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1.
PLoS Negl Trop Dis ; 14(9): e0008705, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32986704

RESUMO

Over the past three decades, Europe has witnessed an increased spread of invasive aedine mosquito species, most notably Aedes albopictus, a key vector of chikungunya, dengue and Zika virus. While its distribution in southern Europe is well documented, its dispersal modes across the Alps remain poorly investigated, preventing a projection of future scenarios beyond its current range in order to target mosquito control. To monitor the presence and frequency of invasive Aedes mosquitoes across and beyond the Alps we set oviposition and BG-Sentinel traps at potential points of entry with a focus on motorway service areas across Switzerland. We placed the traps from June to September and controlled them for the presence of mosquitoes every other week between 2013 and 2018. Over the six years of surveillance we identified three invasive Aedes species, including Ae. albopictus, Ae. japonicus and Ae. koreicus. Based on the frequency and distribution patterns we conclude that Ae. albopictus and Ae. koreicus are being passively spread primarily along the European route E35 from Italy to Germany, crossing the Alps, while Ae. japonicus has been expanding its range from northern Switzerland across the country most likely through active dispersal.


Assuntos
Aedes/classificação , Aedes/fisiologia , Monitoramento Epidemiológico , Mosquitos Vetores/fisiologia , Aedes/virologia , Animais , Europa (Continente) , Feminino , Espécies Introduzidas , Itália , Controle de Mosquitos/instrumentação , Oviposição/fisiologia , Suíça , Zika virus
2.
Exp Parasitol ; 218: 107988, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32890471

RESUMO

In the present work, we synthesized silver nanoparticles supported by rice husk by hydrothermal treatment, as-synthesized silver nanoparticles rice husk (AgNPs-RH) bio-composite mixed with potter clay thoroughly, molded, dried into a disc-shaped before firing and applying as a point of use larvicidal agent. As designed, porous terracotta disc (PTD) infused with AgNPs-RH-biocomposite were characterized by UV spectrophotometer, Fourier-transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction analysis and energy-dispersive X-ray spectroscopy. The amount of silver ions released from the PTD was also found to be within the prescribed limit of 0.1 ppm-level. Later we dropped the PTD and tested its larvicidal activity against the IVth instar larva stage of Aedes, Anopheles and Culex species. We found 100% larvicidal mortality in 24 h of exposure to the designed PTD and the amount of silver released from the porous disc was found to be 0.0343 ppm. Further from the histopathological studies of dead larvae revealed that the silver ions from the PTD have substantially damaged the exoskeleton of larvae.


Assuntos
Aedes , Anopheles , Culex , Nanopartículas Metálicas/normas , Controle de Mosquitos/instrumentação , Animais , Ecossistema , Química Verde , Larva , Nanopartículas Metálicas/economia , Nanopartículas Metálicas/provisão & distribuição , Microscopia Eletrônica de Transmissão , Controle de Mosquitos/economia , Oryza , Prata , Espectrometria por Raios X , Espectrofotometria Atômica , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
3.
PLoS One ; 15(9): e0235548, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32946475

RESUMO

We constructed an electric multi-rotor autonomous unmanned aerial system (UAS) to perform mosquito control activities. The UAS can be equipped with any of four modules for spraying larvicides, dropping larvicide tablets, spreading larvicide granules, and ultra-low volume spraying of adulticides. The larvicide module sprayed 124 µm drops at 591 mL/min over a 14 m swath for a total application rate of 1.6 L/ha. The tablet module was able to repeatedly deliver 40-gram larvicide tablets within 1.1 m of the target site. The granular spreader covered a 6 m swath and treated 0.76 ha in 13 min at an average rate of 1.8 kg/ha. The adulticide module produced 16 µm drops with an average deposition of 2.6 drops/mm2. UAS pesticide applications were made at rates prescribed for conventional aircraft, limited only by the payload capacity and flight time. Despite those limitations, this system can deliver pesticides with much greater precision than conventional aircraft, potentially reducing pesticide use. In smaller, congested environments or in programs with limited resources, UAS may be a preferable alternative to conventional aircraft.


