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1.
Malar J ; 21(1): 13, 2022 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-35027049

RESUMEN

BACKGROUND: Malaria control requires local action. Assessing the vector diversity and abundance provides information on the local malariogenic potential or risk of transmission. This study aimed to determine the Anopheles species composition, habitats, seasonal occurrence, and distribution in areas with autochthonous and imported malaria cases in Roraima State. METHODS: A longitudinal study was conducted from January 2017 to October 2018, sampling larvae and adult mosquitoes in three municipalities of Roraima State: Boa Vista, Pacaraima and São João da Baliza. These areas have different risks of malaria importation. Four to six mosquito larval habitats were selected for larval sampling at each municipality, along with two additional sites for adult mosquito collection. All larval habitats were surveyed every two months using a standardized larval sampling methodology and MosqTent for adult mosquitoes. RESULTS: A total of 544 Anopheles larvae and 1488 adult mosquitoes were collected from the three municipalities studied. Although the species abundance differed between municipalities, the larvae of Anopheles albitarsis s.l., Anopheles nuneztovari s.l. and Anopheles triannulatus s.l. were collected from all larval habitats studied while Anopheles darlingi were collected only from Boa Vista and São João da Baliza. Adults of 11 species of the genus Anopheles were collected, and the predominant species in Boa Vista was An. albitarsis (88.2%) followed by An. darlingi (6.9%), while in São João da Baliza, An. darlingi (85.6%) was the most predominant species followed by An. albitarsis s.l. (9.2%). In contrast, the most abundant species in Pacaraima was Anopheles braziliensis (62%), followed by Anopheles peryassui (18%). Overall, the majority of anophelines exhibited greater extradomicile than peridomicile-biting preference. Anopheles darlingi was the only species found indoors. Variability in biting times was observed among species and municipalities. CONCLUSION: This study revealed the composition of anopheline species and habitats in Boa Vista, Pacaraima and São João da Baliza. The species sampled differed in their behaviour with only An. darlingi being found indoors. Anopheles darlingi appeared to be the most important vector in São João da Baliza, an area of autochthonous malaria, and An. albitarsis s.l. and An. braziliensis in areas of low transmission, although there were increasing reports of imported malaria. Understanding the diversity of vector species and their ecology is essential for designing effective vector control strategies for these municipalities.

2.
PLoS Negl Trop Dis ; 16(1): e0010019, 2022 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-34995277

RESUMEN

BACKGROUND: Yellow fever (YF) is an arboviral disease which is endemic to Brazil due to a sylvatic transmission cycle maintained by infected mosquito vectors, non-human primate (NHP) hosts, and humans. Despite the existence of an effective vaccine, recent sporadic YF epidemics have underscored concerns about sylvatic vector surveillance, as very little is known about their spatial distribution. Here, we model and map the environmental suitability of YF's main vectors in Brazil, Haemagogus spp. and Sabethes spp., and use human population and NHP data to identify locations prone to transmission and spillover risk. METHODOLOGY/PRINCIPAL FINDINGS: We compiled a comprehensive set of occurrence records on Hg. janthinomys, Hg. leucocelaenus, and Sabethes spp. from 1991-2019 using primary and secondary data sources. Linking these data with selected environmental and land-cover variables, we adopted a stacked regression ensemble modelling approach (elastic-net regularized GLM, extreme gradient boosted regression trees, and random forest) to predict the environmental suitability of these species across Brazil at a 1x1 km resolution. We show that while suitability for each species varies spatially, high suitability for all species was predicted in the Southeastern region where recent outbreaks have occurred. By integrating data on NHP host reservoirs and human populations, our risk maps further highlight municipalities within the region that are prone to transmission and spillover. CONCLUSIONS/SIGNIFICANCE: Our maps of sylvatic vector suitability can help elucidate potential locations of sylvatic reservoirs and be used as a tool to help mitigate risk of future YF outbreaks and assist in vector surveillance. Furthermore, at-risk regions identified from our work could help disease control and elucidate gaps in vaccination coverage and NHP host surveillance.

