Practical Zika - Practically Everything You Wanted to Know
Hide your kids. Hide your wives. Zika gonna get you.
Zika is not new. It was discovered over half a century ago in Uganda. But, due to its initial outbreaks occurring in areas with limited access, limited resources, and limited apparent clinical significance, largely nobody cared. This isn’t to say *nobody* cared, of course, just that their work went unrecognized and unknown. Nevertheless, we actually already know a great deal about the virus. True, many details remain to be worked out and a vaccine remains to be found, but fear and misunderstanding of the virus are fast becoming more virulent than the virus itself. Most of us will do just fine when the global Zika pandemic finally strikes. Thus, to provide a little practical clarity, here is practically everything you wanted to know about Zika. Or, for those with a more limited attention span, download the free medical microbiology app Micropedia on iOS and Android to read at your leisure.
First, where is Zika transmitting and where is Zika not transmitting? Currently, it is transmitting in most of Central and South America, the Caribbean, and a few scattered island chains globally. There is risk for transmission more broadly, however, as much of the tropical and subtropical world possesses both the necessary vectors — i.e. the Aedes mosquitoes which spread the disease — and the limited socioeconomic development which facilitates human exposure to said vectors. Notably, Zika is *not* currently transmitting in the United States outside of a few of its overseas territories (Puerto Rico, American Samoa, the US Virgin Islands), despite some border states harboring the necessary Aedes mosquito. This is because Americans in general experience far less daily mosquito contact (and therefore, less potential virus exposure) than individuals elsewhere in the world, thanks to the fact we generally spend far more of our time indoors. It is for this exact same reason that Chikungunya and Dengue, two other viruses also spread by Aedes mosquitos, have never been able to gain a foothold within our borders. This is not to say there have not been cases of Zika in the US — or just about any other well air-conditioned, developed country in the world — just that there is minimal exposure risk to most Americans. Outside of sexual contacts with recent travelers, this risk approaches zero. The distribution of the virus is constantly changing, however, so for up-to-the-moment information, check out CDC’s - Areas with Zika page.
How is Zika spread and how is Zika not spread? Mosquitoes spread it, of course, but so do human semen and blood. This is why the CDC and FDA have recently advised travelers returning from endemic regions to take certain precautions including condoms for men for at least 3 months to protect their partners and delaying blood donations for at least 1 month for all travelers to protect the blood supply. What is important to distinguish, however, is the difference between what is possible and what is probable. Mosquito-transmitted Zika is possible and probable, occurring readily. Sex-transmitted Zika, on the other hand, is clearly possible but appears far less probable. The exact risk remains to be quantified, but they are not the same. What is also important to note is Zika is *not* spread through respiratory secretions, casual contact, coughing, kissing, hugging, contaminated food or water, or any other means not listed. It may possibly be spread through song.
What does Zika feel like? In most cases, like nothing at all. Although the oft-quoted figure of only 1 in 5 cases being symptomatic may be a bit of an overestimate, the fact nevertheless remains most people infected with the virus experience absolutely no discernible symptoms. For the minority that do, the classic presentation is some combination of fever, joint pains (typically of the small joints of the hands and feet), rash, and conjunctivitis. Flu-like symptoms may be noted and, less frequently, gastrointestinal distress as well. In most cases the illness is relatively mild, and in most cases symptoms last 2–7 days before resolving. As there have been no reported deaths to date, dying from Zika appears to be very hard to do.
How do I get tested for Zika? Contact your physician, who will contact the state public health department. There are no commercially available tests as of yet, and all samples must be forwarded to a regional lab or the CDC for appropriate evaluation.
Will this harm my unborn child? Possibly. This is where Zika truly is a threat. For pregnant women, there appears to be an increased risk for fetal loss and microcephaly — an otherwise rare neurodevelopmental disorder in newborns characterized by a small head and, typically, the development of some degree of neurocognitive deficits later in childhood. The risk appears to be greatest if the mother is infected in the first trimester, but the details of the risk, including the magnitude of risk, remain unclear. This, more than any other area of Zika virus research, appears to be the most rapidly evolving. Refer to the CDC’s - For Pregnant Women page regularly for frequent updates, recommendations for women, and guidelines for medical providers.
Will this harm my already born child? Almost assuredly no. For the child already walking terra firma, the risk of Zika appears at the moment to be no greater than it is for an adult, which is to say minimal. They can get sick, of course, but the virus will run its course just like any respiratory or GI bug they acquire on a regular basis. There are concerns regarding the possible association with Guillain-Barre Syndrome (GBS) — an acute, temporary paralysis that starts in the extremities — and it appears this association may be real, but again we must recall the distinction between possible and probable. GBS develops very infrequently in Zika cases, and remains rare even in Zika endemic areas. Just as we don’t have an undue fear of the many respiratory and gastrointestinal infections that regularly occur in the US and may cause GBS (such as mononucleosis, Chlamydophila, Mycoplasma, and parainfluenza), there is no need to have a disproportionate fear of Zika because of GBS. I’d be more worried about all the hamburgers your kid is eating.
Is there a cure for Zika? Unfortunately, no.
Is there a vaccine for Zika? Unfortunately, not yet.
Is there anything I can do to avoid Zika? Aside from avoiding Zika-endemic areas, the only way to prevent Zika infection is to prevent Zika exposure. The Aedes mosquito is most active during the day, and can be dissuaded from biting you by (1) wearing long sleeved, light colored clothing, (2) applying a generous layer of DEET (30% concentration or greater) or picaridin, and (3) letting the mosquitoes know you mean business by making an example of a few of their friends. A fourth additional option is permethrin spraying your clothing prior to travel which serves to repel mosquitoes for weeks to months, even after multiple washes. Permethrin is what the US military uses on the uniforms of service members being deployed. Spray permethrin in a well-ventilated area, and do not let your cat come into contact with it while wet. Lastly, if your male partner has recently returned from a Zika-endemic region, make sure he wears a condom per above.
Where can I get more information on Zika? Currently the best source is the CDC, as evidenced by the fact that I’ve linked to it now almost a half dozen times. They have done an excellent job providing both user-friendly information for the general public, and more technical expertise for medical professionals. More importantly, in the rapidly changing Zika epidemic they keep their information up to date, giving you the most accurate guidance available. For the handheld device, there is also the free app for iOS, Micropedia — Medical Microbiology, which provides a handy summary of not only Zika, but over 200+ other common and not-so-common local and global pathogens. An Android version is also available on Amazon. Notably, your coworker and mother are unverified sources of medical information, unless perhaps they work for the CDC.
And finally, will Zika win the presidency? We could do worse.
