SOURCES: Adam Kucharski, Ph.D., lecturer in infectious disease epidemiology, London School of Hygiene and Tropical Medicine, United Kingdom; Amesh Adalja, M.D., senior associate, Center for Health Security, University of Pittsburgh Medical Center; Oct. 12, 2015, Proceedings of the National Academy of Sciences, online
MONDAY, Oct. 12, 2015 (HealthDay News) -- The world response to the Ebola epidemic in West Africa saved tens of thousands of lives in Sierra Leone, though a quicker response likely would've been even more effective, a new study reports.
The opening of new Ebola centers helped isolate sick people and prevented an estimated 57,000 new Ebola cases and 40,000 deaths in Sierra Leone, the new research says. But, the researchers also estimated that if the centers had been introduced just one month earlier, an additional 12,500 reported and unreported cases could have been prevented.
"Our results show that when responding to a rapidly growing outbreak, every day counts," said lead author Adam Kucharski, a lecturer in infectious disease epidemiology at the London School of Hygiene and Tropical Medicine in England.
By isolating patients and providing them with life-saving medical care, the thousands of new hospital beds created a "cascade effect" that kept Ebola from spreading further, said Dr. Amesh Adalja, a senior associate at the Center for Health Security at the University of Pittsburgh Medical Center.
These findings provide "clear on-the-ground evidence that providing a safe environment for Ebola patients to be cared for is enormously beneficial because, in these treatment units, infection control protocols are adhered to and personal protective equipment is provided to health care workers," Adalja said.
Findings from the new study were published online Oct. 12 in the Proceedings of the National Academy of Sciences.
The Ebola crisis may now be over. Last week, the World Health Organization (WHO) reported no known cases in West Africa. That's the region's first Ebola-free week since the epidemic began in March 2014, the WHO said.
The WHO says there have been 13,945 reported cases of Ebola in Sierra Leone to date. And, in 2014, the estimated death rate from infection was 70 percent, the WHO reported.
But many cases in Sierra Leone have potentially gone unreported. The actual figure is likely to be much higher, researchers said in background information.
To see what difference the global response made on the Ebola epidemic, Kucharski and his team decided to see how the introduction of thousands of new hospital beds might have helped prevent the spread of the deadly virus.
"We looked at the impact of beds as this was a measure that could be easily quantified," Kucharski said. "If a case was in a treatment center, it meant they were not in the community potentially spreading infection."
The researchers focused on Sierra Leone because that country maintained relatively good data on disease incidence and bed capacity in different districts over time, Kucharski said.
Between September 2014 and February 2015, more than 1,500 treatment beds were introduced in Ebola holding centers and community care centers in Sierra Leone, the researchers found. Another 1,200 beds were opened in Ebola treatment units.
Using mathematical models, researchers estimated the impact these additional beds had on the decline of the Ebola outbreak.
Based on both reported and presumed unreported cases, the researchers said nearly 57,000 Ebola cases were prevented up to February 2015 as a direct result of the introduction of treatment beds.
Thousands more cases of Ebola might have been prevented if the global community had responded more quickly and introduced the same number of beds one month earlier, the study concluded.
"The effect would have been greater had the beds been introduced even a few weeks earlier," Kucharski said.
He added that the beds are only one factor in a more complex response that brought Ebola to heel.
"Our results suggest it was a combination of factors that sent the outbreak into decline," he said. "The impact of additional beds coincided with a decline in community transmission, most likely resulting from factors such as safe burials and changes in behavior."
Kucharski said he could not apply these findings to the situation in the other two West African nations involved in the epidemic, Guinea or Liberia.
"Unlike in Sierra Leone and Liberia, the outbreak in Guinea did not rise and fall sharply," he said. "Instead it simmered along for several months, which suggests that control measures had a more gradual effect on the reduction in transmission."
Results like these show that if we heed the lessons of this epidemic, we will be better prepared for the next one, Adalja concluded.
"The cascading effects of rapidly establishing Ebola treatment units in outbreak settings will likely become formally incorporated into response plans for future Ebola and Marburg outbreaks, and have the potential to change the face of future outbreaks," Adalja said. "The new mathematical modeling study illustrates just how big the impact may have been in Sierra Leone."
For more on Ebola, visit the U.S. Centers for Disease Control and Prevention.