Predicting small mammal and flea abundance using landform and soil properties in a plague endemic area in Lushoto District, Tanzania - Tanzania Journal of Health Research Vol. 16 No. 3

Recently, the World Health Organization (WHO) has reported a concentrated outbreak of Bubonic Plague centred off the coast of Africa in Madagascar. While there are only 40 confirmed cases, WHO has stated that it has the potential of spreading rapidly, and that two cases have already been confirmed in the regions capital of Antananarivo. Since the population of Antananarivo is so dense, this creates a problematic situation for overall containment of the outbreak, creating higher than average risks of contraction and overall rapid spread of infection. 


Prior articles such as: "Predicting small mammal and flea abundance using landform and soil properties in a plague endemic area in Lushoto District, Tanzania" by Meliyo et al. have included studies related to the contraction of Bubonic Plague that may help gain more insight into the life cycle of this illness. More specifically, the purpose of this study was to investigate the correlations between landforms and associated soil properties, and small mammals and fleas in the West Usambara Mountains, Tanzania, to determine whether plague persistence in natural foci has a root cause in soils. 

The methods used in this study were of standard field surveys, paired with Geographical Information Systems (GIS) techniques, in order to examine landforms and soil characteristics. Soil samples were analyzed more closely in a laboratory for physico- chemical properties, and the small mammals were trapped on pre-established landform positions, for which they were identified at genus/species level. Fleas were then meticulously picked off the mammal and counted accordingly. 

It is important to note that the relation between landforms and soil data was done using ArcGIS Toolbox functions. Descriptive statistical analysis and the correlation between landforms, soils, small mammals, and fleas were gathered and established by the use a generalized linear regression model (GLM), operated in R statistics software. 

Results showed that landforms and soils influenced the abundance of small mammals and fleas and their overall spatial distribution and that the increase of overall population of small mammals and fleas increased with altitude and elevation. The landform-soil model shows that phosphorus found within the soil, slope and elevation were significant predictors in explaining abundance in small mammals. Fleas' abundance and spatial distribution were strongly linked and influenced by hill-shade, phosphorus, and base saturation. 

In summary, this study suggests that there is a strong correlation between landforms and soils, and small mammals and fleas' overall abundance and could help explain further the dynamics associated with bubonic plague in the region. 

For this journal and others from this issue, click here.

For more on the plague epidemic in Madagascar, click here.