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Spatio-temporal distribution of Aedes aegypti (Diptera: Culicidae) mitochondrial lineages in cities with distinct dengue incidence rates suggests complex population dynamics of the dengue vector in Colombia.

Jaimes-Dueñez J, Arboleda S, Triana-Chávez O, Gómez-Palacio A - PLoS Negl Trop Dis (2015)

Bottom Line: The phylogeographic analyses indicated that one group (associated with West African populations) was found in all the cities throughout the sampling while the second group (associated with East African populations) was found in all the samples from Bello and in only one sampling from Riohacha.Environmental factors such as the use of chemical insecticides showed a significant correlation with decreasing genetic diversity, indicating that environmental factors affect the population structure of Ae. aegypti across time and space in these cities.Our results suggest that two Ae. aegypti lineages are present in Colombia; one that is widespread and related to a West African conspecific, and a second that may have been recently introduced and is related to an East African conspecific.

View Article: PubMed Central - PubMed

Affiliation: Grupo Biología y Control de Enfermedades Infecciosas-BCEI, Universidad de Antioquia UdeA, Medellín, Colombia.

ABSTRACT

Background: Aedes aegypti is the primary vector of the four serotypes of dengue virus (DENV1-4), Chikungunya and yellow fever virus to humans. Previous population genetic studies have revealed a particular genetic structure among the vector populations in the Americas that suggests differences in the ability to transmit DENV. In Colombia, despite its high epidemiologic importance, the genetic population structure and the phylogeographic depiction of Ae. aegypti, as well as its relationship with the epidemiologic landscapes in cities with heterogeneous incidence levels, remains unknown. We conducted a spatiotemporal analysis with the aim of determining the genetic structure and phylogeography of Colombian populations of Ae. aegypti among cities with different eco-epidemiologic characteristics with regard to DENV.

Methods/findings: Mitochondrial cytochrome oxidase C subunit 1 (COI)--NADH dehydrogenase subunit 4 (ND4) genes were sequenced and analyzed from 341 adult mosquitoes collected during 2012 and 2013 in the Colombian cities of Bello, Riohacha and Villavicencio, which exhibit low, medium and high levels of incidence of DENV, respectively. The results demonstrated a low genetic differentiation over time and a high genetic structure between the cities due to changes in the frequency of two highly supported genetic groups. The phylogeographic analyses indicated that one group (associated with West African populations) was found in all the cities throughout the sampling while the second group (associated with East African populations) was found in all the samples from Bello and in only one sampling from Riohacha. Environmental factors such as the use of chemical insecticides showed a significant correlation with decreasing genetic diversity, indicating that environmental factors affect the population structure of Ae. aegypti across time and space in these cities.

Conclusions: Our results suggest that two Ae. aegypti lineages are present in Colombia; one that is widespread and related to a West African conspecific, and a second that may have been recently introduced and is related to an East African conspecific. The first lineage can be found in cities showing a high incidence of dengue fever and the use of chemical insecticides, whereas the second is present in cities showing a low incidence of dengue fever where the use of chemical insecticides is not constant. This study helps to improve our knowledge of the population structure of Ae. aegypti involved in the diversity of dengue fever epidemiology in Colombia.

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IWD interpolation analysis of group 1 (A, B) and group 2 (C, D) of Ae. aegypti in neighborhoods of Cumbre (A, C) and Granjas (B, D) of Bello (BE) city.Green area indicates the classes of search for 0 individuals (absence), and orange areas for 1 or more individuals (presence) in each group. Black circles represent evaluated houses for Ae. aegypti.
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pntd.0003553.g006: IWD interpolation analysis of group 1 (A, B) and group 2 (C, D) of Ae. aegypti in neighborhoods of Cumbre (A, C) and Granjas (B, D) of Bello (BE) city.Green area indicates the classes of search for 0 individuals (absence), and orange areas for 1 or more individuals (presence) in each group. Black circles represent evaluated houses for Ae. aegypti.

Mentions: The spatiotemporal distribution of the frequency of each group across the studied cities was different among them (Fig. 5). Thus, whereas in BE both groups were present with similar frequencies during all samplings, with frequencies ranging from 45%–62% for group 1, and 38%–55% for group 2 (Fig. 5), in RI, group 2 was observed only in sampling A (frequency = 10%) (Fig. 5) and absent in all samplings in VI. Similarly, the distribution of each group in the positive houses indicates that whereas in BE the 66.6% of the positive houses presented both groups, 27.7% were only group 2 and 5.5% were only group 1; in RI, 10.3% of houses presented both groups and in the remaining 89.7% were only group 1; and in VI, 100% of the positive houses showed only group 1 (Fig. 5). Moreover, the interpolation analysis (IWD) performed in the geographic area of neighborhoods from BE indicates that approximately 32.6% of the Cumbre area (Fig. 6A) and 67.3% of Granjas (Fig. 6D) had at least one mosquito of group 1; whereas approximately 32.1% of Cumbre (Fig. 6B) and 80.4% of Granjas (Fig. 6E) had at least one mosquito belonging to group 2. Therefore, a wide potential distribution across the two neighborhoods from BE for both groups was observed, indicating sympatric distribution could be sustained across this city (Fig. 6).


