A Systematic Review of the Natural Virome of Anopheles Mosquitoes

Abstract

Anopheles mosquitoes are vectors of human malaria, but they also harbor viruses, collectively termed the virome. The Anopheles virome is relatively poorly studied, and the number and function of viruses are unknown. Only the o’nyong-nyong arbovirus (ONNV) is known to be consistently transmitted to vertebrates by Anopheles mosquitoes. A systematic literature review searched four databases: PubMed, Web of Science, Scopus, and Lissa. In addition, online and print resources were searched manually. The searches yielded 259 records. After screening for eligibility criteria, we found at least 51 viruses reported in Anopheles, including viruses with potential to cause febrile disease if transmitted to humans or other vertebrates. Studies to date have not provided evidence that Anopheles consistently transmit and maintain arboviruses other than ONNV. However, anthropophilic Anopheles vectors of malaria are constantly exposed to arboviruses in human bloodmeals. It is possible that in malaria-endemic zones, febrile symptoms may be commonly misdiagnosed. It is also possible that anophelines may be inherently less competent arbovirus vectors than culicines, but if true, the biological basis would warrant further study. This systematic review contributes a context to characterize the biology, knowledge gaps, and potential public health risk of Anopheles viruses.

Monthly Population Fluctuations and Abundance Index (SISA) of Mosquitoes (Diptera: Culicidae), as Potential Bridge Vectors of Pathogens to Humans and Animals in Mazandaran Province, Northern Iran

“…maculipennis that fed on wild rabbits by polymerase chain reaction (PCR) in Southern England, UK. Batai virus (BATV) and Anopheles associated C virus (AACV) was also identi ed and isolated from Anopheles maculipennis complex in entomological surveys in Germany, Italy and France [64]. With regards to the malaria historical records and WNV in the northern parts of Iran [52,65], understanding the population dynamics and the maximum monthly peaks of the species is important in controlling the diseases in the study area.…”

De novo profiling of RNA viruses inAnophelesmalaria vector mosquitoes from forest ecological zones in Senegal and Cambodia

“…By analogy, the maintenance of persistent ISVs as non-pathogenic may also result from a dialog with host immunity. Presumably, the same antiviral mechanisms used in basal maintenance of ISVs are also deployed against arboviruses when encountered, which are often in the same families as members of the insect virome [2]. Knowledge of the mechanisms that allow Anopheles to carry a natural RNA virome, but apparently reject arboviruses, may provide new tools to raise the barrier to arbovirus transmission by the more efficient Aedes and Culex vectors.…”

“…Anopheles mosquitoes are the only vectors of human malaria, which kills at least 400,000 persons and causes 200 million cases per year, with the greatest impact concentrated in sub-Saharan Africa and South-East Asia [1]. In addition to malaria, Anopheles mosquitoes also transmit the alphavirus O’nyong nyong (ONNV, family Togaviridae ), which is the only arbovirus known to employ Anopheles mosquitoes as the primary vector [2, 3].…”

“…Anopheles mosquitoes harbor a diverse natural virome of RNA viruses [4-7]. A recent survey found evidence of at least 51 viruses naturally associated with Anopheles [2]. The Anopheles virome is composed mainly of insect specific viruses (ISVs) that multiply only in insects, but also includes relatives of arboviruses that can replicate in both insects and vertebrate cells.…”

“…This apparent division of labor between culicine and Anopheles mosquitoes for transmission of arboviruses and Plasmodium, respectively, has led to a relative lack of study about Anopheles viruses. Anopheles viruses have been discovered by isolation from cultured cells exposed to mosquito extract, serology, specific amplification and sequencing, and more recently, deep sequencing and de novo assembly [2]. Although this work has increased the number of ISVs discovered in Anopheles, it appears that there are many still unknown.…”