Background
The survival of adult female Aedes mosquitoes is a critical component of their ability to transmit pathogens such as dengue viruses. One of the principal determinants of Aedes survival is temperature, which has been associated with seasonal changes in Aedes populations and limits their geographical distribution. The effects of temperature and other sources of mortality have been studied in the field, often via mark-release-recapture experiments, and under controlled conditions in the laboratory. Survival results differ and reconciling predictions between the two settings has been hindered by variable measurements from different experimental protocols, lack of precision in measuring survival of free-ranging mosquitoes, and uncertainty about the role of age-dependent mortality in the field.

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Modelling adult Aedes aegypti and Aedes albopictus survival at different temperatures in laboratory and field settings

Background

Despite doubts about methods used and the association between vector density and dengue transmission, routine sampling of mosquito vector populations is common in dengue-endemic countries worldwide This study examined the evidence from published studies for the existence of any quantitative relationship between vector indices and dengue cases

Methodology/Principal Findings

From a total of 1205 papers identified in database searches following Cochrane and PRISMA Group guidelines, 18 were included for review Eligibility criteria included 3-month study duration and dengue case confirmation by WHO case definition and/or serology
A range of designs were seen, particularly in spatial sampling and analyses, and all but 3 were classed as weak study designs Eleven of eighteen studies generated Stegomyia indices from combined larval and pupal data Adult vector data were reported in only three studies Of thirteen studies that investigated associations between vector indices and dengue cases, 4 reported positive correlations, 4 found no correlation and 5 reported ambiguous or inconclusive associations Six out of 7 studies that measured Breteau Indices reported dengue transmission at levels below the currently accepted threshold of 5

Conclusions/Significance

There was little evidence of quantifiable associations between vector indices and dengue transmission that could reliably be used for outbreak prediction This review highlighted the need for standardized sampling protocols that adequately consider dengue spatial heterogeneity Recommendations for more appropriately designed studies include: standardized study design to elucidate the relationship between vector abundance and dengue transmission; adult mosquito sampling should be routine; single values of Breteau or other indices are not reliable universal dengue transmission thresholds; better knowledge of vector ecology is required

/pdf/assessing-the-relationship-between-vector-indices-and-dengue-2d0e5vr0no.pdf

Assessing the Relationship between Vector Indices and Dengue Transmission: A Systematic Review of the Evidence

Background 
Dengue fever, a mosquito-borne viral disease, is now the fastest spreading tropical disease globally. Previous studies indicate that climate and human behavior interact to influence dengue virus and vector (Aedes aegypti) population dynamics; however, the relative effects of these variables depends on local ecology and social context. We investigated the roles of climate and socio-ecological factors on Ae. aegypti population dynamics in Machala, a city in southern coastal Ecuador where dengue is hyper-endemic.
Methods/Principal findings 
We studied two proximate urban localities where we monitored weekly Ae. aegypti oviposition activity (Nov. 2010-June 2011), conducted seasonal pupal surveys, and surveyed household to identify dengue risk factors. The results of this study provide evidence that Ae. aegypti population dynamics are influenced by social risk factors that vary by season and lagged climate variables that vary by locality. Best-fit models to predict the presence of Ae. aegypti pupae included parameters for household water storage practices, access to piped water, the number of households per property, condition of the house and patio, and knowledge and perceptions of dengue. Rainfall and minimum temperature were significant predictors of oviposition activity, although the effect of rainfall varied by locality due to differences in types of water storage containers.
Conclusions 
These results indicate the potential to reduce the burden of dengue in this region by conducting focused vector control interventions that target high-risk households and containers in each season and by developing predictive models using climate and non-climate information. These findings provide the region's public health sector with key information for conducting time and location-specific vector control campaigns, and highlight the importance of local socio-ecological studies to understand dengue dynamics. See Text S1 for an executive summary in Spanish.

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Dengue Vector Dynamics (Aedes aegypti) Influenced by Climate and Social Factors in Ecuador: Implications for Targeted Control

We use the Box-Jenkins approach to fit an autoregressive integrated moving average (ARIMA) model to dengue incidence in Rio de Janeiro, Brazil, from 1997 to 2004. We find that the number of dengue cases in a month can be estimated by the number of dengue cases occurring one, two, and twelve months prior. We use our fitted model to predict dengue incidence for the year 2005 when two alternative approaches are used: 12-steps ahead versus 1-step ahead. Our calculations show that the 1-step ahead approach for predicting dengue incidence provides significantly more accurate predictions (P value=0.002, Wilcoxon signed-ranks test) than the 12-steps ahead approach. We also explore the predictive power of alternative ARIMA models incorporating climate variables as external regressors. Our findings indicate that ARIMA models are useful tools for monitoring dengue incidence in Rio de Janeiro. Furthermore, these models can be applied to surveillance data for predicting trends in dengue incidence.

