  We study the spreading of cooperative infections in an empirical temporal
network of contacts between people, including health care workers and patients,
in a hospital. The system exhibits a phase transition leading to one or several
endemic branches, depending on the connectivity pattern and the temporal
correlations. There are two endemic branches in the original setting and the
non-cooperative case. However, the cooperative interaction between infections
reinforces the upper branch, leading to a smaller epidemic threshold and a
higher probability for having a big outbreak. We show the microscopic
mechanisms leading to these differences, characterize three different risks,
and use the influenza features as an example for this dynamics.
