Parents have now refused to send their children to Indian Hills Elementary in Jurupa Valley after notes were sent home warning parents that two students "might" be sick with leprosy.
The school, about an hour's drive from Los Angeles, sent out the warning on Friday, CBS Los Angeles has reported.
Jurupa Valley Unified Superintendent Elliott Duchon said the school's classrooms had been decontaminated in response to the threat.
He said the two students, who had been warned of the potential diagnosis by a doctor, had alerted the school's nursing staff.
Mr Duchon said: "For parents, they need to make a decision for their children but we're not recommending any precautions.
"There is not a risk at this time."
The students believed to have been infected have also been pulled out of class for the time being.
It is unclear whether the infected students are related to each other or whether they had recently been overseas.
Riverside County director of disease control Barbara Cole said: "We have not identified any risk at the school and it's very difficult to transmit to others."
Despite the attempted reassurances, dozens of parents have kept their children home from school after receiving the letter.
About 90 students were absent from the school on Tuesday morning, three times the usual number.
The children potentially infected will not have their diagnosis confirmed for several weeks.
More than 400 school parents met with health officials after school on Wednesday but were left frustrated when authorities refused to answer any questions about the potentially-infected children and their condition.
As part of the school's cautionary measures, parents are also set to be interviewed about whether their families have travelled to any less developed countries where the leprosy may have been picked up.
While cases of leprosy in the UK and US are extremely rare, the disease can still create ripples of fear.
But what is leprosy?
Otherwise known as Hansen's, it is a contagious disease that can affect the skin, and in rare cases can cause disfigurements and deformities.
It is caused by a slow-multiplying bacteria, mycobacterium leprae, which starts by damaging the small nerves in the skin's surface, causing discoloured patches with little to no feeling.
The disease can then spread, going on to damage the nerves in the elbow, wrist and ankle,. It can also cause a loss of sensation to the feet and hands.
As its victims are unable to feel pain, they can often suffer burns, ulcers and other injuries without realising.
The infection can also damage eyelids, making it difficult for those infected to blink while other symptoms include a flattened nose or clawed hand.
The disease can be cured with antibiotics and multidrug therapy but the treatments cannot reverse the physical impacts caused.
According to the World Health Organisation, there were about 210,000 new cases of leprosy diagnosed across the globe in 2015.
More than half of the new diagnoses were in India.
Return to News Home