3.
Acta Trop ; : 106305, 2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-34998997

RESUMEN

Visceral leishmaniasis (VL) is endemic to many states in Brazil. To prevent further expansion of the disease, the Brazilian Ministry of Health adopted integrated measures through the Program of Surveillance and Control of Visceral Leishmaniasis (PSCVL), whose actions include the diagnosis and euthanasia of seropositive dogs (the main domestic reservoirs), the use of residual insecticides, environmental management (EM) to control vector population (mainly Lutzomyia longipalpis phlebotomine), rigorous epidemiological surveillance, and health education. The present study was conducted in areas with recent moderate VL transmission to evaluate the efficacy of vector control activities. The systematic capture of phlebotomine was performed for three consecutive days per month, from August 2015 to July 2017. The number of specimens captured was taken as a representative of the monthly insect population. A total of 38,055 phlebotomine specimens were captured and identified at the species level. Lu. longipalpis was consistently found to be the predominant species (97.7%) each month. In the first year of the study, no intervention was performed. In the second year, two cycles of chemical spraying, EM, or a combination of both were performed before and after the rainy season. All interventions, either individually or in combination, reduced the abundance of Lu. longipalpis in the study area.

4.
Acta Trop ; 225: 106157, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34634265

RESUMEN

The Pan American Health Organization (PAHO) has defined Chagas Disease hotspots in Central America associated with the vector Triatoma spp. Triatoma dimidiata is a native vector adapted to multiple environments, including intra-domestic and peri-domestic habitats. A multi-institutional project named "Alliances for the elimination of Chagas in Central America" was created to help reduce the incidence of the disease in the region. Activities performed in the field as part of the project included aspects of vector surveillance and control, improvement of houses, diagnosis and treatment of individuals, health promotion, training of human resources and identification of access barriers to diagnosis and treatment. As a base line study, eleven villages, comprised of 1,572 households, were entomologically evaluated (83.4% overall participation); five were found to have very high infestation rates (>20%), three had high infestation rates (8-20%) and three had low-infestation rates (<8%), coinciding with the category of infestation-risk of the houses within each village. Serological tests were carried out in 812 people (>80% participation) in two of the 11 villages and none of the 128 children tested, less than 5 years of age, were positive for Trypanosoma cruzi infection. Community participation in all the activities was high (>70%). The collaboration between several subnational, national, and international institutions, each with specific roles, promoted community participation in the activities of vector control and patient care, thus, establishing a baseline to continue implementing and monitoring project progress.


Asunto(s)
Enfermedad de Chagas , Triatoma , Trypanosoma cruzi , Animales , Enfermedad de Chagas/diagnóstico , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/prevención & control , Niño , Guatemala/epidemiología , Humanos , Control de Insectos , Insectos Vectores , Salud Pública
5.
Behav Med ; : 1-9, 2021 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-34847825

RESUMEN

Incentives are a useful tool in encouraging healthy behavior as part of public health initiatives. However, there remains concern about motivation crowd out-a decline in levels of motivation to undertake a behavior to below baseline levels after incentives have been removed-and few public health studies have assessed for motivation crowd out. Here, we assess the feasibility of identifying motivation crowd out following a lottery to promote participation in a Chagas disease vector control campaign. We look for evidence of crowd out in subsequent participation in the same behavior, a related behavior, and an unrelated behavior. We identified potential motivation crowd out for the same behavior, but not for related behavior or unrelated behaviors after lottery incentives are removed. Despite some limitations, we conclude that motivation crowd out is feasible to assess in large-scale trials of incentives.

6.
Med Vet Entomol ; 2021 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-34866216

RESUMEN

We assessed whether fluralaner administered to outbred healthy dogs reduced or supressed site infestation and abundance of pyrethroid-resistant populations of Triatoma infestans Klug (Heteroptera: Reduviidae). We conducted a placebo-controlled before-and-after efficacy trial in 28 infested sites in Castelli (Argentine Chaco) over 10 months. All 72 dogs initially present received either an oral dose of fluralaner (treated group) or placebo (control group) at month 0 posttreatment (MPT). Preliminary results justified treating all 38 control-house dogs with fluralaner 1 month later, and 71 of 78 existing dogs at 7 MPT. Site-level infestation and triatomine abundance were evaluated using timed manual searches with a dislodging aerosol. In the fluralaner-treated group, infestation dropped significantly from 100% at baseline to 19% over 6-10 MPT whereas mean abundance fell highly significantly from 5.5 to 0.8-0.9 triatomines per unit effort. In the placebo group, site infestation and mean abundance remained stable between 0 and 1 MPT, and strongly declined after fluralaner administration from 13.0-14.7 - triatomines at 0-1 MPT to 4.0-4.2 over 6-10 MPT. Only one of 81 noninfested sites before fluralaner treatment became infested subsequently. Fluralaner significantly reduced the site-level infestation and abundance of pyrethroid-resistant T. infestans and should be tested more widely in Phase III efficacy trials.

