Did Dinos Get Malaria?

Malaria has long been considered a relatively modern disease - researchers thought the modern parasites had only been around for 15,000 to 8 million years. That may sound like a long time, but a new study from Oregon State University found that malaria originated nearly 100 million years ago!

Modern malaria parasites belong to five species in the genus Plasmodium and are transmitted to humans by the Anopheles mosquito. The first documented case of human malaria was recorded in China in 2,700 BC. Today, the parasites kill more than 400,000 people each year. The malaria parasite’s life cycle within its vertebrate host is quite complex. The parasites first enter the liver, infecting and multiplying within hepatocytes. The second stage of disease occurs when the parasites exit the liver and enter the bloodstream. Here, they infect and lyse red blood cells.
 
According to the fossil record, Plasmodium malaria appeared in the New World at least 15 million years ago -  Plasmodium dominicana was found inside a Culex malariager mosquito trapped in amber from the Dominican Republic.

The new report, authored by George Poinar of Oregon State University, indicates that malaria progenitors, parasites such as Coccidia and Gregarinida, co-evolved with insects (probably biting midges) much earlier than previously thought. Poinar describes oocysts of a malaria progenitor, Paleohaemoproteus burmacis, found in a 100 million year old Protoculicoides biting midge trapped in amber from Myanmar (Think, Jurassic Park! Okay, Cretaceous Park.)

“Scientists have argued and disagreed for a long time about how malaria evolved and how old it is … I think the fossil evidence shows that modern malaria vectored by mosquitoes is at least 20 million years old, and earlier forms of the disease, carried by biting midges, are at least 100 million years old and probably much older”, says Poinar.

With this time frame, dinosaurs could have been among the first vertebrate hosts to these early malaria parasites - Poinar even published a book suggesting that malaria may have played a part in the extinction of the dinosaurs. According to Poinar, “there were catastrophic events known to have happened around that time, such as asteroid impacts and lava flows … but it’s still clear that dinosaurs declined and slowly became extinct over thousands of years, which suggests other issues must also have been at work. Insects, microbial pathogens and vertebrate diseases were just emerging around that same time, including malaria.”
 
Sources: Oregon State University, American Entomologist, Wikipedia