Assuntos
Aeronaves , Culicidae , Monitorização de Parâmetros Ecológicos/instrumentação , Inseticidas/administração & dosagem , Controle de Mosquitos/instrumentação , Animais , Larva
4.
PLoS Negl Trop Dis ; 14(8): e0008528, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32764763

RESUMO

House Index, Container Index, and Breteau Index are the most commonly used indices for dengue vector surveillance. However, these larval indices are a poor proxy for measuring the adult population-which is responsible for disease transmission. Information on the adult distribution and density are important for assessing transmission risk as well as for developing effective control strategies. This study introduces a new entomological index, Gravitrap aegypti index (GAI), which estimates the adult female Aedes aegypti population in the community and presents its association with dengue cases. Gravitraps were deployed across 34 treatment sites in Singapore from September 2013 to September 2016. The GAI, derived from the Gravitrap surveillance data, was analysed to investigate the spatio-temporal patterns of the Ae. aegypti population in Singapore. The index was further categorised into low, moderate, and high-risk groups and its association with dengue cases were examined. A Before-After Control Impact analysis was performed to evaluate the epidemiology impact of Gravitrap system on dengue transmission. The Ae. aegypti population exhibits a seasonal pattern, and spatial heterogeneity in Ae. aegypti abundance was observed among treatment sites. The Ae. aegypti population was also found to be unevenly distributed among floors of an apartment block, with low floors (floors 1-4) having a higher abundance of mosquitoes trapped than mid (floors 5-8) and high (floors ≥9) floors. Areas with high GAI were shown to have higher dengue case count. Gravitrap has also demonstrated to be a good dengue control tool. The contribution of cases by treatment sites to the national numbers was lower after Gravitraps deployment. The GAI, which is of better relevance to dengue transmission risk, could be recommended as an indicator for decision making in vector control efforts, and to monitor the spatio-temporal variability of the adult Aedes population in the country. In addition, findings from this study indicate that Gravitraps can be used as a dengue control tool to reduce dengue transmission.


Assuntos
Aedes/fisiologia , Surtos de Doenças/prevenção & controle , Controle de Mosquitos/instrumentação , Controle de Mosquitos/métodos , Aedes/virologia , Animais , Dengue/epidemiologia , Vírus da Dengue , Meio Ambiente , Feminino , Insetos Vetores , Densidade Demográfica , Singapura
5.
Sci Rep ; 10(1): 12227, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32699237

RESUMO

Royal Guard is a new insecticide-treated bed-net incorporated with a mixture of alpha-cypermethrin and pyriproxyfen (an insect growth regulator). We assessed its efficacy and wash-resistance in laboratory and experimental hut studies following WHO guidelines. Mosquitoes that survived exposure to the net were kept in separate oviposition chambers and observed for the reproductive effects of pyriproxyfen. In laboratory assays, Royal Guard induced > 80% mortality and > 90% blood-feeding inhibition of An. gambiae sl mosquitoes before and after 20 standardised washes and sterilised blood-fed mosquitoes which remained alive after exposure to the net. In an experimental hut trial against wild free-flying pyrethroid-resistant An. gambiae sl in Cové Benin, Royal Guard through the pyrethroid component induced comparable levels of mortality and blood-feeding inhibition to a standard pyrethroid-only treated net before and after 20 washes and sterilised large proportions of surviving blood-fed female mosquitoes through the pyriproxyfen component; Royal Guard induced 83% reduction in oviposition and 95% reduction in offspring before washing and 25% reduction in oviposition and 50% reduction in offspring after 20 washes. Royal Guard has the potential to improve malaria vector control and provide better community protection against clinical malaria in pyrethroid-resistant areas compared to standard pyrethroid-only LLINs.


Assuntos
Anopheles/efeitos dos fármacos , Malária/prevenção & controle , Controle de Mosquitos/instrumentação , Controle de Mosquitos/métodos , Mosquitos Vetores/efeitos dos fármacos , Piretrinas/farmacologia , Piridinas/farmacologia , Animais , Benin , Feminino , Resistência a Inseticidas/efeitos dos fármacos , Mosquiteiros Tratados com Inseticida , Inseticidas/farmacologia , Oviposição/efeitos dos fármacos
6.
J Am Mosq Control Assoc ; 36(1): 43-46, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32497475

RESUMO

Residual pesticide treatment of US military materials such as camouflage netting and HESCO blast wall geotextile is an effective way to reduce biting pressure within protected perimeters. However, residual treatments eventually wane and require retreatment in situ, which may not be possible or practical in military scenarios. One solution is to install pesticide misting systems on treated perimeters, which may additively enhance residual treatments, and gradually retreat perimeter material as misted pesticide settles. In this investigation we show that pesticide misting can extend efficacy of residual treatments on HESCO geotextile against mosquitoes and sand flies in a hot-arid desert environment by 1-2 wk.


