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1.
Rev Saude Publica ; 53: 72, 2019 Sep 02.
Artigo em Inglês, Português | MEDLINE | ID: mdl-31483008

RESUMO

OBJECTIVE: To evaluate the adherence of pregnant women to personal protective measures against mosquito bites, recommended by the Ministry of Health, and to investigate the factors associated with the non-adoption of these measures. METHODS: We interviewed 177 pregnant women between November 2016 and February 2017 in the 10 basic health units of the municipality of Propriá, state of Sergipe, two located in the rural area and eight in the urban area, during prenatal appointments, to raise information about the use of preventive measures against the vector transmission of Zika virus. Data were analyzed using descriptive statistical methods, chi-square test or Fisher's exact test, and the odds ratio was calculated. The independent variables were grouped by the analysis of principal components, and the dependents (the use of repellent, mosquito nets, garments, screens and insecticides) were analyzed using the logistic regression method. RESULTS: Among the measures recommended by the Ministry of Health, mosquito nets were the most used by pregnant women living in rural areas and with low education level, while the repellents were more used by women in the urban area and with higher education level. Women in a vulnerable socio-economic situation presented a risk 2.4 times higher for not using screens in their homes, 1.9 times higher for not changing clothes and 2.5 times higher for not using repellent than pregnant women in better economic conditions. CONCLUSIONS: The socioeconomic status of pregnant women, especially among the less privileged, influenced the use of protective measures against Zika virus, from the purchase of repellent, clothing, insecticides to other resources in the municipality of Propriá, SE.


Assuntos
Controle de Mosquitos/métodos , Complicações Infecciosas na Gravidez/prevenção & controle , Infecção por Zika virus/prevenção & controle , Adolescente , Adulto , Brasil/epidemiologia , Estudos Transversais , Feminino , Humanos , Repelentes de Insetos/administração & dosagem , Inseticidas/administração & dosagem , Pessoa de Meia-Idade , Mosquiteiros/estatística & dados numéricos , Gravidez , Gestantes , Fatores Socioeconômicos , Adulto Jovem , Infecção por Zika virus/epidemiologia
2.
Pan Afr Med J ; 33: 84, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31489062

RESUMO

Introduction: Indoor residual spraying (IRS) is among the major vector control strategies recommended for endemic populations by the World Health Organization (WHO). The success of IRS requires high coverage which is dependent on its acceptability. In Nigeria, IRS pilots have been ongoing and rejection has been a major setback to its coverage. We assessed coverage of IRS and determined factors associated with its acceptability in Nasarawa Eggon district, Nasarawa state, Nigeria. Methods: A cross-sectional survey involving 409 households selected using multi-stage sampling was carried out. Trained data collectors administered pre-tested structured questionnaire to collect data on socio-demographic characteristics of household heads or their representatives, their perceptions on IRS and factors associated with IRS acceptability. Descriptive, bivariate and multivariate analyses were done at 5% level of significance. Results: Majority of respondents were male (79.7%) and married (82.6%), and their mean age was 36.4 ± 13.3 years. Coverage of IRS was 99.3%. However, only 82.6% of those who previously accepted IRS were willing to accept it in again. Factors independently associated with acceptability were perceived effectiveness of IRS (aOR = 21.8; 95%CI = 6.9-68.8) and lower household cost of malaria prevention after IRS (aOR = 5.0; 95%CI = 1.1-21.8). Conclusion: IRS coverage in the communities studied met WHO minimum standard of 85%. However, for similar results to be achieved in future, acceptability must be promoted by providing information on its effectiveness and its ability to reduce household cost of malaria prevention.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Inseticidas/administração & dosagem , Malária/prevenção & controle , Controle de Mosquitos/métodos , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Nigéria , Inquéritos e Questionários , Adulto Jovem
3.
Pan Afr Med J ; 33: 81, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31448043

RESUMO

Introduction: An estimated 125 million pregnancies around the world are at risk of malaria infection every year. Insecticide Treated Bed Nets is a form of personal protection that has reportedly been shown to reduce severe disease and mortality due to malaria in endemic regions. This study investigated ownership and utilization of Long Lasting Insecticide Nets among pregnant women attending antenatal clinics in Wa Municipality of Ghana. Methods: A cross-sectional study design was adopted to collect data among 394 pregnant women in six antenatal clinics. A two stage sampling technique was adopted and the data collection tool used was a semi-structured questionnaire. Descriptive and inferential statistics involving logistic regression were performed using Stata 14. Results: More (33.3%) of the pregnant women were aged between 25-29 years with no formal education (29.9%) whiles most (69.6%) of the pregnant women were in Islam religion. About 95.9% have heard about Long Lasting Insecticide Nets and its benefits. Intuitively, ownership of Long Lasting Insecticide Nets was 82.2% with 69.3% utilization of Long Lasting Insecticide Nets. Pregnant women aged 30-34 and 35 years and above were significant predictors, however, less likely to own Long Lasting Insecticide Nets compared to 15-19 years [AOR(95%CI)=0.29(0.10-0.87) and 0.08(0.01-0.72) respectively] whiles pregnant women aged 35 years and above were significantly less likely to utilize Long Lasting Insecticide Nets compared to 15-19 years [OR(95%CI)=0.12(0.03-0.48)]. Conclusion: The study found utilization of Long Lasting Insecticide Nets among pregnant in the Wa Municipality low as compared to the National Malaria Control Program target in Ghana although Long Lasting Insecticide Nets ownership was high. The study recommends that Public Health Nurses and Disease Control Officers should intensify sensitization on the importance and misconception of the use of Long Lasting Insecticide Nets during outreach clinics.


