EFB is a mixed concoction of bacteria with a few specific dominant signature strains. The bacterial soup gives the off colour, and it out competes the larvae for food. The larvae die of starvation. Yes, it often appears as starving larvae which do wriggle and curl and climb as they are searching for every lick of food they can get. Further a hive that is malnourished or low on incoming resources (dearth) will be further stressed, by lack of food and competition by the infection, resulting in wider spread outbreak. As the infection spreads, the bees cannot keep up with cleaning and what ends up is dead drying larvae that starts to appear to the novice eye as chalk brood. It is not CB. The underlying cause is EFB. If a hive had successfully cleared itself of EFB but the pathogen is still present, then in the next dearth there can be a recurrence.
The primary fix for EFB is FEED high sugar and protein, LOTS. The bees can usually overcome it themselves. The first cycle of larvae/pupae that survive will be weak and short lived. The subsequent cycles will be stronger, longer lived, and the infection clears over time with good abundant nutrition and good weather. If nutrition and/or weather are not cooperative, or the infection is widespread over a threshold, then the hive will not recover it will crash. Be mindful of the state and scope of the infection, it may be necessary to prescribe antibiotics to get the hive above the recoverable threshold.
Hope that helps!