RESUMO
BACKGROUND: Uganda's malaria burden includes the sixth highest number of annual deaths in Africa (10,500) with approximately 16 million cases (2013) and the entire population at risk. The President's Malaria Initiative has been supporting the malaria control interventions of indoor residual spraying (IRS) and distribution of long-lasting insecticidal nets (LLIN) in Uganda since 2007. These interventions are threatened by emerging and spreading insecticide resistance, known to exist in Ugandan malaria vectors. Pyrethroid insecticides have been used in agriculture since the early 1990s and in IRS programmes from the mid-2000s until 2010. A universal LLIN coverage campaign was executed in 2013-2014, distributing pyrethroid-treated LLINs throughout the country. This study investigated insecticide susceptibility, intensity, and oxidase detoxification in Anopheles gambiae sensu lato and Anopheles funestus to permethrin and deltamethrin in four eastern Ugandan sites. METHODS: The susceptibility status of An. gambiae and An. funestus to bendiocarb, permethrin and deltamethrin was determined using the CDC (Centers for Disease Control and Prevention) bottle bioassay. Presence of oxidative enzyme detoxification mechanisms were determined by pre-exposing mosquitoes to piperonyl butoxide followed with exposure to discriminating doses of deltamethrin- and permethrin-coated CDC bottles. Resistance intensity was investigated using serial dosages of 1×, 2×, 5× and 10× the diagnostic dose and scored at 30 min to determine the magnitude of resistance to both of these LLIN pyrethroids. Testing occurred in the Northern and Eastern Regions of Uganda. RESULTS: Anopheles gambiae and An. funestus were fully susceptible to bendiocarb where tested. Anopheles gambiae resistance to deltamethrin and permethrin was observed in all four study sites. Anopheles funestus was resistant to deltamethrin and permethrin in Soroti. Oxidative resistance mechanisms were found in An. gambiae conferring pyrethroid resistance in Lira and Apac. 14.3% of An. gambiae from Tororo survived exposure of 10× concentrations of permethrin. CONCLUSIONS: Both An. gambiae and An. funestus are resistant to pyrethroids but fully susceptible to bendiocarb at all sites. Susceptibility monitoring guided the Ministry of Health's decision to rotate between IRS insecticide classes. Intensity bioassay results may indicate encroaching control failure of pyrethroid-treated LLINs and should inform decision-makers when choosing LLINs for the country.
Assuntos
Anopheles/efeitos dos fármacos , Resistência a Inseticidas , Mosquitos Vetores/efeitos dos fármacos , Nitrilas/farmacologia , Permetrina/farmacologia , Piretrinas/farmacologia , Animais , Feminino , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Desintoxicação Metabólica Fase I , Controle de Mosquitos , UgandaRESUMO
BACKGROUND: In this semi-field study, a new polymer-enhanced deltamethrin formulation, K-Othrine® PolyZone, was compared to a standard deltamethrin product for residual activity against a susceptible strain of laboratory-reared Anopheles gambiae using standard WHO cone bioassays. METHODS: Residual insecticide efficacy was recorded after exposure to metal, cement and wood panels maintained in experimental huts in sub-tropical environmental conditions in north central Florida, USA, and panels stored in a climate controlled chamber located at the Centers for Disease Control and Prevention, Georgia, USA. CONCLUSIONS: K-Othrine® PolyZone demonstrated 100% control on metal and cement panels 1 year post application and > 80% control on wood panels up to 6 mo. The new formulation should be considered for use in indoor residual spray programmes requiring long-term control of malaria vectors.
