Assessing dengue risk globally using non-Markovian models.

Dengue is a vector-borne disease transmitted by Aedes mosquitoes. The worldwide spread of these mosquitoes and the increasing disease burden have emphasized the need for a spatio-temporal risk map capable of assessing dengue outbreak conditions and quantifying the outbreak risk. Given that the life cycle of Aedes mosquitoes is strongly influenced by habitat temperature, numerous studies have utilized temperature-dependent development rates of these mosquitoes to construct virus transmission and outbreak risk models. In this study, we contribute to existing research by developing a mechanistic model for the mosquito life cycle that accurately captures its non-Markovian nature. Beginning with integral equations to track the mosquito population across different life cycle stages, we demonstrate how to derive the corresponding differential equations using phase-type distributions. This approach can be further applied to similar non-Markovian processes that are currently described with less accurate Markovian models. By fitting the model to data on human dengue cases, we estimate several model parameters, allowing the development of a global spatiotemporal dengue risk map. This risk model employs temperature and precipitation data to assess the environmental suitability for dengue outbreaks in a given area.

Entomological assessment of hessian fabric transfluthrin vapour emanators as a means to protect against outdoor-biting Aedes after providing them to households for routine use in Port-au-Prince, Haiti.

BACKGROUND: A simple treated fabric device for passively emanating the volatile pyrethroid transfluthrin was recently developed in Tanzania that protected against nocturnal Anopheles and Culex mosquitoes for several months. Here these transfluthrin emanators were assessed in Port-au-Prince, Haiti against outdoor-biting Aedes. METHODS: Transfluthrin emanators were distributed to participating households in poor-to-middle class urban neighbourhoods and evaluated once every two months in terms of their effects on human landing rates of wild Aedes populations. A series of three such entomological assessment experiments were conducted, to examine the influence of changing weather conditions, various transfluthrin formulations and emanator placement on protective efficacy measurements. Laboratory experiments assessed resistance of local Aedes aegypti to transfluthrin and deltamethrin, and the irritancy and repellency of the transfluthrin-treated fabric used in the field. RESULTS: Across all three entomological field assessments, little evidence of protection against wild Ae. aegypti was observed, regardless of weather conditions, transfluthrin formulation or emanator placement: A generalized linear mixed model fitted to the pooled data from all three assessment rounds (921 females caught over 5129 hours) estimated a relative landing rate [95% Confidence interval] of 0.87 [0.73, 1.04] for users of treated versus untreated emanators (P = 0.1241). Wild Ae. aegypti in this setting were clearly resistant to transfluthrin when compared to a fully susceptible colony. CONCLUSIONS: Transfluthrin emanators had little if any apparent effect upon Aedes landing rates by wild Ae. aegypti in urban Haiti, and similar results have been obtained by comparable studies in Tanzania, Brazil and Peru. In stark contrast, however, parallel sociological assessments of perspectives among these same end-users in urban Haitian communities indicate strong satisfaction in terms of perceived protection against mosquitoes. It remains unclear why the results obtained from these complementary entomological and sociological assessments in Haiti differ so much, as do those from a similar set of studies in Brazil. It is encouraging, however, that similar contrasts between the entomological and epidemiological results of a recent large-scale assessment of another transfluthrin emanator product in Peru, which indicate they provide useful protection against Aedes-borne arboviral infections, despite apparently providing only modest protection against Aedes mosquito bites.

Cost of controlling the dengue vector Aedes aegypti in the Peruvian amazon. / Costo del control de Aedes aegypti en la Amazonía peruana.

OBJECTIVE.: Motivation for the study. Dengue prevention and control is based on the control of its vector. This study was conducted because of the need to know the costs associated with Aedes aegypti control in a region that carries out planned vector control activities. Main findings. The costs incurred in dengue vector control in the Loreto region in 2017 and 2018 amounted to PEN 4,066,380.25 and PEN 3,807,858.73, respectively. Implications. Knowing the cost of vector control activities will allow us to better plan these activities and have a basis for cost-effectiveness studies with other methods of prevention and control of dengue. To estimate the costs incurred in the control of Aedes aegypti in the Loreto region, during the years 2017 and 2018. MATERIALS AND METHODS.: We conducted a partial retrospective economic evaluation of the costs of Aedes aegypti control of the Regional Health Directorate Loreto, during the implementation of the Regional Plan for Surveillance and Control of Aedes aegypti. Documentation such as plans, intervention reports and payment slips were reviewed, and interviews were conducted with professional personnel involved in vector control, on the costs of control interventions. RESULTS.: We found that the costs incurred in dengue vector control in the Loreto Region in the two years were: PEN 3,807,858 and PEN 4,066,380 during 2017 and 2018, respectively (USD 1,175,264 and USD 1,1210,232 at the 2017 and 2018 exchange rate). However, the effect of control activities is short-lived. CONCLUSIONS.: The high cost involved in vector control with the methods currently used and the short duration of its effect make it unsustainable. Studies should be conducted in order to find other more efficient methods for dengue control.

