For native areas, the systematized search yielded 422 occurrences for A. aegypti and 479 for A. albopictus. The records obtained for A. aegypti are found mainly in the central part of the African continent in the sub-Saharan region (Fig. 1a). In turn, A. albopictus in Asia are found in the Asian southeast in countries located around the Bay of Bengal including islands, like Indonesia, the Philippines, Malaysia, and Brunei (Fig. 1b). Occurrences obtained for Colombia register A. aegypti in 24 departments (482 occurrences) in altitudes between 0 and 2,916 m, while the records obtained for A. albopictus are distributed in nine departments (60 occurrences) found in altitudes between 0 and 2,035 m (Fig. 1c).
Table 1 lists the variables selected that were used in the ENM for A. aegypti and A. albopictus in Colombia. A. aegypti under current and future scenarios occurred throughout the Colombian mountain region (1,218–5,453 m). However, it had non-suitable areas in the archipelago of San Andrés y Providencia and in large zones of Putumayo, Caquetá, Nariño, Cauca, Valle, Chocó, Guainía, Vaupés, and Amazonía (Fig. 2a). Meanwhile, A. albopictus would be present to a lesser extent at altitudes between 2,916–5,453 m with non-suitable areas in large zones of La Guajira, Chocó and in southern Nariño (Fig. 2b). The potential areas for both mosquitos would remain constant principally in the central and western regions of the country, varying mostly in mountainous regions and in northern and eastern regions of the country (Fig. 2).
Table 1
Climatic variables selected for the ENM of A. aegypti and A. albopictus in Colombia
Variables | Species | |
A. aegypti | A. albopictus |
Seasonality of the temperature (%) | | X |
Annual precipitation (mm) | X | X |
Precipitation of the wettest month (mm) | X | X |
Precipitation of the driest month (mm) | X | X |
Precipitation of the wettest quarter (mm) | X | |
Mean Diurnal Range (°C) | X | X |
Mean annual temperature (°C) | X | X |
Mean temperature of the coldest quarter (°C) | X | |
Estimations under a current context suggest that A. aegypti (AUC = 0.85 and ROC partial p = 0.00) and A. albopictus (AUC = 0.94 and ROCpartial p = 0.00) are distributed in a vast extension of the country (Table 2). According to the estimations for the current model, A. aegypti could reach altitudes between 0 and 3,300 m with low distribution in the south of the country in the departments of Guainía, Vaupés, Amazonía, and the lower part of Caquetá. Likewise, few potential zones are estimated in the west in the departments of Chocó, Valle, Cauca, Nariño, and Putumayo while for the archipelago of San Andrés y Providencia no potential distribution is estimated (Fig. 3a). The distribution for A. albopictus suggests that it would be in lower altitudes than A. aegypti with maximum altitudes up to 3,000 m. In some departments, like La Guajira, Chocó, Valle, and Cauca its potential distribution is low and has suitable areas in San Andrés y Providencia (Fig. 3b). According with the potential distribution zones of both species, the total population at risk for the current context would be approximately 44 million people, with A. albopictus being the mosquito with greater area occupied (Table 2). Additionally, suitable areas shared between both species are found in large part of the country, except for La Guajira, in high zones and some areas in the western region (Chocó, Valle, and Cauca) (Fig. 3c).
Table 2
Extension and population at risk in areas of potential current and future distribution of A. aegypti and A. albopictus in Colombia
Period | Scenario | Area of potential distribution (Km2) | Area of absence (Km2) | Area occupied (%) | Population at risk | Total population at risk |
A | B | A | B | A | B | A | B |
Current | ‒ | 800,101.3 | 987,997.4 | 341,646.7 | 153,750.6 | 70.1 | 86.5 | 20,045,328.8 | 23,902,724.2 | 43,948,053 |
2041 ‒ 2060 | SSP245 | 711,118.1 | 971,618.6 | 430,629.9 | 170,129.4 | 62.3 | 85.1 | 22,089,795.6 | 26,640,769.6 | 48,730,565 |
SSP370 | 737,533.3 | 951,780.5 | 404,214.7 | 189,967.5 | 64.6 | 83.4 | 24,117,593.7 | 27,138,248.8 | 51,255,843 |
SSP585 | 780,113.7 | 945,865.4 | 361,634.3 | 195,882.6 | 68.3 | 82.8 | 25,398,631.2 | 28,634,137.3 | 54,032,768 |
2081 ‒ 2100 | SSP245 | 787,929.3 | 987,847.9 | 353,818.7 | 153,900.1 | 69.0 | 86.5 | 32,031,753.3 | 29,523,699.7 | 61,555,453 |
SSP370 | 724,806.2 | 819,469.6 | 416,941.8 | 322,278.4 | 63.5 | 71.8 | 31,067,977.4 | 29,441,270.5 | 60,509,248 |
SSP585 | 540,860.6 | 524,289.7 | 600,887.4 | 617,458.3 | 47.4 | 45.9 | 30,825,002.6 | 26,874,759.7 | 57,699,762 |
A: A. aegypti; B: A. albopictus |
Estimations under a future scenario estimate that the distribution of A. aegypti and A. albopictus, as well as the potential population at risk, diminishes considerably during the period 2081–2100 under scenarios SSP370 and SSP585 (Table 2). For the period 2041–2060, A. aegypti and A. albopictus, diminish their distribution under scenario SSP245 with respect to the current distribution (Table 2). Particularly, the distribution of A. aegypti diminishes in departments, like La Guajira, Córdoba, and Norte de Santander, nonetheless, its distribution increases in the southern part of Amazonía on the border with Brazil (Fig. 4a), as well as the distribution of A. albopictus increases in Cauca, Valle, and Chocó (Fig. 4b). In both species, the decrease in potential areas is evidenced in the northern part of the country, specifically in the departments of Magdalena, Atlántico, Bolívar, Cesar, Santander, Sucre, and Antioquia (Fig. 4c).
