyses. CONCLUSIONS: Tiny Targets have reduced the incidence of gHAT by 25% in north-western Uganda.


Asunto(s)
Control de Insectos/métodos , Insectos Vectores/efectos de los fármacos , Insecticidas/farmacología , Salud Pública/normas , Trypanosoma brucei gambiense/patogenicidad , Tripanosomiasis Africana/epidemiología , Tripanosomiasis Africana/prevención & control , Moscas Tse-Tse/efectos de los fármacos , Animales , Gambia , Humanos , Incidencia , Insectos Vectores/parasitología , Salud Pública/métodos , Moscas Tse-Tse/parasitología , Uganda/epidemiología
20.
Int Health ; 14(5): 537-539, 2022 09 07.
Artículo en Inglés | MEDLINE | ID: covidwho-1360352

RESUMEN

We examined the impact of coronavirus disease (COVID) mitigation, supply and distribution interruptions on the delivery of long-lasting insecticide-treated nets (LLINs) in Western Kenya. The median monthly distribution of LLINs declined during COVID mitigation strategies (March-July 2020) and during the health worker strikes (December 2020-February 2021). Recovery periods followed initial declines, indicative of a 'catching up' on missed routine distribution. Mass community campaigns were delayed by 10 months. These observations offer encouragement for routine net distribution resilience, but complete interruptions of planned mass distributions require alternate strategies during pandemics.


Asunto(s)
COVID-19 , Mosquiteros Tratados con Insecticida , Insecticidas , Malaria , COVID-19/prevención & control , Humanos , Kenia/epidemiología , Control de Mosquitos
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