We have not yet begun to scratch the surface of how pathogens and other bugs can manipulate behavior. This is also a major cost of infection that many people don’t even consider; our personalities are no doubt shaped in part by our current and past infections and our microbiome.
I do not know of any direct evidence that sexually transmitted diseases increase the libido of sufferers, but I conjecture that it would be worth looking into. Certainly at least one alleged aphrodisiac, Spanish Fly, is said to work by inducing an itch . . . and making people itch is just the kind of thing viruses are good at. (Dawkins 2006 pg. 247)
A bright woman of ninety, Natasha K., recently came to our clinic. Soon after her eighty-eighth birthday, she said, she noticed ‘a change’. What sort of change? we queried.
“Delightful!’ she exclaimed. ‘I thoroughly enjoyed it. I felt more energetic, more alive—I felt young once again. I took an interest in the young men. I started to feel, you might say, “frisky”—yes, frisky.’…