7.
PLoS Negl Trop Dis ; 15(12): e0009261, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34914703

RESUMEN

BACKGROUND: During 2017, twenty health districts (locations) implemented a dengue outbreak Early Warning and Response System (EWARS) in Mexico, which processes epidemiological, meteorological and entomological alarm indicators to predict dengue outbreaks and triggers early response activities. Out of the 20 priority districts where more than one fifth of all national disease transmission in Mexico occur, eleven districts were purposely selected and analyzed. Nine districts presented outbreak alarms by EWARS but without subsequent outbreaks ("non-outbreak districts") and two presented alarms with subsequent dengue outbreaks ("outbreak districts"). This evaluation study assesses and compares the impact of alarm-informed response activities and the consequences of failing a timely and adequate response across the outbreak groups. METHODS: Five indicators of dengue outbreak response (larval control, entomological studies with water container interventions, focal spraying and indoor residual spraying) were quantitatively analyzed across two groups ("outbreak districts" and "non-outbreak districts"). However, for quality control purposes, only qualitative concluding remarks were derived from the fifth response indicator (fogging). RESULTS: The average coverage of vector control responses was significantly higher in non-outbreak districts and across all four indicators. In the "outbreak districts" the response activities started late and were of much lower intensity compared to "non-outbreak districts". Vector control teams at districts-level demonstrated diverse levels of compliance with local guidelines for 'initial', 'early' and 'late' responses to outbreak alarms, which could potentially explain the different outcomes observed following the outbreak alarms. CONCLUSION: Failing timely and adequate response of alarm signals generated by EWARS showed to negatively impact the disease outbreak control process. On the other hand, districts with adequate and timely response guided by alarm signals demonstrated successful records of outbreak prevention. This study presents important operational scenarios when failing or successding EWARS but warrants investigating the effectiveness and cost-effectiveness of EWARS using a more robust designs.

8.
Malar J ; 20(1): 443, 2021 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-34819092

RESUMEN

BACKGROUND: Though most of Panamá is free from malaria, localized foci of transmission persist, including in the Guna Yala region. Government-led entomological surveillance using an entomological surveillance planning tool (ESPT) sought to answer programmatically-relevant questions that would enhance the understanding of both local entomological drivers of transmission and gaps in protection that result in persisting malaria transmission to guide local vector control decision-making. METHODS: The ESPT was used to design a sampling plan centered around the collection of minimum essential indicators to investigate the relevance of LLINs and IRS in the communities of Permé and Puerto Obaldía, Guna Yala, as well as to pinpoint any remaining spaces and times where humans are exposed to Anopheles bites (gaps in protection). Adult Anopheles were collected at three time points via human landing catches (HLCs), CDC Light Traps (LT), and pyrethrum spray catches (PSCs) during the rainy and dry seasons. Mosquitoes were identified to species via molecular methods. Insecticide susceptibility testing of the main vector species to fenitrothion was conducted. RESULTS: In total, 7537 adult Anopheles were collected from both sites. Of the 493 specimens molecularly confirmed to species, two thirds (n = 340) were identified as Nyssorhynchus albimanus, followed by Anopheles aquasalis. Overall Anopheles human biting rates (HBRs) were higher outdoors than indoors, and were higher in Permé than in Puerto Obaldía: nightly outdoor HBR ranged from 2.71 bites per person per night (bpn) (Puerto Obaldía), to 221.00 bpn (Permé), whereas indoor nightly HBR ranged from 0.70 bpn (Puerto Obaldía) to 81.90 bpn (Permé). Generally, peak biting occurred during the early evening. The CDC LT trap yields were significantly lower than that of HLCs and this collection method was dropped after the first collection. Pyrethrum spray catches resulted in only three indoor resting Anopheles collected. Insecticide resistance (IR) of Ny. albimanus to fenitrothion was confirmed, with only 65.5% mortality at the diagnostic time. CONCLUSION: The early evening exophagic behaviour of Anopheles vectors, the absence of indoor resting behaviours, and the presence of resistance to the primary intervention insecticide demonstrate limitations of the current malaria strategy, including indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs), and point to both gaps in protection and to the drivers of persisting malaria transmission in Guna Yala. These findings highlight the need for continued and directed entomological surveillance, based on programmatic questions, that generates entomological evidence to inform an adaptive malaria elimination strategy.

