Zika Virus (and On Point Radio)
Zika virus causes a flu-like illness in 1/3 of those infected. However, when a pregnant woman is bitten it may cause microencephaly in the fetus: a smaller skull size with a corresponding smaller brain, as well as facial abnormalities.
TWO QUESTIONS:
Should we be surprised that another zoonotic disease has caught us by surprise?
How can Brazil say that it will eradicate Zika when no one knows what the reservoir is?
On Point Radio (one of the few talk/call-in radio shows that is intelligent, civilized and interesting) had as its subject yesterday the emergency crisis caused by this virus. I called in and tried to ask the experts assembled these questions, but I was too far down in the queue. (Someone calling in saying that vitamin B1 would work as a mosquito repellent--it won't--was one of the commenters whose called preempted mine. Although the virus was discovered around a half-century ago, it has only recently hit the news.
FIRST QUESTION:
This can sound like an accusatory, rhetorical question, but it isn't. Ebola caught us by surprise, West Nile Virus caught us by surprise, and we even ran short of flu vaccines just a few years ago (and then vaccinated the wrong people).
If one goes to grants.gov, and in the search box enters "zoonosis", nothing comes up. For "zoonotic", only 5 appear, none are from the National Institutes for Health, and none are involved with surveillance or research of any specific organism.
Tom Ashbrook, the host of the show, said that perhaps not enough NIH dollars were going to Zika research. The expert who answered strongly disagreed, and added that in "the next cycle" that there will certainly be more grants available. Obviously, "the next cycle" is always a reaction rather than what we need in the first place, which is advanced warning.
SECOND QUESTION:
You can use this as a bar bet next time you find yourself at a happy hour with someone from the WHO who says that they're going to eradicate xyz disease:
What diseases have actually been eradicated?
Answer: Smallpox and rinderpest. Most people have heard of the first, and most people have not heard of the second. The point is that eradicating a disease is pretty difficult. We'd like to distinguish between elimination and eradication. Strictly speaking, eradication means removing something from the face of the Earth. Smallpox doesn't exist anymore (well, yes, the US and the Russians have a strategic reserve because we don't trust each other, but that doesn't count). Elimination is the removal of something from within the confines of a border. For example, foot and mouth disease has been eliminated from the United States. Were we to let up on our surveillance, or if someone wants to wreak havoc with our animal agriculture, then this disease could be reintroduced.
It has, so far, been impossible to eradicate diseases that have a wildlife reservoir. Take Lyme disease. The borrelia spirochete is carried around by the white-footed mouse. Deer may amplify the amount of organisms and serve as an intermediate host, but unless we were to eradicate white-footed mice, or somehow treat all of them. It would be nearly impossible to eliminate Lyme disease. Bats and rabies, influenza and birds....you get the idea. And in the whole time that everyone was talking yesterday, there was not one mention of Zika being a zoonosis. So unless Zika only infects humans, which we know isn't true, we can only eradicate this disease if we find the reservoir.
That doesn't mean that we're sunk. Vaccines eliminated measles, polio and mumps from most of the world. A safe, effective disease would relegate this disease to footnote status.