Assuntos
Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Malária/prevenção & controle , Controle de Mosquitos/métodos , Propriedade/estatística & dados numéricos , Adolescente , Adulto , Fatores Etários , Estudos Transversais , Feminino , Gana , Humanos , Modelos Logísticos , Gravidez , Inquéritos e Questionários , Adulto Jovem
4.
Cochrane Database Syst Rev ; 8: CD012736, 2019 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-31425624

RESUMO

BACKGROUND: Larviciding refers to the regular application of chemical or microbial insecticides to water bodies or water containers to kill the aquatic immature forms of the mosquito (the larvae and pupae). OBJECTIVES: To summarize research evidence evaluating whether larviciding with chemical or microbial insecticides prevents malaria transmission. SEARCH METHODS: We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE; Embase; CAB Abstracts; LILACS; the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP); ClinicalTrials.gov; and the ISRCTN registry up to 6 June 2019. SELECTION CRITERIA: We included cluster-randomized controlled trials (cRCTs), interrupted time series (ITS), randomized cross-over studies, non-randomized cross-over studies, and controlled before-and-after studies (CBAs) that compared larviciding with no larviciding. DATA COLLECTION AND ANALYSIS: We independently assessed trials for eligibility and risk of bias, and extracted data. We assessed the certainty of evidence using the GRADE approach. MAIN RESULTS: Four studies (one cRCT, two CBAs, and one non-randomized cross-over design) met the inclusion criteria. All used ground application of larvicides (people hand-delivering larvicides); one evaluated chemical and three evaluated microbial agents. Studies were carried out in The Gambia, Tanzania, Kenya, and Sri Lanka. Three studies were conducted in areas where mosquito aquatic habitats were less extensive (< 1 km²), and one where habitats were more extensive (> 1 km²; a cross-over study from The Gambia).For aquatic habitats of less than 1 km², one cRCT randomized eight villages in Sri Lanka to evaluate chemical larviciding using insect growth regulator; and two CBA studies undertaken in Kenya and Tanzania evaluated microbial larvicides. In the cRCT, larviciding across all villages was associated with lower malaria incidence (rate ratio 0.24, 4649 participants, low-certainty evidence) and parasite prevalence (risk ratio (RR) 0.26, 5897 participants, low-certainty evidence) compared to no larviciding. The two CBA studies reported lower malaria prevalence during the intervention period (parasite prevalence RR 0.79, 95% confidence interval (CI) 0.71 to 0.89; 70,902 participants; low-certainty evidence). The Kenyan study also reported a reduction in the incidence of new malaria cases (RR 0.62, 95% CI 0.38 to 1.01; 720 participants; very low-certainty evidence).For aquatic habitats of more than 1 km², the non-randomized cross-over trial using microbial larvicides did not detect an effect for malaria incidence (RR 1.58, 95% CI 0.94 to 2.65; 4226 participants), or parasite prevalence (RR 1.15, 95% CI 0.41 to 3.20; 3547 participants); both were very low-certainty evidence. The Gambia trial also reported the mean haemoglobin level, and there was no difference across the four comparisons (mean difference -0.13, 95% CI -0.40 to 0.13; 3586 participants).We were unable to summarize or pool entomological outcomes due to unreported and missing data. AUTHORS' CONCLUSIONS: Most controlled studies on larviciding have been performed with microbial agents. Ground larviciding for non-extensive larval habitats may have an effect on malaria transmission, and we do not know if there is an effect in large-scale aquatic habitats. We found no studies using larviciding application techniques that could cover large aquatic habitats, such as aerial spraying using aircraft.


Assuntos
Reservatórios de Doenças/parasitologia , Inseticidas/farmacologia , Malária/prevenção & controle , Controle de Mosquitos/métodos , Animais , Culicidae , Ecossistema , Humanos , Análise de Séries Temporais Interrompida , Larva/efeitos dos fármacos , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos
5.
Ecotoxicol Environ Saf ; 182: 109448, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31398781

RESUMO

The electrocoagulation (EC) technique is an alternative method of isolating natural products with the advantage of minimizing the amounts of organic solvents required for this process, which are often harmful to the environment. In this research, the EC and the conventional solvent extraction methods were used in the isolation of Stemona alkaloids from the aerial parts of Stemona aphylla. A comparison was made between the amounts of the isolated alkaloids and the solvents used. The isolated alkaloids were evaluated for their larvicidal, ovicidal and oviposition-deterrent activities against the dengue vector, Aedes aegypti. The morphology and histopatology of the alkaloid treated larvae were also investigated. Two Stemona alkaloids, (2'S)-hydroxystemofoline and stemofoline, were isolated from both the EC and the conventional method. The amounts of (2'S)-hydroxystemofoline from the EC method was about the same as that obtained from the conventional method. However, the amounts of stemofoline obtained from the EC method were about two times larger than those obtained from the conventional method. Importantly, the EC method required six times less total organic solvents. The larvicidal activity assays of (2'S)-hydroxystemofoline and stemofoline showed that these were highly effective against Aedes aegypti larvae with LC50 values of 3.91 µg/ml and 4.35 µg/ml, respectively. Whereas, the crude EC extract (LC50 = 11.86 µg/ml) showed greater larvicidal activity than the crude extract obtained from the conventional extraction method (LC50 = 53.40 µg/ml). The morphological observations of the (2'S)-hydroxystemofoline and the stemofoline treated larvae revealed that the anal gills were the sites of aberrations. A histopathological study showed that larvae treated with these alkaloids had cytopathological alterations to the epithelial cells of the midgut. At a concentration 40 µg/ml (2'S)-hydroxystemofoline showed 100% ovicidal activity on 24 h old eggs while stemofoline showed 97.2%. Furthermore, the oviposition-deterrent effects of (2'S)-hydroxystemofoline and stemofoline, at a concentration of 80 µg/ml were 99.5% and 97.2%, respectively.


