Using mathematical and economic epidemiology tools for modelling HIV infection in serodiscordant couples.
Date
2015
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Abstract
We investigate the appropriate strategies that reduce the HIV transmission rate amongst the serodiscordant
married couples. In particular, we formulate two discrete sub-models, the formation of
married serodiscordant couples through marriage of single individuals and the formation of married
serodiscordant couples through infection of HIV concordant negative married couples. We incorporate
a constant treatment rate and solve these sub-models analytically. Our results showed that
the formation of married serodiscordant couples through marriage of single individuals sub-model
has no disease free equilibrium point because the serodiscordant couples are always present in the
population. We computed the invasion reproductive number and showed that the endemic equilibrium
point is stable when the invasion reproduction number is greater than one. In the formation
of serodiscordant couples through infection of HIV concordant negative married couples, our results
revealed that there exist a disease free equilibrium point and the endemic equilibrium point. We use
the fixed point theory to determine the existence of the endemic equilibrium. We showed that when
the basic reproduction number is less than unity, then it will be possible to control the HIV epidemic
in serodiscordant couples otherwise the infection will persist. Sensitivity analysis revealed that for
the disease to be controllable, intervention strategies must target to increase the treatment rate to
reduce the HIV transmission rate. We then formulated the main model combining the dynamics of
the two sub-models and incorporate treatment rate as the price-dependent demand function. We
use the main model to explore the effects of treatment under eight different intervention strategic
scenarios. Our results showed that out of the eight strategies only six were capable of reducing the
HIV transmission rate amongst the serodiscordant married couples. The most effective intervention
strategy was to treat directly the serodiscordant married couples. This strategy is expected to be
cost efficient and could be implemented in poor resource setting.
Description
Master of Science in Mathematics.
Keywords
HIV infections -- Mathematical models., HIV infections -- Epidemiology., HIV-positive persons -- Transmission., Theses -- Mathematics., Serodiscordant couples.