- BACKGROUND INFORMATION
Transboundary animal diseases may be defined as those epidemic diseases which are highly contagious or transmissible and have the potential for very rapid spread irrespective of national borders, causing serious socio economic and possible health consequences (FAO, 2004). They constitute only a small minority of the infectious diseases that affect livestock but are dreaded for their suddenness, acuteness, and the wide spread nature of the losses they can produce (Chris et al.,1999).
There are two major types of transboundary animal diseases- the emerging diseases and the zoonoses (OIE, 2012). According to Morens and Fauci 2013, Emerging diseases can be classified into newly emerging diseases and reemerging diseases. Reemerging and newly emerging diseases can be defined respectively as those diseases that are able to expand their epidemiological spectrum appearing in new geographical area, affecting new susceptible species which is usually associated with the acquisition of new genes by an existing microbe; and referring to a completely unknown pathogen which is detected for the first time. Newly emerging infectious agents do not arise spontaneously they must recently have come from somewhere, usually from animal infections, as occurred with HIV infection, Ebola, influenza and Severe Acute Respiratory Syndrome (SARS) (Morens and Fauci 2013). Zoonoses on the other hand are diseases or infections which are naturally transmissible from animals to humans. According to the National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) 2013, approximately 75% of recently emerging infectious diseases affecting humans are diseases of animal origin and approximately 60% of all human pathogens are zoonotic.
Transboundary animal disease outbreaks can be attributed to increasing globalization due to better sea, land and air transport of people, animals and goods; normadism, transhumance and movement of refugees and their animals away from wars and civil disturbances. Outbreaks are also attributed to changes in livestock production systems due to intensification and commercialization of livestock farming leading to the spread of livestock farming into new ecosystems such as tropical rain forests placing human communities and their farm animals into close contact with a completely new range of infectious diseases which may have previously only circulated in wild life reservoirs and may be completely unknown. Global warming and the decline in government veterinary services and other infrastructures are also factors that contribute to the increased outbreaks of transboundary animal diseases (Chris et al 1999).
According to World Health Organization (WHO) 2014, the Ebola virus outbreak was first recorded in Zaire (The Democratic Republic of Congo of Central Africa) in the year 1976. Outbreaks of Ebola virus disease with the exception of the Reston Ebola virus have mainly been restricted to Africa and its recent outbreak is classified as the largest ever in nearly four decades of history of the disease in terms of numbers of cases and deaths. The virus is highly virulent and contagious often consuming the population but government and individuals’ quick response to quarantine areas may help to contain an outbreak (WHO, 2014).