Assuntos
Aedes/efeitos dos fármacos , Alcaloides/toxicidade , Controle de Mosquitos/métodos , Componentes Aéreos da Planta/química , Extratos Vegetais/toxicidade , Stemonaceae/química , Animais , Dengue/transmissão , Vetores de Doenças , Eletrocoagulação , Feminino , Compostos Heterocíclicos de 4 ou mais Anéis , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Mosquitos Vetores , Oviposição/efeitos dos fármacos
6.
BMC Public Health ; 19(1): 987, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337359

RESUMO

BACKGROUND: The Gulf Coast of the United States is home to mosquito vectors that may spread disease causing pathogens, and environmental conditions that are ideal for the sustained transmission of mosquito-borne pathogens. Understanding public perceptions of mosquito-borne diseases and mosquito prevention strategies is critical for the development of effective vector control strategies and public health interventions. Here, we present a survey conducted in Mobile, Alabama along the Gulf Coast to better understand public perceptions of mosquito-borne diseases, mosquito control activities, and potential risk factors. METHODS: Using Knowledge, Attitude, and Practice (KAPs) assessments, we surveyed populations living in 12 zip codes in Mobile, Alabama using a 7-point Likert scale and frequency assessments. Survey participants were asked about vector control efforts, knowledge of mosquito-borne diseases, and understanding of mosquito ecology and breeding habitats. RESULTS: One hundred twenty-six surveys were completed in Mobile, Alabama, revealing that 73% of participants reported being bitten by a mosquito in the last 30 days and mosquitoes were frequently seen in their homes. Ninety-four percent of respondents had heard of Zika Virus at the time of the survey, and respondents reported being least familiar with dengue virus and chikungunya virus. CONCLUSIONS: Chikungunya virus, dengue virus, malaria, West Nile virus, and Zika virus have been documented in the Gulf Coast of the United States. The mosquitoes which vector all of these diseases are presently in the Gulf Coast meaning all five diseases pose a potential risk to human health. The results of this survey emphasize knowledge gaps that public health officials can address to empower the population to reduce their risk of these mosquito-borne diseases. Each species of mosquito has specific preferences for breeding and feeding and there is no one size fits all prevention approach, educating people on the need for a variety of approaches in order to address all species will further empower them to control mosquitoes where they live and further reduce their risk of disease.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Controle de Mosquitos/métodos , Mosquitos Vetores , Alabama , Vírus Chikungunya , Vírus da Dengue , Humanos , Malária/prevenção & controle , Saúde Pública , Fatores de Risco , Inquéritos e Questionários , Vírus do Nilo Ocidental , Zika virus
7.
Rev Soc Bras Med Trop ; 52: e20180341, 2019 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-31271613

RESUMO

INTRODUCTION: Areas at risk of transmission of arboviruses have been monitored using ovitraps. This study aimed to evaluate the spatial distribution of Aedes aegypti in vulnerable areas for the transmission of arboviruses and assess the influence of climatic conditions on the infestation of these culicids. METHODS: Ovitraps were installed in Agrestina, Pernambuco, Northeastern Brazil. RESULTS: Overall, 44,936 eggs were collected, and the indexes of infestation varied. Relative humidity was significantly associated with the infestations. CONCLUSIONS: Using ovitraps, entomologic indexes and analysis of climatic factors might be good strategies for monitoring vulnerable areas for the transmission of arboviruses.


Assuntos
Arbovirus , Febre de Chikungunya/prevenção & controle , Dengue/prevenção & controle , Controle de Mosquitos/métodos , Oviposição , Infecção por Zika virus/prevenção & controle , Aedes/fisiologia , Animais , Brasil , Febre de Chikungunya/transmissão , Dengue/transmissão , Humanos , Umidade , Mosquitos Vetores/fisiologia , Chuva , Características de Residência , Estações do Ano , Análise Espacial , Temperatura Ambiente , Infecção por Zika virus/transmissão
8.
Malar J ; 18(1): 190, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31170984

RESUMO

Mozambique has historically been one of the countries with the highest malaria burden in the world. Starting in the 1960s, malaria control efforts were intensified in the southern region of the country, especially in Maputo city and Maputo province, to aid regional initiatives aimed to eliminate malaria in South Africa and eSwatini. Despite significant reductions in malaria prevalence, elimination was never achieved. Following the World Health Organization's renewed vision of a malaria-free-world, and considering the achievements from the past, the Mozambican National Malaria Control Programme (NMCP) embarked on the development and implementation of a strategic plan to accelerate from malaria control to malaria elimination in southern Mozambique. An initial partnership, supported by the Bill and Melinda Gates Foundation and the La Caixa Foundation, led to the creation of the Mozambican Alliance Towards the Elimination of Malaria (MALTEM) and the Malaria Technical and Advisory Committee (MTAC) to promote national ownership and partner coordination to work towards the goal of malaria elimination in local and cross-border initiatives. Surveillance systems to generate epidemiological and entomological intelligence to inform the malaria control strategies were strengthened, and an impact and feasibility assessment of various interventions aimed to interrupt malaria transmission were conducted in Magude district (Maputo Province) through the "Magude Project". The primary aim of this project was to generate evidence to inform malaria elimination strategies for southern Mozambique. The goal of malaria elimination in areas of low transmission intensity is now included in the national malaria strategic plan for 2017-22 and the NMCP and its partners have started to work towards this goal while evidence continues to be generated to move the national elimination agenda forward.


