Scientific Method —

Conspiracy theories, wonky rumors, doubts buzz around Zika, hassle WHO

Organisation says it needs £39 million to fight infection, misinformation.

With notable gaps in scientists’ understanding of Zika, there have been plenty of pet theories, ridiculous rumors, doubts, and fears to fill the spaces. Among the ideas circulating as the mosquito-born virus continues to spread in the Western hemisphere, rumors have swirled that Zika’s emergence is the making of mad scientists who unleashed genetically engineered mosquitoes or that it's from drinking water “tainted” with a harmless, mosquito-killing insecticide. Another theory says it's a Scrooge-like plot by the one percent to decrease the surplus population.

While the World Health Organization and other experts have quickly smacked down those more far-fetched explanations—usually with responses that include “ridiculous,” “not credible,” and “no scientific basis”—other theories have been a little harder to bat away as scientists await more data. In particular, there’s lingering speculation that the commingling of Zika and dengue viruses may be to blame for Zika’s suspected link to microcephaly—a birth defect that leaves babies with malformed heads and brains. On the other hand, there are persistent rumblings among media and some scientists that the alarming uptick in microcephaly in Brazil, which is currently seeing an explosive outbreak of Zika, may simply be due to poor medical reporting.

Amid the competing chatter and conjecture, the WHO is attempting to coordinate emergency international efforts to fight the virus’ spread, treat those affected, and keep the facts straight. On Wednesday, the organization put out a $56 million plan (PDF) to get it all done—with the largest chunk, $15.4 million, going to communications. As part of those communication efforts, "[n]ews and social media channels will be monitored and analysed to identify audience concerns, knowledge gaps, rumours, and misinformation,” the agency wrote. The rest of the money will go to surveillance, mosquito control, healthcare for the affected, research, and coordination.

Clearly explaining the facts about Zika’s link to microcephaly is central to those efforts. To date, there’s still no definitive data that proves the virus causes birth defects. However, circumstantial evidence is piling up, building a pretty convincing case, many health experts say.

Since Zika arrived in Brazil in early 2015 and began infecting an estimated 500,000 to 1,500,000 people, the country has seen a startling spike in microcephaly cases. In 2014, there were 147 cases, while there have been 4,180 confirmed and suspected cases from 2015 to January 27, 2016. Additionally, traces of Zika virus have been found in pregnant women who gave birth to babies with microcephaly, in amniotic fluid, in babies with microcephaly, and in the brains of babies who died in utero.

Though Zika has caused outbreaks in the past and is currently spreading into dozens of new countries in Central and South America, Brazil is unique in seeing such a large uptick in microcephaly cases. Thus, theories abound. One that has gained a notable foothold is the connection to dengue—a related virus that’s also circulating in mosquito populations there.

Like Zika, dengue usually only causes mild fevers and body aches. But there are four flavors of dengue virus, which together can spark haywire immune responses. After one dengue infection, a person will be immune to that strain. However, exposure to a different dengue strain can, in some cases, ignite “enhanced” immune responses that can lead to full-body hemorrhaging and shock.

An infection with Zika, a viral relative to dengue, could spur similar berserk immune responses and microcephaly in dengue-exposed populations such as those in Brazil, the theory goes.

That is, if Zika even causes microcephaly. Others say the pre-Zika numbers of microcephaly cases in Brazil are low, and the current high numbers are likely inflated by loose definitions of what counts as microcephaly and people specifically looking for new cases to report. Of the 4,180 confirmed and suspected cases of microcephaly, only 270 cases have been confirmed, 462 were tossed, and 3,448 are still being investigated. Of the 270 confirmed cases, only six cases had confirmed evidence of a Zika infection.

Still, at a recent scientific conference Christopher Dye, WHO director of strategy, brushed off the theory. Absolute numbers are always hard to nail down, he told Ars, but the trends are informative and impossible to ignore in this case.

Until there's more data, the WHO, along with the Centers for Disease Control and Prevention, recommend that pregnant women and women planning on becoming pregnant take precautions to prevent Zika infections and avoid traveling to Zika-affected areas.

This post originated on Ars Technica

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