Abstract:
We report on the effect of tsetse fly starvation on the maturation of an established
Trypanosoma brucei brucei midgut infection, i.e., the development of procyclic infection into the
infectious metacyclic parasites in the tsetse fly salivary glands. Glossina morsitans morsitans flies
were nutritionally stressed 10 d after the uptake of a T. b. brucei-infected bloodmeal by depriving
these flies from feeding for seven consecutive days, whereas the control fly group (nonstarved
group) continued to be fed three times a week. After this period, both fly groups were again fed
three times per week on uninfected rabbit. Thirty days after the infected bloodmeal, all surviving
flies were dissected and examined for the presence of an immature midgut and a mature salivary
gland trypanosome infections. Results showed a significantly increased proportion of flies with
salivary gland infection in the nutritionally stressed fly group suggesting an enhanced maturation
of the trypanosome infection. These data suggest that environmental factors that cause nutritional
stress in a tsetse population do not only make tsetse flies significantly more susceptible to establish
a midgut infection as was shown previously but also boost the maturation of these midgut
infections.