OBJETIVO.: Motivación para realizar el estudio. La prevención y control del dengue se basa en el control de su vector. Este estudio se realizó por la necesidad de conocer los costos asociados al control Aedes aegypti en una región que realiza actividades planificadas de control vectorial. Principales hallazgos. Los costos incurridos en el control del vector del dengue en la región Loreto en los años 2017 y 2018, ascienden a 4,066,380.25 y 3,807,858.73 PEN, respectivamente. Implicancias. Conocer el costo de las actividades de control vectorial nos permitirá planificar mejor estas actividades y tener una base para estudios de costo efectividad con otros métodos de prevención y control del dengue. Estimar los costos incurridos en el control del Aedes aegypti en la región Loreto, en los años 2017 y 2018. MATERIALES Y MÉTODOS.: Se realizó una evaluación económica retrospectiva parcial de los costos del control del Aedes aegypti de la Dirección Regional de Salud Loreto, durante la ejecución del Plan Regional de Vigilancia y Control de Aedes aegypti. Se revisó documentación como planes, informes de intervenciones y planillas de pago y se realizaron entrevistas al personal profesional implicado en el control vectorial, sobre los costos de las intervenciones de control. RESULTADOS.: Se halló, que los costos incurridos en el control del vector del dengue en la Región Loreto en los dos años estudiados ascienden a: 3,807,858 PEN y 4,066,380 PEN durante el 2017 y 2018, respectivamente (1´175,264 USD y 1´1210,232 USD al tipo de cambio del 2017 y 2018). Sin embargo, el efecto de las actividades de control es de corta duración. CONCLUSIONES.: El alto costo que implica el control vectorial con los métodos usados actualmente y la corta duración de su efecto lo hace insostenible. Se deben realizar estudios para hallar otros métodos más eficientes para el control del dengue.

The rising global economic costs of invasive Aedes mosquitoes and Aedes-borne diseases.

Invasive Aedes aegypti and Aedes albopictus mosquitoes transmit viruses such as dengue, chikungunya and Zika, posing a huge public health burden as well as having a less well understood economic impact. We present a comprehensive, global-scale synthesis of studies reporting these economic costs, spanning 166 countries and territories over 45 years. The minimum cumulative reported cost estimate expressed in 2022 US$ was 94.7 billion, although this figure reflects considerable underreporting and underestimation. The analysis suggests a 14-fold increase in costs, with an average annual expenditure of US$ 3.1 billion, and a maximum of US$ 20.3 billion in 2013. Damage and losses were an order of magnitude higher than investment in management, with only a modest portion allocated to prevention. Effective control measures are urgently needed to safeguard global health and well-being, and to reduce the economic burden on human societies. This study fills a critical gap by addressing the increasing economic costs of Aedes and Aedes-borne diseases and offers insights to inform evidence-based policy.

Zika emergence, persistence, and transmission rate in Colombia: a nationwide application of a space-time Markov switching model.

Zika, a viral disease transmitted to humans by Aedes mosquitoes, emerged in the Americas in 2015, causing large-scale epidemics. Colombia alone reported over 72,000 Zika cases between 2015 and 2016. Using national surveillance data from 1121 municipalities over 70 weeks, we identified sociodemographic and environmental factors associated with Zika's emergence, re-emergence, persistence, and transmission intensity in Colombia. We fitted a zero-state Markov-switching model under the Bayesian framework, assuming Zika switched between periods of presence and absence according to spatially and temporally varying probabilities of emergence/re-emergence (from absence to presence) and persistence (from presence to presence). These probabilities were assumed to follow a series of mixed multiple logistic regressions. When Zika was present, assuming that the cases follow a negative binomial distribution, we estimated the transmission intensity rate. Our results indicate that Zika emerged/re-emerged sooner and that transmission was intensified in municipalities that were more densely populated, at lower altitudes and/or with less vegetation cover. Warmer temperatures and less weekly-accumulated rain were also associated with Zika emergence. Zika cases persisted for longer in more densely populated areas with more cases reported in the previous week. Overall, population density, elevation, and temperature were identified as the main contributors to the first Zika epidemic in Colombia. We also estimated the probability of Zika presence by municipality and week, and the results suggest that the disease circulated undetected by the surveillance system on many occasions. Our results offer insights into priority areas for public health interventions against emerging and re-emerging Aedes-borne diseases.

Entomological assessment of hessian fabric transfluthrin vapour emanators for protecting against outdoor-biting Aedes aegypti in coastal Tanzania.

