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Vector-borne diseases continue to pose a major global health threat, affecting nearly 30% of the world’s population. Among them, mosquito-transmitted arboviruses such as dengue, Zika, and chikungunya have rapidly expanded in incidence and geographic range, driving recurring outbreaks across tropical and subtropical regions.
These viruses are primarily transmitted by Aedes aegypti (Ae. aegypti) and Aedes albopictus (Ae. albopictus) mosquitoes. As their range grows, so does the threat of arboviral epidemics, challenging current public health and vector control efforts.
In this blog, I explore the feeding behavior, infection dynamics, and transmission cycles of these key mosquito species.
Table of Contents
Aedes aegypti: Primary Vector of Arboviruses
Photo by CDC.gov | Picryl
Feeding Patterns of Aedes Aegypti Mosquitoes
Ae. aegypti, the primary vector of dengue, Zika, and chikungunya, is mainly a daytime biter with peak feeding activity around sunrise and before sunset. Although they are less active at night, artificial lighting in urban environments can significantly increase nocturnal biting, especially indoors where these mosquitoes often follow humans to feed.
Unlike many other mosquito species, Ae. aegypti shows a strong preference for human blood, making them highly efficient disease transmitters. A recent study by Kamau et al., published in Frontiers in Tropical Diseases, examined Ae. aegypti populations in two regions of Kenya, one dengue-endemic and one non-endemic.
The researchers found that when mosquito densities were low, surviving mosquitoes tended to live longer and bite humans more frequently, particularly during the dry season in coastal areas. In contrast, mosquitoes in rural regions were less abundant and fed less on humans.
The study also identified two populations of Ae. aegypti: one adapted to human habitats and another to wild environments. The human-adapted mosquitoes displayed higher human blood-feeding rates, increasing the risk of dengue outbreaks.
Vector Competence of Aedes aegypti Mosquitoes
The infection rates of Ae. aegypti mosquitoes vary widely depending on the circulating virus and local environmental conditions. A study by Kirstein et al., published in PLOS Neglected Tropical Diseases, analyzed 2,161 female Ae. aegypti collected from 200 households in Mérida, Mexico, using Prokopack aspirators.
Researchers found that 7.7% of mosquitoes were infected with at least one arbovirus, with chikungunya virus (CHIKV) being the most common (77.7%), followed by dengue virus (DENV, 11.4%) and Zika virus (ZIKV, 9.0%).
Interestingly, infections were highly localized, a small number of houses accounted for most infected mosquitoes, suggesting that transmission risk can vary dramatically within the same community. The study also noted that short indoor sampling periods were less effective at detecting infected mosquitoes, emphasizing the need for intensive surveillance to obtain accurate infection rate estimates.
In Colombia, research by Gómez et al., published in Frontiers in Ecology and Evolution, examined Aedes aegypti populations across several departments, including Amazonas, Boyacá, Magdalena, and Vichada.
All 558 mosquitoes collected were identified as Aedes aegypti, and many tested positive for dengue virus, particularly DENV-1 (1.7%) and DENV-2 (14.5%). The authors concluded that arboviral infection patterns in Aedes aegypti closely reflect the epidemiological behavior of dengue in Colombia, reinforcing the importance of continuous vector surveillance to guide local public health responses.
Transmission Cycle of Aedes aegypti
A female mosquito becomes infected by biting a person carrying the virus. Once inside the mosquito, the virus replicates during an incubation period of 7–12 days before reaching the salivary glands, enabling transmission to a new human host during subsequent bites.
Transmission efficiency is highest at temperatures between 25°C and 30°C, with humidity and urban density further enhancing viral spread. Water storage practices are also critical, as mosquitoes lay eggs on the walls of containers holding water, supporting population growth.
Other transmission pathways include mechanical transmission, where a mosquito briefly carries the virus from an infected person to another before viral replication, and transovarial transmission, in which an infected female passes the virus to her offspring via eggs.
Combined, these factors make Ae. aegypti an exceptionally effective vector, particularly in densely populated urban areas, contributing to sustained arboviral outbreaks.
