RESUMO
African horse sickness is a vector-borne, non-contagious and highly infectious disease of equines caused by African horse sickness viruses (AHSv) that mainly affect horses. The occurrence of the disease causes huge economic impacts because of its high fatality rate, trade ban and disease control costs. In the planning of vectors and vector-borne diseases like AHS, the application of Ecological niche models (ENM) used an enormous contribution in precisely delineating the suitable habitats of the vector. We developed an ENM to delineate the global suitability of AHSv based on retrospective outbreak data records from 2005 to 2019. The model was developed in an R software program using the Biomod2 package with an Ensemble modeling technique. Predictive environmental variables like mean diurnal range, mean precipitation of driest month(mm), precipitation seasonality (cv), mean annual maximum temperature (oc), mean annual minimum temperature (oc), mean precipitation of warmest quarter(mm), mean precipitation of coldest quarter (mm), mean annual precipitation (mm), solar radiation (kj /day), elevation/altitude (m), wind speed (m/s) were used to develop the model. From these variables, solar radiation, mean maximum temperature, average annual precipitation, altitude and precipitation seasonality contributed 36.83%, 17.1%, 14.34%, 7.61%, and 6.4%, respectively. The model depicted the sub-Sahara African continent as the most suitable area for the virus. Mainly Senegal, Burkina Faso, Niger, Nigeria, Ethiopia, Sudan, Somalia, South Africa, Zimbabwe, Madagascar and Malawi are African countries identified as highly suitable countries for the virus. Besides, OIE-listed disease-free countries like India, Australia, Brazil, Paraguay and Bolivia have been found suitable for the virus. This model can be used as an epidemiological tool in planning control and surveillance of diseases nationally or internationally.
Assuntos
Vírus da Doença Equina Africana , Doença Equina Africana , Ecossistema , Modelos Estatísticos , África/epidemiologia , Doença Equina Africana/epidemiologia , Doença Equina Africana/transmissão , Animais , Ceratopogonidae/virologia , Surtos de Doenças/veterinária , Cavalos , Índia/epidemiologia , Insetos Vetores/virologia , Software , África do Sul/epidemiologia , América do Sul/epidemiologia , Temperatura , Doenças Transmitidas por Vetores/epidemiologia , Doenças Transmitidas por Vetores/transmissão , Doenças Transmitidas por Vetores/veterináriaAssuntos
Vírus da Doença Equina Africana , Doença Equina Africana , Animais , Animais Domésticos , CãesRESUMO
The arthropod-borne virus (arbovirus) diseases of livestock have worldwide impact. The prevention of an introduction of an exotic disease and the control of one subsequent to an introduction will require the attention, cooperation, and support of the livestock industry, regulatory agencies, and researchers. The most effective protection of our livestock industries is to prevent the introduction of an exotic disease agent. This implies complete restriction of animal imports and exports. However, "zero risk" is an unacceptable option in today's world of internationally integrated and interdependent agriculture. Scientifically sound and factually based regulatory decisions must be combined with continued vigilance and preparedness, as well as appropriately directed surveillance and research, to protect the world agricultural marketplace. Two exotic arbovirus diseases that are of current concern to the livestock industries and regulatory officials of the North American and Caribbean Basin countries are VEE and AHS. Devastating epizootics of VEE in equines have occurred frequently in the Western Hemisphere, but no recent epizootic activity has been documented. Naturally occurring foci of sylvatic, equine nonpathogenic VEE virus subtypes, however, do exist in the tropical countries of the hemisphere. The relationship of these sylvatic virus foci to the origin of equine virulent epizootic VEE virus subtypes is unknown. AHS epizootics had been confined to Africa, the Middle East, and the Indian subcontinent until recent outbreaks in 1966 and 1987-1990 in Spain. With the recurrence of AHS in Spain for the past four years, concern about the possible introduction into potential vector species and equines in the Western Hemisphere has increased. This review addresses the current VEE and AHS virus activity and the potential for outbreaks in the Western Hemisphere.