FOUR people in the US have died this year after being infected with an incurable disease spread by rats. They were all diagnosed with hantavirus , a family of viruses that kill around 38 per cent of patients and spread via rodent droppings. It typically only causes around 30 cases per year in the US but some parts of the country are recording a surge in the disease.

Arizona public health officials have confirmed six cases and three deaths in the past six months. This is compared to 11 cases in the six years from 2016 to 2022. There have also been two cases and one death in California this year, including in a country that hasn't detected the virus in humans in two decades.

Experts speculate the extreme heat waves sweeping across the county, may be partly to blame. “Many carrying-disease species get on the move with climate change," Dr Camilo Mora, professor in the Department of Geography and Environment at the University of Hawaii at Mānoa, said. "While for any specific case, it is difficult to conclude the role of climate change, climate change has all the attributes to cause outbreaks of vector-borne diseases,” he told NBC News .

Rats and mice can carry hantavirus but not suffer any symptoms. Most read in Health Meanwhile, humans can suffer an abrupt onset of fever, muscle aches, nausea and abdominal pain nine to 33 days after infection. MORE SERIOUS INFECTION Sometimes, this can progress to something more serious called Hantavirus Pulmonary Syndrome , which has a 50 .