9.
PLoS Negl Trop Dis ; 15(11): e0009931, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34784348

RESUMEN

Arboviruses transmitted by Aedes aegypti (e.g., dengue, chikungunya, Zika) are of major public health concern on the arid coastal border of Ecuador and Peru. This high transit border is a critical disease surveillance site due to human movement-associated risk of transmission. Local level studies are thus integral to capturing the dynamics and distribution of vector populations and social-ecological drivers of risk, to inform targeted public health interventions. Our study examines factors associated with household-level Ae. aegypti presence in Huaquillas, Ecuador, while accounting for spatial and temporal effects. From January to May of 2017, adult mosquitoes were collected from a cohort of households (n = 63) in clusters (n = 10), across the city of Huaquillas, using aspirator backpacks. Household surveys describing housing conditions, demographics, economics, travel, disease prevention, and city services were conducted by local enumerators. This study was conducted during the normal arbovirus transmission season (January-May), but during an exceptionally dry year. Household level Ae. aegypti presence peaked in February, and counts were highest in weeks with high temperatures and a week after increased rainfall. Univariate analyses with proportional odds logistic regression were used to explore household social-ecological variables and female Ae. aegypti presence. We found that homes were more likely to have Ae. aegypti when households had interruptions in piped water service. Ae. aegypti presence was less likely in households with septic systems. Based on our findings, infrastructure access and seasonal climate are important considerations for vector control in this city, and even in dry years, the arid environment of Huaquillas supports Ae. aegypti breeding habitat.

10.
J Med Entomol ; 2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34617566

RESUMEN

Severe human arboviral diseases can be transmitted by the mosquito Aedes aegypti (Linnaeus), including dengue, chikungunya, Zika, and yellow fever. Adult control using spatial sprays with adulticides is recommended only when dengue outbreaks occur. In Argentina, mainly pyrethroids, like cis-permethrin, have been used as an adulticide, especially since 2008. The evolution and spread of resistance to insecticides is a major concern for vector control. This study reports for the first time pyrethroid resistance in Ae. aegypti adults from Argentina, in the city of Salvador Mazza (Salta). WHO discriminating doses of 0.75% were used for permethrin, 0.05% for deltamethrin, and 5% for malathion. Also the discriminating dose for cis-permethrin (0.6%) was calculated and evaluated for the first time. We found a resistance ratio 50 (RR50) of 10.3 (9.7-10.4) for cis-permethrin, which is considered as high resistance. Our results also indicated resistance to deltamethrin (22.6% mortality) and permethrin (53.6% mortality), and a total susceptibility to malathion (100% mortality). Results from this study highlight the importance of the correct use of insecticides within an Integrated Vector Management (IVM) approach and of early detection of resistance to enable Ae. aegypti control in Argentina. More studies are needed to determine the spread of mosquito resistance to pyrethroids.

11.
Appl Microbiol Biotechnol ; 105(23): 8703-8714, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34716787

RESUMEN

Entomopathogenic fungi can achieve important innovative outcomes for integrated mosquito control especially of Aedes aegypti, the key vector of arboviruses to humans in the tropics and subtropics. This study sought to design and to develop a simple dissemination device to attract and to infect gravid A. aegypti adults with a granular formulation of the ascomycete Metarhizium humberi IP 46, and to validate this device in the laboratory as well as in semi-field and field conditions. Hydrogel (polyacrylamide potassium polyacrylate) was confirmed to be a suitable substitute for water used in the device that attracted gravid females under field conditions. Females laid eggs on black polyethylene terephthalate carpet fixed in the device that also proved to be a suitable substrate for a granular formulation of fungal microsclerotia and/or conidia. The plastic device (29.5 cm high) was divided into a lower closed compartment with a water reservoir and an upper, laterally open but covered compartment with continuously hydrated gel and the fungal formulation attached to the carpet. The uppermost compartment permitted free circulation of mosquito adults. The device attracted both male and female A. aegypti. The fungal formulations of IP 46 propagules tested in the device were effective against adults in laboratory, semi-field, and field settings. Findings in the laboratory, semi-field, and especially in field conditions strengthen the value and utility of this innovative device for focal applications of a mycoinsecticide against this important mosquito vector.Key points• Low-cost and simple disseminating device for focal control of Aedes aegypti.• Granulized Metarhizium humberi IP 46 and hydrogel yield extended control.• Findings in field tests strengthen benefit of the device for focal application.


