A History of Paralytic Bovine Rabies Transmitted by Vampire Bats in Mexico

Some of the first inhabitants of the American continent cited by paleoanthropologists are placed in what is now Mexico. The oldest evidence available so far describes them as hunters and gatherers, living in a cave in the state of Zacatecas, between 18,000 and 27,000 years ago. Along with the human remains, evidence of contact with various other mammals was found, including bears, rodents, and also vampire bats of the genus Desmodus, based on the environmental DNA. It is noteworthy that no evidence of dogs or wolves was found in the remains from that time. In fact, when the Spaniards arrived on the continent, they found three abundant Mesoamerican dog breeds that coexisted very closely with the people and that practically disappeared, replaced by the canine European breeds. Despite the richness of the pre-Hispanic civilization, there are no direct archaeological records such as monuments, sculptures or ceramics, nor indigenous medicine traditions of any disease that would suggest that there was rabies in humans or dogs in pre-Hispanic times, despite the presence of vampires, who were the object of adoration. The European colonizers brought cattle for the first time to the Americas and with it, the food that vampires needed to become a plague. It was then that the Spaniards noticed vampire attacks on people and later on cattle. One historian wrote that the Spaniards learned to treat wounds with hot water, which suggested for the first time in history that the natives already knew about rabies or some similar disease. Bovine paralytic rabies was first described in Brazil and later in Mexico. Once the disease was identified, this species began to be vaccinated with different types of biologics in the twentieth century. With international support, several projects arose to investigate bovine paralytic rabies in Mexico, which contemplated molecular diagnosis, cell culture vaccines, and control of vampire populations. More recently, research on bovine paralytic rabies in Mexico encompassed the use of monoclonal antibodies and molecular epidemiology, which culminated in the discovery of several viral variants, the geographic distribution of lineages, new reservoirs in wildlife, and the experimental development of oral vaccines, such as using transgenic plants. Now that Mexico is free of human rabies transmitted by dogs, it is urgent to focus and coordinate efforts to combat this disease in wildlife, of interest to public health, agriculture and conservation biology, in the context of One Health.