Other skills are coming from Atrium Health, Boston Hospital's post-surgery program and Swedish Health Connect. Amazon is also making an "HIPAA eligible environment" available to Alexa developers on an invitation basis in the US, so you can expect other skills that transmit sensitive health data.
The company is well aware that people will be nervous about trusting their medical information to a voice assistant. In a statement to TechCrunch, Amazon noted that it securely stores data with access controls and encryption. On top of this, HIPAA rules also require identifying any protected data as well as controlling and reviewing access. It's ultimately the individual developers' responsibility to ensure they honor the law, but Amazon is making sure it holds up its end of the bargain.
This is a major step for voice assistants, but not unexpected from a company that has been pushing aggressively into healthcare as of late. It bought PillPack to help start an online pharmacy business, and its team-up with JP Morgan Chase aims to keep health care costs down for employees. Alexa is really just the next logical step -- Amazon could make itself indispensable to medical institutions wanting to simplify access to their services.