Over the weekend relief efforts ramped up in Puerto Rico, but the U.S. territory may be on the verge of an even larger health crisis.

"Puerto Rico has gone back in time 100 years," said Dr. Peter Hotez, Dean of the National School of Tropical Medicine at Baylor College of Medicine.

Puerto Rico has no power and more than half of the population doesn't have access to clean drinking water. The island was already dealing with high levels of poverty, now it's even worse. It's a toxic mix that has health officials in Houston and on the island very worried.

"Diarrheal diseases are almost certainly going to occur," said Hotez.

Hotez says that includes diseases like e coli, typhoid fever, salmonella or even worse.

"There is the possibility of cholera erupting on the island of Puerto Rico," said Hotez.

It's happened before on the island and this devastation on the ground raises the likelihood it may happen again. So Hotez says it's critical the U.S. response is swift and focused.

"It depends on the national response to this," said Hotez. "If you bring in the Army and the National Guard to start putting elements of infrastructure in place it can mitigate that likelihood."

Hotez says it's too early to consider using cholera vaccines, but he believes health officials in Puerto Rico should consider vaccinating for hepatitis A and typhoid fever now.

"Relief is absolutely critical," said Hotez. "It's not just diarrheal disease. It's additional medical intervention and additional interventions over all."

Hotez says the island needs additional support and supplies from the CDC, but most of the heavy lifting to prevent disease will fall on the shoulders of local health departments in Puerto Rico. The problem is many of those same health departments were destroyed too.