Assuntos
Culicidae , Inseticidas , Controle de Mosquitos/instrumentação , Resíduos de Praguicidas , Psychodidae , Animais
7.
Sci Rep ; 10(1): 6803, 2020 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-32321946

RESUMO

Aedes aegypti is the main vector of arboviral diseases such as dengue, chikungunya and Zika. A key feature for disease transmission modeling and vector control planning is adult mosquito dispersal. We studied Ae aegypti adult dispersal by conducting a mark-capture study of naturally occurring Ae. aegypti from discarded containers found along a canal that divided two residential communities in Donna, Texas, USA. Stable isotopes were used to enrich containers with either 13C or 15N. Adult mosquitoes were collected outdoors in the yards of households throughout the communities with BG Sentinel 2 traps during a 12-week period. Marked mosquito pools with stable isotopes were used to estimate the mean distance travelled using three different approaches (Net, Strip or Circular) and the probability of detecting an isotopically marked adult at different distances from the larval habitat of origin. We consistently observed, using the three approaches that male (Net: 220 m, Strip: 255 m, Circular: 250 m) Ae. aegypti dispersed further in comparison to gravid (Net: 135 m, Strip: 176 m, Circular: 189 m) and unfed females (Net: 192 m, Strip: 213 m, Circular: 198 m). We also observed that marked male capture probability slightly increased with distance, while, for both unfed and gravid females, such probability decreased with distance. Using a unique study design documenting adult dispersal from natural larval habitat, our results suggest that Ae. aegypti adults disperse longer distances than previously reported. These results may help guide local vector control authorities in their fight against Ae. aegypti and the diseases it transmits, suggesting coverage of 200 m for the use of insecticides and innovative vector control tools.


Assuntos
Isótopos de Carbono/metabolismo , Ecossistema , Meio Ambiente , Controle de Mosquitos/métodos , Isótopos de Nitrogênio/metabolismo , Algoritmos , Animais , Febre de Chikungunya/prevenção & controle , Febre de Chikungunya/transmissão , Febre de Chikungunya/virologia , Dengue/prevenção & controle , Dengue/transmissão , Dengue/virologia , Feminino , Humanos , Inseticidas/farmacologia , Masculino , Modelos Teóricos , Controle de Mosquitos/instrumentação , Mosquitos Vetores/efeitos dos fármacos , Mosquitos Vetores/metabolismo , Mosquitos Vetores/virologia , Texas , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia
8.
Malar J ; 19(1): 158, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32303240

RESUMO

Most malaria-endemic countries have struggled in the past decade to establish effective national-scale continuous distribution mechanisms for long-lasting insecticidal nets (LLINs). Since the implementation of the Tanzania National Voucher Scheme in 2004 and mass-distribution campaigns in 2009-2011 and 2015-2016, Tanzania has been committed to finding new and innovative ways of achieving and maintaining universal bed net coverage. Planning for the School Net Programme (SNP) began in 2011 and in 2013, the country piloted a SNP in three regions. Nets were distributed annually to children attending schools in selected primary and secondary grades. Intra-family re-distribution was assumed, and hence the family as a whole, rather than just the children themselves, were the targeted beneficiaries. The programme has since expanded to 14 regions and has seen six rounds of annual distribution. In its fifth year, 3 million nets were distributed at a cost of USD 3.64 per net and USD 0.60 per person-year of protection (including the net). ITN access and use were maintained at a high level (~ 50-75%) over the first 4 years of distribution within selected evaluation areas, even in the absence of a mass distribution event. Net distribution through primary schools has proven to be a feasible and effective strategy for maintaining consistently high coverage in Tanzania.


Assuntos
Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Malária/prevenção & controle , Controle de Mosquitos/instrumentação , Controle de Mosquitos/estatística & dados numéricos , Propriedade , Instituições Acadêmicas , Tanzânia
9.
Malar J ; 19(1): 138, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32264875

RESUMO

BACKGROUND: Malaria has been described as an urgent public health priority with almost half of the world's population being at risk. Use of insecticide-treated nets is considered one of the effective ways of preventing malaria. Nigeria, which is ranked among the five countries that are responsible for almost half of the global malaria cases, has less than half of its women population using mosquito nets. This study examined the effects of individual and contextual factors on the use of mosquito nets among women of reproductive age in Nigeria. METHODS: This study used data obtained from 2015 Nigeria Malaria Indicator Survey (NMIS) which involved 6048 women aged 15-49 who possessed at least one mosquito net. Multilevel binary logistic regression models were applied in the multivariable analysis. RESULTS: About 53% of the women used mosquito nets with more than 60% of uneducated and poor women in this category. The use of mosquito nets was significantly associated with being from poor households, having knowledge about the cause of malaria, having access to malaria messages, possessing knowledge about the efficacy of malaria prevention drugs during pregnancy, having knowledge about the importance of tests to detect malaria, maintaining small household size and living in the most socioeconomically disadvantaged communities and states. CONCLUSIONS: The study revealed that mosquito net use among women in Nigeria is affected by individual and contextual factors. It is important for policy makers to design a mosquito-net-use model which would take individual and contextual factors into consideration.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Malária/prevenção & controle , Controle de Mosquitos/instrumentação , Adolescente , Adulto , Estudos Transversais , Características da Família , Feminino , Humanos , Modelos Logísticos , Malária/epidemiologia , Pessoa de Meia-Idade , Controle de Mosquitos/métodos , Nigéria/epidemiologia , Inquéritos e Questionários , Adulto Jovem
10.
Malar J ; 19(1): 110, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32169081