Assuntos
Controle de Doenças Transmissíveis/organização & administração , Erradicação de Doenças/organização & administração , Transmissão de Doença Infecciosa/prevenção & controle , Malária/epidemiologia , Malária/prevenção & controle , Financiamento de Capital , Controle de Doenças Transmissíveis/economia , Controle de Doenças Transmissíveis/métodos , Erradicação de Doenças/economia , Erradicação de Doenças/métodos , Política de Saúde , Humanos , Controle de Mosquitos/economia , Controle de Mosquitos/métodos , Controle de Mosquitos/organização & administração , Moçambique/epidemiologia
9.
Malar J ; 18(1): 198, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31196091

RESUMO

BACKGROUND: From 2011 to 2014, an indoor residual spray (IRS) programme for malaria vectors control was implemented in six health districts in Senegal. The main objective of the present study was to evaluate the efficacy of bendiocarb (FICAM WP 80) sprayed on different wall surfaces and its impact on malaria vectors. The entomological monitoring activities were carried out monthly in five treated sentinel villages and one control untreated village in each district. METHODS: The residual efficacy of bendiocarb applied at a dosage of 0.4 g/sq m was monitored for a period up to 9 months post-IRS using WHO cone bioassay method. This assay consisted to expose 2-5 days old unfed susceptible Anopheles coluzzii females to sprayed walls for a period of 30 min. The mortality rates after 24 h post-exposure were estimated and compared between the different types of walls sprayed in each sentinel village. RESULTS: The results showed that the residual efficacy varied between the different sprayed walls, from one sentinel village to another and between the different campaigns. The FICAM had a residual efficacy of 3-6 months post-IRS on mud and cement wall surfaces. In some cases, the observed mortality rates were much higher than those reported elsewhere particularly during the first campaign in all the six districts. CONCLUSIONS: The FICAM was found to be effective with a residual efficacy varying from 3 to 6 months. If the quality of the IRS application is excluded as a possible explanation of the short efficacy duration, the results suggest at least two rounds of treatments in order to cover the rainy season that lasts 5 to 6 months in the area. Such treatments could be carried out before the intensification of the rains in July and August in order to better cover the transmission period that occurs between late August and October in the area.


Assuntos
Aerossóis/farmacologia , Anopheles/efeitos dos fármacos , Inseticidas/farmacologia , Controle de Mosquitos/métodos , Mosquitos Vetores/efeitos dos fármacos , Fenilcarbamatos/farmacologia , Aerossóis/administração & dosagem , Animais , Bioensaio , Entomologia , Feminino , Humanos , Inseticidas/administração & dosagem , Fenilcarbamatos/administração & dosagem , Senegal , Inquéritos e Questionários , Fatores de Tempo
10.
Malar J ; 18(1): 199, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31200704

RESUMO

BACKGROUND: Indoor residual spraying (IRS), the coating of interior walls of houses with insecticides, is common in malaria-endemic areas. While important in malaria control, IRS potentially exposes residents to harmful insecticides. The World Health Organization recommends steps to minimize exposure; however, no programme has focused on educating populations. METHODS: A dramatic presentation and song were developed by study personnel and performed by lay performers in order to spread awareness of the importance of IRS and to minimize insecticide exposure. Performances were staged at 16 sprayed villages in the Vhembe District of Limpopo, South Africa, at which 592 attendees completed short questionnaires before and after the performance about behaviors that might limit insecticide exposure. Overall indices of the attendees' change in knowledge of precautions to take prior to and after spraying to prevent insecticide exposure were analyzed using hierarchical mixed models to assess the effect of the performance on change in participants' knowledge. RESULTS: Approximately half of attendees lived in homes that had been sprayed for malaria and 62% were female. Over 90% thought it better to allow IRS prior to the presentation, but knowledge of proper precautions to prevent exposure was low. The proportion answering correctly about proper distance from home during spraying increased from 49.4% pre-performance to 62.0% post-performance (RR = 1.26, 95% CI = 1.13, 1.41), and the proportion reporting correctly about home re-entry interval after spraying increased from 58.5 to 91.1% (RR = 1.54, 95% CI 1.35, 1.77). Attendees improved in their knowledge about precautions to take prior to and after spraying from mean of 57.9% correct to a mean of 69.7% (ß = 12.1%, 95% CI 10.9, 13.4). Specifically, increased knowledge in closing cupboards, removing food and bedding from the home, covering immoveable items with plastic, and leading animals away from the home prior to spraying were observed, as was increased knowledge in sweeping the floors, proper disposal of dead insects, and discarding dirty washrags after spraying. CONCLUSIONS: A dramatic presentation and song were able to increase the attendees' knowledge of precautions to take prior to and after spraying in order to limit their insecticide exposure resulting from IRS. This approach to community education is promising and deserves additional study.


