Category: Pathobiome of wildlife in Brazil

  • Uncovering the link between armadillo hunting, deforestation and leprosy

    Uncovering the link between armadillo hunting, deforestation and leprosy

    A nine-banded armadillo (Dasypus novemcinctus). Photo by Jim Mullhaupt.

    By Daniella Silva

    This content was originally posted on Forests News.


    6 Jul. 2026 — Leprosy (caused by the bacterium Mycobacterium leprae) is an ongoing public health challenge across the tropical Americas. The disease primarily affects the skin and peripheral nerves and – until recently – was thought to spread mainly from human to human through respiratory droplets. Mounting evidence, however, suggests armadillos can also transmit the disease to humans, especially when people hunt and handle them directly.

    An estimated 25 percent of all new human leprosy cases in Brazil are now linked to armadillos, and that figure jumps to 40 percent in deforestation hotspots, such as the Amazon’s so-called “arc of deforestation“.

    These findings come from a 2025 study in Infectious Diseases of Poverty, which maps where armadillo-to-human leprosy transmission happens most and where public health interventions work best.

    Drawing on more than 326,000 reported leprosy cases across Brazil between 2013 and 2022 and a dataset of 554 hunted armadillos across 175 municipalities, the researchers developed a model to estimate the armadillo-hunting infection risk. They also identified other factors that amplify the risk, including higher population density, environmental degradation (deforestation), malnutrition and socioeconomic status.

    Hani Rocha El Bizri, lead author and coordinator of the Sustainable Use of Wild Species Transformative Partnership Platform (SU-TPP), sat down with Forests News to share more.

    What is the link between armadillo hunting, deforestation and leprosy in Brazil?

    The most important finding of the study is that an estimated 25 percent of all new human leprosy cases in Brazil relate to hunting and consumption of armadillo meat.

    Before this study, the World Health Organization (WHO) recognized a link between armadillos and leprosy transmission; a few human cases had been reported in the United States that matched the genotype of the leprosy bacteria, Mycobacterium leprae. However, our findings suggest the number of people infected through hunting armadillos is much higher than expected.

    We also identified several other variables responsible for zoonotic disease transfer. In heavily deforested areas, we see a higher prevalence of the disease in both humans and armadillos. In some municipalities located in Brazil’s ‘arc of deforestation,’ up to 40 percent of leprosy cases could be attributed to armadillo hunting and use. This is very high and very concerning.


    Acknowledgements

    Landscape Alliance scientists contributed key data sets and collaborated on this research with researchers from many institutions; funding comes from the University of Malaga, the TRADEHub project and the Leprosy Research Initiative (LRI).

  • Wild monkeys are catching HBV in the Brazilian Amazon deforestation frontier

    Wild monkeys are catching HBV in the Brazilian Amazon deforestation frontier

    6 Apr. 2026 — A new study in EcoHealth is the first report of human hepatitis B virus (HBV) in wild neotropical primates. 

    Researchers tested blood or liver samples from 88 primates across 28 species and two Brazilian Amazonian regions—one human-impacted area (Rondonia and Mato Grosso states) and one remote area (upper Japurá River, Amazonas state). They found HBV in 17 out of 49 primates from the human-impacted areas. None of the 39 primate samples from the remote area had contracted HBV.  

    The findings suggest that human population density significantly predicts human HBV infection in wild primates, supporting the hypothesis of human-to-primate disease spillover that is driven by deforestation and encroachment (Figure 1) 

    Figure 1: A scatter plot showing the positive correlation between HBV probability in monkeys and human population density (persons/km2) 

    Why it matters

    Increasing deforestation and human encroachment into wildlife habitats is increasing human-primate interactions, which could lead to more cross-species disease transmission. In the Amazon, Indigenous people and local communities consume an estimated three million primates from the genara AlouattaAteles and Sapajus for subsistence. Other primate species, especially squirrel monkeys (Samiri spp.) are often traded as pets. Both the pet trade and subsistence hunting increase instances of human-primate interaction. 

    Primates (e.g. chimpanzees) who contract HBV have been shown in experimental studies to develop symptoms such as lethargy, jaundice and anorexia. However, there are currently no clinical studies involving New World primates. 

    What’s next?

    The study recommends increased monitoring and preventative measures to mitigate the risk of human-primate disease transmission. 


    Acknowledgements

    Molecular analyses and Japura field expeditions were funded by CNPq SISBIOTA Program to IPF, and in Rondˆonia by grants from the Fundac¸a˜o Oswaldo Cruz Rondˆonia (FIOCRUZ/RO), Fiocruz- Rondˆonia, CT-Amazˆonia, and CNPq Universal.