[Reading Science] The Paradox of the Vampire Bat: "Is Eradication Futile?"

South America Launches Rabies Eradication Efforts but Ineffective in High Spread Areas
"Comprehensive Measures Needed Including Preventive Population Control and Rabies Vaccination"

South American countries are attempting to eradicate the vampire bat (scientific name Desmodus rotundus), known as the host of rabies, to prevent the spread of the disease, but they are surprised by unexpected results. While the efforts were effective in areas where rabies had not yet spread, reducing the bat population in regions where the disease was already present did not help. Experts emphasize the urgent need for proactive preventive measures.

A research team from the University of Glasgow in the UK reported these findings in a paper published on the 10th in the international journal Science Advances. Vampire bats found in South America feed on the blood of animals such as cattle, and these bats serve as hosts for the rabies virus. Many animals die from rabies after being bitten by vampire bats, causing significant financial losses to farmers. Even humans can become infected with rabies after being bitten by vampire bats or other animals, and if left untreated until the terminal stage, it becomes difficult to cure, posing a public health threat. South American countries like Peru have been using a toxic substance called "vampiricide" to eradicate vampire bats and prevent the spread of rabies.

Bat. Stock photo.

The research team conducted a study in Peru to verify the effectiveness of this policy. They collected blood serum from animals in three regions of Peru for two years before and after the vampire bat eradication policy was implemented, analyzing rabies virus infection rates and genetic sequencing. The results showed that in areas where rabies had not yet spread, the eradication efforts slowed the virus's spread. This is because reducing the vampire bat population decreased opportunities for rabies virus transmission. The problem was that in regions where outbreaks had already begun, animals continued to die from rabies regardless of vampire bat eradication efforts. In other words, the findings directly contradict the health authorities' belief that reducing the vampire bat population helps prevent the spread of rabies.

The research team analyzed that the "Reactive culling" approach to disease control is showing its limitations. Vampire bats flee and migrate to avoid eradication efforts, leaving their usual habitats and thereby expanding the range of rabies virus spread. Previous studies had also shown that slaughtering vampire bats does not prevent rabies spread, but this paper utilized more extensive data and provided a comprehensive review of the effectiveness of culling policies.

Professor Daniel Streicker of the University of Glasgow said, "It is like trying to extinguish one fire while being unaware that another fire is burning elsewhere," adding, "Efforts are needed to reduce vampire bat populations through preventive culling before rabies outbreaks occur and to distribute rabies vaccines."