During the period 2081–2100, A. aegypti increases its distribution range in Tolima and Santander and even reaches altitudes between 2,916–5,453 m in departments, like Cundinamarca, Boyacá, and Nariño; however, its distribution diminishes in La Guajira and Córdoba (Fig. 5a). Furthermore, the presence of A. aegypti observed during the previous period in southern Amazonía disappears completely for this period (Fig. 5a). For A. albopictus, the distribution increases in Quindío, Meta, and Norte de Santander, but diminishes in Cesar, Santander, Antioquia, and Vichada (Fig. 5b). Likewise, A. albopictus increases its spread in altitudes between 2,035–2,916 m. The distribution of both mosquitos increases mostly in the western region (Nariño, Cauca, Valle, Putumayo, Huila, Risaralda, Caldas, Antioquia, and Cundinamarca) in some zones of the eastern region (Caquetá and Boyacá) and diminishes in the north of the country (Magdalena, Atlántico, Bolívar, Córdoba, and Sucre) (Fig. 5c).
For the period 2041–2060, under the SSP370 scenario, distribution of A. aegypti diminishes in Norte de Santander (Fig. 4d) while diminishing for A. albopictus in Vichada. In San Andrés y Providencia, the distribution does not change (Fig. 4e). In turn, and for both species, their distribution diminishes in the north of the country (Guajira, Magdalena, Atlántico, Bolívar, Sucre, Cesar, Córdoba, Santander, and Antioquia) (Fig. 4f). For the period 2081–2100, the distribution of A. aegypti diminishes in Norte de Santander and Guainía, nevertheless, it increases in Antioquia and Santander with suitable zones in the southern Amazonía on the border with Peru (Fig. 5d). In addition, A. albopictus diminishes its distribution in Santander, Caldas, Casanare, San Andrés y Providencia (Fig. 5e). For both mosquitos, a decrease is estimated in the northwestern region (La Guajira, Magdalena, Atlántico, Bolívar, Cesar, Sucre, Córdoba, Antioquia, and Chocó) and in the eastern region (Vichada, Arauca, Meta and Guaviare). However, it increases in the central and western zones of the country (Nariño, Putumayo, Valle, Cauca, Caquetá, Huila, Tolima, Quindío, Risaralda, Caldas, Cundinamarca, and Boyacá) (Fig. 5f). In this scenario, A. aegypti and A. albopictus have suitable zones in altitudes between 2,916 and 5,453 m.
For the period 2041–2060 under scenario SSP585, A. aegypti diminishes its potential area in the western region (Valle, Tolima, Quindío, Risaralda, Chocó, and Caldas) and has new suitable zones in the southern part of Amazonía (Fig. 4g). Likewise, A. albopictus diminishes in Vichada and Casanare (Fig. 4h). In both species, the distribution diminishes in the north of the country (La Guajira, Magdalena, Atlántico, Bolívar, Cesar, Santander, Sucre, Antioquia, and Córdoba), maintaining shared areas in the eastern, western, and southern regions (Amazonía) of the country (Fig. 4i).
In the period 2081–2100 and for A. aegypti, a decrease is estimated in Vichada and in southern Amazonía, but increases to its north, on the border with the department of Caquetá (Fig. 5h). In turn, A. albopictus would disappear completely from the archipelago of San Andrés y Providencia and in a large extension of Vaupés and Amazonía (Fig. 5h). The distribution for both species diminishes in the departments located in the north of the country (Guajira, Magdalena, Atlántico, Bolívar, Cesar, Sucre, Antioquia, Córdoba) and in the southeastern part (Caquetá, Arauca, Guainía, Casanare, Meta, and Guaviare). However, an increase of it is estimated toward higher zones in the northern and western parts (Nariño, Putumayo, Cauca, Huila, Risaralda, Caldas, Caquetá, Tolima, Quindío, Cundinamarca, Norte de Santander, Santander and Boyacá) (Fig. 5i).
Figure 6 Three-dimensional graphic including the variables selected implemented in the ENM and which shows the ecological niche overlap between A. aegypti (orange ellipsoid) and A. albopictus (blue ellipsoid) under the current conditions in Colombia. The grey points correspond to the environmental cloud. The axes are represented by three environmental variables selected by default in the software