Reports of Zika-related birth defects are coming in at shockingly low rates in Puerto Rico. While that might be something to cheer, one former US government official is saying there could be a nefarious reason for the low numbers.
Last July, the Puerto Rico Department of Health reported that at least 3,448 pregnant women had contracted the Zika virus during their pregnancy from 2016 to 2017. Of these women, 1,898 displayed symptoms, 415 were hospitalized, and five died. Despite the high number of pregnant women with Zika, only 16 cases of microcephaly or other congenital defects related to Zika have been reported, although it is not known how many of the 3,000 women have given birth.
That's only 0.5% of women infected during pregnancy, much lower than the rate of Zika-related birth defects in babies born to US women infected with Zika, which came in around 10%, (15% for women infected in their first trimester).
A Zika virus infection can be anywhere from mild to devastating. Most infected people don't have any symptoms, but it can cause Guillain–Barré syndrome — a disorder that affects the immune system and damages nerves. Some small percentage of babies born to women infected with Zika virus are born with a severely small head, called microcephaly, and other brain and medical problems. The frequency of this complication has been found to be anywhere between 1% and 13% in previous studies.
Puerto Rico's birth defect number is well under these rates, and unreasonably low compared to the US statistics, drawn from the US Zika Pregnancy Registry, which keeps track of pregnant women who were suspected to have been infected with Zika from January to December 2016.
The US tracked 972 completed pregnancies with possible Zika infections (based on symptoms and travel history), of which 51 of women reported birth defects, about 5% of the pool. But when looking specifically at the 250 pregnant women confirmed to have had Zika in a lab test, 24 had a fetus or baby with Zika-related birth defects, which jumps the rate up to 10%.
That number jumps even higher, to 15%, when looking at women who are known to have contracted the virus in the first trimester of pregnancy.
One possible — and troubling — cause for Puerto Rico's low numbers? They may be downplaying the Zika problem due to its heavy dependence on tourism, according to an unnamed former US official who talked to STAT. The anonymous official explained that the Puerto Rican government is in "denial" and "hiding." This individual also claims there were "dozens and dozens" of babies that appeared to have Zika-related damage that health officials did not label as such. They caution that down the line "there will be all these babies who aren't learning and all these problems that will come to light."
A slightly less terrifying reason for the small number could be the way Puerto Rico is counting the cases, which according to the Centers for Disease Control (CDC) is vastly different from the US.
Although it is not clear how Puerto Rico is collecting its data, it seems as though the CDC has cast a much broader net in terms of symptoms and signs of Zika damage. The CDC included all the children of women infected with Zika during pregnancy with any signs that were related to Zika, even if the defects were not yet confirmed to be related to the virus.
Dr. Jose Cordero, a professor of public health at the University of Georgia, has been keeping track of Zika-related birth defects. He heard from Dr. Miguel Valencia, director of Puerto Rico's health department's division for infants with special medical needs, that Puerto Rican health officials require a child to be diagnosed with microcephaly before considering any birth defects to be caused by Zika.
Even local newspapers have been questioning the stats. However, given Puerto Rico's devastating financial problems, it makes sense that Zika data isn't their number one priority. Let's just hope the children and families affected can get the help they need in coming years; and that all travelers take appropriate caution against the disease. As Zika is transmitted largely through misquito bites, the CDC recommends covering exposed skin by wearing long sleeved shirts and pants, using insect repellents, sleeping with a mosquito net, and staying in places with door screens to keep mosquitoes out. As the disease can also be sexually transmitted, the CDC recommends using condoms when having sex while traveling in the area.