Assuntos
Anopheles/efeitos dos fármacos , Anopheles/crescimento & desenvolvimento , Materiais de Construção , Inseticidas/farmacologia , Nitrilas/farmacologia , Piretrinas/farmacologia , Animais , Bioensaio , Interações Medicamentosas , Florida , Georgia , Análise de SobrevidaRESUMO
Three insecticides commonly used for mosquito and sand fly control were applied 30 min to 3 h after sunset during June and July 2010, at Camp Buehring, Kuwait, to determine the relative quantity of pesticides to height and distance traveled in a hot desert environment. A BVA dilution oil was used for the control. Oil-based adulticides were sprayed using a truck-mounted Curtis DynaFog Maxi-Pro 4 ultra-low volume (ULV) sprayer. Malathion (Fyfanon ULV, 96% active ingredient [AI]), resmethrin (Scourge 4+12, 4% AI), pyrethrins (ULD BP-300, 3% AI), and BVA Spray 13 (100% refined petroleum distillate) were mixed with Uvitex optical brightener fluorescent dye and applied at 2 speeds on evenings when wind speed was less than 16.1 km/h (10 mph). Collection targets using biodegradable cotton ribbons (1 m×2.5 cm) were later read with a fluorometer to quantify the amount of insecticide deposited on targets set at heights of 15.2, 76.2, and 152.4 cm (6, 30, and 60 in.) and distances of 1.5, 6.1, 15.2, 30.5, 61.0, and 91.4 m (5, 20, 50, 100, 200, and 300 ft). Mean insecticide deposition across all distances was 31% on 76.2-cm targets and 49% on 152.4-cm targets, while 15.2-cm targets typically collected <20% of test spray. Mean ground temperatures were typically within 5°C of air temperatures at 152.4 cm and within 1 to 5°C of air at 15.2 cm or 76.2 cm. Collectively, mean insecticide deposition was 80% at or above 76.2 cm for all insecticides. This finding may explain in part why control of low-flying phlebotomine sand flies with ULV insecticides has been met with less than optimal success by US military forces deployed in the Middle East.
Assuntos
Clima Desértico , Controle de Insetos/métodos , Inseticidas/química , Psychodidae/efeitos dos fármacos , Saúde Pública , Animais , Humanos , Inseticidas/administração & dosagem , Inseticidas/farmacologia , Kuweit , Malation/administração & dosagem , Malation/química , Malation/farmacologia , Nebulizadores e Vaporizadores , Resíduos de Praguicidas , Petróleo , Piretrinas/administração & dosagem , Piretrinas/química , Piretrinas/farmacologiaRESUMO
Traditional sources of carbon dioxide (CO2), dry ice, and compressed gas, were tested against 3 combinations of food-grade reagents known to generate CO2using a compact, lightweight generator delivery system with Centers for Disease Control and Prevention light traps. Three 6 × 6 Latin square trials were completed near the Florida Gulf Coast in the Lower Suwannee Wildlife Refuge during the summer of 2013, collecting a total of 31,632 female mosquitoes. Treatments included dry ice, compressed CO2gas, a control trap (no CO2), citric acid + sodium bicarbonate, vinegar + sodium bicarbonate, and yeast + sugar. Decreasing order of trap collections (treatment mean number of mosquitoes per trap night ± standard error) were dry ice 773.5 (± 110.1) > compressed gas 440.7 (± 42.3) > citric acid + sodium bicarbonate 197.6 (± 30.4), yeast + sugar 153.6 (± 27.4) > vinegar + sodium bicarbonate 109.6 (± 16.2) > control 82.4 (± 14.0). A 2-way Kruskal-Wallis analysis by treatment, site, and treatment × site interaction identified significant differences between all treatments. Although dry ice and compressed CO2gas collected significantly more mosquitoes than other combinations (P < 0.05), use of citric acid and sodium bicarbonate or yeast and sugar greatly outperformed unbaited traps and offer a good alternative to dry ice and compressed gas in areas where these agents are not readily available or are difficult to obtain due to logistical constraints. An inexpensive, portable CO2generator for use with food-grade reagents is described.
Assuntos
Dióxido de Carbono/fisiologia , Culicidae/fisiologia , Controle de Mosquitos/métodos , Animais , Gelo-Seco , Feminino , Florida , Luz , Controle de Mosquitos/instrumentação , Saccharomyces cerevisiae/metabolismoRESUMO
Tick-borne diseases pose significant risks to U.S. military personnel who conduct operations, both domestic and abroad. To determine the feasibility of protecting personnel from tick vectors during short-term field deployments, acaricides cypermethrin (Demon WP, Syngenta, Greensboro, NC) and lambda-cyhalothrin (Surrender Pestabs, CSI, Pasadena, TX) were applied to plots within two separate field sites on Camp Blanding Joint Training Center in Starke, FL, from May to June 2011. We analyzed their effectiveness in reducing tick counts for 6 wk after application. In total, 8,193 ticks were identified and counted, of which > 99% were a mix of nymphs and adult-stage Amblyomma americanum (L.). Our results indicate that both cypermethrin and lambda-cyhalothrin were effective in significantly reducing tick numbers and preventing entry into treated plots for 6 wk after application. Thus, these two acaracides can be used to effectively suppress tick populations and provide residual protection in small geographic areas of recreation or public health significance.