BACKGROUND: A low technology emanator device for slowly releasing vapour of the volatile pyrethroid transfluthrin was recently developed in Tanzania that provides robust protection against night biting Anopheles and Culex vectors of malaria and filariasis for several months. Here these same emanator devices were assessed in Dar es Salaam city, as a means of protection against outdoor-biting Aedes (Stegomia) aegypti, the most important vector of human arboviruses worldwide, in parallel with similar studies in Haiti and Brazil. METHODS: A series of entomological experiments were conducted under field and semi-field conditions, to evaluate whether transfluthrin emanators protect against wild Ae. aegypti, and also compare the transfluthrin responsiveness of Ae. aegypti originating from wild-caught eggs to established pyrethroid-susceptible Ae. aegypti and Anopheles gambiae colonies. Preliminary measurements of transfluthrin vapour concentration in air samples collected near treated emanators were conducted by gas chromatography-mass spectrometry. RESULTS: Two full field experiments with four different emanator designs and three different transfluthrin formulations consistently indicated negligible reduction of human landing rates by wild Ae. aegypti. Under semi-field conditions in large cages, 50 to 60% reductions of landing rates were observed, regardless of which transfluthrin dose, capture method, emanator placement position, or source of mosquitoes (mildly pyrethroid resistant wild caught Ae. aegypti or pyrethroid-susceptible colonies of Ae. aegypti and An. gambiae) was used. Air samples collected immediately downwind from an emanator treated with the highest transfluthrin dose (15g), contained 12 to 19 µg/m3 transfluthrin vapour. CONCLUSIONS: It appears unlikely that the moderate levels of pyrethroid resistance observed in wild Ae. aegypti can explain the modest-to-undetectable levels of protection exhibited. While potential inhalation exposure could be of concern for the highest (15g) dose evaluated, 3g of transfluthrin appears sufficient to achieve the modest levels of protection that were demonstrated entomologically. While the generally low levels of protection against Aedes reported here from Tanzania, and from similar entomological studies in Haiti and Brazil, are discouraging, complementary social science studies in Haiti and Brazil suggest end-users perceive valuable levels of protection against mosquitoes. It therefore remains unclear whether transfluthrin emanators have potential for protecting against Aedes vectors of important human arboviruses.

Assessment of larval and pupal indices of dengue mosquito vectors in a North-Eastern state of Tripura, India.

BACKGROUND OBJECTIVES: Dengue is a major vector-borne disease having public health importance. It is caused by Dengue Virus (DENV) and is transmitted by mosquitoes of Aedes species. With the unavailability of a vaccine, vector control remains the only preventive measure for dengue. Studies have already been conducted to establish the presence of dengue vectors in the north-eastern states of India. However, limited studies have been conducted in Tripura state. In the present study we aimed to identify the preferred breeding habitats of dengue vectors in the state. METHODS: Clinical case data of dengue since the last five years was studied and the areas with the highest case numbers were identified. Entomological investigation was carried out in areas reporting the highest number of cases. Larvae were collected from the breeding habitats using standard protocol followed by morphological and molecular identification. Further, House index (HI), Container index (CI) and Pupal index (PI) were determined. The positive pools were then processed for incrimination for the presence of dengue virus. Calculation of entomological indices was done. RESULTS: Of the total 815 containers searched, 36.80% containers were positive for mosquito larvae. Among the immature mosquito collection, 836 adults emerged and were identified as Aedes albopictus using standard taxonomic keys followed by molecular methods. HI, CI and PI, varied from 15.38% to 100%, 21% to 31.04 %, and 2.93% to 110.53% respectively. However, none of the pools was positive for dengue virus. INTERPRETATION CONCLUSION: The present study identified Ae. albopictus as a potential vector of dengue in Tripura. The study gave important insights on the preferred larval habitats and provides information on the indication of displacement of Ae. albopictus from rural to urban and semi-urban areas. However, longitudinal studies for longer time frame are necessary for any conclusive remarks.

Entomological assessment in 'hotspots' of four lymphatic filariasis endemic districts, Central Nepal during post-MDA surveillance.

BACKGROUND OBJECTIVES: Annual mass drug administration (MDA) is the main strategy to interrupt the transmission of lymphatic filariasis (LF) in the community. The main aim of monitoring the MDA program, for its effectiveness and interruption of LF is the post-MDA surveillance using antigen survey in children born after MDA. The latest technique of new research suggests that xenomonitoring is an effective tool for monitoring LF intervention. The objective of this study was to assess the W. bancrofti infection/or infectivity in vector mosquitoes by xenomonitoring during post-MDA surveillance. METHODS: A descriptive cross-sectional study was conducted in the hotspots of selected four districts of Central Nepal. A gravid trap technique was used for sampling mosquitoes. Infection/or infectivity was determined via the dissection of vector mosquitoes. Anopheles, Aedes, Armigerus and Culex species were collected from hotspots of four endemic districts, two from the hilly region (Lalitpur and Dhading) and two from Terai region (Bara and Mahottari) of Central Nepal. RESULTS: A total of 4450 mosquitoes belonging to four genera, Anopheles, Culex, Armigeres, and Aedes were collected from four hotspots. The distribution of Culex quinquefasciatus was found to be the highest, 88.9% (n=3955/4450) followed by Cx. vishnui (4.5%), Armigeres sp (5.8%), An. culicifascies (0.2%), Aedes spp (0.8%). The proportion of female mosquitoes trapped is significantly higher. A total of 3344 parous Cx. quinquefasciatus mosquitoes were dissected for any larval stage of W. bancrofti. We could not find any filarial infection in dissected mosquito samples. INTERPRETATION CONCLUSION: We conclude that the gravid trap is an efficient tool for the collection of gravid Cx. quinquefasciatus mosquitoes for xenomonitoring studies of filariasis endemic regions. Vector composition indicated a maximum number of vector mosquitoes of lymphatic filariasis were trapped compared with the other three species. Distribution and density of Cx. quinquefasciatus was found highest in four hotspots of endemic districts. None of the Cx. quinquefasciatus dissected were found to be infected by larval forms of filaria. Since the low levels of infection persistence in the human population in these hot spots, vector infection and infectivity can't be ignored. Microscopic xenomonitoring at a low level of infection persistent is less likely to be efficient so molecular xenomonitoring along with a large sample should be required in each of the hot spots of the districts. Additionally, area is receptive so further vector control intervention should be required to reduce the risk of resurgence of infection.

