The Little-Known Virus Causing a Panic Over Infant Brain Deformities in Brazil
The crisis is stark example of how difficult it still is to predict and control an epidemic.
Luiza Arruda, born in October with microcephaly, has her head measured by a neurologist at the Mestre Vitalino Hospital in Caruaru, Pernambuco state, Brazil. Image: AP Photo/Felipe Dana
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Microcephaly is hard to miss. Babies with this potentially life-threatening condition are born with noticeably smaller-than-normal heads. So when the number of babies born in Brazil with microcephaly increased almost 20-fold—from an average of about 150 a year to nearly 3,000 cases in 2015—it's understandable that the country's healthcare system took notice.
In the midst of this crisis, Brazilian healthcare officials noticed something else: five months before the first reports of an increase in microcephalic births started to emerge, a new virus arrived in the country. Zika fever, a little-known, largely innocuous mosquito-borne viral infection has now been singled out by Brazilian researchers as the cause of the jump in babies born with microcephaly. Doctors are telling families not to get pregnant. Local governments have declared states of emergency. Expectant mothers are, understandably, panicked.
"What frightened me most was that I felt that people were [suddenly] changing the discourse about the zika virus," said Luciana Obniski, a screenwriter and translator in São Paulo who is 27 weeks pregnant. "At first, [they said] it was only a risk for pregnant women in the first trimester, then they started to tell women not to get pregnant [at all], which I think also generated a panic that was not real. When you're already pregnant and read these things, it doesn't help."
A sudden surge in a typically rare, debilitating, and sometimes deadly birth defect is certainly cause for concern, but there's more to this story. Epidemiologists have yet to conclusively find that the zika virus is causing the increase in microcephaly or, if it is, what the risks are. And in a country like Brazil, where reproductive health care is already lacking, a panic among expectant mothers is particularly dangerous. It's a stark example of how difficult it still is to predict and control an epidemic and how a lack of public health information can lead to dire consequences.
"There's no need to panic," said Dr. Marcos Espinal, the director of the communicable disease department at the Pan American Health Organization. "Until further evidence comes out, it's very dangerous to draw conclusions like 'try not to get pregnant,' and things like that."
Aside from the obvious chronological correlation—which isn't something to be disregarded—there isn't a lot of evidence yet to show that zika, which typically produces mild symptoms, is causing the spike in microcephaly. Some mothers who gave birth to microcephalic babies reported zika-virus-like symptoms early in their pregnancy, and the virus has been detected in the amniotic fluid of some of the babies.
"There is some limited data that suggested women delivering children with microcephaly were infected with zika virus at the time, but it's still that cause-and-effect issue," said Michael Osterholm, an epidemiologist and the director of the center for infectious disease research and policy at the University of Minnesota.
Even if we establish that causal relationship for sure (researchers are working to do that right now), it's unclear how big of a risk factor there is. How many of the women who gave birth to healthy babies in Brazil last year also contracted zika virus, for example? So far, 40 of the newborns with microcephaly have died, and the life expectancy for children with this condition is reduced, as is the likelihood they'll ever develop full cognitive function, though it is possible.
So, until we know more, many researchers are stressing the need for vector control: government-backed initiatives to curb the spread of the virus. This can be achieved through simple measures like dumping out pools of standings water (AKA mosquito love nests) and increasing public education so people wear bug spray and long sleeves. Not getting bit is the best way to avoid zika infection, and to reduce the risk of any negative side effects if indeed they exist.
But some doctors in Brazil have been urging more severe actions, like holding off on starting a family altogether.
"Our advice is to not get pregnant in the first place, if you can avoid it, because at this moment the epidemic is growing," Dr. Nelson Nisenbaum, a doctor and internal medicine specialist in São Bernardo do Campo, said, speaking in Portugeuse. "We don't have exact numbers, we don't have tools to monitor the epidemic all over the country with accuracy. So that's the first thing: if you want to get pregnant, it's better to wait three to six months."
Nisenbaum said women who are already pregnant should check if they're in a high-risk area for dengue fever. If so, they should be extra diligent about avoiding mosquito bites, because the type of mosquito that carries dengue (Aedes aegypt) also carries zika. The trouble is that this advice was not doled out prior to the microcephaly outbreak, so women who are already pregnant and just learning about the potential risks now are understandably worried.
"Another thing that scares me is the lack of information," Obniski said. "If you have no easy way of knowing where the contagion is, it makes things difficult for women who line in at-risk areas. I'm not in an at-risk area, but I can imagine what it's like for women who live in these places and who do not have the right information and have no way to prevent zika."
This knowledge gap was created because, until the microcephaly outbreak, no one was too concerned about zika. It wasn't well tracked and information about avoiding the virus wasn't widely offered to the public, because zika was only associated with a mild fever.
"Zika is a very mild disease," Espinal said over the phone. "It can cause a rash, pain in muscles—symptoms any virus could produce. So some people won't even go to health services. They take some pain killers and that's it."
Because of this, the virus was not a high priority for government officials when it first cropped up in Brazil. At the time the first cases were confirmed, Arthur Chioro, Brazil's then-health minister, told reporters that the "the zika virus doesn't worry us," adding that the government was more concerned about dengue fever, another viral infection that was spreading at the time, because "dengue kills."
Zika also wasn't very widespread. Until last year, the virus was mostly confined to tropical Africa, Southeast Asia, and the Pacific Islands. And since it was a comparatively innocuous infection (symptoms are mild, serious infection is rare, and no deaths have ever been reported) there wasn't much research or attention paid to it over the last few decades, according to Dr. Alain Kohl, a University of Glasgow virologist who has studied zika.
"Nobody really cared much about it," Kohl told me. "It was more of a curiosity than anything else."
Kohl said prior to the correlation of outbreaks in Brazil, securing funding to look specifically at zika would have been a tough task. Now, multiple institutions have launched new research into the virus, including Kohl's team at Glasgow, but they're racing the clock as expectant mothers fret.
There's lots that researchers want to find out, beyond determining whether or not the virus is truly to blame for the wave of microcephalic births. Because zika hasn't yet been widely studied, there aren't very good diagnostic tests for it. Kohl said it's similar enough to viruses like dengue that they can be tough to distinguish.
Another issue is that other flaviviruses like zika haven't been linked to this kind of congenital deformity before. But Osterholm said there could be a few explanations for that: the strain of zika in Brazil could be different than ones that had circulated in other areas, or it could be that the correlation to microcephaly went unnoticed because tracking of the disease was so poor. It just serves to illustrate how difficult it is to predict, track, and study epidemics. Until a causal link is found between zika and microcephaly, researchers urge officials to focus on prevention tactics, as public panic will only exacerbate the issue.
It just serves to illustrate how difficult it is to predict, track, and study epidemics and illuminates the risks that come with a lack of public health information. If researchers had more resources to track even seemingly-benign viruses, if Brazil had met the virus's arrival with more concern, if we knew even marginally more about this virus than we do now, there's at least a chance some lives could have been saved. But now that Brazil is in the midst of crisis, the good news is the solution is fairly simple, according to Nisenbaum.
"Technically, there are no challenges. We have to eliminate the mosquitos outbreaks by killing breeding grounds," Nisenbaum said. "That's what we have to do: fight the mosquitoes. There's nothing else to do."