/pdf/time-series-analysis-of-dengue-incidence-in-rio-de-janeiro-3x21s9oi3t.pdf

Time series analysis of dengue incidence in Rio de Janeiro, Brazil.

Background
Rio de Janeiro, Brazil, experienced a severe dengue fever epidemic in 2008. This was the worst epidemic ever, characterized by a sharp increase in case-fatality rate, mainly among younger individuals. A combination of factors, such as climate, mosquito abundance, buildup of the susceptible population, or viral evolution, could explain the severity of this epidemic. The main objective of this study is to model the spatial patterns of dengue seroprevalence in three neighborhoods with different socioeconomic profiles in Rio de Janeiro. As blood sampling coincided with the peak of dengue transmission, we were also able to identify recent dengue infections and visually relate them to Aedes aegypti spatial distribution abundance. We analyzed individual and spatial factors associated with seroprevalence using Generalized Additive Model (GAM).

/pdf/spatial-evaluation-and-modeling-of-dengue-seroprevalence-and-4c1b04e1nc.pdf

Spatial Evaluation and Modeling of Dengue Seroprevalence and Vector Density in Rio de Janeiro, Brazil

Seasonal variation in container productivity and infestation levels by Aedes aegypti were evaluated in two areas with distinct levels of urbanization degrees in Rio de Janeiro, a slum and a suburban neighborhood. The four most productive containers can generate up to 90% of total pupae. Large and open-mouthed containers, such as water tanks and metal drums, located outdoors were the most productive in both areas, with up to 47.49% of total Ae. aegypti pupae collected in the shaded sites in the suburban area. Water-tanks were identified as key containers in both areas during both the dry and rainy seasons. Container productivity varied according to seasons and urbanization degree. However, the mean number of pupae per house was higher in the suburban area, but not varied between seasons within each area (P > 0.05). High infestation indexes were observed for both localities, with a house index of 20.5-21.14 in the suburban and of 9.56-11.22 in the urban area. This report gives potential support to a more focused and cost-effective Ae. aegypti control in Rio de Janeiro.

/pdf/variation-in-aedes-aegypti-diptera-culicidae-container-4z6fu3uu7k.pdf

Variation in Aedes aegypti(Diptera: Culicidae) container productivity in a slum and a suburban district of Rio de Janeiro during dry and wet seasons

1Secretaria Municipal de Saude do Rio de Janeiro, Rio de Janeiro, RJ, Brasil In this report, the efficiency of Adultrap under field conditions is compared to a CDC backpack aspirator and to MosquiTRAP. An urban dengue-endemic area of Rio de Janeiro was selected to evaluate the efficiency of mosquito traps in capturing Aedes aegypti females. Adultrap and aspirator captured similar numbers of Ae. aegypti females, with the former showing high specificity to gravid individuals (93.6%). A subsequent mark-release-recapture experiment was conducted to evaluate Adultrap and MosquiTRAP efficiency concomitantly. With a 6.34% recapture rate, MosquiTRAP captured a higher mean number of female Ae. aegypti per trap than Adultrap (χ 2 = 14.26; df = 1; p < 0,05). However, some MosquiTRAPs (28.12%) contained immature Ae. aegypti after 18 days of exposure in the field and could be pointed as an oviposition site for female mosquitoes. Both trapping methods, designed to collect gravid Ae. aegypti females, seem to be efficient, reliable and may aid routine Ae. aegypti surveillance.

/pdf/mosquito-traps-designed-to-capture-aedes-aegypti-diptera-2w87caetk3.pdf

Mosquito traps designed to capture Aedes aegypti (Diptera: Culicidae) females: preliminary comparison of Adultrap, MosquiTRAP and backpack aspirator efficiency in a dengue-endemic area of Brazil

5 ABSTRACT. This report presents a set of field experiments designed to assess different protocols for the use of ovitrap and MosquiTRAP, a promising new trap for dengue vector monitoring. Percentage of positive houses, calculated either by the use of 2 traps (outside + inside) or 1 trap (outside) per house, tended to increase with time of exposure, at similar rates. When the aim was either to obtain a qualitative index (Aedes aegypti-positive site) or to determine percentage of positive houses in a selected neighborhood, the use of 1 ovitrap per house with only 5 days of exposure at the peridomestic area was quite sensitive. Seven days of exposure was too long, as saturation is expected in some places. The number of eggs collected per site increased with the time of exposure in all sites. At the 3-day trap exposure, we were not able to discriminate neighborhoods in terms of egg productivity per house. At the 5-day trap exposure, a rank of 4 sites was achieved. There was no correlation between the number of adults caught in MosquiTRAPs and number of eggs collected in ovitraps, neither per neighborhood nor per house where both traps were simultaneously exposed for 7 days in the peridomestic area.

https://bioone.org/journals/journal-of-the-american-mosquito-control-association/volume-24/issue-3/5585.1/Comparison-of-Different-Uses-of-Adult-Traps-and-Ovitraps-for/10.2987/5585.1.pdf

Comparison of different uses of adult traps and ovitraps for assessing dengue vector infestation in endemic areas.

