The health department reported 10 people fell ill after eating contaminated food at two different family events.
One took place June 21 in Caruthers, and the second was on Saturday, June 22, in Clovis.
On Tuesday, the health department revealed the source of that contamination was a cactus salad.
Eight people have now been treated with an anti-toxin.
Two young sisters remain hospitalized after receiving that infusion.
The Fresno County Public Health Department says in cases of food botulism, it's important patients be treated with that anti-toxin as soon as possible.
It's a rare but serious illness related to bacteria that can attack the nerves, cause difficulty breathing and even death.
So far, there have been no other reported cases.