The novel's resolution begins in this chapter - winter has arrived and the cold weather and frost promises an end to the epidemic. While this is clearly good news to Mattie, it does not end her personal development which continues through the end of the novel. Life in the city continues to return to normal albeit at a greatly accelerated pace. As soon as the winter arrives, the farmers begin to return to the city and provide produce. Thus, foodstuffs become available and the markets open again. Social calls become possible and business begins to pick up.
The frost ends the epidemic because it kills the mosquitoes that transmit the disease. Medical science has not yet recognized that the disease is transmitted in this way, however, or else simple methods such as mosquito netting could have prevented such widespread transmission.