A boy squirms as he is vaccinated Friday in Constitucion, Chile. An 8.8-magnitude earthquake struck central Chile last Saturday, causing widespread damage and prompting concerns about disease outbreaks..

Concepcion, Chile ? Chile launched a hepatitis and tetanus vaccination campaign Friday and doctors warned of outbreaks of diarrhea and infection among thousands of people displaced by the earthquake and the tsunami that heavily damaged or destroyed 36 hospitals and made garbage dumps of coastal towns and cities.

With many pharmacies looted, people suffering from diabetes, hypertension and psychological illnesses are going without medicine.

Doctors report increasing cases of diarrhea among people drinking unclean water and worry that huge piles of garbage and tons of rotting fish and other debris along the coast have become nests of infection. A growing number of patients are getting injured as they wade through the mess.

“We are going to keep needing water, electric systems, a functioning sewage system. We need to clean up rotting fish in the streets. We need chemical toilets, and when it starts raining, people living in tents are going to get wet and sick. All this is going to cause infections,” said Talcahuano Mayor Gaston Saavedra, whose port city was heavily damaged by the Feb. 27 quake and tsunami.

Chile said more than a dozen of its own military and civilian field hospitals were operating Friday. Mobile hospitals from a half-dozen other countries also were opening or about to open — an unusual situation for a country that proudly sends rescue and relief teams to the world’s trouble spots.

But most of the foreign units weren’t treating anyone a week after the disaster. Chile insisted donor nations first figure out how to coordinate with Chile’s advanced, if wounded, public health system.

A Peruvian field hospital opened in Concepcion on Thursday with three operating rooms and 28 beds. But surgeons, trauma specialists and stood with their arms crossed Friday, waiting for patients to be sent by local health officials.

Luis Ojeda, a Spanish doctor working with Doctors Without Borders, said his team arrived Monday but was still waiting for Chile’s instructions on where to deploy.

Chile signed an operating agreement for a U.S. field hospital Friday, enabling 57 U.S. military personnel to work side by side with civilian Chilean doctors in coming days to support a population of 3,000 in the town of Angol. Two U.S. Air National Guard C-130 transport planes were en route to Chile to help deliver supplies.

Field hospitals being provided by Argentina, Brazil, Cuba, Peru, Spain and the U.S. are meant to relieve 36 heavily damaged or destroyed Chilean hospitals, including Santiago’s now-closed 522-bed Felix Bulnes Hospital. Brazil’s emergency field hospital was sent to western Santiago to pick up the slack.

Powerful aftershocks Friday forced the evacuation of an older wing of Concepcion’s five-story regional hospital.

The magnitude-6.6 aftershock sent terrified Chileans fleeing into the streets and forced doctors to evacuate the regional hospital.