As a 35-year veteran of multiple international humanitarian medical relief missions (in Cambodia in 1979, in Honduras in 1998 and in Haiti in 2010), I am accustomed to landing on the ground a few days after a catastrophe and daily treating 90 to 100 acute care patients. I’ve seen endless cases of physical trauma, pneumonia, diarrhea, skin infections, conjunctivitis and a host of tropical infections. So when I signed up with Project Hope to join its medical team in Puerto Rico a week after the devastation of Hurricane Maria, I expected a similar experience.

What I soon learned was that U.S. government agencies and American nongovernmental organizations completely misunderstood or failed to evaluate the medical conditions in Puerto Rico immediately after the hurricane.

Before the hurricane, Puerto Rico, a U.S. commonwealth of 3.4 million people, received relatively good medical services through private insurance and U.S. government-sponsored health care programs. Unfortunately, Puerto Ricans appear to be plagued, perhaps because of their diet, with chronic diseases such as diabetes, hypertension and heart disease, but they were being treated for such disorders.

So when my Project Hope team ventured out of San Juan into towns that suffered massive infrastructure destruction and personal property losses, the team of experienced medical personnel with decades of international experience treating acute diseases ended up distributing a limited number of medications for treatment of chronic diseases, medications not available because pharmacies and hospitals were closed. No wonder that the USNS Comfort, a naval vessel with roughly 800 medical and support personnel and 250 beds that docked in San Juan on Oct. 3 and sailed around the island, treated on average 12 patients a day. Or why 200 medical personnel, employees of the U.S. Public Health Service, spent the majority of their 10-day tour idle in the San Juan Convention Center, waiting for assignments.

Had Federal Emergency Management Agency experts better understood medical conditions in Puerto Rico, these resources could and should have been diverted to backing up the island’s 70 hospitals with generators, medicines and potable water and clearing roads so residents would have access to hospitals and clinics in the immediate aftermath. What Puerto Rico experienced after Hurricane Maria was not an acute medical crisis, but a public health catastrophe and the gross failure of U.S. government agencies to deliver to the victims of the hurricane life-saving essentials of food, clean water and shelter.

Twelve days after the hurricane, my Project Hope team traveled by car on passable roads to Toa Baja, a coastal town 45 minutes west of San Juan. Toa Baja, where entire neighborhoods were submerged by overflowing rivers and now littered with decaying garbage, human waste, animal carcasses and discarded household furniture covered with mildew, had not received any material aid from the central Puerto Rican government or FEMA in the first 10 days after the hurricane.

It wasn’t until the municipal government and Toa Baja residents organized their resources to provide food, clothing and shelter — and local medical personnel set up a temporary emergency room with medications later transported by Project Hope — that services started to reach the community.

How ironic that the acute diseases that I had expected to encounter when I first entered Puerto Rico are now appearing with serious health consequences: bacterial infections from tainted water, bronchitis and asthma from air pollution, polluted groundwater, numerous animal-borne diseases and skin diseases from lack of ability to bathe or wash clothes with uncontaminated water.

And Puerto Ricans continue to die from chronic diseases such as diabetes, kidney failure and hypertension because they still cannot readily access medications and medical care.

The U.S. government did not conduct itself admirably in Puerto Rico in the first month after Hurricane Maria. For a country that rebuilt Europe after World War II and is magnanimous in victory to our enemies in defeat, we now owe it to the U.S. citizens of Puerto Rico to rebuild their island with the same vigor and commitment that we offered to the citizens of Houston and Miami.

Larry Kaplan, M.D., is a resident of Cape Elizabeth.