British Red Squirrels Face to Face With Leprosy

A British red squirrel sitting on a man's backpack.

Scientists have recently discovered that many British red squirrels died of medieval leprosy.

Although leprosy is a disease remembered for causing the death of many people in the 1500s, it seems that it’s still present in some animal species, such as the British red squirrels. Based on the latest study conducted by a team of scientists from the University of Edinburgh and EPFL, many red squirrels across Ireland, Scotland, and England died due to leprosy.

Furthermore, the researchers discovered a leprosy strain in Brownsea Island squirrels which was similar to the one which killed thousands of people in five hundred years before. It means that the disease has not been completely eradicated from the country, but it remained hidden in other animal species.

The scientists say that they will continue their investigation to find out the source of this outbreak. This way, they will be able to develop an efficient strategy to address this issue and to make sure that this life-threatening disease will not spread to humans.

Leprosy is a contagious disease caused by a bacterium which can live in the host’s body for several years without triggering any symptoms. It usually leads to nerve decays, eyesight problems, and severe skin lesions.

The team found similar symptoms in the British red squirrels including swollen digits, ears, eyes, and alopecia or hair loss. Despite the fact that many specimens were infected with leprosy, this is not the primary factor influencing the massive decline in the squirrels’ population.

Experts stress that many British red squirrels died due to habitat loss, pollution, lack of food, and excessive hunting. More precisely, these animals were hunted in the middle ages because their fur brought great profit to merchants.

Although there were once more than a few million British red squirrels across the world, just 120,000 specimens are remaining. Biologists observed that the squirrel population plummeted, so they decided to collect samples from various regions throughout the United Kingdom.

The team compared the samples with the DNA of infected people in Mexico and skeletons from the 1500s. Based on the lab results, they concluded that all of them presented the Mycobacterium leprae, which caused the classic form of leprosy.

The researchers say that one of their projects is to develop a captive breeding program aimed to boost the immunity of the British red squirrels. If the program is successful, the mortality rates will drop as well as the risk of an outbreak among humans.

Image Source: Geograph