N Increased risk of tick-borne diseases with climate and environmental changes

Bovines Harbor a Diverse Array of Vector-Borne Pathogens in Northeast Algeria

Arthropod-borne hemoparasites represent a serious health problem in livestock, causing significant production losses. Currently, the evidence of Anaplasma spp., Theileria spp., Babesia spp., and hemotropic Mycoplasma spp. in Algeria remains limited to a few scattered geographical regions. In this work, our objectives were to study the prevalence of these vector-borne pathogens and to search other agents not yet described in Algeria as well as the identification of statistical associations with various risk factors in cattle in the northeast of Algeria. Among the 205 cattle blood samples tested by PCR analysis, 42.4% positive results were obtained for at least one pathogen. The overall rates of Anaplasma spp., Theileria/Babesia spp., and Mycoplasma spp. in the cattle sampled were respectively 30.7%, 18.5%, and 2.9%; co-infections with multiple species was also detected. Anaplasma spp. and Theileria/Babesia spp. were detected at a higher rate in cattle under 3 years old, according to univariate analysis. Anaplasma spp. DNA was detected more frequently in our sample in cattle living in semi extensive farming. Our study provides additional data about Anaplasma spp., Theileria/Babesia spp. and reveals for the first time that Mycoplasma wenyonii and ‘Candidatus Mycoplasma hemobos are present in cattle in Northeast Algeria.

Climatic changes and their role in emergence and re-emergence of diseases

Global warming and the associated climate changes are predictable. They are enhanced by burning of fossil fuels and the emission of huge amounts of CO₂ gas which resulted in greenhouse effect. It is expected that the average global temperature will increase with 2-5 °C in the next decades. As a result, the earth will exhibit marked climatic changes characterized by extremer weather events in the coming decades, such as the increase in temperature, rainfall, summertime, droughts, more frequent and stronger tornadoes and hurricanes. Epidemiological disease cycle includes host, pathogen and in certain cases intermediate host/vector. A complex mixture of various environmental conditions (e.g. temperature and humidity) determines the suitable habitat/ecological niche for every vector host. The availability of suitable vectors is a precondition for the emergence of vector-borne pathogens. Climate changes and global warming will have catastrophic effects on human, animal and environmental ecosystems. Pathogens, especially neglected tropical disease agents, are expected to emerge and re-emerge in several countries including Europe and North America. The lives of millions of people especially in developing countries will be at risk in direct and indirect ways. In the present review, the role of climate changes in the spread of infectious agents and their vectors is discussed. Examples of the major emerging viral, bacterial and parasitic diseases are also summarized.