Efficiency assessment of a novel automatic mosquito pupae sex separation system in support of area-wide male-based release strategies.

This study provides a comparative analysis of two state-of-the-art automatic mosquito pupae sex sorters currently available: the ORINNO and the WOLBAKI Biotech pupae sex separation systems, which both exploit the sexual size dimorphism of pupae. In Aedes aegypti, the WOLBAKI sex sorter and the ORINNO with a sieve mesh size of 1.050 mm achieved sex separation with female contamination rates below 1%, low pupae mortality rates and high male flight capacity. However, in Ae. albopictus, there was more variability, with female contamination rates above the 1% threshold and pupae mortality reaching 27% when using the ORINNO sorter. On the other hand, the WOLBAKI sorter achieved a male pupae recovery of 47.99 ± 8.81% and 50.91 ± 11.77% in Ae. aegypti and Ae. albopictus, respectively, while the ORINNO sorter with a smaller sieve size achieved male pupae recoveries of 38.08 ± 9.69% and 40.16 ± 2.73% in Ae. aegypti and Ae. albopictus, respectively. This study provides valuable information for researchers and practitioners in the field, assisting in the selection of the most suitable system for mosquito control, management and research programs depending on their specific requirements.

Local Economic Conditions Affect Aedes albopictus Management.

Invasive mosquitoes are an emerging public health issue, as many species are competent vectors for pathogens. We assessed how multiple environmental and socio-economic factors affected the engagement of municipalities in Italy (n = 7679) in actions against Aedes albopictus, an invasive mosquito affecting human health and well-being, between 2000 and 2020. We collected information about mosquito control from official documents and municipal websites and modeled the role played by multiple environmental and socioeconomic factors characterizing each municipality through the random forest algorithm. Municipalities are more prone to manage A. albopictus if more urbanized, in lowlands and with long infestation periods. Moreover, these variables are more predictive of management in municipalities with a high median income and thus more economic resources. Only 25.5% of Italian municipalities approved regulations for managing A. albopictus, and very few of them were in Southern Italy, the most deprived area of the country. Our findings indicate that local economic conditions moderate the effect of other drivers of mosquito control and ultimately can lead to better management of A. albopictus. If the management of invasive mosquitoes, or other forms of global change, is subjected to local economic conditions, economic inequalities will jeopardize the success of large-scale policies, also raising issues of environmental and climate justice.

Assessment of Mayaro virus vector competence of the mosquito Aedes aegypti (Linnaeus, 1762) populations in Argentine using dose-response assays.

Mayaro virus (MAYV; Alphavirus: Togaviridae) is an emerging pathogen in Latin America, causing fever and polyarthritis. Sporadic outbreaks of MAYV have occurred in the region, with reported human cases being imported to Europe and North America. Although primarily a risk for those residing in the Amazon basin's tropical forests, recent reports highlight that urbanization would increase the risk of MAYV transmission in Latin America. Urban emergence depends on human susceptibility and the ability of mosquitos like Aedes aegypti  (Linnaeus, 1762) (Diptera: Culicidae) to transmit MAYV. Despite the absence of active MAYV transmission in Argentine, the risk of introduction is substantial due to human movement and the presence of Ae. aegypti in the region. This study aimed to evaluate the susceptibility of different Argentine Ae. aegypti populations to MAYV genotype L (MAYV-L) using dose-response assays and determine barriers to virus infection, dissemination and transmission. Immature mosquito stages were collected in Buenos Aires, Córdoba and Rosario cities. Female Ae. aegypti (F2) were orally infected by feeding on five concentrations of MAYV-L, ranging from 1.0 to 6.0 log10 PFU/mL. Abdomens, legs and saliva were analysed using viral plaque assays. Results revealed that MAYV-L between infection and dissemination were associated with viral doses rather than the population origin. Infection rates varied between 3% and 65%, with a 50% infectious dose >5.5 log10 PFU/mL. Dissemination occurred at 39%, with a 50% dissemination dose of ~6.0 log10 PFU/mL. Dissemination among infected mosquitoes ranged from 60% to 86%, and transmission from disseminated mosquitoes ranged from 11% to 20%. Argentine Ae. aegypti populations exhibited a need for higher viral doses of MAYV-L than those typically found in humans to become infected. In addition, only a small proportion of infected mosquitoes were capable of transmitting the virus. Understanding MAYV transmission in urban areas is crucial for public health interventions.

Economic optimization of Wolbachia-infected Aedes aegypti release to prevent dengue.