Asunto(s)
Aedes , Metarhizium , Animales , Brasil , Femenino , Humanos , Masculino , Mosquitos Vectores
12.
Malar J ; 20(1): 431, 2021 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-34717641

RESUMEN

BACKGROUND: Although considerable success in reducing the incidence of malaria has been achieved in Brazil in recent years, an increase in the proportion of cases caused by the harder-to-eliminate Plasmodium vivax parasite can be noted. Recurrences in P. vivax malaria cases are due to new mosquito-bite infections, drug resistance or especially from relapses arising from hypnozoites. As such, new innovative surveillance strategies are needed. The aim of this study was to develop an infographic visualization tool to improve individual-level malaria surveillance focused on malaria elimination in the Brazilian Amazon. METHODS: Action Research methodology was employed to deal with the complex malaria surveillance problem in the Amazon region. Iterative cycles were used, totalling four cycles with a formal validation of an operational version of the Malaria Trigram tool at the end of the process. Further probabilistic data linkage was carried out so that information on the same patients could be linked, allowing for follow-up analysis since the official system was not planned in such way that includes this purpose. RESULTS: An infographic user interface was developed for the Malaria Trigram that incorporates all the visual and descriptive power of the Trigram concept. It is a multidimensional and interactive historical representation of malaria cases per patient over time and provides visual input to decision-makers on recurrences of malaria. CONCLUSIONS: The Malaria Trigram is aimed to help public health professionals and policy makers to recognise and analyse different types of patterns in malaria events, including recurrences and reinfections, based on the current Brazilian health surveillance system, the SIVEP-Malária system, with no additional primary data collection or change in the current process. By using the Malaria Trigram, it is possible to plan and coordinate interventions for malaria elimination that are integrated with other parallel actions in the Brazilian Amazon region, such as vector control management, effective drug and vaccine deployment strategies.


Asunto(s)
Visualización de Datos , Erradicación de la Enfermedad/estadística & datos numéricos , Monitoreo Epidemiológico , Malaria Vivax/prevención & control , Vigilancia de la Población/métodos , Brasil , Humanos , Plasmodium vivax , Recurrencia
13.
Rev Soc Bras Med Trop ; 54: e0223, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34586289

RESUMEN

INTRODUCTION: Dengue, chikungunya, and Zika are a growing global health problem. This study analyzed the spatial distribution of dengue, chikungunya, and Zika cases in São Luís, Maranhão, from 2015 to 2016 and investigated the association between socio-environmental and economic factors and hotspots for mosquito proliferation. METHODS: This was a socio-ecological study using data from the National Information System of Notifiable Diseases. The spatial units of analysis were census tracts. The incidence rates of the combined cases of the three diseases were calculated and smoothed using empirical local Bayes estimates. The spatial autocorrelation of the smoothed incidence rate was measured using Local Moran's I and Global Moran's I. Multiple linear regression and spatial autoregressive models were fitted using the log of the smoothed disease incidence rate as the dependent variable and socio-environmental factors, demographics, and mosquito hotspots as independent variables. RESULTS: The findings showed a significant spatial autocorrelation of the smoothed incidence rate. The model that best fit the data was the spatial lag model, revealing a positive association between disease incidence and the proportion of households with surrounding garbage accumulation. CONCLUSIONS: The distribution of dengue, chikungunya, and Zika cases showed a significant spatial pattern, in which the high-risk areas for the three diseases were explained by the variable "garbage accumulated in the surrounding environment," demonstrating the need for an intersectoral approach for vector control and prevention that goes beyond health actions.


