‘Six Months Of Hell’: Zika Is Hitting Some Travellers Harder Than Expected

In August of 2016, Jen took a trip to central America. The 35-year-old Canadian knew that Zika was circulating in the area, but she wasn't overly worried—she wasn't planning to have a baby at that time, and her impression was that the virus was only really a problem for pregnant women who are infected. (It's been linked to birth defects.)

Near the end of her trip, Jen (whose name was changed to protect her health details, and who declined to say exactly which country she'd visited to further protect her identity) developed a rash, "followed by odd sensations in my lower extremities," she said. She was diagnosed with Zika, but not only that—she'd come down Zika-triggered Guillain-Barré Syndrome (GBS), which can cause muscle weakness and temporary paralysis.

GBS appears to be associated with the virus, but it's thought to be rare. Public health agencies including the CDC say that Zika symptoms are typically mild, and could include fever, rash and joint pain. In fact, you might not even notice you're sick at all.

Now a new study in the Canadian Medical Association Journal makes the case that Zika is hitting Canadian travellers harder than anyone anticipated. After analyzing a group who'd been infected with Zika, researchers concluded that the disease produced more severe side effects than what they'd expected—including GBS and congenital infection, when a pregnant woman passes it to her fetus. (Jen was not included in this study.)

"There's a common perception that Zika is a very benign illness," lead author Dr. Andrea Boggild, clinical director of the Tropical Disease Unit at the University Health Network in Toronto, told me in an interview, echoing what Jen also said. That wasn't borne out in the data: Zika was diagnosed as frequently as dengue (another mosquito-borne virus) in people returning from the Americas and the Caribbean. But the rate of complications was higher in people with Zika than in those with dengue.

The CMAJ study looked at a year's worth of data from the Canadian Travel Medicine Network (CanTravNet), clinics across the country staffed by infectious disease specialists who detect travel-related illness in people who've been abroad. Out of 1118 travellers, 41 had Zika (nearly 4 percent), 41 had dengue, and 23 had chikungunya, yet another mosquito-borne virus.

Of the travellers, three pregnant women were infected, resulting in two cases of congenital infection. Another two travellers had GBS (or something similar). In all, 10 percent of Zika cases resulted in severe complications—whereas none of the people infected with dengue or chikungunya had severe complications in this study.

For Jen, Zika and its aftermath meant "six months of hell," she told me. She was initially confined to a wheelchair, then used a walker, and finally a cane. She couldn't walk unassisted until January, and had to take time off work. "It flipped my life upside down."

Jen, who is still on medication for pain, is alarmed by what she sees as a "huge gap in knowledge" around the virus: for all the media reports about microcephaly and other alarming health effects in babies and fetuses, many people still feel that if they aren't pregnant or planning to have a baby soon, they shouldn't be overly worried.

Read More: This Single Vaccine Could Protect Against Zika, Dengue, and Malaria

In Canada, as of Feb. 9, 473 people were infected with Zika while travelling, and another three from sex, including 27 pregnant women, according to the Public Health Agency. Two "Zika-related anomalies" have been reported in babies or fetuses here.

Boggild was quick to caution that the CMAJ study is of a specific group of people—Canadian travellers who must have felt sick, because they sought a doctor—and not the general population. "This is a specific ill cohort," she said. "It doesn't extend to all travellers."

Maybe most importantly, though, the new study goes to show that we still don't have a full understanding of this virus, which swept through the Americas in 2015 and continues to be widespread. For Jen, that's been one of the scariest parts of all this.

"The doctors have been fantastic, but they acknowledge they're still learning," she told me. "It should all eventually clear up, but because it's the emerging disease, they just don't know."

Get six of our favorite Motherboard stories every day by signing up for our newsletter.