GENEVA — Deaths from Ebola in West Africa surpassed 1,900, more than in all previous outbreaks combined, as a lack of health workers and fear of the often-fatal illness keep infections hidden and fuel the spread of the disease.
Since the virus surfaced in Guinea in December, more than 3,500 people have been infected, World Health Organization Director-General Margaret Chan said Wednesday in Washington. In 24 earlier outbreaks, including the first recorded one in 1976, 1,590 people died, statistics from the Geneva-based agency show.
The number of cases may exceed 20,000 before the epidemic is controlled, the WHO said last week in announcing a plan to respond to the outbreak. Months of work are needed to bring the situation in Guinea, Sierra Leone and Liberia under control, Chan wrote in the New England Journal of Medicine last month.
The unexpected appearance of the virus in countries that hadn’t had it before, and which have weak health systems, contributed to the worsening of the epidemic, said Andrew Easton of the University of Warwick.
“Nobody would have predicted the appearance of this in West Africa,” Easton, a virologist, said by phone. “It was entirely unexpected in that regard, and there was no local experience, which inevitably means there’s a delay in the response.”
After aid groups criticized the WHO’s initial reaction, the agency accelerated its effort. The outbreak also has jump- started programs to develop drugs and vaccines against Ebola, which kills more than half of those infected. The virus has since spread to Nigeria and Senegal, and an unrelated outbreak is underway in the Democratic Republic of Congo.
More than 240 health workers have contracted Ebola, an unprecedented number, and more than 120 of them have died, the WHO said last week. Among the dead are prominent doctors in Sierra Leone and Liberia, robbing those countries of experienced medical personnel and thwarting outbreak control.
Ebola is passed to people through the blood and other secretions of wild animals such as chimpanzees, gorillas, bats and porcupines, according to the WHO.
Humans transmit the virus to each other through direct contact with blood and other body fluids. Early symptoms include a sudden onset of fever, intense weakness, muscle pain, headache and sore throat. That’s followed by vomiting, diarrhea, a rash, and sometimes, both internal and external bleeding.
Other, more common diseases kill far more people — malaria resulted in more than 600,000 deaths in 2012, 90 percent of those in Africa. Malaria is preventable and curable, while there’s no treatment yet for Ebola and as many as 90 percent of those with the virus die. The fatality rate in the current outbreak is about 54 percent.
In the absence of an effective treatment, patients are kept hydrated and given nutrition as the body’s immune system tries to fight off the infection.
Ebola in the past has been seen almost exclusively in central and eastern Africa. The virus was named for a river in what is now the Democratic Republic of Congo, where the first recorded outbreak occurred.