Assuntos
Inseticidas , Ixodidae , Nitrilas , Piretrinas , Controle de Ácaros e Carrapatos , Animais , Florida , Ninfa/crescimento & desenvolvimento , Pós , Estações do AnoRESUMO
Surveillance of malaria vectors in Africa is most often accomplished using CDC-type light traps or human landing catches (HLCs). Over the past 30 yr, a variety of commercial and experimental mosquito traps have been developed for residential mosquito control or for improved surveillance of disease vector species, including the BG Sentinel (BGS) trap. To optimize collection of Anopheles gambiae Giles using this trap, BGS traps were modified with an opening (vent) added to the trap base to decrease exhaust airflow. Four traps configurations were tested with colony-reared host-seeking female An. gambiae in free-flying laboratory enclosures. Six attractant treatments (three attractants: BG-Lure, Limburger cheese, and a blank, with and without CO2) were tested concurrently. Across all trap-attractant combinations, significantly more mosquitoes (P < 0.05) were collected in standard, unmodified traps set upright (mean: 10.0) or upside down (9.8) than vented traps, whether upright (5.9) or upside down (7.0). The BG-Lure + CO2 and Limburger Cheese + CO2 bait combinations were more attractive than the other attractants tested alone. All attractant combinations collected significantly more mosquitoes than unbaited traps. Field studies are needed to determine if BG-Lure + CO2- or Limburger cheese + CO2-baited BGS traps are comparable with HLCs in collecting host-seeking An. gambiae.
Assuntos
Anopheles , Controle de Mosquitos/instrumentação , Animais , FemininoRESUMO
Sprayer comparisons and larval morality assays were conducted following SR450 backpack mist blower and Superhawk XP thermal fogger applications of Vectobac® WDG Bacillus thuringiensis israelensis (Bti) against Culex quinquefasciatus. Bacillus thuringiensis israelensis was applied at maximum label rate in a 232.26-m(2) field plot located in north-central Florida with containers placed at 2 heights (ground level and 1.52 m above ground) on stakes positioned 3.04, 6.09, 9.14, 12.19, and 15.24 m from the spray line. Results indicated that there was no significant (P > 0.05) difference in 24- and 48-h larval mortality between the 2 sprayers or between the 2 heights. There was significant difference (P < 0.05) among the 5 rows, with mortality continuously decreasing with increasing distance from sprayer. Both sprayers provided on average >70% larval mortality 3.04-9.14 m from the spray line, and <60% mortality at 12.19 and 15.24 m. The data suggest that the SR450 and Superhawk XP may be comparable sprayers for use with Bti to control mosquito larvae.
Assuntos
Bacillus thuringiensis/patogenicidade , Culex/microbiologia , Controle de Mosquitos/métodos , Controle Biológico de Vetores/métodos , Animais , Culex/crescimento & desenvolvimento , Florida , Larva/crescimento & desenvolvimento , Larva/microbiologia , Controle de Mosquitos/instrumentação , Controle Biológico de Vetores/instrumentaçãoRESUMO
The yellow fever mosquito, Aedes aegypti L., can transmit several pathogens responsible for human diseases. With insecticide resistance development becoming a concern, alternative control strategies are needed for Ae. aegypti. Sterile insect technique (SIT) is an increasingly popular option being explored. However, logistical issues in mass production and sterilization make it difficult to maintain a SIT program. Male mosquitoes are typically irradiated as pupae because this is the earliest developmental point at which females can be separated from males, but asynchrony in pupation and high variability in pupal responses to irradiation based on pupal age make it difficult to sterilize mass quantities of pupae on a regular schedule in a rearing facility. Young adult mosquitoes have wider windows for irradiation sterilization than pupae, which can allow facilities to have fixed schedules for irradiation. We produced a workflow for adult Ae. aegypti irradiation in a mosquito control district with an operational SIT program that currently irradiates pupae. The impacts of chilling, compaction, and radiation dose on survival were all assessed before combining them into a complete adult irradiation protocol. Males chilled up to 16 h prior to compaction and compacted to 100 males/cm3 during radiation resulted in low mortality. Males irradiated as adults had increased longevity and similar sterility compared to males irradiated as pupae. Additionally, males sterilized as adults were more sexually competitive than males sterilized as pupae. Thus, we have shown that irradiating adult males can be a viable option to increase the efficiency of this operational mosquito SIT program.
