By Brenda Goodman, MA
WebMD Health News
Reviewed by Hansa D. Bhargava, MD
March 22, 2016 -- As the Zika virus spreads, "the world will face a severe public health crisis," the head of the World Health Organization warned Tuesday.
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"In less than a year, the status of Zika has changed from a mild medical curiosity to a disease with severe public health implications," WHO director-general Margaret Chan, MD, said in a press briefing. "The more we know, the worse things look."
Scientists are hard at work on a vaccine, which may enter clinical trials as early this year, but Chan said it would probably come too late to help.
"The first explosive wave of spread may be over before a vaccine is available," she said.
Development of a vaccine is "imperative," she said, since more than half of the world's population lives in areas with the mosquito that spreads Zika.
The virus is now being passed from mosquitos to people in 38 countries and territories, most of them in North and South America.
Because Zika is new to these areas, residents have no natural immunity to it, which makes it easy for the disease to spread and for people to get sick.
But in an estimated 1% of cases, Zika infection may trigger more serious problems, including Guillain-Barre syndrome, which paralyzes the muscles. Most people who get Guillain-Barre eventually get better, but a full recovery may take months of rehabilitation and medical treatment.
Reports of this syndrome emerge about 3 weeks after the virus first appears in an area, Chan said. So far, a total of 12 countries and territories have reported an increase of Guillain-Barre cases linked to Zika.
Earlier this month, doctors reported the first case of brain swelling linked to the virus. The patient was an 81-year-old man who was on a cruise through the South Pacific when he ran a fever and lapsed into a coma. Doctors diagnosed swelling of the membranes that cover the brain and spinal cord, a condition called meningoencephalitis. Tests found Zika virus in his spinal fluid, and no other infectious agents were detected. He recovered after 38 days in the hospital.
But by far, the most serious complications of Zika play out during pregnancy. In laboratory experiments, scientists have watched the virus infect and kill a type of cell that's critical for a baby's brain development. During the early weeks of pregnancy, Zika appears to stunt the growth of the fetal brain and nervous system. This leads to a range of outcomes including miscarriage, stillbirth, birth defects, and microcephaly, where a baby is born with an abnormally small head and brain.
In Brazil, where millions of people are believed to have been infected by Zika, doctors are double-checking 6,480 cases of babies with microcephaly in an effort to make sure that the infants were given the right diagnosis, and to see whether or not it was related to Zika infection. Doctors have completed their investigations of 2,212 of those cases, and so far 863, or around 39%, have been found to be correctly diagnosed.
If that pattern holds, experts predict 2,527 cases of microcephaly will be linked to Zika virus in Northeast Brazil, a number that's 20 to 30 times more than the region would normally see, said Anthony Costello, MD, a pediatrician who heads the Department of Maternal, Newborn, Child and Adolescent Health at the WHO.
In the current outbreak, Brazil and Panama have reported cases of microcephaly linked to Zika. A WHO team has arrived in Cape Verde to investigate the country's first reported case of microcephaly there.
It takes about 6 months after the virus is first detected in an area for the first cases of microcephaly to follow. The virus has not been circulating long enough in other areas for cases of the condition to appear, Chan said.
But given the lifelong care that some children with microcephaly will need, Chan warned that countries should shift their focus from the care of individual patients to bolstering the health systems and programs that will be needed to care for many such cases.
Thus far, she said, there are not enough resources to fund the effort.
"The situation is still pretty serious in terms of lack of funding," Chan said. The WHO has asked for $25 million to respond to the emergency, but has only received $3 million so far.
The organization gets most of its funding from its member states, including the U.S. The remainder comes from private sources, including charitable organizations.
SOURCES: Margaret Chan, MD, director-general, World Health Organization, Geneva, Switzerland. Anthony Costello, MD, director, WHO Department of Maternal, Newborn, Child and Adolescent Health. Press briefing, World Health Organization.
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