Analysis of Soils and Landform Properties for Description of Plague Disease Ecology in West Usambara Mountains, Tanzania

PhD candidate, Boniface Hussein John Massawe, will present his Doctoral Scholarly Seminar in 333C Kottman Hall with a video link to 123 Williams Hall. His presentation is titled Analysis of Soils and Landform Properties for Description of Plague Disease Ecology in West Usambara Mountains, Tanzania.

Plague is a human disease which results from infection by Yersinia pestis bacterium. The disease has a case-fatality ratio of 30 to 100% if not treated, and its transmission to human beings is reported to occur largely from bites by rodent-associated fleas. During the period 1954 to 2009, WHO documented 93,116 human cases including 7,430 deaths in 38 countries in Africa, Asia and the Americas. Plague ecology is still mysterious. The disease is reported to be characterized by geographical foci from which it re-emerges after a number of quiescent years. Studies conducted have related the plague foci distribution with some landscape factors such as high altitudes in Madagascar and Tanzania, and soil properties in Asia, America and Africa. Implicit in the relations between patterns of living organisms and landforms are the influences of elevation and aspect on solar energy and water regimes, and also provision for habitats. Soil physical properties such as soil depth, soil texture, and soil bulk density have been found to have influence on ecology of burrowing animals by their determination of the burrows’ structure and stability, as well as the energy required to construct them. Occurrence of plague epizootics have been correlated with soils which have medium or high concentration of iron, cobalt, and titanium, and low concentrations of copper, nickel, and vanadium in Altay Mountains and Kyzyl Kum Desert (in Uzbekistan) and in the Caspian lowlands. The distribution of plague foci in China is correlated with calcium and iron enriched soil environments. This study analyses landform features and soil properties in relation to distribution and abundance of potential plague reservoirs and vectors in Western Usambara, Tanzania, so as to contribute to the knowledge that link landscape features with plague foci worldwide and generate part of information needed to control the outbreaks in this plague focus.