Assuntos
Aedes , Infertilidade Masculina , Feminino , Humanos , Masculino , Animais , Pupa/efeitos da radiação , Aedes/fisiologia , Reprodução , Controle de Mosquitos/métodos , Insetos , EsterilizaçãoRESUMO
To date, Triatoma dimidiata sensu lato [Reduviidae: Triatominae (Latreille 1811)] remains the sole vector species associated with Chagas disease transmission reported from Belize. Human infection data are limited for Belize and the disease transmission dynamics have not been thoroughly investigated, yet the likelihood of autochthonous transmission is supported by the widespread collection of infected vectors from within local households. Here, we report updated infection rates of the vector population and infestation rates for villages in north and central Belize. Overall, 275 households were enrolled in an ongoing vector surveillance program. Of the 41 insects collected, 25 were PCR positive for T. cruzi, indicating an infection rate as high as 60%. To further characterize the epidemiological risk of human-vector contact, determinants of household invasion were modeled. Local households were surveyed and characterized with respect to over 25 key factors that may be associated with household infestation by T. dimidiata s.l. While final models were not strongly predictive with respect to the risk factors that were surveyed, likely due to the low number of collection observations, the presence of domestic/peri-domestic dogs, nearby light sources, and household structure materials could be the focus of continued risk assessments. In northern Belize, this vector survey lends support to T. dimidiata s.l. inhabiting sylvatic settings as opposed to the classical paradigm of domiciliated vector populations. This designation has strong implications for the local level of human exposure risk which can help guide vector surveillance and control resources.
Assuntos
Doença de Chagas , Doenças do Cão , Triatoma , Triatominae , Trypanosoma cruzi , Animais , Belize , América Central , Doença de Chagas/epidemiologia , Cães , Insetos Vetores , Fatores de RiscoRESUMO
BACKGROUND: Sand fly saliva can drive the outcome of Leishmania infection in animal models, and salivary components have been postulated as vaccine candidates against leishmaniasis. In the sand fly Phlebotomus papatasi, natural sugar-sources modulate the activity of proteins involved in meal digestion, and possibly influence vectorial capacity. However, only a handful of studies have assessed the variability of salivary components in sand flies, focusing on the effects of environmental factors in natural habitats. In order to better understand such interactions, we compared the expression profiles of nine P. papatasi salivary gland genes of specimens inhabiting different ecological habitats in Egypt and Jordan and throughout the sand fly season in each habitat. RESULTS: The majority of investigated genes were up-regulated in specimens from Swaymeh late in the season, when the availability of sugar sources is reduced due to water deprivation. On the other hand, these genes were not up-regulated in specimens collected from Aswan, an irrigated area less susceptible to drought effects. CONCLUSION: Expression plasticity of genes involved with vectorial capacity in disease vectors may play an important epidemiological role in the establishment of diseases in natural habitats.
Assuntos
Genes de Insetos , Phlebotomus/genética , Estações do Ano , Animais , Metabolismo dos Carboidratos , Secas , Egito , Jordânia , Leishmania/fisiologia , Phlebotomus/parasitologia , Glândulas Salivares , Regulação para CimaRESUMO
We sought to visually enhance the attractiveness of a standard black ovitrap routinely used in surveillance of the Asian tiger mosquito, Aedes albopictus, and now being used as lethal ovitraps in Ae. aegypti dengue control programs. Black plastic drinking cups (ovitraps) were visually altered to offer field populations of gravid female Ae. albopictus 6 different oviposition site choices. Trials were conducted at 3 field locations in Gainesville, Orange Park, and Jacksonville, FL, during July-August 2009. A black glossy cup served as the control and was tested against 5 cup choices consisting of white, blue, orange, or black-and-white contrasting patterns (checkered or vertically striped). Means (SE) of eggs collected over 6 wk for each choice were: black 122.53 (9.63) > blue 116.74 (10.74) > checkered 101.84 (9.53) > orange 97.15 (7.95) > striped 84.62 (8.17) > white 81.84 (8.74). Black ovitraps outperformed competing colored and contrasting patterned ovicups with respect to choice from gravid Ae. albopictus seeking artificial oviposition sites.
