Seroepidemiological Studies of Arboviruses in Africa

Abstract

The literature on sero-epidemiological studies of flaviviral infections in the African continent is quite scarce. Much of the viral epidemiology studies have been focussing on diseases such as HIV/AIDS because of their sheer magnitude and impact on the lives of people in the various affected countries. Increasingly disease outbreaks caused by arboviruses such as the recent cases of chikungunya virus, dengue virus and yellow fever virus have prompted renewed interest in studying these viruses. International agencies from the US, several EU nations and China are starting to build collaborations to build capacity in many African countries together with established institutions to conduct these studies. The Tofo Advanced Study Week (TASW) was established to bring the best scientists from the world to the tiny seaside town of Praia do Tofo to rub shoulders with African virologists and discuss cutting-edge science and listen to the work of researchers in the field. In 2015 the 1st TASW focussed on Ebola virus. The collections of abstracts from participants at the 2nd TASW which focused on Dengue and Zika virus as well as presentations on other arboviruses are collated in this chapter.

Evidence of transovarial transmission of Chikungunya and Dengue viruses in field-caught mosquitoes in Kenya

“…Over 100 arboviruses are known to cause pathology in humans, creating a significant global health burden, yet the transmission, epidemiology, and incidence of arbovirus-related human disease remain poorly defined, particularly in sub-Saharan Africa. Kenya has had multiple arbovirus outbreaks in the past 2 decades including yellow fever [1,2], chikungunya [3], Rift Valley fever [4][5][6] and dengue fever [7], which have resulted in significant effects to local economies and community health [8][9][10][11][12][13]. Thus, the characterization of arboviral circulation in the rapidly changing Kenyan environments that support vector proliferation is essential to better inform human risk assessment and vector control practices.…”

Zika Virus in West Africa: A Seroepidemiological Study between 2007 and 2012

“…Serological data suggest that ZIKV transmission has occurred among humans, animals and mosquitoes throughout tropical Africa for more than 70 years; however, ZIKV epidemics were never reported, and fewer than 20 human infections were recorded [ 3 ] between its isolation and the first large epidemic, occurring in Micronesia in 2007 [ 4 ]. ZIKV gained new attention after its spread in the Pacific and then to the Americas [ 5 ], and in recent years serological studies were conducted in Africa, documenting the presence of ZIKV antibodies in humans [ 6 , 7 , 8 , 9 ]. Moreover, a ZIKV outbreak that occurred in Gabon in 2007 was retrospectively identified [ 10 ].…”

Serological Data Shows Low Levels of Chikungunya Exposure in Senegalese Nomadic Pastoralists

“…CHIKV was first isolated from a Tanzanian patient with dengue-like symptoms in the early 1950s [7], and has been confirmed on the continent in numerous African studies since the initial report [8,9,10]. Besides attempting to identify persons with active infection, seroepidemiological studies have also shed light on individual- and population-level exposure to CHIKV, with the added advantage of expanding the window of time of finding a “positive” through antibody detection [11,12]. In humans, IgG responses are known to occur to CHIKV E1 and E2 antigens, which are attractive for serological studies [12,13,14,15].…”