Asunto(s)
Fiebre Chikungunya , Dengue , Infección por el Virus Zika , Virus Zika , Animales , Teorema de Bayes , Brasil/epidemiología , Fiebre Chikungunya/epidemiología , Dengue/epidemiología , Incidencia , Mosquitos Vectores , Análisis Espacial , Infección por el Virus Zika/epidemiología
14.
Acta Trop ; 224: 106130, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34536368

RESUMEN

Assays for parasite detection in insect vectors provide important information for disease control. American Trypanosomiasis (Chagas disease) is the most devastating vector-borne illness and the fourth most common in Central America behind HIV/AIDS and acute respiratory and diarrheal infections (Peterson et al., 2019). Under-detection of parasites is a general problem which may be influenced by parasite genetic variation; however, little is known about the genetic variation of the Chagas parasite, especially in this region. In this study we compared six assays for detecting the Chagas parasite, Trypanosoma cruzi: genomic reduced representation sequencing (here referred to as genotype-by-sequencing or GBS), two with conventional PCR (i.e., agarose gel detection), two with qPCR, and microscopy. Our results show that, compared to GBS genomic analysis, microscopy and PCR under-detected T. cruzi in vectors from Central America. Of 94 samples, 44% (50/94) were positive based on genomic analysis. The lowest detection, 9% (3/32) was in a subset assayed with microscopy. Four PCR assays, two with conventional PCR and two with qPCR showed intermediate levels of detection. Both qPCR tests and one conventional PCR test targeted the 195 bp repeat of satellite DNA while the fourth test targeted the 18S gene. Statistical analyses of the genomic and PCR results indicate that the PCR assays significantly under detect infections of Central American T. cruzi genotypes.


Asunto(s)
Enfermedad de Chagas , Triatoma , Trypanosoma cruzi , Animales , América Central , Enfermedad de Chagas/diagnóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , Triatoma/genética , Trypanosoma cruzi/genética
15.
PLoS Negl Trop Dis ; 15(9): e0009686, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34529649

RESUMEN

BACKGROUND: Early warning systems (EWSs) are of increasing importance in the context of outbreak-prone diseases such as chikungunya, dengue, malaria, yellow fever, and Zika. A scoping review has been undertaken for all 5 diseases to summarize existing evidence of EWS tools in terms of their structural and statistical designs, feasibility of integration and implementation into national surveillance programs, and the users' perspective of their applications. METHODS: Data were extracted from Cochrane Database of Systematic Reviews (CDSR), Google Scholar, Latin American and Caribbean Health Sciences Literature (LILACS), PubMed, Web of Science, and WHO Library Database (WHOLIS) databases until August 2019. Included were studies reporting on (a) experiences with existing EWS, including implemented tools; and (b) the development or implementation of EWS in a particular setting. No restrictions were applied regarding year of publication, language or geographical area. FINDINGS: Through the first screening, 11,710 documents for dengue, 2,757 for Zika, 2,706 for chikungunya, 24,611 for malaria, and 4,963 for yellow fever were identified. After applying the selection criteria, a total of 37 studies were included in this review. Key findings were the following: (1) a large number of studies showed the quality performance of their prediction models but except for dengue outbreaks, only few presented statistical prediction validity of EWS; (2) while entomological, epidemiological, and social media alarm indicators are potentially useful for outbreak warning, almost all studies focus primarily or exclusively on meteorological indicators, which tends to limit the prediction capacity; (3) no assessment of the integration of the EWS into a routine surveillance system could be found, and only few studies addressed the users' perspective of the tool; (4) almost all EWS tools require highly skilled users with advanced statistics; and (5) spatial prediction remains a limitation with no tool currently able to map high transmission areas at small spatial level. CONCLUSIONS: In view of the escalating infectious diseases as global threats, gaps and challenges are significantly present within the EWS applications. While some advanced EWS showed high prediction abilities, the scarcity of tool assessments in terms of integration into existing national surveillance systems as well as of the feasibility of transforming model outputs into local vector control or action plans tends to limit in most cases the support of countries in controlling disease outbreaks.