Assuntos
Aedes , Comportamento Animal , Controle de Mosquitos/instrumentação , Oviposição , Animais , Cor , Feminino , FloridaRESUMO
Florida faces the challenge of repeated introduction and autochthonous transmission of arboviruses transmitted by Aedes aegypti and Aedes albopictus. Empirically-based predictive models of the spatial distribution of these species would aid surveillance and vector control efforts. To predict the occurrence and abundance of these species, we fit a mixed-effects zero-inflated negative binomial regression to a mosquito surveillance dataset with records from more than 200,000 trap days, representative of 53% of the land area and ranging from 2004 to 2018 in Florida. We found an asymmetrical competitive interaction between adult populations of Aedes aegypti and Aedes albopictus for the sampled sites. Wind speed was negatively associated with the occurrence and abundance of both vectors. Our model predictions show high accuracy (72.9% to 94.5%) in validation tests leaving out a random 10% subset of sites and data since 2017, suggesting a potential for predicting the distribution of the two Aedes vectors.
Assuntos
Aedes/fisiologia , Distribuição Animal , Modelos Biológicos , Mosquitos Vetores/fisiologia , Animais , Clima , Comportamento Competitivo , Ecossistema , Feminino , Florida , Masculino , Densidade Demográfica , Especificidade da EspécieRESUMO
Phlebotomus papatasi sand flies inject their hosts with a myriad of pharmacologically active salivary proteins to assist with blood feeding and to modulate host defenses. In addition, salivary proteins can influence cutaneous leishmaniasis disease outcome, highlighting the potential of the salivary components to be used as a vaccine. Variability of vaccine targets in natural populations influences antigen choice for vaccine development. Therefore, the objective of this study was to investigate the variability in the predicted protein sequences of nine of the most abundantly expressed salivary proteins from field populations, testing the hypothesis that salivary proteins appropriate to target for vaccination strategies will be possible. PpSP12, PpSP14, PpSP28, PpSP29, PpSP30, PpSP32, PpSP36, PpSP42, and PpSP44 mature cDNAs from field collected P. papatasi from three distinct ecotopes in the Middle East and North Africa were amplified, sequenced, and in silico translated to assess the predicted amino acid variability. Two of the predicted sequences, PpSP12 and PpSP14, demonstrated low genetic variability across the three geographic isolated sand fly populations, with conserved multiple predicted MHCII epitope binding sites suggestive of their potential application in vaccination approaches. The other seven predicted salivary proteins revealed greater allelic variation across the same sand fly populations, possibly precluding their use as vaccine targets.
Assuntos
Proteínas de Insetos/genética , Insetos Vetores/genética , Phlebotomus/genética , Proteínas e Peptídeos Salivares/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Egito , Humanos , Proteínas de Insetos/imunologia , Insetos Vetores/imunologia , Jordânia , Phlebotomus/imunologia , Proteínas e Peptídeos Salivares/imunologia , Alinhamento de SequênciaRESUMO
Determination of the residual activity of insecticides is an essential component in the selection of an appropriate insecticide for indoor residual spraying operations. This report presents the results of a laboratory study to evaluate the residual bio-efficacy of four insecticides sprayed on the most common house-wall surfaces that occur in Egypt (wood, mud, and cement) against Phlebotomus papatasi (Scopoli, 1786) (Diptera: Psychodidae) and Culex pipiens Linnaeus, 1758 (Diptera: Culicidae). In total, 28,050 P. papatasi females and 31,275 Cx. pipiens females were subjected to the WHO cone bioassay. Effective and extended control (≥80% mortality) was produced by lambda-cyhalothrin on indoor wood and cement surfaces. Lambda-cyhalothrin effectively controlled (>80% mortality) P. papatasi and Cx. pipiens for 10 and 12 wk postspray on wood surfaces, respectively. Deltamethrin effectively controlled Cx. pipiens for 8 wk on indoor wood, mud, and cement surfaces. Indoor and outdoor-kept surfaces treated with permethrin and malathion provided negligible efficacy against P. papatasi and Cx. pipiens. Phlebotomus papatasi was better able to survive bioassay exposure than Cx. pipiens against all insecticides investigated. The role surfaces might play in inhibiting IRS-based vector control endeavors in rural areas in developing countries was highlighted in this study. The current insecticide labeling system that includes both sand flies with mosquitoes under the same dosage category should be revised periodically.
