Arboviruses in the East African Community partner states: a review of medically important mosquito-borne Arboviruses

Abstract

Mosquito-borne diseases, including arbovirus-related diseases, make up a large proportion of infectious disease cases worldwide, causing a serious global public health burden with over 700,000 deaths annually. Mosquito-borne arbovirus outbreaks can range from global to regional. In the East African Community (EAC) region, these viruses have caused a series of emerging and reemerging infectious disease outbreaks. Member states in the EAC share a lot in common including regional trade and transport, some of the factors highlighted to be the cause of mosquito-borne arbovirus disease outbreaks worldwide. In this review, characteristics of 24 mosquito-borne arboviruses indigenous to the EAC are reviewed, including lesser or poorly understood viruses, like Batai virus (BATV) and Ndumu virus (NDUV), which may escape their origins under perfect conditions to establish a foothold in new geographical locations. Factors that may influence the future spread of these viruses within the EAC are addressed. With the continued development observed in the EAC, strategies should be developed by the Community in improving mosquito and mosquito-borne arbovirus surveillance to prevent future outbreaks.

Pathogenesis and Immune Response of Ebinur Lake Virus: A Newly Identified Orthobunyavirus That Exhibited Strong Virulence in Mice

“…Mosquitoes are known to act as reservoirs of extensive pathogens ( Xia et al, 2018 ; Nyaruaba et al, 2019 ), several mosquito-borne viruses (arboviruses) causing human diseases remain the global public health concerns ( Tandina et al, 2018 ). However, with the constant evolution and crossing species barrier, the emergence of novel zoonotic pathogens is one of the greatest challenges to global health security ( Borland et al, 2020 ).…”

Present and Future Ecological Niche Modeling of Rift Valley fever in East Africa in Response to Climate Change

“…This is because the relationships between nature, human activities, and climate are As a result of the increased anthropogenic activities, livestock movement, urbanization, and predicted climate change, there is a real risk that these factors might jointly enable the spread of RVF in East Africa. East Africa continues to be an endemic region for RVF, and the ongoing trade partnerships (38) could lead to the introduction of the virus to new non-endemic regions, e.g., in Uganda and Burundi. Therefore, it is vital to assess its effect on RVF distribution and spread to successive suitable areas to help design timely mitigation measures and decrease the negative impacts of future climate change.…”

Tick-borne pathogens, including Crimean-Congo haemorrhagic fever virus, at livestock markets and slaughterhouses in western Kenya

“…With travel and trade thought to be major drivers of emerging pathogen spread (Kilpatrick, 2012), the movement of livestock and people among East African countries could enhance the circulation of emerging pathogens, especially given that high arboviral activity has been reported across the region (Mossel et al, 2017;Nyaruaba et al, 2019). Smallholder livestock production in East Africa is associated with livestock movement across provincial and national borders to livestock markets (LMs) in peri-urban areas (Fèvre et al, 2005) in which animals have been found to be heavily infested by ticks (Sang et al, 2006).…”

“…Outbreaks of CCHF (Dunster et al, 2002) and RVF (WHO, 2018) have been reported before in Western Kenya, and there is serological evidence of circulation of chikungunya, yellow fever, West Nile, and RVF viruses (Cook et al, 2017;Inziani et al, 2020;Mease et al, 2011;Nyaruaba et al, 2019). While reports on the occurrence of zoonotic vector-borne bacteria are scant, the high prevalence of malaria in Western Kenya results in under-investigation of other causes of febrile illnesses.…”

“…A broad spectrum of bacteria and protozoa of veterinary and public health importance have also been detected, including Theileria parva , Ehrlichia ruminantium , Ehrlichia chaffeensis ,Anaplasma marginale , Anaplasma phagocytophilum , andAnaplasma platys (Oundo et al, 2020;Ringo et al, 2018;Omondi et al, 2017;Mwamuye et al, 2017;Teshale et al, 2015).Hyalomma , Amblyomma , and Rhipicephalus ticks sampled from livestock in North-Eastern Kenya were previously shown to be infected with CCHF, Bunyamwera, Dugbe, Ndumu, Semliki forest, Thogoto, Ngari, Dhori, and West Nile viruses (Lwande et al, 2013;Sang et al, 2011Sang et al, , 2006. These viruses are endemic in East Africa (Nyaruaba et al, 2019) and some, such as Semliki Forest, Wesselsbron, Ngari, and Bunyamwera viruses, have only been isolated from mosquitoes (Ajamma et al, 2018;Villinger et al, 2017;Lwande et al, 2013). In most instances, ticks with arboviruses were collected from cattle at LMs and abattoirs, confirming the importance of these facilities for epidemiological investigations of these viruses.…”