RESUMO

BACKGROUND: Long-lasting insecticidal nets (LLINs) are the most sustainable and effective malaria control tool currently available. Global targets are for 80% of the population living in malaria endemic areas to have access to (own) and use a LLIN. However, current access to LLINs in endemic areas is 56% due to system inefficiencies and budget limitations. Thus, cost-effective approaches to maximize access to effective LLINs in endemic areas are required. This study evaluated whether LLINs that had been stored for 5 years under manufacturer's recommended conditions may be optimally effective against Anopheles mosquitoes, to inform malaria control programmes and governments on the periods over which LLINs may be stored between distributions, in an effort to maximize use of available LLINs. METHODS: Standard World Health Organization (WHO) bioassays (cone and tunnel test) were used to evaluate the bio-efficacy and wash resistance of Olyset® and DawaPlus® 2.0 (rebranded Tsara® Soft) LLINs after 5 years of storage at 25 °C to 33.4 °C and 40% to 100% relative humidity. In addition, a small scale Ifakara Ambient Chamber test (I-ACT) was conducted to compare the bio-efficacy of one long stored LLINs to one new LLIN of the same brand, washed or unwashed. LLINs were evaluated using laboratory reared fully susceptible Anopheles gambiae sensu stricto (s.s.) (Ifakara strain) and pyrethroid resistant Anopheles arabiensis (Kingani strain). RESULTS: After 5 years of storage, both unwashed and washed, Olyset® and DawaPlus® 2.0 (Tsara® Soft) LLINs passed WHO bio-efficacy criteria on knockdown (KD60) ≥ 95%, 24-h mortality ≥ 80% and ≥ 90% blood-feeding inhibition in WHO assays against susceptible An. gambiae s.s. DawaPlus® 2.0 LLINs also passed combined WHO bioassay criteria against resistant An. arabiensis. Confirmatory I-ACT tests using whole nets demonstrated that long-stored LLINs showed higher efficacy than new LLINs on both feeding inhibition and mortality endpoints against resistant strains. CONCLUSIONS: Even after long-term storage of around 5 years, both Olyset® and DawaPlus® 2.0 LLINs remain efficacious against susceptible Anopheles mosquitoes at optimal storage range of 25 °C to 33.4 °C for temperature and 40% to 100% relative humidity measured by standard WHO methods. DawaPlus® 2.0 (Tsara® Soft) remained efficacious against resistant strain.


Assuntos
Anopheles , Mosquiteiros Tratados com Inseticida/normas , Inseticidas , Controle de Mosquitos/instrumentação , Animais , Bioensaio , Feminino , Mosquiteiros Tratados com Inseticida/economia , Mosquiteiros Tratados com Inseticida/provisão & distribuição , Fatores de Tempo , Organização Mundial da Saúde
11.
Malar J ; 19(1): 105, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32131834

RESUMO

BACKGROUND: Insecticide-treated nets (ITNs) are one of the most cost-effective measures for preventing malaria. The World Health Organization recommends both large-scale mass distribution campaigns and continuous distributions (CD) as part of a multifaceted strategy to achieve and sustain universal access to ITNs. A combination of these strategies has been effective for scaling up ITN access. For policy makers to make informed decisions on how to efficiently implement CD or combined strategies, information on the costs and cost-effectiveness of these delivery systems is necessary, but relatively few published studies of the cost continuous distribution systems exist. METHODS: To address the gap in continuous distribution cost data, four types of delivery systems-CD through antenatal care services (ANC) and the expanded programme on immunization (EPI) (Ghana, Mali, and mainland Tanzania), CD through schools (Ghana and mainland Tanzania), and a combined community/health facility-based distribution (Zanzibar, Tanzania), as well as mass distributions (Mali)-were costed. Data on costs were collected retrospectively from financial and operational records, stakeholder interviews, and resource use surveys. RESULTS: Overall, from a full provider perspective, mass distributions and continuous systems delivered ITNs at overlapping economic costs per net distributed (mass distributions: 4.37-4.61 USD, CD channels: 3.56-9.90 USD), with two of the school-based systems and the mass distributions at the lower end of this range. From the perspective of international donors, the costs of the CD systems were, for the most part, less costly than the mass distributions (mass distributions: 4.34-4.55 USD, Ghana and Tanzania 2017 school-based: 3.30-3.69 USD, health facility-based: 3.90-4.55 USD, combined community/health facility 4.55 USD). The 2015 school-based distribution (7.30 USD) and 2016 health facility-based distribution (6.52 USD) programmes in Tanzania were an exception. Mass distributions were more heavily financed by donors, while CD relied more extensively on domestic resource contributions. CONCLUSIONS: These results suggest that CD strategies can continue to deliver nets at a comparable cost to mass distributions, especially from the perspective of the donor.