Assuntos
Culex , Controle de Insetos , Insetos Vetores , Inseticidas , Phlebotomus , Animais , Egito , Feminino , Controle de Mosquitos , Mosquitos VetoresRESUMO
A previously unknown Leishmania spp., inferred by DNA sequence analysis of the small subunit ribosomal RNA gene and the internal transcribed spacer region (ITS1), was detected in tissue biopsies from patients living in the Eastern Ghanaian community of Taviefe. Restriction fragment length polymorphism analysis of the ITS1 amplicon supports the possibility of an uncharacterized Leishmania spp.
Assuntos
Surtos de Doenças , Leishmania/classificação , Leishmania/isolamento & purificação , Leishmaniose/epidemiologia , Leishmaniose/parasitologia , Animais , DNA Intergênico/química , DNA Intergênico/genética , DNA de Protozoário/química , DNA de Protozoário/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Gana/epidemiologia , Humanos , Filogenia , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 18S/genética , Homologia de Sequência do Ácido NucleicoRESUMO
In an attempt to find diurnal resting sites of adult phlebotomine sand flies, potential phlebotomine adult habitats were aspirated in the village of Bahrif in Aswan, Egypt. During this survey, sand flies were aspirated from low (30-45 cm high) irregular piles of mud bricks found under high date palm canopies between the village and the Nile River. There were 5 males and 7 females of Phlebotomus papatasi and 3 males of Sergentomyia schwetzi. Six of the 7 aspirated females were engorged with blood. A total of 78 sand flies was captured on 3 glue boards placed overnight on the ground next to the mud bricks. Attempts to aspirate sand flies from adjacent walls and plants were unsuccessful. The identification of diurnal resting sites in less structured habitats may ultimately lead to more effective adult sand fly control.
Assuntos
Comportamento Animal , Ritmo Circadiano , Psychodidae/fisiologia , Animais , Egito , Feminino , MasculinoRESUMO
BACKGROUND: Phlebotomus papatasi sand flies are major vectors of Leishmania major and phlebovirus infection in North Africa and across the Middle East to the Indian subcontinent. Population genetics is a valuable tool in understanding the level of genetic variability present in vector populations, vector competence, and the development of novel control strategies. This study investigated the genetic differentiation between P. papatasi populations in Egypt and Jordan that inhabit distinct ecotopes and compared this structure to P. papatasi populations from a broader geographical range. METHODS: A 461 base pair (bp) fragment from the mtDNA cytochrome b (cyt b) gene was PCR amplified and sequenced from 116 individual female sand flies from Aswan and North Sinai, Egypt, as well as Swaimeh and Malka, Jordan. Haplotypes were identified and used to generate a median-joining network, F ST values and isolation-by-distance were also evaluated. Additional sand fly individuals from Afghanistan, Iran, Israel, Jordan, Libya, Tunisia and Turkey were included as well as previously published haplotypes to provide a geographically broad genetic variation analysis. RESULTS: Thirteen haplotypes displaying nine variant sites were identified from P. papatasi collected in Egypt and Jordan. No private haplotypes were identified from samples in North Sinai, Egypt, two were observed in Aswan, Egypt, four from Swaimeh, Jordan and two in Malka, Jordan. The Jordan populations clustered separately from the Egypt populations and produced more private haplotypes than those from Egypt. Pairwise F ST values fall in the range 0.024-0.648. CONCLUSION: The clustering patterns and pairwise F ST values indicate a strong differentiation between Egyptian and Jordanian populations, although this population structure is not due to isolation-by-distance. Other factors, such as environmental influences and the genetic variability in the circulating Le. major parasites, could possibly contribute to this heterogeneity. The present study aligns with previous reports in that pockets of genetic differentiation exists between populations of this widely dispersed species but, overall, the species remains relatively homogeneous.
