Do tissue-dwelling trypanosomes sustain transmission populations?

Trypanosoma brucei infectious populations are marked by considerable diversity in the parasite's major antigen, the variant surface glycoprotein (VSG). However, most parasites in the bloodstream are non-replicating, questioning how VSG diversity arises. Beaver et al. show that extravascular parasites in host tissues many explain this paradox and provide insight into trypanosome transmission.