The case of a 15-year-old teen catching cowpox has left medical experts surprised.
According to the BBC, the viral disease, which was common in the 18th century, is rarely seen in humans or animals. The unnamed 15 year old had lesions full of pus on his hands, arms and feet about three months ago. And although it wasn’t particularly painful, doctors add the teen developed itchiness and discomfort.
Public Health Wales said the last reported human case of cowpox was 10 to 15 years ago, and others cases often involve cats.
“We were really unsure what it was,” the teen’s mother told the BBC. “The one on his ankle was worrying — it was weeping a clear liquid down his ankle.”
“I didn’t really know what it was, so I was quite concerned,” she continued. “The first thing you do is look on the internet and that’s when I found out it was quite rare.”
What is cowpox?
The virus is not contagious from person-to-person, but in the 18th century, it was common among milkmaids who milked infected cows with their hands. The BBC notes industrial farming methods meant less people were touching cows with their bare hands, and soon, the virus slowly began to disappear.
Encyclopaedia Britannica notes cowpox is similar to variola, the causative virus of smallpox, and it is also commonly referred to as live vaccinia virus in humans.
In 1798, the World Health Organization notes, English physician Edward Jenner figured out cowpox could protect humans from smallpox. “This brought the first hope that the disease could be controlled. Vaccinia vaccine has been used continuously since then,” the organization notes.
In a 2005 report published in the Baylor University Medical Center Proceedings journal, authors pointed out Jenner was told by milkmaids that they wouldn’t get smallpox because they had cowpox, which eventually led him to be one of the first physicians to create a foundation of immunology.
In an experiment, he found a milkmaid with cowpox and inoculated a young boy with matter from the maid’s lesions.
Pustules on a dairymaid’s arm infected with cowpox. Photo by: Universal History Archive/UIG via Getty Images
“Jenner concluded that cowpox not only protected against smallpox but also could be transmitted from one person to another as a deliberate mechanism of protection,” authors noted. “The Latin word for cow is vacca, and cowpox is vaccinia; Jenner decided to call this new procedure vaccination.”
Speaking with the BBC, Dr. Aysha Javed, who diagnosed the 15-year-old U.K. teen, said it was the first case of cowpox she had ever seen. She concluded his rash vanished after six weeks without treatment.
“I think the boy and his family were quite bemused when we told them — I don’t think they expected that to be the diagnosis,” she told the site. “We don’t really see cowpox anymore — it’s one of those diseases that went away.”
Because of how rare it is, Javed explained it was important for public health professionals to be alerted, especially if there is a possibility an older virus can reemerge.
In early 2009, the CDC reports, there were four cases of cowpox virus cutaneous infection after four individuals came in contact with infected pet rats.
One patient was an 18-year-old woman who developed the virus after a pet rat had scratched her right arm. “Sporadic human cases of cowpox virus infection have occurred in several European countries over the past few years. For most cases the source was domestic cats,” authors explained.
Diseases making a comeback
It’s also not unheard of when diseases make comebacks. Recently, a measles outbreak from earlier this year in Europe was caused by a growing anti-vaccination movement, experts say.
The British Association of Dermatologists told the BBC that although this makes an interesting case to study, it shouldn’t cause public panic.
“Although this resurgence is interesting, it’s not something that is particularly worrying as cowpox tends to be benign in nature to otherwise healthy people.”