Assuntos
Aerossóis/efeitos adversos , Terapia Comportamental/métodos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Educação em Saúde/métodos , Conhecimentos, Atitudes e Prática em Saúde , Inseticidas/efeitos adversos , Controle de Mosquitos/métodos , Adolescente , Adulto , Aerossóis/administração & dosagem , Idoso , Feminino , Pesquisa sobre Serviços de Saúde , Humanos , Inseticidas/administração & dosagem , Masculino , Pessoa de Meia-Idade , África do Sul , Inquéritos e Questionários , Adulto Jovem
11.
Parasit Vectors ; 12(1): 311, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31234914

RESUMO

BACKGROUND: The cuticle is an indispensable structure that protects the mosquito against adverse environmental conditions and prevents pathogen entry. While most cuticles are hard and rigid, some parts of cuticle are soft and flexible to allow movement and blood-feeding. It has been reported that 3, 4-dihydroxyphenylacetaldehyde (DOPAL) synthase is associated with flexible cuticle formation in Aedes aegypti. However, the molecular function of DOPAL synthase in the ontogenesis of mosquito remains largely unknown. In this study, we characterized gene expression profiles of DOPAL synthase and investigated its functions in larvae and female adults of Aedes agypti by RNAi. RESULTS: Our results suggest that the expression of DOPAL synthase is different during development and the transcriptional level reached its peak at the female white pupal stage, and DOPAL synthase was more highly expressed in the cuticle and midgut than other tissues in the adult. The development process from larva to pupa was slowed down strikingly by feeding the first-instar larvae with chitosan/DOPAL synthase dsRNA nanoparticles. A qRT-PCR analysis confirmed that the dsRNA-mediated transcription of the DOPAL synthase was reduced > 50% in fourth-instar larvae. Meanwhile, larval molt was abnormal during development. Transmission electron microscopy results indicated that the formation of endocuticle and exocuticle was blocked. In addition, we detected that the dsDOPAL synthase RNA caused significant mortality when injected into the female adult mosquitoes. CONCLUSIONS: Our findings demonstrate that DOPAL synthase plays a critical role in mosquito larval development and adult survival and suggest that DOPAL synthase could be a good candidate gene in RNAi intervention strategies in mosquito control.


Assuntos
Aedes/enzimologia , Aedes/genética , Descarboxilases de Aminoácido-L-Aromático/genética , Proteínas de Insetos/genética , Larva/crescimento & desenvolvimento , Interferência de RNA , Animais , Feminino , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Controle de Mosquitos/métodos
12.
Parasit Vectors ; 12(1): 278, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31151470

RESUMO

BACKGROUND: Surveillance of outdoor resting malaria vector populations is crucial to monitor possible changes in vector resting and feeding behaviour following the widespread use of indoor-based vector control interventions. However, it is seldom included in the routine vector surveillance system in Africa due to lack of well standardized and efficient traps. This study was conducted to evaluate the performance of sticky pots for outdoor resting malaria vector surveillance in western Kenya. METHODS: Mosquito collections were conducted from September 2015 to April 2016 in Ahero and Iguhu sites, western Kenya using sticky pots, pit shelters, clay pots, exit traps, Prokopack aspirator and CDC light traps (outdoor and indoor). Species within Anopheles gambiae (s.l.) were identified using polymerase chain reaction (PCR). Enzyme-linked immunosorbent assay (ELISA) was used to determine blood meal sources of malaria vectors. RESULTS: A total of 23,772 mosquitoes were collected, of which 13,054 were female anophelines comprising An. gambiae (s.l.) (72.9%), An. funestus (13.2%), An. coustani (8.0%) and An. pharoensis (5.9%). Based on PCR assay (n = 672), 98.6% An. arabiensis and 1.4% An. gambiae (s.s.) constituted An. gambiae (s.l.) in Ahero, while this was 87.2% An. gambiae (s.s.) and 12.8% An. arabiensis in Iguhu. The sticky pots and pit shelters showed similar performance with regard to the relative abundance and host blood meal indices of An. gambiae (s.l.) and An. funestus. In terms of density per trap, a pit shelter caught on average 4.02 (95% CI: 3.06-5.27) times as many An. gambiae (s.l.) as a sticky pot, while a sticky pot captured 1.60 (95% CI: 1.19-2.12) times as many An. gambiae (s.l.) as a clay pot. Exit traps yielded a significantly lower number of An. gambiae (s.l.) than all other traps in Ahero, but a higher number of An. gambiae (s.l.) compared to the other outdoor traps in Iguhu. Indoor CDC light traps captured a significantly higher number of An. funestus than other traps. CONCLUSIONS: Sticky pots could be a useful and complementary tool for outdoor resting malaria vector surveillance, in settings where using pit shelters is not feasible and less productive. The lower vector density in the sticky pots compared to pit shelters suggests that batches of sticky pots (i.e. four per compound) need to be deployed in order to make a direct comparison. This study also highlighted the need to concurrently undertake indoor and outdoor vector surveillance to better understand residual malaria transmission.


Assuntos
Anopheles , Comportamento Alimentar , Controle de Mosquitos/instrumentação , Animais , Feminino , Habitação , Quênia , Controle de Mosquitos/métodos , Mosquitos Vetores , Densidade Demográfica , Vigilância da População
13.
Parasit Vectors ; 12(1): 299, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31196222