Aedes albopictus: The Asian Tiger Mosquito
Photo by Dror Feitelson | Wikimedia Commons
Aedes (Stegomyia) albopictus, commonly known as the Asian tiger mosquito, is a species originally native to Southeast Asia. First described by Skuse in 1894 in Calcutta, India, this mosquito was historically considered a regional concern, limited to parts of Asia and Africa.
However, since the early 2000s, Aedes albopictus has rapidly expanded its global range, establishing populations on every continent except Antarctica. Its spread has transformed it into a major public health threat, capable of transmitting arboviruses such as dengue, chikungunya, and Zika.
Feeding Patterns of Aedes albopictus
Ae. albopictus, also known as the Asian tiger mosquito, is primarily a daytime biter with peak activity in the early morning and late afternoon, depending on location and season.
This species is mostly exophilic and exophagic, meaning it prefers to rest and feed outdoors, though it can opportunistically seek hosts indoors, especially in urban environments.
Aedes albopictus is an opportunistic feeder, with a strong preference for mammals, including humans, rabbits, deer, and dogs, but it can also feed on birds and, less commonly, amphibians or reptiles.
In the study by Savage et al., published in the Journal of Medical Entomology, examined host-feeding patterns in Potosi, Missouri, during the summers of 1989–1990. The researchers found that 64% of blood meals came from mammals, 16.9% from birds, and none from turtles or snakes.
These feeding behaviors make Ae. albopictus an effective vector for multiple arboviruses, highlighting its role in transmitting diseases like dengue, chikungunya, and Zika in both urban and rural settings.
Vector Competence of Aedes albopictus
Studies show that Ae. albopictus is a highly competent vector for several arboviruses, including Ross River virus and dengue virus.
Fu et al., in a study published in PLOS Neglected Tropical Diseases, found that Ae. albopictus from Kuala Lumpur, Malaysia, exhibited higher viral loads in heads and saliva and a greater transmission rate of Ross River virus compared with Aedes aegypti.
In contrast, Ae. aegypti displayed stronger barriers to viral replication, including midgut escape and salivary gland infection, which reduced transmission efficiency.
Similarly, a study by Kobayashi et al., published in BMC Tropical Medicine and Health, examined Ae. albopictus colonies from Japan and an Ae. aegypti colony from Vietnam exposed to dengue virus through rabbit blood feeding.
The researchers found that Ae. albopictus was susceptible to all dengue virus serotypes, with particularly high compatibility for DENV-1, although its infection and dissemination rates were lower than those of Ae. aegypti.
These findings highlight the important role of Ae. albopictus as a global vector for arboviral diseases, emphasizing its public health significance in Asia and beyond.
Transmission Dynamics of Aedes albopictus
Ae. albopictus, commonly known as the Asian tiger mosquito, is a highly competent vector capable of transmitting multiple arboviruses, including dengue and chikungunya, through both horizontal transmission (between mosquitoes and humans) and vertical transmission (from female mosquitoes to their offspring).
Since its first detection in Texas in 1985, Ae. albopictus has rapidly expanded across North, Central, and South America, with surveillance programs mapping its growing geographic distribution.
This species is highly opportunistic, feeding on humans as well as a wide range of domestic and wild animals. DNA analyses of blood meals indicate that Ae. albopictus can adapt its feeding preferences based on local host availability, enhancing its vector potential and ability to sustain arbovirus transmission.
Studies in the United States and Brazil highlight its flexible feeding behavior and the role this adaptability plays in the spread of mosquito-borne diseases.
Conclusion
The global expansion of Aedes aegypti and Aedes albopictus mosquitoes underscores an urgent public health challenge. Their adaptability to urban and rural environments, diverse feeding habits, and proven competence in transmitting dengue, Zika, and chikungunya viruses make them powerful drivers of arboviral epidemics worldwide.
As climate change, globalization, and urbanization continue to favor their spread, coordinated surveillance, vector control, and community engagement become essential to prevent future outbreaks. Understanding the biology and behavior of these mosquito species is not only vital for scientific progress but also for protecting millions at risk across tropical and subtropical regions.
Call to Action
Protect Yourself and Your Community from Mosquito-Borne Diseases! Stay informed about dengue, Zika, and chikungunya outbreaks in your area, eliminate standing water around your home, use mosquito repellents, and support local vector control programs. Join the fight against arboviruses today. Your actions can save lives!
