Remedial Google Practice
Up until a few days ago, I'd never heard of Francisco de Eguia; he gets a mention in The Slave Trade by Hugh Thomas as, seemingly, the first person to carry smallpox to Mexico in 1519. It's only a passing mention on page 96 so I'm unable to tell you if he had any other claims to fame. Later, another Francisco de Eguia served in the Peninsula wars - he may have been a member of the noble and ancient lineage of Eguia whose arms are:
Of gold, with five panelas of gules put in sotuer, and bordura of sinople with a gold chain.
I don't know what that means either; the best I can come up with is that it's a gold shield with five red (gules) panelas in a sotuer. A panela is either a pan (Portuguese) or a small cigar, or one of those hunchbacked heraldic animals that look like roadkill. So a sotuer could be either a heraldic stove, some kind of humidor, or a road.
It's a bit stiff that the reputation of a noble house with such a fine (if incomprehensible) escutcheon should be remembered more for the fact that an early de Eguia was Mexico's Patient Zero (especially if, as is quite possible, he wasn't a real de Eguia at all). So, if you happen to go to Spain and find yourself a guest in a house where they have a shield with five red panelas in a sotuer hanging over the mantlepiece, it would probably be tactful to avoid mentioning Mexico.
While we're on the subject of the international trade in infectious diseases, it's worth mentioning that while the Spanish and Portuguese explorers might have taken smallpox to the New World, they did take home one unpleasant souvenir of their own; syphilis. In Syphilis and the Shepherd of Atlantis, Stephen Jay Gould tells the story of the naming of syphilis with the help of Nahum Tate's English translation of Girolamo Fracastoro's Syphilis sive morbus Gallicus (Syphilis or the French Disease):
To Naples first it came
From France, and justly took
from France his name
Companion from the war....
If then by Traffick thence this
plague was brought
How dearly dearly was that
If you want to read more of Nahum Tate's writing, a good place to start is his famous revision of King Lear in which Edgar gets the girl.
Afterword: The Slave Trade is where I found much of the information for that Who Am I question earlier this week.