Natural vertical transmission of medical interest Flavivirus in Aedes aegypti and Aedes albopictus

Abstract

Aedes aegypti and Aedes albopictus are important vectors in the transmission of several arboviruses. Among medical important arthropod bourne viruses, the most important are the the Flavivirus genus (Flaviviridae family) such as dengue (DENV) virus, Zika virus (ZIKV), Yellow fever virus (YF) and encephalitis virus Saint Louis (SLEV) which are a very important topic in public health today.Since the 80's Brazil has been affected by several epidemics of dengue (1-4) and after May 2015 the Ministry of Health has reported indigenous cases of ZIKV increasing the impact of viruses transmitted by the Aedes aegypti in the healthcare system of Brazil.The main vector of these viruses is the mosquito Aedes aegypti, which is also a vector of yellow fever and a secondary vector is involved: Aedes albopictus. Once infected, the mosquito remains with the virus throughout their lives, spreading the disease through the bite. Another way of Aedes aegypti acquiring the virus is through vertical transmission, also called transovarian transmission, ie when the female infected with DENV transfers the virus to the offspring when performing posture, and the same are born already infected. Transovarian transmission in A. aegypti, can play a significant role in maintaining the dengue virus in nature, allowing the virus to survive drought or cold seasons, or even temporary absence of hosts, while it is transmitted vertically by several generations of the mosquito. There are foreign and native reports on the vertical transmission of DENV in populations of A. aegypti and A. albopictus. Vertical transmission can be identified in the larval stage of the mosquito, or even in eggs. The presence of virus in eggs, larvae or mosquitoes collected in the field can be detected six to eight weeks before the start of a possible epidemic cycle. Knowledge of viral presence in these life stages allows the enhancement of vector control. Thus, the aim of this study is to detect the presence of Flavivirus of medical importance in larvae of A. aegypti and A. albopictus through molecular analysis. PCR's will be performed in real time's pool on the 4th stage larvae after hatching in the insectary. Once detected viral presence in the larvae from the eggs collected, ie before its transmission capacity, is expected to improve vector surveillance and control strategies. (AU)