We compute the linear power spectrum of cosmic string sedeed fluctuations
in the context of neutrinos with a strong self-interaction and show that it
is very similar to that obtained in the context of `normal' neutrinos. We
compare our results with observational data and show that for any value of the
cosmological parameters $h$ and $\Omega_0$ the interacting hot dark matter
power spectrum requires a large scale dependent biasing parameter.