Assuntos
Atenção à Saúde/economia , Mosquiteiros Tratados com Inseticida/economia , Malária/prevenção & controle , Controle de Mosquitos/economia , África ao Sul do Saara , Análise Custo-Benefício , Atenção à Saúde/métodos , Feminino , Humanos , Mosquiteiros Tratados com Inseticida/provisão & distribuição , Controle de Mosquitos/instrumentação , Gravidez , Gestantes , Saúde Pública/economia , Estudos Retrospectivos , Inquéritos e Questionários
12.
Malar J ; 19(1): 109, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32156280

RESUMO

BACKGROUND: Residents of malaria-endemic communities spend several hours outdoors performing different activities, e.g. cooking, story-telling or eating, thereby exposing themselves to potentially-infectious mosquitoes. This compromises effectiveness of indoor interventions, notably long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS). This study characterized common peri-domestic spaces in rural south-eastern Tanzania, and assessed protective efficacy against mosquitoes of hessian fabric mats and ribbons treated with the spatial repellent, transfluthrin, and fitted to chairs and outdoor kitchens, respectively. METHODS: Two hundred households were surveyed, and their most-used peri-domestic spaces physically characterized. Protective efficacies of locally-made transfluthrin-emanating chairs and hessian ribbons were tested in outdoor environments of 28 households in dry and wet seasons, using volunteer-occupied exposure-free double net traps. CDC light traps were used to estimate host-seeking mosquito densities within open-structure outdoor kitchens. Field-collected Anopheles arabiensis and Anopheles funestus mosquitoes were exposed underneath the chairs to estimate 24 h-mortality. Finally, The World Health Organization insecticide susceptibility tests were conducted on wild-caught Anopheles from the villages. RESULTS: Approximately half (52%) of houses had verandas. Aside from these verandas, most houses also had peri-domestic spaces where residents stayed most times (67% of houses with verandas and 94% of non-veranda houses). Two-thirds of these spaces were sited under trees, and only one third (34.4%) were built-up. The outdoor structures were usually makeshift kitchens having roofs and partial walls. Transfluthrin-treated chairs reduced outdoor-biting An. arabiensis densities by 70-85%, while transfluthrin-treated hessian ribbons fitted to the outdoor kitchens caused 77-81% reduction in the general peri-domestic area. Almost all the field-collected An. arabiensis (99.4%) and An. funestus (100%) exposed under transfluthrin-treated chairs died. The An. arabiensis were susceptible to non-pyrethroids (pirimiphos methyl and bendiocarb), but resistant to pyrethroids commonly used on LLINs (deltamethrin and permethrin). CONCLUSION: Most houses had actively-used peri-domestic outdoor spaces where exposure to mosquitoes occurred. The transfluthrin-treated chairs and ribbons reduced outdoor-biting malaria vectors in these peri-domestic spaces, and also elicited significant mortality among pyrethroid-resistant field-caught malaria vectors. These two new prototype formats for transfluthrin emanators, if developed further, may constitute new options for complementing LLINs and IRS with outdoor protection against malaria and other mosquito-borne pathogens in areas where peri-domestic human activities are common.


Assuntos
Ciclopropanos , Fluorbenzenos , Mordeduras e Picadas de Insetos/prevenção & controle , Repelentes de Insetos , Inseticidas , Controle de Mosquitos/instrumentação , Controle de Mosquitos/métodos , Adulto , Animais , Anopheles , Feminino , Habitação , Humanos , Masculino , Tanzânia
13.
Parasit Vectors ; 13(1): 121, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32143711

