Hurricane Maria’s death toll in Puerto Rico topped 1,100, a new study says

Analysis of vital statistics records shows spike in deaths in September and October of 2017

RIVER CROSSING A woman uses a cable line to get food and supplies across a river in the mountains around Utuado, Puerto Rico, in October of 2017. The community’s bridge was destroyed by Hurricane Maria.

U.S. Air Force photo by Master Sgt. Joshua L. DeMotts, USDA

By Aimee Cunningham

August 2, 2018 at 2:46 pm

The question of how many died in the aftermath of Hurricane Maria has yet another answer.

Using vital statistics records from hard-hit Puerto Rico, researchers estimate that 1,139 more people died than expected from September 20, 2017 — the day the Category 5 hurricane made landfall — through that December.

Alexis Santos-Lozada of Penn State and Jeffrey Howard of the University of Texas at San Antonio tallied monthly death counts from January 2010 through December 2017 to determine the expected number of deaths and the variability in these numbers over time. Excess deaths spiked in September, the month the hurricane hit, and peaked in October 2017, with 564 more deaths than expected that month, the pair report online August 2 in JAMA. However, the vital statistics data don’t pinpoint individual causes of death.

The official death toll from the Puerto Rican government is 64, based on death certificates that document if a death was directly due to the hurricane. But this method doesn’t factor in deaths indirectly related to the storm, such as those from infectious-disease outbreaks or because of disruptions in electricity or medical care.

Out of range

Using vital statistics data, researchers counted deaths in Puerto Rico per month in 2017 (blue line) and compared them with the average historical range of deaths per month from 2010–2016 data (yellow line and shaded area). There was a spike in deaths in September, when Hurricane Maria hit the island, that grew in October, the analysis showed.

Comparing deaths in Puerto Rico: 2017 versus 2010–2016

Source: A.R. Santos-Lozada and J.T. Howard/JAMA 2018

Last May, another study in the New England Journal of Medicine based on surveys of 3,299 randomly selected households across the island estimated at least 4,645 deaths from the hurricane (SN Online: 5/29/18). Survey participants were asked about deaths, delays in medical care, and electricity, water and cell phone interruptions to capture deaths indirectly related to the disaster.

Getting a good estimate on deaths after natural disasters is crucial for guiding rescue and recovery efforts, Santos-Lozada and Howard say.

Of these methods, “using excess death counts from dependable vital statistics data is probably a more solid approach,” says James Shultz, director of the Center for Disaster & Extreme Event Preparedness at the University of Miami Miller School of Medicine. But he finds it interesting that the excess deaths in the new study are concentrated in September and October, while the previous survey-based research assumes excess deaths continued past this time.

“Hopefully, future calculations will extend the analysis into the first half of 2018, when many areas of Puerto Rico still lacked power and health care services were only partially restored,” Shultz says.