The white-tailed deer, most popular game species and best-studied wild animal in North America, has been carrying a malaria parasite that researchers have failed to notice for many years. Though it’s a sheer coincidence, the new find could help science in understanding how malaria originated, thanks to a DNA technology used.

Malaria parasites have hundreds of species spreading all over the globe, except southernmost continent Antarctica. Many of them are found in birds and lizards, even on remote ocean islands. Most of the science community has accepted an old belief that mammal-infecting malaria parasites were originated in the Old World. According to them, continents like Africa and Asia are the distributor of the microorganisms that infect animals.

The new research led by biologist Ellen Martinsen from the Smithsonian Conservation Biology Institute found the malaria parasite in white-tailed deer when she and her team were finding clues on malaria parasites’ origin in birds at the national zoo. They used polymerase chain reaction (PCR) technology and discovered something linked to malaria parasite, named Plasmodium odocoilei. It was the first time when the parasite was found in the Americas.

Martinsen and the team obtained blood sample from the mosquito’s enlarged abdomen to know its origin to the North America’s white-tailed deer. “We weren’t out there, testing a hypothesis. We serendipitously stumbled upon this weird sequence”, said Martinsen.

To find if the infections are common, the team examined over 300 white-tailed deer with the PCR technology. According to the researchers, they surveyed the animals from 10 of the 17 states and found that about 40 animals were with the parasite. The east had many infected deer, while west didn’t have any. One-fourth of the white-tailed deer from Virginia and West Virginia were carrying the infection, as per the research featured in Science Advances.