n elderly man in Puerto Rico who contracted the Zika virus has died of the infection, according to the US Centers for Disease Control and Prevention.
The man in his 70s developed a severe case of a condition called thrombocytopenia — a blood clotting problem that can lead to internal bleeding.
This is the first Zika-related death reported among the more than 1,000 cases that have been diagnosed in the United States and US territories.
“It is a rare outcome,” said Tyler Sharp, acting head epidemiologist at the CDC’s dengue branch, which is based in the Puerto Rican capital of San Juan.
Most people who contract Zika have either no symptoms or quite mild illness. “But there are some manifestations of Zika virus infection that are associated with potentially fatal outcomes,” Sharp noted — including birth defects like microcephaly, neurological disorders like Guillain-Barré syndrome, and blood problems like those suffered by the man who died.
CDC officials reported the case Friday in the agency’s Morbidity and Mortality Weekly Review.
Sharp said the man had appeared to recover from his infection, but then developed a particular type of thrombocytopenia called immune thrombocytopenic purpura, or ITP, in which the man’s immune system attacked the platelets in his blood, leading to a clotting disorder.
Dutch researchers in February reported a very similar fatal case in a 54-year-old woman who was infected by Zika in Suriname.
In Colombia, health officials have also reported four deaths, three of which involved thrombocytopenia. But there aren’t enough details of those cases in the medical literature to know if they were the same kind of the condition suffered by the man in Puerto Rico, Sharp said. The deaths in Colombia crossed the age spectrum, involving a 2-year-old girl, a 30-year-old woman, a 61-year-old man, and a 72-year-old woman.
Sharp said the Zika virus continues to surprise researchers who are studying its impact.
“Certainly the association with the autoimmune condition Guillain-Barré syndrome was surprising. And now we appear to be seeing an association with another autoimmune condition, ITP, that is also a little bit surprising,” he said.
“So each day that goes by we continue to learn more about Zika and better understand it so we can best combat it and provide the appropriate medical interventions for infected individuals.’’
Puerto Rico, which is expected to be hard hit by the Zika virus, has diagnosed 707 cases of Zika infection so far. Of those, 89 are among pregnant women, according to the territory’s Department of Health.
So far, none of the women who contracted Zika during pregnancy have been diagnosed as carrying a fetus with microcephaly, according to Sharp.
A total of 19 people in Puerto Rico have been hospitalized with complications caused by Zika infection. There have also been five reported cases of Zika-related Guillain-Barré.
In the 50 states, 426 Zika cases have been diagnosed, 36 of them pregnant women. All the cases were people infected abroad or who were infected by having sex with someone who had returned to the United States infected with Zika.