BACKGROUND: Dengue virus, primarily transmitted by the Aedes aegypti mosquito, is a major public health concern affecting ≈3.83 billion people worldwide. Recent releases of Wolbachia-transinfected Ae. aegypti in several cities worldwide have shown that it can reduce dengue transmission. However, these releases are costly, and, to date, no framework has been proposed for determining economically optimal release strategies that account for both costs associated with disease risk and releases. RESULTS: We present a flexible stochastic dynamic programming framework for determining optimal release schedules for Wolbachia-transinfected mosquitoes that balances the cost of dengue infection with the costs of rearing and releasing transinfected mosquitoes. Using an ordinary differential equation model of Wolbachia and dengue in a hypothetical city loosely describing areas at risk of new dengue epidemics, we determined that an all-or-nothing release strategy that quickly brings Wolbachia to fixation is often the optimal solution. Based on this, we examined the optimal facility size, finding that it was inelastic with respect to the mosquito population size, with a 100% increase in population size resulting in a 50-67% increase in optimal facility size. Furthermore, we found that these results are robust to mosquito life-history parameters and are mostly determined by the mosquito population size and the fitness costs associated with Wolbachia. CONCLUSIONS: These results reinforce that Wolbachia-transinfected mosquitoes can reduce the cost of dengue epidemics. Furthermore, they emphasize the importance of determining the size of the target population and fitness costs associated with Wolbachia before releases occur. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The costs of transgenerational immune priming for homologous and heterologous infections with different serotypes of dengue virus in Aedes aegypti mosquitoes.

The immune system is a network of molecules, signaling pathways, transcription, and effector modulation that controls, mitigates, or eradicates agents that may affect the integrity of the host. In mosquitoes, the innate immune system is highly efficient at combating foreign organisms but has the capacity to tolerate vector-borne diseases. These implications lead to replication, dissemination, and ultimately the transmission of pathogenic organisms when feeding on a host. In recent years, it has been discovered that the innate immune response of mosquitoes can trigger an enhanced immunity response to the stimulus of a previously encountered pathogen. This phenomenon, called immune priming, is characterized by a molecular response that prevents the replication of viruses, parasites, or bacteria in the body. It has been documented that immune priming can be stimulated through homologous organisms or molecules, although it has also been documented that closely related pathogens can generate an enhanced immune response to a second stimulus with a related organism. However, the cost involved in this immune response has not been characterized through the transmission of the immunological experience from parents to offspring by transgenerational immune priming (TGIP) in mosquitoes. Here, we address the impact on the rates of oviposition, hatching, development, and immune response in Aedes aegypti mosquitoes, the mothers of which were stimulated with dengue virus serotypes 2 and/or 4, having found a cost of TGIP on the development time of the progeny of mothers with heterologous infections, with respect to mothers with homologous infections. Our results showed a significant effect on the sex ratio, with females being more abundant than males. We found a decrease in transcripts of the siRNA pathway in daughters of mothers who had been exposed to an immune challenge with DV. Our research demonstrates that there are costs and benefits associated with TGIP in Aedes aegypti mosquitoes exposed to DV. Specifically, priming results in a lower viral load in the offspring of mothers who have previously been infected with the virus. Although some results from tests of two dengue virus serotypes show similarities, such as the percentage of pupae emergence, there are differences in the percentage of adult emergence, indicating differences in TGIP costs even within the same virus with different serotypes. This finding has crucial implications in the context of dengue virus transmission in endemic areas where multiple serotypes circulate simultaneously.

Integrative analysis in toxicological assessment of the insecticide Malathion in Allium cepa L system / Análise integrativa na avaliação toxicológica do inseticida Malation no sistema Allium cepa L

For many centuries human populations have been suffering and trying to fight with disease-bearing mosquitoes. Emerging and reemerging diseases such as Dengue, Zika, and Chikungunya affect billions of people around the world and recently has been appealing to control with chemical pesticides. Malathion (MT) is one of the main pesticides used against mosquitoes, the vectors of these diseases. This study aimed to assess cytotoxicity and mutagenicity of the malathion for the bioindicator Allium cepa L. using a multivariate and integrative approach. Moreover, an appendix table was compiled with all available literature of insecticides assessed by the Allium cepa system to support our discussion. Exposures during 48h to 0.5 mg mL-¹ and 1.0 mg mL-¹ MT were compared to the negative control (distilled water) and positive control (MMS solution at 10 mg L-¹). The presence of chromosomal aberrations, micronuclei frequency, and mitotic index abnormalities was evaluated. Anaphase bridges were the alterations with higher incidence and presented a significantly elevated rate in the concentration of 0.5 mg mL-¹, including when compared to the positive control. The integrative discriminant analysis summarizes that MT in assessed concentrations presented effects like the positive control, corroborating its potential of toxicity to DNA. Therefore, it is concluded that MT in its pure composition and in realistic concentrations used, has genotoxic potential in the biological assessment of A. cepa cells. The multivariate integrative analysis was fundamental to show a whole response of all data, providing a global view of the effect of MT on DNA.

