Factors enhancing the transmission of mosquito-borne arboviruses in Africa

Abstract

Arthropod-borne viruses (Arboviruses) replicate in vertebrates and invertebrates and are mainly transmitted by mosquitoes. Between 2000 and 2021, several arbovirus outbreaks were recorded in African countries, including dengue, yellow fever, Chikungunya, Zika, and O’nyong nyong. Most often, the causes and factors involved in these outbreaks are unknown. We aimed to understand current knowledge regarding factors responsible for the persistent transmission and emergence of mosquito-borne arboviruses in Africa and to identify critical research gaps important for preventing future outbreaks. We used a systematic literature review between 2020 and 2021, to show that the main identified factors favoring the arbovirus outbreak in Africa are low vaccination coverage, high density and diversity of competent mosquitoes, insecticide resistance of mosquito vectors, and a scarcity of data on arboviruses. Further studies on arboviruses may include studies of competence to viral strains and the susceptibility of mosquito vectors to insecticides. Because of the detrimental effects of insecticides on human health and the environment, viral paratransgenesis and other biological control methods should be explored as alternatives or as supplements to insecticides. Graphical abstract Illustration of factors identified for promoting the transmission of arbovirus in Africa. The main factors are the lack of drugs and vaccines, low coverage of vaccination when a vaccine exists, competence of mosquitoes to viruses, diversity and high density of vectors. Climate change, urbanization, deforestation and agricultural practices, lead to a richness and high density of vectors.

Determination of mosquito diversity using 3D digital microscope in Cibinong district, Bogor Regency

“…Furthermore, deforestation can alter the availability and quality of larval habitats for different mosquito species, as well as the distribution and abundance of their hosts and predators. A study in Brazil found that deforestation increased the abundance of Anopheles darlingi, a major malaria vector, by creating more suitable breeding sites [32]. Lastly, spatial and temporal patterns of mosquito population dynamics, which are influenced by various environmental and biological factors.…”

Heat shock proteins, thermotolerance, and insecticide resistance in mosquitoes

“…Much of the increase in these diseases has been attributed to habitat expansion due to climate change and widespread insecticide resistance ( 4 ). Insecticide resistance is arguably one of the most significant challenges for pest control professionals today and plagues the public health, agricultural, and urban pest control sectors ( 5 , 6 ).…”

Bridging Vectors of Dengue Fever: The Endless Cycle

“…Despite extensive attempts to help contain or eradicate their outbreaks, the majority of arboviral diseases continue to be more prevalent in Africa for a variety of reasons [4,5]. Arboviral illnesses are not exempt from concerns about public health.…”