16.
One Health ; 13: 100316, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34485673

RESUMEN

Introduction: Neglected tropical diseases (NTDs) in developing countries like the Caribbean, negatively affect multiple income-generating sectors, including the tourism industry upon which island states are highly dependent. Insect-transmitted NTDs include, but are not limited to, malaria, dengue and lymphatic filariasis. Control measures for these disease, are often ignored because of the associated cost. Many of the developing country members are thus retained in a financially crippling cycle, balancing the cost of prophylactic measures with that of controlling an outbreak.The purpose of the paper is to bring awareness to NTDs transmitted by insects of importance to humans, and to assess factors affecting such control, in the English-speaking Caribbean. Method: Comprehensive literature review on reports pertaining to NTDs transmitted by insects in the Caribbean and Latin America was conducted. Data search was carried out on PubMed, and WHO and PAHO websites. Results and conclusion: Potential risk factors for NTDs transmitted by arthropods in the English-speaking Caribbean are summarised. The mosquito appears to be the main insect-vector of human importance within the region of concern. Arthropod-vectors of diseases of veterinary importance are also relevant because they affect the livelihood of farmers, in highly agriculture based economies. Other NTDs may also be in circulation gauged by the presence of antibodies in Caribbean individuals. However, routine diagnostic tests for specific diseases are expensive and tests may not be conducted when diseases are not prevalent in the population. It appears that only a few English-speaking Caribbean countries have examined secondary reservoirs of pathogens or assessed the effectivity of their insect control methods. As such, disease risk assessment appears incomplete. Although continuous control is financially demanding, an integrated and multisectoral approach might help to deflect the cost. Such interventions are now being promoted by health agencies within the region and various countries are creating and exploring the use of novel tools to be incorporated in their insect-vector control programmes.

17.
Parasit Vectors ; 14(1): 445, 2021 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-34479606

RESUMEN

BACKGROUND: Larvicides are typically applied to fixed and findable mosquito breeding sites, such as fish farming ponds used in commercial aquaculture, to kill immature forms and thereby reduce the size of adult malaria vector populations. However, there is little evidence suggesting that larviciding may suppress community-wide malaria transmission outside Africa. Here, we tested whether the biological larvicide VectoMax FG applied at monthly intervals to fish farming ponds can reduce malaria incidence in Amazonian Brazil. METHODS: This study was carried out in Vila Assis Brasil (VAB; population 1700), a peri-urban malaria hotspot in northwestern Brazil with a baseline annual parasite incidence of 553 malaria cases per 1000 inhabitants. The intervention consisted of monthly treatments with 20 kg/ha of VectoMax FG of all water-filled fish ponds in VAB (n ranging between 167 and 170) with a surface area between 20 and 8000 m2, using knapsack power mistblowers. We used single-group interrupted time-series analysis to compare monthly larval density measurements in fish ponds during a 14-month pre-intervention period (September 2017-October 2018), with measurements made during November 2018-October 2019 and shortly after the 12-month intervention (November 2019). We used interrupted time-series analysis with a comparison group to contrast the malaria incidence trends in VAB and nearby nonintervention localities before and during the intervention. RESULTS: Average larval densities decreased tenfold in treated fish farming ponds, from 0.467 (95% confidence interval [CI], 0.444-0.490) anopheline larvae per dip pre-intervention (September 2017-October 2018) to 0.046 (95% CI, 0.041-0.051) larvae per dip during (November 2018-October 2019) and shortly after the intervention (November 2019). Average malaria incidence rates decreased by 0.08 (95% CI, 0.04-0.11) cases per 100 person-months (P < 0.0001) during the intervention in VAB and remained nearly unchanged in comparison localities. We estimate that the intervention averted 24.5 (95% CI, 6.2-42.8) malaria cases in VAB between January and December 2019. CONCLUSIONS: Regular larviciding is associated with a dramatic decrease in larval density and a modest but significant decrease in community-wide malaria incidence. Larviciding may provide a valuable complementary vector control strategy in commercial aquaculture settings across the Amazon.

18.
Rev. cuba. med ; 60(3): e2029, 2021.
Artículo en Español | LILACS, CUMED | ID: biblio-1347519

RESUMEN

Introducción: El dengue es una enfermedad infecciosa causada por el virus del dengue. Es un problema complejo tanto por su magnitud como por los elementos que hay que tener presentes para su control. En la situación actual de nuestra Región, esta realidad constituye un reto para el control del mosquito vector, y, por tanto, de la enfermedad. Objetivo: Caracterizar a esta enfermedad y demostrar la necesidad de realizar acciones comunitarias para control del dengue y su prevención. Métodos: Se realizó una revisión sistemática de documentos de sociedades científicas dedicadas a la Epidemiologia en la Biblioteca Virtual de Salud (BVS) con límite de fecha de abril de 2015 a abril de 2020, e incluyendo artículos tanto en inglés como en español. Se localizaron 262 estudios finalmente se seleccionaron 20. Conclusiones: En el futuro se espera la aparición de cepas productoras de una mayor viremia por la diversidad genética del virus, con casos clínicos más complicados; se está ante una enfermedad que ofrece un reto a los médicos, de ahí la importancia de trabajar en su prevención para evitar la propagación de la enfermedad en nuestra población(AU)