Por muitos séculos, as populações humanas sofrem e tentam combater os mosquitos transmissores de doenças. Doenças emergentes e reemergentes como Dengue, Zika e Chikungunya afetam bilhões de pessoas em todo o mundo e, recentemente, vem apelando ao controle com pesticidas químicos. O Malation (MT) é um dos principais pesticidas usados contra mosquitos, vetores dessas doenças. O objetivo deste estudo foi avaliar a citotoxicidade e a mutagenicidade do MT para o bioindicador Allium cepa L. usando uma abordagem multivariada e integrativa. Além disso, uma tabela suplementar foi compilada com toda a literatura disponível de inseticidas avaliada pelo sistema Allium cepa para apoiar nossa discussão. Exposições ao MT durante 48h a 0,5 mg mL-¹ e 1,0 mg mL-¹ foram comparadas a um controle negativo (água destilada) e um controle positivo (10 mg L-¹ de MMS). Foram avaliadas a presença de aberrações cromossômicas, frequência de micronúcleos e anormalidades no índice mitótico. As pontes anafásicas foram as alterações com maior incidência e apresentaram uma taxa significativamente elevada na concentração de 0,5 mg mL-¹, inclusive quando comparadas ao controle positivo. A análise discriminante integrativa resume que o MT nas concentrações avaliadas apresentou efeitos semelhantes ao controle positivo, corroborando seu potencial de toxicidade para o DNA. Portanto, conclui-se que o MT, em sua composição pura e nas concentrações realistas utilizadas, possui potencial genotóxico na avaliação biológica de células de A. cepa. A análise integrativa multivariada foi fundamental para mostrar uma resposta completa de todos os dados, fornecendo uma visão global do efeito da MT no DNA.

Prevenção e controle da febre amarela: avaliação de ações de vigilância em área indene no Brasil / Yellow fever prevention and control: assessment of surveillance activities in a previously unaffected area in Brazil / Prevención y control de la fiebre amarilla: evaluación de acciones de vigilancia en un área indemne de Brasil

A partir da reemergência da febre amarela em 2014/2015, o Brasil registrou nos anos sequentes sua maior epidemia de febre amarela das últimas décadas, atingindo principalmente a região sudeste. A febre amarela, doença viral hemorrágica, é causada por um flavivírus, transmitido por mosquitos silvestres (Haemagogus; Sabethes). Na ocorrência do ciclo urbano, erradicado no Brasil desde 1942, a transmissão se dá pelo Aedes aegypti. Primatas não humanos são os principais hospedeiros do vírus e constituem "sentinelas" na vigilância da febre amarela. Este artigo descreve as ações de controle e prevenção desencadeadas durante a epidemia de febre amarela no Estado do Espírito Santo, Brasil, e a implementação da vacinação por meio de um estudo ecológico com abordagem espacial. O estudo evidenciou a falha na detecção de epizootias em primatas não humanos pelos serviços de vigilância do Espírito Santo, sendo simultânea à detecção em humanos. Apresentou a evolução das ações de vacinação, com alcance de 85% de cobertura vacinal geral para o estado em seis meses, sendo heterogênea entre os municípios (de 59% a 122%). Destaca-se que 55% dos municípios com ações de imunização em tempo oportuno, considerando o intervalo adotado para este estudo, não apresentaram casos em humanos. A intensificação das ações de vigilância, interlocução entre as áreas e equipes multidisciplinares na condução da epidemia otimizou a detecção e o diagnóstico dos casos em humanos e viabilizou o controle da epidemia. Foi possível reconhecer avanços, apontar algumas medidas tardias e lacunas na vigilância que necessitam melhorias.

Following the reemergence of yellow fever in 2014/2015, Brazil recorded its largest yellow fever epidemic in recent decades, mainly affecting the country's Southeast region. Yellow fever is a hemorrhagic viral disease caused by a flavivirus transmitted by sylvatic mosquitos (Haemagogus; Sabethes). In the urban cycle, eradicated in Brazil since 1942, the virus is transmitted by Aedes aegypti. Nonhuman primates are the principal hosts of the virus and constitute "sentinels" in yellow fever surveillance. This article describes the control and prevention activities launched during the yellow fever epidemic in the State of Espírito Santo, Brazil, and the implementation of vaccination, through an ecological study with a spatial approach. The study revealed the lack of detection of epizootics in nonhuman primates by surveillance services in Espírito Santo, with simultaneous detection in humans. The study presented the evolution of vaccination activities, reaching 85% overall coverage for the state in six months, varying widely, from 59% to 122%, between municipalities (counties). Importantly, 55% of the municipalities with timely immunization, considering the interval adopted for this study, did not present human cases. The intensification of surveillance activities, communication between areas, and multidisciplinary teams in managing the epidemic optimized the detection and diagnosis of human cases and allowed control of the epidemic. The study identifies progress and points to some late measures and gaps in surveillance that require improvements.

