Two elementary school students in California have been diagnosed with leprosy, officials claim.

The disease, also known as Hansen's, is an incredibly rare condition caused by slow multiplying bacteria which can destroy sufferers' eyesight and all sensation in their skin.

It is most typically associated with Asia and the Middle Ages, when and where the disease was most prevalent.

But to the horror of parents in Jurupa Valley, an hour's drive from Los Angeles, the infectious condition appears to have reached the West Coast.

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Two students at Indian Hills Elementary School in Riverside, California, have reportedly been diagnosed with leprosy. Scores of families kept their kids at home after hearing the news

WHAT IS LEPROSY? Leprosy, also known as Hansen's, is an incredibly rare condition. It is caused by slow multiplying bacteria (Mycobacterium leprae) which can destroy sufferers' eyesight and all sensation in their skin. The disease is spread through prolonged or repeated contact with an untreated patient - specifically, contact with their saliva or nasal mucus. It mainly affects the eyes, the upper respiratory tract, and the skin. Symptoms can appear as late as 20 years after a person has been infected. Patients are treated with a combination of antibiotics, and studies suggest antibiotics can protect healthy people from catching the disease. Advertisement

It is not clear whether the two patients are related, nor whether they recently traveled abroad.

According to the county's disease control director Barbara Cole, neither are hospitalized; both are at home near school in west Riverside County.

The Jurupa Unified School District informed families at Indian Hills Elementary School about the unconfirmed cases in a letter sent on Friday.

They insisted the diagnoses cannot be confirmed for a few weeks, but the district is doing everything possible to monitor and control the risk.

Parents were also issued with fact sheets explaining the disease, how it is transmitted, and how it is treated.

Leprosy is spread through prolonged or repeated contact with an untreated patient.

Specifically, it is spread through contact with their saliva or nasal mucus, which contains the infectious bacteria Mycobacterium leprae (or, M. leprae).

The disease mainly affects the eyes, the upper respiratory tract, and the surface nerves of the skin, which can eventually destroy the sensation in, for example, the feet, hands or face.

Symptoms can appear as late as 20 years after a person has been infected.

Patients are treated with a combination of antibiotics, and studies suggest antibiotics can protect healthy people from catching the disease.

As of 2014, there were fewer than 200,000 cases of the disease globally.

Jurupa Valley District Superintendent Elliott Duchon said classrooms at the school have been disinfected.

But she insists no further action is needed since schools are not a likely place of infection.

The disease is most typically associated with Asia and the Middle Ages. But to the horror of parents in Jurupa Valley, an hour's drive from LA, the condition may have hit the West Coast

'Even if the cases were confirmed, leprosy is not easily transmitted to others, and we don’t feel like there’s a risk in the school setting,' Duchon said.

'It's not a highly contagious disease.'