I have been treated for trichomoniasis, my partner and i have not had sex at all since. he will be treated monday, can i be re infected without sex?

Only by sex: Trichomonas is an STD and is transmitted only by sex. You cannot be reinfected unless and until you have sex with an infected partner. However, the standard treatment for trichomonas, a single dose of metronidazole, fails to cure about 10% of infections. Therefore, apparently new infections sometimes are actually previous infections that weren't cured and need more prolonged metronidazole Rx.