A partir del resurgimiento de la fiebre amarilla en 2014/2015, Brasil registró los años siguientes su mayor epidemia de fiebre amarilla de las últimas décadas, alcanzando principalmente la región sudeste. La fiebre amarilla, enfermedad viral hemorrágica, es causada por un flavivirus, transmitido por mosquitos silvestres (Haemagogus; Sabethes). Respecto a la ocurrencia del ciclo urbano, erradicado en Brasil desde 1942, la transmisión se produce por el Aedes aegypti. Primates no humanos son los principales huéspedes del virus, y constituyen "centinelas" en la vigilancia de la fiebre amarilla. Este artículo describe las acciones de control y prevención desencadenadas durante la epidemia de fiebre amarilla en el Estado de Espírito Santo, Brasil, y la implementación de la vacunación mediante un estudio ecológico con abordaje espacial. El estudio evidenció el fallo en la detección de epizootias en primates no humanos por los servicios de vigilancia de Espírito Santo, siendo simultánea a la detección en humanos. Presentó la evolución de las acciones de vacunación, con alcance de un 85% de cobertura en la vacunación general para el estado en seis meses, siendo heterogénea entre los municipios (de 59% a 122%). Se destaca que un 55% de los municipios con acciones de inmunización en tiempo oportuno, considerando el intervalo adoptado para este estudio, no presentaron casos humanos. La intensificación de las acciones de vigilancia, interlocución entre las áreas y equipos multidisciplinarios en la gestión de la epidemia optimizó la detección y diagnóstico de los casos humanos y viabilizó el control de la epidemia. Fue posible reconocer avances, apuntar algunas medidas tardías y lagunas en la vigilancia que necesitan mejorías.

COVID-19 y su impacto en el control del mosquito Aedes (Stegomyia) aegypti y la vigilancia epidemiológica de infecciones por arbovirus / COVID-19 and its impact on the control of Aedes (Stegomyia) aegypti mosquito and the epidemiological surveillance of arbovirus infections

Resumen En países americanos, simultáneas a la pandemia de enfermedad por coronavirus 2019 (COVID-19) se están dando epidemias ocasionadas por diferentes arbovirus (del dengue, chikunguña y virus del Zika). En México, varias de las estrategias para control del mosquito Aedes aegypti, transmisor de arbovirus, involucran la interacción del personal salubrista y los moradores. Debido a la pandemia de COVID-19 se han implementado medidas de distanciamiento social y resguardo domiciliario. Para respetar estas medidas y evitar riesgo de contagio por coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2), el Centro Nacional de Programas Preventivos y Control de Enfermedades (CENAPRECE) ha presentado la estrategia de control de vectores en el escenario de transmisión simultánea por dengue y COVID-19 en México. En este trabajo mencionamos las medidas habituales de manejo integral de mosquito y mencionamos las adaptaciones realizadas. De igual forma, discutimos la relevancia de la capacitación y la supervisión al personal médico, esto debido a la similitud entre la sintomatología entre ambas patologías.

Abstract Countries of Latin America are dealing with a simultaneous COVID-19 and vector borne disease (VBDs, Dengue, Zika and Chikungunya) outbreaks. In Mexico, certain activities to control Aedes aegypti mosquito (the main VBDs vector) comprise community participation through the interaction between householders and vector control personnel. Preventive measures against COVID-19 include social distancing and stay-at-home strategy, to obey these policies, and reduce the risk of infection, the National Center for Preventive Programs and Disease Control of Mexico (CENAPRECE) has adapted the vector control approaches in the country. In this paper we mention routine prevention and control activities to control mosquitoes and show the adapted measures. Because, a number of symptoms of the COVID-19 and dengue fever overlap with each other, we also discuss the relevance of accurate disease surveillance and medic’s training and supervision.

O uso de uma plataforma virtual para mobilização social no enfrentamento de arboviroses e controle do Aedes aegypti / The use of a virtual platform for social mobilization in the confrontation of arboviruses and control of Aedes aegypti / El uso de una plataforma virtual para la movilización social para combatir los arbovirus y el control de Aedes aegypti

A mobilização social para o enfrentamento da dengue, zika, chikungunya e controle do Aedes aegypti tem sido um desafio no país. Esse artigo apresenta o processo de elaboração de uma plataforma virtual, incluindo a composição do seu acervo e a análise exploratória do seu uso, como ferramenta, numa proposta de mobilização social que envolve a criação de comitês populares nos territórios para o enfrentamento das três doenças e vetor. A construção da plataforma considerou: facilidade para usuário; acesso; armazenamento de material; interatividade e banco para monitoramento de dados. A seleção do acervo baseou-se em critérios: técnico, referente à fonte e autoria; acurácia, concordância entre informação e evidência em saúde; e legibilidade, garantindo a compreensão por diferentes grupos. A análise exploratória utilizou o banco de dados da plataforma. Os resultados apontaram a plataforma como uma ferramenta que pode contribuir com a comunicação e informação em saúde nessa proposta de mobilização social.

Social mobilization for dengue, zika and chikungunya prevention and control of Aedes aegypti has been a challenge in the country. This paper presents the process of elaboration of a virtual platform, including the composition of its collection and the exploratory analysis of its use, as a tool in a social mobilization proposal that encompasses the creation of popular committees in the territories for the confrontation of the three diseases and vector. The construction of the platform considered: ease of use; access; material storage; interactivity and database for data monitoring. The selection of the collection was based on the following criteria: technical, considering source and authorship; accuracy, regarding the agreement between health information and evidence; legibility, ensuring the understanding by different groups. The exploratory analysis used the platform database. The results showed the platform as a tool which can contribute to health communication and information in this proposal of social mobilization.

