Wild monkeys in the Amazon have been discovered carrying a lethal human disease for the first time, a finding that experts attribute to the encroachment of civilization into the rainforest. Researchers from the University of Salford in the UK and Brazil’s Federal University of Amazonas identified human hepatitis B in samples taken from 88 ‘new world’ primates of 28 different species.
The study revealed instances of human-to-monkey transmission in regions heavily affected by deforestation and urban expansion. In states like Rondonia and Mato Grosso in Brazil, where forests have been extensively cleared and urban areas have encroached upon the forest perimeters, 17 out of 49 tested monkeys were positive for hepatitis B virus (HBV), showing genetic similarities to strains found in the local human population.
Conversely, in a remote area along the upper Japurá River in Amazonas state, none of the 39 sampled monkeys tested positive for the infection, as reported by Refractor. This disparity serves as a warning sign that closer human-wildlife interaction increases the likelihood of disease transmission, posing risks for both sides.
HBV attacks the liver and can lead to serious conditions like cirrhosis and cancer in humans. The virus primarily spreads through blood and specific bodily fluids, making its presence in wild primates a perplexing phenomenon. The research, published in the journal EcoHealth, marks the first documentation of HBV in New World primates in Central and South America, prompting urgent inquiries into its origins and potential implications.
Lead researcher Professor Jean Boubli from the University of Salford emphasized the mystery surrounding the transmission route. Plausible factors include the thriving pet trade in the region, where young monkeys may be exposed to infection before being released into the wild as they mature. Additionally, the proximity of urban centers and settlements to forest boundaries has increased human-wildlife interactions, escalating the risk of cross-species disease transfer.
Boubli underscored deforestation as the primary threat, as it brings humans, livestock, and wildlife into closer contact, fostering opportunities for disease spillover. The research team advocates for halting deforestation and establishing buffer zones between communities and native forests to mitigate these risks and safeguard the health of both animals and humans.
While the infected monkeys do not exhibit obvious clinical symptoms in the wild, the study urges further investigation in captivity to assess the impact of HBV on New World primates and its potential consequences upon their return to the wild. The study also highlights broader public health concerns, as Indigenous populations and local communities in the Amazon region consume primates for sustenance, raising the possibility of disease transmission between species due to changing environmental dynamics.
Although the emergence of a new pandemic is not imminent, the study serves as a stark reminder that human activities are reshaping disease dynamics within the Amazon rainforest.
