Tweeted Photo by CDC Chief Sums Up Zika Problem '50 years of neglect' By Newser Editors and Wire Services Posted Feb 12, 2016 1:07 PM CST 9 comments Comments This is why we don't know a lot about the Zika virus. (Twitter) (Newser) – One big reason the world is in something of a panic over the Zika virus is summed up succinctly in a photo tweeted Friday by CDC chief Tom Frieden. The image is of a paltry stack of papers on a desk, with the caption: "Entire world literature on Zika. 50 years of neglect." A post at Vox says it exemplifies that scientists have been caught "flat-footed" and adds this for context: A search of "dengue fever" on the PubMed database turns up more than 14,000 hits, "West Nile virus" nearly 6,000 hits, and "Zika virus" only 146. Meanwhile, the US has thus far shipped 62,000 Zika test kits for pregnant women to health departments around the country, reports the AP. Frieden said Thursday the CDC is working to send more but "there may be a period of weeks or a couple of months where there aren't enough tests for the women who want to have them done."