RESUMO

BACKGROUND: Emerging arboviral diseases like Zika, dengue and chikungunya that are transmitted by Aedes aegypti mosquitoes, are increasingly threatening human health. Blends of human-like synthetic chemical attractants can be used to attract host-seeking mosquitoes. The aim of this study was to test new combinations of traps and odour baits in the laboratory, followed by testing the best candidates in the field to improve Ae. aegypti monitoring and surveillance. METHODS: First, the BG-Suna trap was evaluated for capturing laboratory-reared Ae. aegypti by testing normal and inverted positions in screen cage tests. Secondly, the attractiveness of the MB5 blend, CO2, and their combination was tested. Thirdly, we tested the attractiveness of different trap types (BG-Suna, BG-Sentinel, MM-X and CDC light trap). Finally, we confirmed laboratory results in the field in Paramaribo, Suriname, using the MB5 and BG-Lure odour blends, CO2 and the BG-Sentinel and BG-Bowl trap using a Latin Square design. RESULTS: The MB5 blend in combination with CO2 outperformed traps baited only with CO2 or MB5 in screen cage tests (P < 0.0001). The BG-Sentinel trap performed equally well as the inverted BG-Suna and was taken to the field (P = 0.729). In the field, we captured Ae. aegypti, Cx. quinquefasciatus and Cx. nigripalpus. We confirmed the laboratory results and found that the combination of the MB5 blend and CO2 almost doubled Ae. aegypti female captures (P = 0.004) and more than doubled Culex spp. female captures (P = 0.005) compared to using only CO2. Interestingly, the MB5 blend outperformed the commercially available BG-Lure, in the BG-Sentinel (P < 0.001). The BG-Bowl also attracted Ae. aegypti when baited with the MB5 blend in similar numbers as the BG-Sentinel baited with the MB5 (P = 0.362). CONCLUSIONS: Our study demonstrated that the BG-Sentinel trap baited with the MB5 blend and CO2 outperforms the current golden standard (BG-Sentinel trap with BG-Lure) for monitoring Ae. aegypti females and males, in both laboratory and field experiments. The BG-Bowl baited with the MB5 blend is a good candidate for home use. Finally, the results show that CO2 is an indispensable component of the attractive blend.


Assuntos
Comportamento Animal/fisiologia , Controle de Mosquitos/métodos , Mosquitos Vetores/fisiologia , Odorantes , Aedes/fisiologia , Animais , Dióxido de Carbono/farmacologia , Culex , Masculino , Controle de Mosquitos/instrumentação , Feromônios , Suriname
14.
Parasit Vectors ; 13(1): 150, 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32209116

RESUMO

BACKGROUND: Several mosquito collection methods are routinely used in vector control programmes. However, they target different behaviours causing bias in estimation of species diversity and abundance. Given the paucity of mosquito trap data in West Africa, we compared the performance of five trap-lure combinations and Human Landing Catches (HLCs) in Guinea. METHODS: CDC light traps (LT), BG sentinel 2 traps (BG2T), gravid traps (GT) and Stealth traps (ST) were compared in a 5 × 5 Latin Square design in three villages in Guinea between June and July 2018. The ST, a portable trap which performs similarly to a LT but incorporates LEDs and incandescent light, was included since it has not been widely tested. BG2T were used with BG and MB5 lures instead of CO2 to test the efficacy of these attractants. HLCs were performed for 5 nights, but not as part of the Latin Square. A Generalised Linear Mixed Model was applied to compare the effect of the traps, sites and collection times on mosquito abundance. Species identification was confirmed using PCR-based analysis and Sanger sequencing. RESULTS: A total of 10,610 mosquitoes were captured across five traps. ST collected significantly more mosquitoes (7096) than the rest of the traps, but resulted in a higher number of damaged specimens. ST and BG2T collected the highest numbers of Anopheles gambiae (s.l.) and Aedes aegypti mosquitoes, respectively. HLCs captured predominantly An. coluzzii (41%) and hybrids of An. gambiae and An. coluzzii (36%) in contrast to the five traps, which captured predominantly An. melas (83%). The rural site (Senguelen) presented the highest abundance of mosquitoes and overall diversity in comparison with Fandie (semi-rural) and Maferinyah Centre I (semi-urban). Our results confirm the presence of four species for the first time in Guinea. CONCLUSIONS: ST collected the highest number of mosquitoes suggesting this trap may play an important role for mosquito surveillance in Guinea and similar sites in West Africa. We recommend the incorporation of molecular tools in entomological studies since they have helped to identify 25 mosquito species in this area.


