Pharmaceutical companies are going to Third World countries to test drugs. Part of their protocol is to infect volunteers with a disease then test treatments on them. So far, there have been no complaints from those who have been experimented on, and companies have been careful to explain to potential subjects the risks and rewards. But this could change quickly. It takes only one unethical operator to create a PR crisis. That is why drug companies are stepping carefully to avoid charges of exploitation. There is good reason for them to be in these locales. It is where the diseases are and where populations have developed different immune responses based on proximity. But the temptation to pay subjects little and to expose them to greater risks is ever present. It is almost assured that someone will take an unethical action at some point then all pharmaceutical companies will be brought to the bar.