Summary


Objectives To evaluate: (1) the occurrence, maintenance, productivity, spatial distribution and premise condition index score of Adese aegypti-infested houses and key-premises in a suburban district (Tubiacanga) and a slum (Favela do Amorim) of Rio de Janeiro and (2) the role of these factors in adult Ae. aegypti female spatial distribution.



Methods and Results  A total of 2456 premises were inspected for immature and 1100 for adult collection. Key-premises corresponded to 16.08% and 17.86% of infested houses in Tubiacanga, and 13.5% and 11.1% in Favela do Amorim, during the dry and wet seasons, respectively. Key-premises held significantly more immature Ae. aegypti, pupae and larvae than infested houses in Favela do Amorim and Tubiacanga during the dry and wet seasons. In Favela do Amorim, key-premises had a significantly higher PCI score than infested but non-key houses.



Conclusion  The spatial distribution of key-premises and adult Ae. aegypti females was often congruent, indicating that key-premises influence the infestation pattern observed in the study areas.




Objectifs:  Evaluer (1) l’apparition, le maintient, la reproduction, la repartition spatiale et le score d’indice des conditions de premisse (PCI) des maisons infestees par Ae. Aegypti et des premisses principaux dans un district de banlieue (Tubiacanga) et un bidonville (Favela do Amorim) de Rio de Janeiro et (2) le role de ces facteurs dans la distribution spatiale des femelles adultes d’Ae. aegypti.



Methodes et resultats:  2456 premisses ont ete inspectees pour la collecte d’insectes immatures et 1100 premisses pour celle d’insectes adultes. Les premisses principales correspondaient a 16,08% et 17,86% des maisons infestees a Tubiacanga, et 13,5% et 11,1% dans la Favela do Amorim, durant les saisons seches et pluvieuses respectivement. Les premisses principales renfermaient significativement plus d’Ae. aegypti immatures, de larves et de pupes que les maisons infestees dans la Favela do Amorim et a Tubiacanga durant les saisons seches et pluvieuses. Dans la Favela do Amorim, les premisses principales avaient un score PCI beaucoup plus eleve que maisons infestees mais qui n’etaient pas des premisses principales.



Conclusion:  La distribution spatiale des premisses principales et des femelles adultes d’Ae. aegyptietait souvent harmonieuse, indiquant que les premisses principales influencent le profil d’infestation observe dans les regions etudiees.





Objetivos:  Evaluar (1) la ocurrencia, el mantenimiento, la productividad, la distribucion espacial, y la puntuacion en el indice de condicion de premisas (ICP) de casas infestadas con Ae. Aegypti en un distrito suburbano (Tubiacanga) y una barriada (Favela do Amorim) de Rio de Janeiro; y (2) el papel de estos factores en la distribucion espacial de hembras adultas de Ae. aegypti.



Metodos y Resultados: Se inspeccionaron  2,456 lugares para inmaduros y 1,100 para la coleccion de adultos. Las premisas clave correspondian a 16.08 y 17.86% de las casas infestadas en Tubiacanga, y 13.5 y 11.1% en la Favela do Amorim, durante las estaciones seca y lluviosa, respectivamente. Las premisas clave tenian significativamente mas Ae. Aegypti inmaduros, pupas y larvas que las casas infestadas en la Favela do Amorim y Tubiacanga durante las estaciones seca y lluviosa. En la Favela do Amorim, las premisas clave tenian un puntaje de ICP significativamente mayor que las casas infestadas, pero no que las no-claves.



Conclusion:  La distribucion especial de las premisas clave y las hembras adultas de Ae. aegypti era a menudo congruente, indicando que las premisas clave tienen influencia sobre el patron de infestacion observado en las areas de estudio.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3156.2008.02162.x

Occurrence, productivity and spatial distribution of key‐premises in two dengue‐endemic areas of Rio de Janeiro and their role in adult Aedes aegypti spatial infestation pattern

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1948-7134.2013.12027.x

Roberto C. Peres

Papers

Variation in Aedes aegypti(Diptera: Culicidae) container productivity in a slum and a suburban district of Rio de Janeiro during dry and wet seasons

Mosquito traps designed to capture Aedes aegypti (Diptera: Culicidae) females: preliminary comparison of Adultrap, MosquiTRAP and backpack aspirator efficiency in a dengue-endemic area of Brazil

Comparison of different uses of adult traps and ovitraps for assessing dengue vector infestation in endemic areas.

Occurrence, productivity and spatial distribution of key‐premises in two dengue‐endemic areas of Rio de Janeiro and their role in adult Aedes aegypti spatial infestation pattern

The use of the Premise Condition Index (PCI) to Provide Guidelines for Aedes aegypti Surveys