Assuntos
Culicidae , Entomologia/instrumentação , Entomologia/métodos , Animais , Anopheles , Biodiversidade , Dióxido de Carbono , Culicidae/classificação , Feminino , Guiné , Humanos , Luz , Masculino , Controle de Mosquitos/instrumentação , Controle de Mosquitos/métodos , Pesquisa
15.
Parasit Vectors ; 13(1): 91, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32075683

RESUMO

BACKGROUND: The international movement of used tyres is a major factor responsible for global introductions of Aedes invasive mosquitoes (AIMs) (Diptera: Culicidae) that are major disease vectors (e.g. dengue, Zika, chikungunya and yellow fever). Surveillance methods are restricted by expense, availability and efficiency to detect all life stages. Currently, no tested method exists to screen imported used tyres for eggs in diapause, the life stage most at risk from accidental introduction. Here we test the efficiency of adhesive tape as an affordable and readily available material to screen tyres for eggs, testing its effect on hatch rate, larval development, DNA amplification and structural damage on the egg surface. RESULTS: We demonstrated that the properties of adhesive tape can influence pick up of dormant eggs attached to dry surfaces. Tapes with high levels of adhesion, such as duct tape, removed eggs with high levels of efficiency (97% ± 3.14). Egg numbers collected from cleaned used tyres were found to explain larval hatch rate success well, particularly in subsequent larval to adult emergence experiments. The strength of this relationship decreased when we tested dirty tyres. Damage to the exochorion was observed following scanning electron microscopy (SEM), possibly resulting in the high variance in the observed model. We found that five days was the optimal time for eggs to remain on all tested tapes for maximum return on hatch rate success. Tape type did not inhibit amplification of DNA of eggs from three, five or ten days of exposure. Using this DNA, genotyping of AIMs was possible using species-specific markers. CONCLUSIONS: We demonstrated for the first time that adhesive tapes are effective at removing AIM eggs from tyres. We propose that this method could be a standardised tool for surveillance to provide public health authorities and researchers with an additional method to screen tyre cargo. We provide a screening protocol for this purpose. This method has a global applicability and in turn can lead to increased predictability of introductions and improve screening methods at high risk entry points.


Assuntos
Aedes/fisiologia , Controle de Mosquitos/métodos , Adesivos/economia , Aedes/classificação , Aedes/genética , Animais , Espécies Introduzidas/economia , Espécies Introduzidas/estatística & dados numéricos , Controle de Mosquitos/economia , Controle de Mosquitos/instrumentação , Mosquitos Vetores/classificação , Mosquitos Vetores/fisiologia , Óvulo/classificação , Óvulo/fisiologia
16.
Rev Soc Bras Med Trop ; 53: e20190043, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31994655

RESUMO

INTRODUCTION: Aedes aegypti is the main vector responsible for the transmission of numerous arboviruses. Adultrap® has been developed to catch these insects. METHODS: We tested the effectiveness of capturing adults with and without one of the components of Adultrap®. RESULTS: The mean number of insects caught by the original trap was 1.25 (standard deviation = 1.28), while the average obtained with the modified trap was 8.88 (standard deviation = 3.44). The medians were statistically different (p = 0.001) according to the Mann-Whitney test. CONCLUSIONS: The modification of Adultrap® increased the average catch of Ae. aegypti by up to seven times.


Assuntos
Aedes/classificação , Desenho de Equipamento , Controle de Mosquitos/instrumentação , Mosquitos Vetores/classificação , Animais , Controle de Mosquitos/métodos
17.
Nat Microbiol ; 5(1): 40-47, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31792426

RESUMO

Transmission of Plasmodium falciparum malaria parasites occurs when nocturnal Anopheles mosquito vectors feed on human blood. In Africa, where malaria burden is highest, bednets treated with pyrethroid insecticide were highly effective in preventing mosquito bites and reducing transmission, and essential to achieving unprecedented reductions in malaria until 2015 (ref. 1). Since then, progress has stalled2, and with insecticidal bednets losing efficacy against pyrethroid-resistant Anopheles vectors3,4, methods that restore performance are urgently needed to eliminate any risk of malaria returning to the levels seen before their widespread use throughout sub-Saharan Africa5. Here, we show that the primary malaria vector Anopheles gambiae is targeted and killed by small insecticidal net barriers positioned above a standard bednet in a spatial region of high mosquito activity but zero contact with sleepers, opening the way for deploying many more insecticides on bednets than is currently possible. Tested against wild pyrethroid-resistant A. gambiae in Burkina Faso, pyrethroid bednets with organophosphate barriers achieved significantly higher killing rates than bednets alone. Treated barriers on untreated bednets were equally effective, without significant loss of personal protection. Mathematical modelling of transmission dynamics predicted reductions in clinical malaria incidence with barrier bednets that matched those of 'next-generation' nets recommended by the World Health Organization against resistant vectors. Mathematical models of mosquito-barrier interactions identified alternative barrier designs to increase performance. Barrier bednets that overcome insecticide resistance are feasible using existing insecticides and production technology, and early implementation of affordable vector control tools is a realistic prospect.