RESUMO

BACKGROUND: Insecticide resistance of Anopheles gambiae (s.l.) against public health insecticides is increasingly reported in Ghana and need to be closely monitored. This study investigated the intensity of insecticide resistance of An. gambiae (s.l.) found in a vegetable growing area in Accra, Ghana, where insecticides, herbicides and fertilizers are massively used for plant protection. The bioefficacy of long-lasting insecticidal nets (LLINs) currently distributed in the country was also assessed to delimitate the impact of the insecticide resistance intensity on the effectiveness of those nets. METHODS: Three- to five-day-old adult mosquitoes that emerged from collected larvae from Opeibea, Accra (Ghana), were assayed using CDC bottle and WHO tube intensity assays against different insecticides. The Vgsc-L1014F and ace-1 mutations within the population were also characterized using PCR methods. Furthermore, cone bioassays against different types of LLINs were conducted to evaluate the extent and impact of the resistance of An. gambiae (s.l.) from Opeibea. RESULTS: Anopheles gambiae (s.l.) from Opeibea were resistant to all the insecticides tested with very low mortality observed against organochlorine, carbamates and pyrethroid insecticides using WHO susceptibility tests at diagnostic doses during three consecutive years of monitoring. The average frequencies of Vgsc-1014F and ace-1 in the An. gambiae (s.l.) population tested were 0.99 and 0.76, respectively. The intensity assays using both CDC bottle and WHO tubes showed high resistance intensity to pyrethroids and carbamates with survivals at 10× the diagnostic doses of the insecticides tested. Only pirimiphos methyl recorded a low resistance intensity with 100% mortality at 5× the diagnostic dose. The bioefficacy of pyrethroid LLINs ranged from 2.2 to 16.2% mortality while the PBO LLIN, PermaNet® 3.0, was 73%. CONCLUSIONS: WHO susceptibility tests using the diagnostic doses described the susceptibility status of the mosquito colony while CDC bottle and WHO tube intensity assays showed varying degrees of resistance intensity. Although both methods are not directly comparable, the indication of the resistance intensity showed the alarming insecticide resistance intensity in Opeibea and its surroundings, which could have an operational impact on the efficacy of vector control tools and particularly on pyrethroid LLINs.


Assuntos
Anopheles , Resistência a Inseticidas , Mosquiteiros Tratados com Inseticida/normas , Malária/prevenção & controle , Piretrinas , Agricultura , Animais , Bioensaio , Feminino , Gana/epidemiologia , Larva , Malária/epidemiologia , Controle de Mosquitos/métodos , Controle de Mosquitos/normas , Organização Mundial da Saúde
14.
Malar J ; 18(1): 189, 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159821

RESUMO

BACKGROUND: Mosquito net use is an essential part of malaria prevention. Although previous research has shown that many people sleep under a mosquito net in endemic areas, it is unknown whether people underestimate how common it is to sleep under a net every night. Furthermore, perceived social norms about whether most others sleep under a mosquito net every night may contribute to personally sleeping under a net, given decades of research showing that people often mimic others' behaviours. METHODS: Population-based data were collected from 1669 adults across eight villages in one rural parish in southwestern Uganda. Individuals' perception about whether most adults in their community sleep under a mosquito net every night was compared with whether daily mosquito net use was the actual norm in their community to identify the extent of norm misperception. The association between whether an individual perceived daily mosquito net use to be the norm and personal mosquito net use was assessed while adjusting for the ratio of nets:people in the household and other factors. RESULTS: Although the majority (65%) of participants reported sleeping under a mosquito net every night (and 75% did so among the 86% of people with at least one net), one-quarter of participants thought that most adults in their community did not sleep under a mosquito net every night. Another 8% were unsure how many nights per week most adults in their community sleep under a mosquito net. Participants who perceived that daily mosquito net use was the norm were 2.94 times more likely to report personally sleeping under a mosquito net every night (95% CI 2.09-4.14, p < 0.001) compared to participants who thought doing so was not normative, adjusting for other factors. CONCLUSIONS: Results suggest an opportunity for anti-malarial interventions to reduce misperceptions about mosquito net use norms and emphasize the commonness of daily mosquito net use in malaria-endemic regions. If people correctly perceive most others to sleep under a net every night, then they may personally do so when possible and support others to do so too.


Assuntos
Controle de Mosquitos/métodos , Mosquiteiros/estatística & dados numéricos , Normas Sociais , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Utilização de Equipamentos e Suprimentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , População Rural , Uganda , Adulto Jovem
15.
BMC Public Health ; 19(1): 669, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31146722

RESUMO

BACKGROUND: Thermal fogging of Insecticides is a vector control strategy used by the Medellin Secretary of Health to combat dengue. This method is employed during outbreaks to curb populations of potentially infectious adult mosquitoes and interrupt transmission cycles. While this strategy has been used in Medellin since 2007, in some years it has not reduced dengue cases as expected. Difficulties in the implementation of fumigation strategies, such as lack of opportunity for treatment and public perception may be factors that limit its utility. The objective of this study was to identify barriers that hinder the implementation of thermal fogging, as well as attitudes and beliefs that prevent its acceptance. METHODS: We used a cross-sectional observational study of mixed methods carried out in neighborhoods prioritized for fumigation treatment in Medellin, Colombia. First, we assessed the timeliness of treatment by determining the latency period between reported dengue cases and the implementation of fumigation in response to those cases. Next, we administered structured questionnaires to residents in the area of fumigation treatments (n = 4455 homes) to quantify acceptance and rejection, as well as factors associated with rejection. RESULTS: The median time between notification and treatment was 25 days (IQR 20.0-36.5). Fumigators were only able to treat 53.7% of total households scheduled for treatment; 9.6% rejected treatment, and treatment teams were unable to fumigate the remaining 36.7% of homes due to absent residents, no adults being present, and other reasons. The most frequent causes for rejection were residents being busy at the time of treatment (33.1%) and no interest in the treatment (24.5%). Other reasons for rejection include the perceptions that fumigation does not control pests other than mosquitoes (4.3%), that no mosquitoes were present in the home (3.3%), and that fumigation affects human health (3.1%). CONCLUSIONS: The high percentage of houses where it was not possible to perform fumigation limits control of the vector. Future strategies should consider more flexible treatment schedules and incorporate informational messages to educate residents about the safety and importance of treatment.


