West Nile Disease Epidemiology in North-West Africa: Bibliographical Review

Abstract

West Nile fever (WNF) or West Nile disease (WND) is a mosquito-borne viral disease that can affect birds, humans and horses. West Nile virus (WNV) is a member of the genus Flavivirus in the family Flaviviridae. WNV is maintained in a mosquito-bird-mosquito transmission cycle, whereas humans and horses are considered dead-end hosts. In human and horses, symptoms range from unapparent infection to mild febrile illness, meningitis, encephalitis or death. WNV has a wide geographical range that includes portions of Europe, Asia, Africa, Australia (Kunjin virus), and in North, Central and South America. Migratory birds are thought to be primarily responsible for virus dispersal, including reintroduction of WNV from endemic areas into regions that experience sporadic outbreaks (Fields Virology, 2001, Lippincott Williams and Wilkins, Philadelphia, Pennsylvania, USA, 1043-1125). The occurrence of disease in humans and animals along with birds and mosquitoes surveillance for WNV activity demonstrates that the virus range has dramatically expanded including North, Central and South America as well as Europe and countries facing the Mediterranean Basin. WND infection in humans has been reported in Morocco in 1996 (Virologie, 1, 1997, 248), in Tunisia in 2007 (Ann. N. Y. Acad., 951, 2001, 117) (Med. Trop., 61, 2001, 487) and 2003 (Epidémiologie de la fièvre West Nile, 2012, Thèse de doctorat, Université Montpellier II, Sciences et techniques du Langueduc, Montpellier, France), and in Algeria in 1994 (Rev. Sci. Tech., 31, 2012, 829). Outbreaks of equine encephalitis have been also reported in Morocco in 1996 (Bull. OIE, 11, 1996, 867), in 2003 (Emerg. Infect. Dis., 11, 2005, 306) and in 2010 (World Animal Health Information Database. WAHID, 2010). Serological evidence of WNV has been demonstrated in the three countries in many species. The aim of this review was to assess the epidemiological situation of WND in north-west Africa comprising Morocco, Algeria and Tunisia, with an updated literature review based on of human cases and equine outbreaks reports as well as serological studies in these countries.

Seroprevalence of West Nile virus in horses in different Moroccan regions

“…Since the infection by WNV was also described in humans in Morocco (Benjelloun et al . ) in the Gharb region and in the areas of Rabat, Kenitra and Meknes, a defined surveillance systems embracing different components and cooperative integration of both human and animal health should be considered by Veterinary and Public Health Authorities at national level.…”

“…Therefore, a permanent surveillance system on mosquito vectors, bird populations and horses should be implemented firstly in this area to better understand WND epidemiology. Since the infection by WNV was also described in humans in Morocco (Benjelloun et al 2016) in the Gharb region and in the areas of Rabat, Kenitra and Meknes, a defined surveillance systems embracing different components and cooperative integration of both human and animal health should be considered by Veterinary and Public Health Authorities at national level.…”

Standardization of sample homogenization for mosquito identification using an innovative proteomic tool based on protein profiling

“…Over the last decade, the regular emergence of arthropodborne disease outbreaks [35][36][37], which are spreading into temperate areas [38][39][40], necessitates an improvement in arthropod monitoring. The recent application of MALDI-TOF MS as an innovative tool for arthropod identification paved the way to an alternative low-cost, reliable, and high-throughput strategy for insect surveillance [10,30,41].…”

Systematic Review of Important Viral Diseases in Africa in Light of the ‘One Health’ Concept

“…Likewise, the high seroprevalence of HIV-1 in people of Cameroon who have been reported to be in frequent contact with non-human primates either through hunting activities for bushmeat or butchering reflected the zoonotic and pandemic potential of HIV-1 [158]. WNV is another deadly zoonotic virus disease, which has been reported to be transmitted by migratory birds into new regions [8]. The significance of the environment in the emergence and re-emergence of infectious zoonotic virus diseases can be understood from the RVF outbreaks within Africa.…”

“…The WNV is another deadly zoonotic virus, which is thought to be transmitted by migratory birds into new regions [8]. Mosquitoes of the genus Culex are reported as the main reservoir of the virus [36].…”