As important as tsetse mapping is the
study of Trypanosomosis occurrence (prevalence) and its disease
expression (i.e. anaemia: the most important symptom of Trypanosomosis).
Nonetheless, there are very few known records of the systematic
mapping of trypanosome distribution and prevalence rates.
This is in part due to the fact that flies abundance was expected
to reflect disease risk. Thus, Trypanosomosis surveys were
often not carried out. Among those few studies, surveys in
south-west Zambia revealed that the extent of the Trypanosomosis
problem covered a wider area than expected from historical
fly distribution data alone. In some cases, herds were systematically
sampled to map parasite distribution and prevalence as well
as average anaemia in herds. When such data sets are available,
it is possible to use GIS analysis to map epidemiological
patterns and show their correlation with physical features
such as the drainage system.
In mapping trypanosome and anaemia distribution, it can
be argued that RS gives more accurate results for the disease
itself than for anaemia, since many causes other than Trypanosomosis
may result in anaemia.