The dynamical implications of disease interference: correlations and coexistence

Area of Science:

• Epidemiology
• Mathematical Biology
• Disease Ecology

Background:

• Ecological interference, where infection with one disease affects susceptibility to another, may significantly influence epidemic patterns.
• Understanding these interactions is crucial for predicting and managing infectious disease outbreaks.

Purpose of the Study:

• To investigate the dynamic consequences of ecological interference between two unrelated diseases using a mathematical model.
• To analyze how disease-induced mortality and seasonal variations affect the stability and dynamics of co-circulating diseases.

Main Methods:

• Analysis of a two-disease mathematical model.
• Examination of the stability domains of model equilibria.
• Study of bifurcation structures for periodic cycles under seasonal transmission variations.

Main Results:

• Increased interference strength, particularly disease-induced mortality, reduces the stable region for the co-endemic state.
• Seasonal transmission can lead to multiple coexisting attractors when mean transmission rates are similar.
• When transmission rates differ significantly, the dominant disease may dictate the system's overall dynamics.

Conclusions:

• Ecological interference plays a significant role in shaping the dynamics of interacting diseases.
• The impact of interference is contingent on specific epidemiological features, notably mean transmission rates.
• These findings highlight the complexity of multi-disease epidemics and the need for nuanced modeling approaches.