Although the economic impact of the cholera epidemic in Haiti would be very hard to put into numbers, it is likely that the epidemic had some amount of an impact. The cholera epidemic probably had essentially no beneficial impacts on the Haitian economy.
The cholera epidemic would not have had any real positive impact on the economy because the steps needed to fight the outbreak would not have included the use of locally-made products. If medicines and supplies for rehydrating victims were made in Haiti, there would be some positive impact, but they generally are not.
Instead, the impact will be almost all negative. First, there will be the loss of labor suffered due to the outbreak. Any adults who contract the disease will be unable to work for a period of time. Some adults will have to stop working to care for children or other loved ones. In both cases, their labor will be lost and economic output will drop. Second, there will be losses to local agriculture. Any agricultural exports that Haiti might have would probably be embargoed so as not to spread the disease. Even within Haiti, people would be likely to shun locally-grown food for fear that it would be contaminated. Third, any tourism would likely grind to a halt. People would not want to visit Haiti for fear of becoming ill. Finally, to the degree that Haiti and Haitians had to buy medicines (rather than having them donated), the epidemic would lead to a loss of money as the country paid to import medicine and other necessities.
In these ways, the cholera epidemic in Haiti surely harmed their economy.