The Effects of Climate Change and Globalization on Mosquito Vectors: Evidence from Jeju Island, South Korea on the Potential for Asian Tiger Mosquito (Aedes albopictus) Influxes and Survival from Vietnam Rather Than Japan

Abstract

BackgroundClimate change affects the survival and transmission of arthropod vectors as well as the development rates of vector-borne pathogens. Increased international travel is also an important factor in the spread of vector-borne diseases (VBDs) such as dengue, West Nile, yellow fever, chikungunya, and malaria. Dengue is the most important vector-borne viral disease. An estimated 2.5 billion people are at risk of infection in the world and there are approximately 50 million dengue infections and an estimated 500,000 individuals are hospitalized with dengue haemorrhagic fever annually. The Asian tiger mosquito (Aedes albopictus) is one of the vectors of dengue virus, and populations already exist on Jeju Island, South Korea. Currently, colder winter temperatures kill off Asian tiger mosquito populations and there is no evidence of the mosquitos being vectors for the dengue virus in this location. However, dengue virus-bearing mosquito vectors can inflow to Jeju Island from endemic area such as Vietnam by increased international travel, and this mosquito vector's survival during colder winter months will likely occur due to the effects of climate change.Methods and ResultsIn this section, we show the geographical distribution of medically important mosquito vectors such as Ae. albopictus, a vector of both dengue and chikungunya viruses; Culex pipiens, a vector of West Nile virus; and Anopheles sinensis, a vector of Plasmodium vivax, within Jeju Island, South Korea. We found a significant association between the mean temperature, amount of precipitation, and density of mosquitoes. The phylogenetic analyses show that an Ae. albopictus, collected in southern area of Jeju Island, was identical to specimens found in Ho Chi Minh, Vietnam, and not Nagasaki, Japan.ConclusionOur results suggest that mosquito vectors or virus-bearing vectors can transmit from epidemic regions of Southeast Asia to Jeju Island and can survive during colder winter months. Therefore, Jeju Island is no longer safe from vector borne diseases (VBDs) due to the effects of globalization and climate change, and we should immediately monitor regional climate change to identify newly emerging VBDs.

Climate Change, Health and Mosquito-Borne Diseases: Trends and Implications to the Pacific Region

“…The development of mosquito larvae is furthermore promoted with increased surrounding temperature, allowing for faster maturation. Moreover, adult female mosquitos feed more often on blood and thus may transmit infectious agents with higher frequency [25]. Viral replication within the mosquitos is furthermore increased, leading to a reduced extrinsic incubation time with a rise in environmental temperature.…”

Increased risk of endemic mosquito-borne diseases in Canada due to climate change

“…These elevated temperatures shorten the extrinsic incubation period, so mosquitoes that have acquired infection become infectious sooner; for example, outbreaks of WNV infection appear to occur more frequently in Canada when seasonal temperatures are above average, as these conditions promote rapid build-up of virus in vector mosquitoes and favour extended host-seeking by potentially infected female mosquitoes (26). It has been reported that in Korea and Japan, the duration of the transmission season can be extended by several months when average summer temperatures increase by as little as 5°C (27). Changes in rainfall affect the availability of standing water, which is where mosquitoes lay their eggs and where immature mosquitoes live.…”

Augmentation du risque de maladies endémiques au Canada transmises par des moustiques en raison du changement climatique

“…Ces températures élevées réduisent la période d'incubation extrinsèque, de sorte que les moustiques qui ont contracté l'infection deviennent infectieux plus tôt; par exemple, les éclosions d'infection par le virus du Nil occidental semblent se produire plus fréquemment au Canada lorsque les températures saisonnières sont supérieures à la moyenne, car ces conditions favorisent l'acquisition rapide du virus chez les moustiques vecteurs et prolongent la recherche d'hôtes par les moustiques femelles potentiellement infectés (26). Il a été signalé qu'en Corée et au Japon, la durée de la saison de transmission peut être prolongée de plusieurs mois lorsque les températures moyennes estivales augmentent d'aussi peu que de 5°C (27). Des changements dans les précipitations augmentent la disponibilité d'eau stagnante, où les moustiques pondent leurs oeufs et où vivent les moustiques qui n'ont pas atteint la maturité.…”