
CUCUTA, Colombia — Sitting in the tiled waiting room of a hospital’s maternity wing here, Windy Gelvez Mandón passed the time making jokes. The other pregnant patients slumped in their seats, stretching their tummies skyward, but Mandón sat tall as clinicians in white, green, and navy blue scrubs pulsed through the wing.
Her body language changed quickly, however, when the conversation turned to the latest mosquito-borne threat in this area, the Zika virus.
Mandón, 21, had taken a taxi from her home an hour outside Cúcuta to E.S.E. Hospital Universitario Erasmo Meoz because she had been having headaches and joint pain, symptoms of the virus. She came not out of concern for her own health, but because she feared what the virus could do to her unborn baby. Her smile faded and her dark eyes lost their brightness as she talked of Zika.
“Nerviosa,” Mandón said. Nervous.
Global health officials say evidence increasingly suggests the Zika outbreak in Brazil is responsible for a surge in that country of babies born with abnormally small heads, a condition called microcephaly. The Zika virus has spread across almost all of Latin America.
But so far, no microcephaly cases in this current outbreak have been tied to a Zika infection that was contracted anywhere outside Brazil. (A Zika outbreak may have been behind an increase in microcephaly cases in French Polynesia in 2013 and 2014.)
The lack of microcephaly outside Brazil may indicate that scientists have been mistaken; maybe the virus doesn’t in fact cause the birth defect. Or maybe there are unknown factors specific to Brazil.
Or maybe it’s just a matter of time.
Some infectious disease experts believe cases of the birth defect could soon start to appear along the path of Zika’s spread. And except for Brazil, no country has seen as many Zika cases as Colombia.
“Perhaps Zika just hasn’t been in Colombia long enough at this point,” said Matthew Aliota, a researcher at the University of Wisconsin School of Veterinary Medicine who helped detect Zika in Colombia.
“The speed [of transmission] is very fast in Colombia right now. The disease almost flies.”
Fernando Ruiz, Colombian vice minister of health
Dr. Thomas Frieden, director of the US Centers for Disease Control and Prevention, echoed that point: “We’re not surprised not to see cases of microcephaly in other countries because of the time frame between infection and delivery,” he said Friday.
Colombian health officials have identified more than 20,000 Zika cases, a figure experts said likely underestimated the true number because it only counted people who had gone to the doctor. Of those patients, more than 2,100 are pregnant women.
Health officials anticipate Colombia could see 400 to 600 cases of microcephaly during the epidemic, which they project to last until August.
Concern is so strong that the national health ministry has asked women to delay pregnancies. That’s a challenge in a country where access to sex education and contraception are uneven at best, and abortion is prohibited in most cases.
Health officials are also investigating whether Zika can cause Guillain-Barré syndrome, a neurological condition that causes progressive — and generally, temporary — paralysis, but that can lead to death. Colombia typically sees 240 cases of GBS each year, but had 86 in just five weeks in December and January, according to the World Health Organization.
On Friday, Colombian health officials said three people with GBS tied to Zika had died. They were awaiting test results from six other GBS deaths possibly stemming from Zika.
The WHO has declared a global public health emergency associated with Zika.
Here in Cúcuta, a city of more than 600,000 near the Venezuelan border, residents grew worried as the number of Zika cases started to rise in December. Cúcuta is the largest city in the state of Norte de Santander, which has seen more Zika cases than any other in Colombia.

“What we have seen is that the speed [of transmission] is very fast in Colombia right now,” Fernando Ruiz, the vice minister of health in Colombia, told STAT. “The disease almost flies.”
As residents here have learned, Zika does not pose a serious health threat in most cases. An estimated 80 percent of people who contract Zika show no symptoms, and most who do have just a few days of fever, joint pain, headaches, rash, or conjunctivitis. Past outbreaks of chikungunya and dengue fever — which, like Zika, are carried by Aedes mosquitos — made people sicker, residents said.
Only after talking about Zika for several minutes did local priest Ruber Carrero López mention he had contracted it himself, shrugging it off like an American would dismiss last month’s head cold.
But people do grow concerned when pregnant women or GBS are mentioned along with Zika.
A nurse talking about a pregnant woman diagnosed with Zika crossed herself. In the hospital’s maternity wing, some women dropped their voices when Zika came up.
“It’s spreading so quickly here,” said Dr. Nadia Karina Arana, an epidemiologist at IPS Unipamplona, a clinic affiliated with a local medical school.
Arana added, however, that more research needs to be done to tease apart what complications Zika can actually cause. Maybe microcephaly cases will arrive in Cúcuta, she said, but so far, none have.
One expectant mother who was not worried was Paola Andrea Escalante, who on Thursday was the only pregnant woman admitted at Erasmo Meoz hospital with Zika.

Seventeen years old and eight months pregnant, Escalante explained as she ate a lunch of soup, chicken, cabbage, and rice that she had barely heard of Zika before this week. She had gone to the hospital earlier in the week after a red rash that dotted her hands and stomach had spread all over her body. Doctors told her she had Zika. But they also told her her baby boy appeared healthy.
“I feel normal,” Escalante said.
Escalante — wearing a white dress marked with red anchors, each dotted with a heart —was sharing the hospital room with three other pregnant women, but only her bed had a mosquito net rigged up. It was not so much to protect her, but to prevent a mosquito from biting her and transmitting Zika to other patients, hospital officials said. She spent all day under the net, taking a quick reprieve to enjoy her lunch.
Federal and local health officials here have sought to show they are taking the virus seriously after some residents and doctors said they were slow to react in the early months of the outbreak.
In Cúcuta Friday, a dozen officials from the area’s hospitals and clinics that serve poor patients gathered to discuss their prevention and surveillance efforts. If microcephaly cases appear in town, they said, they would make sure patients had access to specialists.
And in Washington this week, Colombian President Juan Manuel Santos and President Barack Obama announced the two countries would collaborate on Zika research.
Despite the stepped-up response, officials here don’t want to cause alarm, they say, so they speak about microcephaly as a possibility — an if, not a when.
Indeed, scientists have not shown a causal relationship between the virus and the birth defect. And hundreds of cases originally reported as Zika-associated microcephaly in Brazil have been found not be related to Zika — or not to be actual cases of microcephaly.

But officials at the WHO and the CDC say they strongly suspect the virus can cause microcephaly in a developing fetus. Dr. Lyle Petersen, director of the CDC’s division of vector-borne diseases, told STAT this week that the evidence is “quite strong at this point.”
Back in the hospital’s maternity wing, Shirley Dayana Rivera was getting her blood pressure measured. Rivera, 17, had come to the hospital Thursday because it was her due date, but she wasn’t yet in labor.
In December, Rivera had a fever and headaches, and an itchy rash broke out over her stomach. She was diagnosed with Zika and recovered. She said doctors told her that her baby girl, whom she planned to name Sara, seemed unaffected.
So her trepidation this week was not specifically about the virus, but just the anxiety that comes with impending motherhood.
“I just understand that there’s always a little fear,” she said, “but I’m hoping for the best.”
Helen Branswell contributed reporting.