La movilización social para combatir el dengue, zika, chikungunya y control de Aedes ha sido un desafío. Este artículo presenta el proceso de elaboración de una plataforma virtual, que incluye la composición de su acervo y el análisis exploratorio de su uso, como herramienta en una propuesta de movilización social que implica la creación de comités populares en los territorios para enfrentar las enfermedades y el vector. La construcción de la plataforma consideró: facilidad para usuario; acceso; almacenamiento de material; interactividad y bases de datos para el monitoreo. La selección del acervo se basó en criterios: técnico, con fuente y autoría; precisión, concordancia entre información y evidencia en salud; legibilidad, para garantizar la comprensión por diferentes grupos. El análisis utilizó datos de la plataforma. Los resultados mostraron que la plataforma puede ser una herramienta para contribuir a la comunicación e información de salud en esta propuesta de movilización social.

Incidência de dengue e indicadores socioeconômicos e entomológicos em Santos, São Paulo, 2012-2016 / Incidence of dengue and socioeconomic and entomological indicators in Santos, São Paulo State, 2012-2016 / Incidência de dengue e indicadores socioeconómicos y entomológicos en Santos, Estado De São Paulo, 2012-2016

Objetivo: descrever incidência de dengue em Santos/SP e relacionar coeficiente de incidência (CI) de dengue com indicadores socioeconômicos e entomológicos de 2012-2016. Método: estudo epidemiológico, descritivo, ecológico dos casos confirmados de dengue, residentes em Santos, de 2012-2016, do Sistema de Informação de Agravos de Notificação-Online; foram obtidos seis indicadores socioeconômicos da base de setores censitários do Instituto Brasileiro de Geografia e Estatística-2010; o sétimo do Índice Paulista de Vulnerabilidade Social-2010 e os indicadores entomológicos da Secretaria de Saúde; foi aplicada Correlação bivariada de Spearman (SPSS-Statistics®). Aprovado pelo Comitê de Ética em Pesquisa-CAAE nº79776017.1.0000.5479. Resultados: de 2012-2016 ocorreram 16.451 casos, com CI de 117,4 (2012) a 2.122,8 (2013) casos/100.000 habitantes, maior no sexo feminino e de 15-29 anos; os fatores socioeconômicos foram mais significativos entre 2015-2016; o Índice de Densidade de fêmeas Aedes aegypti apresentou maior correlação positiva. Conclusão: descreveu-se perfil epidemiológico/entomológico da dengue, apoiando gestores nas ações locais de controle.(AU)

Objectives: describe incidence of dengue in Santos/SP and relate dengue incidence coefficient (IC) with socioeconomic and entomological indicators from 2012-2016. Methods: epidemiological, descriptive, ecological study of confirmed cases of dengue, resident in Santos, from 2012-2016, of the Online-Notifiable Diseases Information System; six socioeconomic indicators were obtained from census sectors base of Brazilian Institute of Geography and Statistics-2010; the seventh from the São Paulo Index of Social Vulnerability-2010 and the entomological indicators from the Health Department; Spearman's Bivariate Correlation (SPSS-Statistics®) was applied. Approved by the Research Ethics Committee-CAAE nº79776017.1.0000.5479. Results: from 2012-2016 there were 16.451 cases, with IC from 117,4 (2012) to 2.122,8 (2013) cases/100.000 inhabitants, higher in females and between 15-29 years old; socioeconomic factors were more significant between 2015-2016; the Density Index of Aedes aegypti females showed a greater positive correlation. Conclusion: epidemiological/entomological profile of dengue was described, supporting managers in local control actions.(AU)

Objetivos: describir incidencia del dengue en Santos/SP y relacionar coeficiente de incidencia (CI) del dengue con indicadores socioeconómicos y entomológicos para 2012-2016. Métodos: estudio epidemiológico, descriptivo, ecológico de casos confirmados de dengue, residentes en Santos, desde 2012-2016, del Sistema de Información de Enfermedades de Notificación-Online; obtuvieron-se seis indicadores socioeconómicos desde base de sectores censales del Instituto Brasileño de Geografía y Estadística-2010, el séptimo del Índice de Vulnerabilidad Social de São Paulo-2010 y los indicadores entomológicos del Departamento de Salud. Aplicó-se Correlación Bivariada de Spearman (SPSS-Statistics®). Aprobado por el Comité de Ética en Investigación-CAAE nº79776017.1.0000.5479. Resultados: desde 2012-2016 hubo 16.451 casos, con CI de 117,4 (2012) a 2.122,8 (2013) casos/100.000 habitantes, mayor en mujeres y de 15-29 años; los factores socioeconómicos fueron más significativos entre 2015-2016; el Índice de Densidad de hembras Aedes aegypti mostró mayor correlación positiva. Conclusión: describió-se perfil epidemiológico/entomológico del dengue, apoyando a los gerentes en acciones de control local.(AU)