Spatio-temporal distribution of Aedes aegypti (Diptera: Culicidae) mitochondrial lineages in cities with distinct dengue incidence rates suggests complex population dynamics of the dengue vector in Colombia.

Jaimes-Dueñez J, Arboleda S, Triana-Chávez O, Gómez-Palacio A - PLoS Negl Trop Dis (2015)

IWD interpolation analysis of group 1 (A, B) and group 2 (C, D) of Ae. aegypti in neighborhoods of Cumbre (A, C) and Granjas (B, D) of Bello (BE) city.Green area indicates the classes of search for 0 individuals (absence), and orange areas for 1 or more individuals (presence) in each group. Black circles represent evaluated houses for Ae. aegypti.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4403987&req=5

pntd.0003553.g006: IWD interpolation analysis of group 1 (A, B) and group 2 (C, D) of Ae. aegypti in neighborhoods of Cumbre (A, C) and Granjas (B, D) of Bello (BE) city.Green area indicates the classes of search for 0 individuals (absence), and orange areas for 1 or more individuals (presence) in each group. Black circles represent evaluated houses for Ae. aegypti.
Mentions: The spatiotemporal distribution of the frequency of each group across the studied cities was different among them (Fig. 5). Thus, whereas in BE both groups were present with similar frequencies during all samplings, with frequencies ranging from 45%–62% for group 1, and 38%–55% for group 2 (Fig. 5), in RI, group 2 was observed only in sampling A (frequency = 10%) (Fig. 5) and absent in all samplings in VI. Similarly, the distribution of each group in the positive houses indicates that whereas in BE the 66.6% of the positive houses presented both groups, 27.7% were only group 2 and 5.5% were only group 1; in RI, 10.3% of houses presented both groups and in the remaining 89.7% were only group 1; and in VI, 100% of the positive houses showed only group 1 (Fig. 5). Moreover, the interpolation analysis (IWD) performed in the geographic area of neighborhoods from BE indicates that approximately 32.6% of the Cumbre area (Fig. 6A) and 67.3% of Granjas (Fig. 6D) had at least one mosquito of group 1; whereas approximately 32.1% of Cumbre (Fig. 6B) and 80.4% of Granjas (Fig. 6E) had at least one mosquito belonging to group 2. Therefore, a wide potential distribution across the two neighborhoods from BE for both groups was observed, indicating sympatric distribution could be sustained across this city (Fig. 6).

Bottom Line: The phylogeographic analyses indicated that one group (associated with West African populations) was found in all the cities throughout the sampling while the second group (associated with East African populations) was found in all the samples from Bello and in only one sampling from Riohacha.Environmental factors such as the use of chemical insecticides showed a significant correlation with decreasing genetic diversity, indicating that environmental factors affect the population structure of Ae. aegypti across time and space in these cities.Our results suggest that two Ae. aegypti lineages are present in Colombia; one that is widespread and related to a West African conspecific, and a second that may have been recently introduced and is related to an East African conspecific.

View Article: PubMed Central - PubMed

Affiliation: Grupo Biología y Control de Enfermedades Infecciosas-BCEI, Universidad de Antioquia UdeA, Medellín, Colombia.

ABSTRACT

Background: Aedes aegypti is the primary vector of the four serotypes of dengue virus (DENV1-4), Chikungunya and yellow fever virus to humans. Previous population genetic studies have revealed a particular genetic structure among the vector populations in the Americas that suggests differences in the ability to transmit DENV. In Colombia, despite its high epidemiologic importance, the genetic population structure and the phylogeographic depiction of Ae. aegypti, as well as its relationship with the epidemiologic landscapes in cities with heterogeneous incidence levels, remains unknown. We conducted a spatiotemporal analysis with the aim of determining the genetic structure and phylogeography of Colombian populations of Ae. aegypti among cities with different eco-epidemiologic characteristics with regard to DENV.

Methods/findings: Mitochondrial cytochrome oxidase C subunit 1 (COI)--NADH dehydrogenase subunit 4 (ND4) genes were sequenced and analyzed from 341 adult mosquitoes collected during 2012 and 2013 in the Colombian cities of Bello, Riohacha and Villavicencio, which exhibit low, medium and high levels of incidence of DENV, respectively. The results demonstrated a low genetic differentiation over time and a high genetic structure between the cities due to changes in the frequency of two highly supported genetic groups. The phylogeographic analyses indicated that one group (associated with West African populations) was found in all the cities throughout the sampling while the second group (associated with East African populations) was found in all the samples from Bello and in only one sampling from Riohacha. Environmental factors such as the use of chemical insecticides showed a significant correlation with decreasing genetic diversity, indicating that environmental factors affect the population structure of Ae. aegypti across time and space in these cities.

Conclusions: Our results suggest that two Ae. aegypti lineages are present in Colombia; one that is widespread and related to a West African conspecific, and a second that may have been recently introduced and is related to an East African conspecific. The first lineage can be found in cities showing a high incidence of dengue fever and the use of chemical insecticides, whereas the second is present in cities showing a low incidence of dengue fever where the use of chemical insecticides is not constant. This study helps to improve our knowledge of the population structure of Ae. aegypti involved in the diversity of dengue fever epidemiology in Colombia.

Show MeSH
Related in: MedlinePlus