الفهرس 
The plan of the present workOnly 14 pages are availabe for public view
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Abstract
Aedes aegypti and Ae. albopictus are the primary vectors that transmit several arboviral diseases, including dengue, chikungunya, and Zika. The world is presently experiencing a series of outbreaks of these diseases, so, we still require to better understand the current distributions and possible future shifts of their vectors for successful surveillance and control programs. Few studies assessed the influences of climate change on the spatial distributional patterns and abundance of these important vectors, particularly using the most recent climatic scenarios. Here, we updated the current potential distributions of both vectors and assessed their distributional changes under future climate conditions. We used an ecological niche modeling approach to estimate the potential distributions of Ae. aegypti and Ae. albopictus under present-day and future climate conditions. This approach fits the ecological niche model from the occurrence records of each species and environmental variables. For each species, future projections were based on climatic data from 9 general circulation models (GCMs) for each representative concentration pathway (RCP) in each period, with a total of 72 combinations in four RCPs in 2050 and 2070. All ENMs were tested using the partial receiver operating characteristic (pROC) and a set of 2,048 and 2,003 additional independent records for Ae. aegypti and Ae. albopictus, respectively. Finally, we used the background similarity test to assess the similarity between the ENMs of Ae. aegypti and Ae. albopictus. The predicted potential distribution of Ae. aegypti and Ae. albopictus coincided with the current and historical known distributions of both species. Aedes aegypti showed a markedly broader distributional potential across tropical and subtropical regions than Ae. albopictus. Interestingly, Ae. albopictus was markedly broader in distributional potential across temperate Europe and the United States. All ecological niche models (ENMs) were statistically robust (P<0.001). ENMs successfully anticipated 98% (1,999/2,048) and 99% (1,985/ 2,003) of additional independent records for both Ae. aegypti and Ae. albopictus, respectively (P<0.001). ENMs based on future conditions showed similarity between the overall distributional patterns of future-day and present-day conditions; however, there was a northern range expansion in the continental USA to include parts of Southern Canada in the case of Ae. albopictus in both 2050 and 2070. Future models also anticipated further expansion of Ae. albopictus to the East to include most of Europe in both periods. Aedes aegypti was anticipated to expand to the South in East Australia in 2050 and 2070. The predictions showed differences in the distributional potential of both species between diverse RCPs in 2050 and 2070. Finally, the background similarity test comparing the ENMs of Ae. aegypti and Ae. albopictus was unable to reject the null hypothesis of niche similarity between both species (P>0.05). These updated maps provided details to better guide the surveillance and control programs of Ae. aegypti and Ae. albopictus. They have also significant public health importance as a baseline for predicting the emergence of arboviral diseases transmitted by both vectors in new areas across the world.
6.2. Predicting the Current and Future Global Potential Distribution of a Mosquito-Borne Dengue Virus
Dengue virus (DENV) is one of the most distributed arboviruses worldwide. The past few decades witnessed an elevated frequency of dengue epidemics and severity across the tropics and subtropics. Here, we revisited the current global potential distribution of DENV and assessed the potential effect of climate change on DENV distribution under climate change. The distributional potential of DENV coincided with its current known distribution. Our prediction anticipated new areas at risk of DENV occurrence across the world. The prediction coincided with recent reports of DENV cases and outbreaks including the recent outbreak in the Red Sea coast in Sudan and Egypt. DENV model was statistically significant and performed better than random expectation (P<0.001). Our model successfully predicted 99.9 % (6606/6610) of additional recent records from January 1, 2013 to April 1, 2020 (P<0.001). The model of DENV in future showed similar distributional patterns of future-day and present-day conditions; however, it anticipate a range expansion in both 2050 and 2070. These updated maps provided a significant public health importance as a baseline for predicting the emergence of DENV in new areas across the world.
6.3. Validating the Predicted Habitat Suitability of Dengue Vectors Across the Red Sea Governorate, Egypt Through Vector Surveillance
Egypt suffered a recent DENV outbreak in two cites of Red Sea Governorate (RSG), Safaga and El-Quseir during 2017. Although, DENV vectors’ presence was not confirmed in Egypt since the historical eradication of Ae. aegypti in the forties of the twentieth century. According to our generated ENMs for both DENV and its vectors habitat suitability across the Red Sea Governorate was anticipated for both DENV and its vectors Ae. aegypti and Ae. albopictus. This habitat suitability coincided with a recent report of Ae. aegypti reemergence in RSG. Here we carried out a field survey in RSG in two seasons to validate the predicted habitat suitability and confirm the possible establishment of DENV vectors in the governorate. Aedes aegypti establishment was confirmed in RSG with samples collected from Hurgada city, the capital of RSG and the largest population density in late summer survey 2019. In the late autumn survey of the same year, Ae. aegypti was also identified in 4 cities across RSG including Safaga and El-Quseir the cities where the DENV outbreak occurred in 2017. Aedes aegypti is suggested to be introduced to RSG via the shared borders with Sudan or across the Red Sea from Saudi Arabia or Yemen. The water storage beside the climatic suitability was to a great extent responsible for reemergence and establishment of Ae. aegypti populations across the RSG. The House index of Ae. aegypti larvae (HI) for Hurgada city increased from summer to autumn (7.5% in late summer to 23% in late autumn) this increment may relate to the high summer temperatures which increase the rate of development leading to decrease of immatures and increase in adult density. These results may reveal DENV occurrence during early autumn. The majority of the positive containers were found indoor and uncovered. Between RSG cities; El-Quseir was the highest city at risk (HI =26%, CI=14.5, and BI=38) followed by Safaga (HI =24%, CI=13.18, and BI=34), then Hurgada (HI =23%, CI=12.12, and BI=31.5) and the least risk was that of Ras Garib (HI =12%, CI=7.14, and BI=18). These results revealed the risk decrement to the north of the governorate and logically explained the occurrence of the DENV outbreak in El-Quseir and Safaga. The container availability and coverage were found to be more responsible for breeding Ae. aegypti immatures rather than the type of container. The number of positive containers found indoors was high compared to that found outdoors. This result may be related to the behavioral tendency of Ae. aegypti to indoor conditions and also the slower developmental rate indoors which correlated to lower temperature indoors compared to outdoors thus delayed emergence of adult at indoors is supposed to occur. These results may help to understand the ecological behavior of Ae. aegypti across the RSG thus helps in constructing efficient control strategies. The construction of water appropriate infrastructure and improved hygiene through the establishment of piped water systems could help in the control of DENV vectors in the Red Sea Governorate preventing any outbreaks in the future. More routinely surveys are still required to reveal more information about the distribution of Ae. aegypti across the RSG.