Assuntos
Mosquiteiros Tratados com Inseticida , Inseticidas/administração & dosagem , Malária/prevenção & controle , Controle de Mosquitos/métodos , Mosquitos Vetores/fisiologia , Animais , Anopheles/fisiologia , Burkina Faso/epidemiologia , Desenho de Equipamento , Fenitrotion , Humanos , Resistência a Inseticidas , Malária/epidemiologia , Malária/transmissão , Modelos Biológicos , Controle de Mosquitos/instrumentação , Piretrinas
18.
J Am Mosq Control Assoc ; 36(4): 240-244, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33647108

RESUMO

The shape and color of an ovitrap affect the sampling efficiency of mosquitoes. We examined the effect of perforated lids of different colored cups on the preference of Aedes aegypti and Ae. albopictus for oviposition containers. The mosquito species were collected from Tuy Hoa City, Phu Yen Province, Vietnam in April 2016. Females of both species laid eggs in cups without a lid in the order of black, red, and green. However, the number of eggs laid by both species was not different between the black cups with a perforated lid and those without a lid. Aedes aegypti females laid more eggs in red cups with a perforated lid than cups without a lid. Green cups with a perforated lid were not preferred by Ae. aegypti and Ae. albopictus. Our results showed that the effect of perforated lids on oviposition preference was dependent on cup color and that it differed between the mosquito species. Out study provides valuable insights for the development of more effective ovitraps for Aedes mosquito surveillance and control.


Assuntos
Aedes , Controle de Mosquitos/instrumentação , Oviposição , Animais , Comportamento Animal , Cor , Feminino
19.
J Am Mosq Control Assoc ; 36(2): 74-80, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33647123

RESUMO

There is a clear need for improved vector surveillance approaches that are affordable, labor efficient, and safer than traditional methods. The BG-Counter (Biogents USA, Moorefield, WV) is a device for remotely monitoring mosquito activity in combination with the BG-Sentinel (Biogents USA), a widely used trap for the collection of host-seeking mosquitoes. The BG-Counter uses a wireless connection to provide real-time counts of mosquitoes captured by the BG-Sentinel, allowing users to remotely monitor mosquito populations. This study tested the effectiveness of the BG-Counter in 5 North Carolina counties. A total of 96 trap-days resulted in the collection of >45,000 individual mosquitoes representing 35 species. Aedes albopictus was the most common species collected in all counties, except for New Hanover County where Culex nigripalpus was the most common. The mean daily accuracy ranged from 80.1% (New Hanover County) to 9.4% (Jackson County). There was a significant linear relationship between the actual number of mosquitoes collected and the device counts at all sites except Jackson County, the site with the lowest relative mosquito abundance compared with nontarget organisms. A linear regression of daily BG-Counter accuracy and the daily proportion of mosquitoes to the total number of arthropods collected revealed a significant positive linear relationship, supporting the premise that the BG-Counter is less effective when the relative abundance of mosquitoes is low. Mosquito surveillance programs using the BG-Counter should recognize its context-dependent accuracy and routinely evaluate the accuracy of the device based on local conditions.


Assuntos
Culicidae , Controle de Mosquitos/instrumentação , Animais , Controle de Mosquitos/estatística & dados numéricos , North Carolina
20.
J Am Mosq Control Assoc ; 36(2): 66-73, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33647132

RESUMO

To improve detection and assessment of Aedes aegypti abundance, we investigated whether microhabitat factors of the location of autocidal gravid ovitraps (AGO traps) influenced captures of gravid females in 2 locations in southern Puerto Rico. One location had been under vector control for several years using mass AGO trapping (intervention site), where Ae. aegypti abundance was several times lower than in the other study site without mosquito control (nonintervention site). We observed 10 environmental factors describing trap microhabitat location, and monitored water volume and minimum, maximum, and average temperature in AGO traps. Air temperature, relative humidity, and rainfall were recorded at each site. We conducted a hot-spot analysis of AGO traps to understand whether trap captures were influenced by the local abundance of mosquitoes rather than or in addition to trap microhabitat factors. AGO traps were classified using a 2-step cluster analysis based on attributes of trap microhabitats, water temperature, and water volume. Captures of female Ae. aegypti in each cluster per site were compared between resulting clusters to determine whether trap microhabitat factors defining the clusters were associated with trap captures. Trap captures in both study sites were mostly correlated with captures in nearby traps regardless of trap microhabitat factors, possibly reflecting the influence of the spatial aggregation of mosquitoes coming from nearby aquatic habitats or the concentration of dispersing adults. These results indicated that AGO traps can be located at places that can be easily reached during periodic inspections, such as in front of houses, without much regard to local microhabitat conditions.


Assuntos
Aedes , Controle de Mosquitos/instrumentação , Animais , Meio Ambiente , Feminino , Masculino , Controle de Mosquitos/métodos , Densidade Demográfica , Porto Rico
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