Assuntos
Citocromos b/genética , Variação Genética , Genética Populacional , Haplótipos , Phlebotomus/classificação , Phlebotomus/crescimento & desenvolvimento , Filogeografia , Animais , Egito , Insetos Vetores/classificação , Insetos Vetores/genética , Insetos Vetores/crescimento & desenvolvimento , Jordânia , Phlebotomus/genéticaRESUMO
Insecticide decay rate on different wall surfaces is of importance to indoor residual spray (IRS) programs used as a malaria control intervention. Past IRS operations showed increasing populations of endophilic malaria vectors resting on indoor surfaces from various sites in Uganda following use of Ficam VC (bendiocarb) insecticide; variability of insecticide life was believed to be primarily due to wall surface type. Bendiocarb longevity was tested in the northern Uganda districts of Amuru, Apac, and Pader to assess its residual efficacy on three commonly encountered wall surfaces. Wall types included mud and wattle, plain brick, and painted plaster. A susceptible mosquito strain (Anopheles gambiae Kisumu) was used in all trials. Nine houses in each of the three districts were set with three test cones and one control cone per house, divided evenly among the three wall surfaces. Bioassays were run monthly through 6 mo. Painted plastered surfaces produced 100% mortality (at 24 h) through 6 mo. Plain brick surfaces killed 100% of test mosquitoes through 4 mo, while mud and wattle wall surfaces produced a 98% mortality rate at 3 mo post spray. The KD60 (knockdown at 60 min) for painted plastered surfaces was 100% for 6 mo, plain brick surface KD60 was 80% at 6 mo, and the mud and wattle surface KD60 was >80% at 3 mo. There was a significant effect on Ficam VC longevity by wall type and evidence of a relationship between test period and wall type on the KD60.
Assuntos
Anopheles , Inseticidas , Controle de Mosquitos , Resíduos de Praguicidas , Fenilcarbamatos , Animais , Habitação , Fatores de Tempo , UgandaRESUMO
Little is known about tick-borne rickettsial pathogens in Belize, Central America. We tested ixodid ticks for the presence of Rickettsia species in three of the six northern and western Belizean districts. Ticks were collected from domestic animals and tick drags over vegetation in 23 different villages in November 2014, February 2015, and May 2015. A total of 2,506 collected ticks were identified to the following species: Dermacentor nitens Neumann (46.69%), Rhipicephalus sanguineus (Latreille) (19.55%), Rhipicephalus microplus (Canestrini) (19.47%), Amblyomma cajennense complex (9.74%), Amblyomma maculatum Koch (3.47%), Amblyomma ovale Koch (0.68%), Ixodes nr affinis (0.16%), Amblyomma nr maculatum (0.12%), and Amblyomma nr oblongoguttatum (0.12%). Ticks were pooled according to species, life stage (larva, nymph, or adult), and location (n = 509) for DNA extraction and screened for genus Rickettsia by quantitative real-time polymerase chain reaction (qPCR). All 42 positive pools were found to be positive for spotted fever group (SFG) Rickettsia in pools of A. cajennense complex (n = 33), A. maculatum (n = 4), A. nr maculatum (n = 1), A. ovale (n = 1), R. sanguineus (n = 1), and I. nr affinis (n = 2). Rickettsia amblyommatis was identified from A. cajennense complex and A. nr maculatum. Rickettsia parkeri was found in A. maculatum, and Rickettsia sp. endosymbiont was detected in I. nr affinis. The presence of infected ticks suggests a risk of tick-borne rickettsioses to humans and animals in Belize. This knowledge can contribute to an effective tick management and disease control program benefiting residents and travelers.
Assuntos
Vetores Artrópodes/microbiologia , Ixodidae/microbiologia , Rickettsia/classificação , Rickettsia/isolamento & purificação , Animais , Belize , Feminino , Masculino , Rickettsia/genéticaRESUMO
BACKGROUND: The Phlebotomus papatasi salivary protein PpSP15 was shown to protect mice against Leishmania major, suggesting that incorporation of salivary molecules in multi-component vaccines may be a viable strategy for anti-Leishmania vaccines. METHODS: Here, we investigated PpSP15 predicted amino acid sequence variability and mRNA profile of P. papatasi field populations from the Middle East. In addition, predicted MHC class II T-cell epitopes were obtained and compared to areas of amino acid sequence variability within the secreted protein. RESULTS: The analysis of PpSP15 expression from field populations revealed significant intra- and interpopulation variation.. In spite of the variability detected for P. papatasi populations, common epitopes for MHC class II binding are still present and may potentially be used to boost the response against Le. major infections. CONCLUSIONS: Conserved epitopes of PpSP15 could potentially be used in the development of a salivary gland antigen-based vaccine.