Assuntos
Dengue/prevenção & controle , Fumigação/estatística & dados numéricos , Inseticidas/administração & dosagem , Controle de Mosquitos/métodos , Adulto , Colômbia/epidemiologia , Estudos Transversais , Dengue/epidemiologia , Características da Família , Feminino , Fumigação/métodos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Mosquitos Vetores , Características de Residência , Inquéritos e Questionários
16.
MMWR Morb Mortal Wkly Rep ; 68(22): 500-504, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31170124

RESUMO

Aedes aegypti, the mosquito that carries dengue, chikungunya, and Zika viruses, is present throughout the U.S. Virgin Islands (USVI). To reduce mosquitoborne disease transmission, the USVI Department of Health (VIDOH) is responsible for integrated mosquito management. During January 2016-January 2018, USVI experienced its first Zika outbreak, with most cases reported during January-December 2016, as well as two Category 5 hurricanes (Irma on St. Thomas/St. John on September 6, 2017, and Maria on St. Croix on September 19, 2017). The hurricanes severely damaged mosquito protection-related building structures (e.g., screens, roofs) and infrastructure (e.g., electricity, air conditioning) and might have created an environment more conducive to mosquito breeding. VIDOH, with requested technical assistance from CDC, conducted three Community Assessments for Public Health Emergency Response (CASPERs) to provide rapid community information at the household level. The three CASPERs were conducted to inform 1) the Zika outbreak response, 2) the hurricane response, and 3) the hurricane recovery. The CASPERs assessed mosquito prevention and control-related experiences, attitudes, and practices; household and environmental conditions associated with mosquito breeding, prevention, and control; and other nonmosquito-related information to inform outbreak and disaster response planning. Approximately 40% of households were very concerned about contracting Zika virus during the Zika outbreak and hurricane responses. Environmental conditions were reported to become more favorable for mosquito breeding between the Zika outbreak and hurricane response. Between 75%-80% of the community supported mosquito-spraying in all assessments. VIDOH used these data to support real-time outbreak and hurricane response planning. Mosquito prevention and control community assessments can provide rapid, actionable information to advise both mosquito education and control and emergency response and recovery efforts. The CASPER design can be used by vector control programs to enhance routine and response operations.


Assuntos
Tempestades Ciclônicas , Surtos de Doenças/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde , Controle de Mosquitos/métodos , Características de Residência , Infecção por Zika virus/prevenção & controle , Adolescente , Adulto , Idoso , Humanos , Pessoa de Meia-Idade , Ilhas Virgens Americanas/epidemiologia , Adulto Jovem , Infecção por Zika virus/epidemiologia
17.
IET Nanobiotechnol ; 13(2): 170-177, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31051447

RESUMO

Malaria is a dangerous disease affecting humans and animals in tropical and subtropical areas worldwide. According to recent estimates, 3.2 billion people are at risk of malaria. Many drugs are in practices to control this disease and their vectors. Eco-friendly control tools are needed to fight vectors of this important disease. Nanotechnology is playing a key role in the fight against many public health emergencies. In the present study, Lagenaria siceraria aqueous peel extract was used to prepare zinc oxide nanoparticles (ZnO NPs), then tested on Anopheles stephensi eggs, larvae and pupae. The L. siceraria-synthesised ZnO NPs were characterized additionally by FTIR, AFM, XRD, UV-Vis spectroscopy, EDX, and SEM spectroscopy The ovicidal, larvicidal, pupicidal and repellent activities of L. siceraria and green-synthesised ZnO NPs were analysed on A. stephensi. The potential mechanism of action of ZnO NPs was studied investigating the changes in various enzyme activities in A. stephensi IV instar larvae. Furthermore, the smoke toxicity of L. siceraria-based cones against A. stephensi evoked higher mortality if compared with the control. Overall, the present study concluded that L. siceraria peel extract and its mediated green synthesised ZnO NPs represent a valuable green option to manage against malaria vectors.


Assuntos
Anopheles/efeitos dos fármacos , Cucurbitaceae/química , Inseticidas/farmacologia , Nanopartículas Metálicas/química , Mosquitos Vetores/efeitos dos fármacos , Óxido de Zinco/farmacologia , Animais , Química Verde , Inseticidas/química , Larva/efeitos dos fármacos , Malária/prevenção & controle , Malária/transmissão , Controle de Mosquitos/métodos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Óxido de Zinco/química
18.
PLoS Negl Trop Dis ; 13(5): e0007422, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31107878

RESUMO

New mosquito control strategies are vitally needed to address established and emerging arthropod-borne infectious diseases. Here we describe the characterization of a yeast interfering RNA larvicide that was developed through the genetic engineering of Saccharomyces cerevisiae (baker's yeast) to express a short hairpin RNA targeting the Aedes aegypti synaptotagmin (Aae syt) gene. The larvicide effectively silences the Aae syt gene, causes defects at the larval neural synapse, and induces high rates of A. aegypti larval mortality in laboratory, simulated-field, and semi-field trials. Conservation of the interfering RNA target site in multiple mosquito species, but not in humans or other non-target species, suggested that it may function as a broad-range mosquito larvicide. In support of this, consumption of the yeast interfering RNA larvicide was also found to induce high rates of larval mortality in Aedes albopictus, Anopheles gambiae, and Culex quinquefasciatus mosquito larvae. The results of these studies suggest that this biorational yeast interfering RNA larvicide may represent a new intervention that can be used to combat multiple mosquito vectors of human diseases.


