Related by context. Frequent words. (Click for all words.) 30 originated 29 studied 28 infected 27 transmitted 25 origin 25 lived 24 traced 24 detected 24 origins 23 circulating 23 commonly 21 derived 21 died 21 traveled 21 spreading 21 traces 20 existed 20 spread 20 belonged 20 ancient 20 linked 19 prevalent 19 discovered 18 resemble 18 spawned 17 exported 17 contained 17 manufactured 17 developed 17 belong 17 invented 16 imported 16 uncovered 16 similar 15 circulated 15 spreads 15 caused 15 exist 15 occurred 15 belongs 14 #th century 14 triggered 14 occurring 14 shipped 14 produced 13 located 13 provoked 13 adapted 13 used 13 purported 13 exists 12 surfaced 12 marketed 12 operates 12 spurred 11 based 11 pioneered 11 fueled 11 sparked 11 filmed 11 ignited 11 came 11 encompasses 11 inspired 11 stemmed 10 epicenter 10 consisted 10 modeled 10 brought 10 evolved 10 applies 10 resides 10 borne 9 rooted 8 consumed 8 consists 8 #s [002] 8 operated 8 erupted 8 originally 8 original 8 conceived 7 related 7 stems 7 refers 6 generated 6 resulted 6 referred 5 revived 5 incorporated 4 arose 4 stemming 4 centered 3 primarily 3 principally 3 started 3 created 2 popular 1 relates 1 founded 0 central