Introduction: Dengue is an infectious disease caused by the dengue virus. It is a complex problem both because of its magnitude and because of the elements that must be taken into account to its control. In our region current situation, this reality constitutes a challenge for the control of the mosquito vector, and therefore, of the disease. Objective: To describe this disease and to demonstrate the need for community actions to control dengue and its prevention. Methods: A systematic review of documents from scientific societies dedicated to Epidemiology was carried out in the Virtual Health Library (VHL) with a date limit from April 2015 to April 2020, and including articles in both English and Spanish. Two hundred sixty-two studies were located, finally 20 were selected. Conclusions: In the future, the appearance of strains producing higher viremia due to the genetic diversity of the virus is expected, with more complicated clinical cases. We are facing a disease that offers a challenge to doctors, hence the importance of working on its prevention to avoid the spread of the disease in our population(AU)


Asunto(s)
Humanos , Aedes , Control de Vectores , Dengue/prevención & control , Virus del Dengue
19.
Artículo en Inglés | MEDLINE | ID: mdl-34407161

RESUMEN

The majority of malaria cases in South America occur in rural areas of the Amazon region. Although these areas have a significant impact on malaria cases, few entomological studies have been carried out there. This study aimed to describe entomological parameters in settlements in Rondonia State, Brazil. Collections of anopheles were carried out using the Protected Human Attraction Technique (PHAT). The risk and the potential for malaria transmission were assessed using the human biting rate (HBR), the sporozoite rate (SR) and the entomological inoculation rate (EIR). The results confirmed that Nyssorhynchus darlingi is the predominant species in the two studied locations. Although settlement in the two study sites has occurred at different times, the species richness found was low, showing that environmental changes caused by anthropological actions have probably favor the adaptation of Ny. darlingi species. From the total of 615 anopheline mosquitoes assessed, seven (1.1%) were positive for Plasmodium sp. infections. The EIR revealed that Ny. darlingi contributes to malaria transmission in both locations, as it was responsible for 0.05 infectious bites in humans at night in the old settlement and 0.02 in the recent occupation. In the two study sites, the biting occurred more frequently at dusk. Nyssorhynchus darlingi was prevalent in areas of recent colonization but, even when present in a low density, this species could maintain the transmission of malaria in the older settlement. The entomological information obtained in this study is important and may aid the selection of vector control actions in these locations.


Asunto(s)
Anopheles , Malaria , Plasmodium , Animales , Brasil , Humanos , Mosquitos Vectores
20.
J Am Mosq Control Assoc ; 37(3): 164-168, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34407169

RESUMEN

In recent years, Aedes albopictus has become the most important invasive mosquito species worldwide. In 2018, Ae. albopictus was found in a suburban area of Merida, one of the cities with the highest number of arbovirus cases in Mexico in the last 10 years. As Ae. albopictus continues its range expansion, there is a need to monitor its susceptibility to existing insecticide classes, since countries like Mexico currently do not consider Ae. albopictus in its insecticide management programs. In order to determine its susceptibility to the insecticides usually applied by the vector control program in Mexico, the Centers for Disease Control and Prevention bottle bioassays were performed on individuals from established population of Ae. albopictus from Merida, Yucatan, Mexico. Results suggested that the population recently found in the suburban area of Merida is susceptible to permethrin, deltamethrin, chlorpyrifos, malathion, bendiocarb, and propoxur. Further studies of insecticide resistance using biochemical and molecular tools together with more knowledge of the biology and ecology of this species are necessary to generate specific and efficient control strategies in Mexico.


Asunto(s)
Aedes , Insecticidas , Animales , Humanos , Resistencia a los Insecticidas , Insecticidas/farmacología , México , Mosquitos Vectores
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