Assuntos
Proteínas de Insetos/genética , Controle de Mosquitos/métodos , Mosquitos Vetores/genética , Controle Biológico de Vetores/métodos , Interferência de RNA , Saccharomyces cerevisiae/genética , Sinaptotagminas/genética , Aedes/genética , Aedes/metabolismo , Aedes/microbiologia , Animais , Anopheles/genética , Anopheles/metabolismo , Anopheles/microbiologia , Culex/genética , Culex/metabolismo , Culex/microbiologia , Feminino , Engenharia Genética , Proteínas de Insetos/metabolismo , Larva/genética , Larva/metabolismo , Larva/virologia , Masculino , Mosquitos Vetores/metabolismo , Mosquitos Vetores/virologia , Saccharomyces cerevisiae/metabolismo , Sinaptotagminas/metabolismo
19.
PLoS Negl Trop Dis ; 13(5): e0007443, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31107912

RESUMO

BACKGROUND: Wolbachia's ability to restrict arbovirus transmission makes it a promising tool to combat mosquito-transmitted diseases. Wolbachia-infected Aedes aegypti are currently being released in locations such as Brazil, which regularly experience concurrent outbreaks of different arboviruses. A. aegypti can become co-infected with, and transmit multiple arboviruses with one bite, which can complicate patient diagnosis and treatment. METHODOLOGY/PRINCIPLE FINDINGS: Using experimental oral infection of A. aegypti and then RT-qPCR, we examined ZIKV/DENV-1 and ZIKV/DENV-3 co-infection in Wolbachia-infected A. aegypti and observed that Wolbachia-infected mosquitoes experienced lower prevalence of infection and viral load than wildtype mosquitoes, even with an extra infecting virus. Critically, ZIKV/DENV co-infection had no significant impact on Wolbachia's ability to reduce viral transmission. Wolbachia infection also strongly altered expression levels of key immune genes Defensin C and Transferrin 1, in a virus-dependent manner. CONCLUSIONS/SIGNIFICANCE: Our results suggest that pathogen interference in Wolbachia-infected A. aegypti is not adversely affected by ZIKV/DENV co-infection, which suggests that Wolbachia-infected A. aegypti will likely prove suitable for controlling mosquito-borne diseases in environments with complex patterns of arbovirus transmission.


Assuntos
Aedes/microbiologia , Aedes/virologia , Vírus da Dengue/fisiologia , Controle de Mosquitos/métodos , Mosquitos Vetores/microbiologia , Mosquitos Vetores/virologia , Wolbachia/fisiologia , Zika virus/fisiologia , Animais , Brasil , Vírus da Dengue/genética , Feminino , Masculino , Wolbachia/genética , Zika virus/genética
20.
Acta Trop ; 196: 42-47, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31077641

RESUMO

Over the past decade, insecticide resistance to malaria vectors has been identified in 71 malaria endemic countries. This has posed a major global health challenge in the fight against malaria, with declining rates of indoor residual spraying coverage attributed to pyrethroid-resistance. As part of its vector control monitoring strategies, the Bioko Island Malaria Control Project (BIMCP) in Equatorial Guinea conducted routine insecticide resistance bioassays using the WHO's standard susceptibility tests from 2013 to 2018. During the same period, the frequency of the target-site knockdown resistance allele (kdr) in the local vector population was also determined via PCR for detection of the L1014 F mutation. Biochemical analysis for metabolic resistance was also conducted in 2015. From 2016-2017, Fludora™ fusion, a formulated combination of clothianidin (a neonicotinoid) and deltamethrin (a pyrethroid) was evaluated for 9 months on Bioko Island, using the WHO's standard test procedure for determining residual effectiveness of insecticides on sprayed surfaces. In 2016, the mortality rate of the vectors on 0.05% deltamethrin was as low as 38%. The frequency of the West African form of knockdown resistance allele, L1014 F, in the vector population was as high as 80%, and metabolic resistance analysis indicated high upregulated cytochrome P450 s. However, the residual effectiveness of Fludora™ fusion recorded mortalities above 80% after 72 h of exposure for 8 months. Although both target-site knockdown resistance and metabolic resistance to pyrethroids were implicated in the local malaria vector population, Fludora™ fusion was effective under field conditions in controlling the resistant vectors for a period of 8 months on wooden surfaces on Bioko Island and represents a valuable addition to IRS programs, especially in regions with high levels of pyrethroid resistance.


Assuntos
Anopheles/efeitos dos fármacos , Guanidinas/farmacologia , Controle de Mosquitos/métodos , Mosquitos Vetores/efeitos dos fármacos , Neonicotinoides/farmacologia , Nitrilos/farmacologia , Piretrinas/farmacologia , Tiazóis/farmacologia , Animais , Guiné Equatorial/epidemiologia , Guanidinas/administração & dosagem , Guanidinas/química , Humanos , Resistência a Inseticidas/genética , Inseticidas/administração & dosagem , Inseticidas/química , Inseticidas/farmacologia , Ilhas , Malária/epidemiologia , Malária/prevenção & controle , Neonicotinoides/administração & dosagem , Neonicotinoides/química , Nitrilos/administração & dosagem , Nitrilos/química , Piretrinas/administração & dosagem , Piretrinas/química , Tiazóis/administração & dosagem , Tiazóis/química
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