Scientists have discovered a dangerous new bacteria in Amazon sand flies that shares genetic material with deadly Andean strains known to cause fatal human disease.

Story Highlights

• New Bartonella bacteria found in Brazilian Amazon sand flies genetically matches deadly Andean disease strains
• Pathogen causes Carrión’s disease with potentially fatal fever and skin eruptions in humans
• Remote Amazon location has limited healthcare access and inadequate disease surveillance systems
• No current evidence of human infection, but researchers warn of “stealthy pathogenic potential”

Genetic Links to Deadly Andean Pathogens Discovered

Brazilian researchers from São Paulo State University identified an unknown Bartonella species in sand flies from Amazon National Park that shares DNA with B. bacilliformis and B. ancashensis. These Andean cousins cause Carrión’s disease, characterized by acute Oroya fever and chronic Peruvian wart eruptions. The genetic similarity raises immediate concerns about pathogenic capability, though human infection remains unconfirmed. This marks the first identification of such closely related strains outside the traditional Andean endemic zones.

🇧🇷 NEW BACTERIA FOUND IN AMAZON SAND FLIES

Scientists in Brazil just discovered a new Bartonella species lurking in sand flies deep in the Amazon.

That’s the same bacterial family behind Carrión’s disease in the Andes – a rare but deadly fever spread by the same kind of… https://t.co/9F3eihVDJT pic.twitter.com/9zfJiWttmO

— Mario Nawfal (@MarioNawfal) September 7, 2025

Remote Location Compounds Surveillance Challenges

Amazon National Park in Pará represents a perfect storm for disease emergence—extreme biodiversity, limited healthcare infrastructure, and inadequate monitoring systems. The region already harbors sand flies carrying leishmaniasis, demonstrating established vector-borne disease transmission pathways. Indigenous and rural populations face heightened vulnerability due to geographic isolation and restricted medical access. These conditions mirror historical patterns where remote regions become breeding grounds for emerging infectious diseases that eventually spread globally.

Watch: New Amazon Bacterium: Linked to Andean Disease-Causing Species

Research Reveals Urgent Need for Enhanced Monitoring

Lead researcher Marcos Rogério André warns of Bartonella’s “stealthy pathogenic potential,” particularly threatening immunocompromised individuals. The bacteria genus remains underrecognized in medical literature beyond cat scratch disease, creating dangerous knowledge gaps. Scientists conducted molecular screening from 2022-2024, publishing findings in September 2025 through Acta Tropica journal. Current research limitations prevent determining mammalian reservoir hosts or sand fly feeding behaviors—critical factors for assessing human transmission risk.

Global Health Security Implications Emerge

This discovery exposes broader vulnerabilities in international disease surveillance systems, particularly in biodiverse tropical regions where ecological changes accelerate pathogen evolution. Vector-borne diseases like leishmaniasis and Chagas disease have expanded their ranges throughout South America due to increased human activity in forested areas. The potential emergence of new Bartonella strains capable of human infection could strain healthcare resources and demand enhanced international cooperation for monitoring and response protocols.

Sources:

New Bacteria Species Discovered in Brazil’s Amazon May Be Linked to Diseases Caused by Andean Counterparts
New Bacteria Species Discovered in Brazil’s Amazon May Be Linked to Diseases Caused by Andean Counterparts
Mysterious New Bacteria Discovered in the Amazon Raises Global Health Questions
Newly Discovered Amazonian Bacterium Closely Related to Andean Species Responsible for Human Bartonellosis
New Bartonella Bacteria Found in Amazon Sand Flies Sparks Health Concerns