If you look at the research done on disease prevalent in Rich population vs prevalent diseases in the poor -- you will see a clear pattern.
For example: There are significantly more resources (Time, People and Money) focused on Rare Genetic Diseases such as Cystic Fibrosis (a rare genetic disease in Caucasians) Vs resources to find cure for malaria or better medications (in spite of the growing problem of resistance)
Although many of the disease that are more common in poorer people are always linked to socio-economic issues and are not just a disease in themselves. From intestinal parasites to malaria.
But not providing adequate resources to all such disease can turn out to be a disaster -- like that happened with US ignoring Tuberculosis as a significant health problem and then subsequent re-emergence of TB due hiv and MDR (drug resistant) forms of TB