Pregnant women and those with compromised immune systems should never change a litter box. And everyone should try not to inhale the dust from clay litter boxes. Most people try not inhale at all when changing a litter box. For obvious reasons. It seems all baby animals come with worms.
Hookworms are more severe and can cause a weak kitten to die.
This parasite is obtained in the usual way or from eating infected rodents. Outside cats are more susceptible. Dogs have these worms too and they also get whipworm. Sticky eggs that fall on clothes or furniture, or lying about outside can accidentally contaminate food or drink. Fleas can bite you.