Hello everyone! Our relatives with children came to visit us for a fe…

Hello everyone! Our relatives with children came to visit us for a few hours. The kids played with toys, of course, they were crawling everywhere. Then between conversations, the grandmother says that the eldest has lamblia, and the youngest says "probably not" and we're treating it. Lamblia is scary in this case, can it spread so quickly? What should we do besides wash the toys? Or is it unnecessary to worry? We are 6.5 months old Thank you