'I Am Finally Free': Leonard Peltier Released From Prison After Nearly 50 Years

"They may have imprisoned me but they never took my spirit!" said Peltier. "I am finally going home."


Leonard Peltier was released from a federal prison in Florida on Tuesday, February 18, 2025.
(Photo: Angel White Eyes / NDN Collective)

Julia Conley
Feb 18, 2025
COMMON DREAMS

Indigenous rights and criminal justice reform advocates on Tuesday celebrated as Native American political activist Leonard Peltier, who has maintained his innocence for nearly 50 years since being sentenced to life in prison for the killing of two FBI agents, walked out of a high-security prison in Florida and headed home to North Dakota.

"Today I am finally free," said Peltier in a statement to the Native news outlet Indianz.com. "They may have imprisoned me but they never took my spirit! Thank you to all my supporters throughout the world who fought for my freedom. I am finally going home. I look forward to seeing my friends, my family, and my community. It's a good day today."

Advocates for Peltier, who is 80 years old, have long called for a presidential pardon and celebrated in January when former President Joe Biden announced he was commuting Peltier's sentence. He will serve out the rest of his sentence in home confinement.

Nick Tilsen, CEO of the advocacy group NDN Collective, noted that before his conviction Peltier was one of thousands of Indigenous children who were taken from their families and sent to boarding schools, where many suffered abuse.

"He hasn't really had a home since he was taken away to boarding school," Tilsen told The Associated Press. "So he is excited to be at home and paint and have grandkids running around."

"Leonard's step outside the prison walls today marks a step toward his long overdue freedom and a step toward reconciliation with Native Americans."

Peltier, an enrolled member of the Turtle Mountain Band of Chippewa Indians in North Dakota, was convicted of two counts of first-degree murder and given two consecutive life sentences after prosecutors accused him of shooting two FBI agents at point-blank range during a confrontation at the Oglala Sioux Indian Reservation in Pine Ridge, South Dakota in 1975.

Peltier has always maintained that he did fire a gun during the confrontation, but from a distance and in self-defense. A witness who claimed that she saw Peltier shoot the agents later said she had been coerced into testifying and recanted her testimony.

Lynn Crooks, the federal chief prosecutor in the case, later admitted that the government "knew we hadn't proved" that Peltier was guilty.


The American Indian Movement, which fought for Native American treaty rights and tribal self-determination and in which Peltier was active, was subject to FBI surveillance and harassment when the shooting took place.

Kevin Sharp, an attorney and former federal judge who has represented Peltier and filed numerous clemency petitions for him, said the violent confrontation in 1975 was "unquestionably" a tragedy that was "only further compounded by the nearly 50 years of wrongful incarceration for Leonard Peltier."

"Misconduct by the government in the investigation and prosecution of Mr. Peltier has been a stain on our system of justice," said Sharp. "Leonard's step outside the prison walls today marks a step toward his long overdue freedom and a step toward reconciliation with Native Americans."

The AP reported that Peltier left USP Coleman in Sumterville, Florida in an SUV on Tuesday morning and didn't stop to speak to members of the press who were gathered outside.

Amnesty International, which has long campaigned for Peltier and considers him a political prisoner, applauded his release.

"Leonard Peltier's release is the right thing to do given the serious and ongoing human rights concerns about the fairness of his trial, his nearly 50 years behind bars, his health, and his age," Paul O'Brien, executive director of Amnesty International USA, said in a statement. "While we welcome his release from prison, he should not be restricted to home confinement."

Tilsen said that Peltier's "wrongful incarceration represented the oppression of Indigenous Peoples everywhere."


"Peltier's liberation is invaluable in and of itself," said Tilsen. "His release today is a symbol of our collective power and inherent freedom."

Probes Reveal Depth of Big Tech Complicity in Israel's AI-Driven Gaza Slaughter

"Many nations are looking to Israel and its use of AI in Gaza with admiration and jealousy," said one expert. "Expect to see a form of Google, Microsoft, and Amazon-backed AI in other war zones soon."


An aerial view shows Palestinians walking through the ruins of destroyed buildings in the Jabalia refugee camp, northern Gaza Strip, on February 5, 2025.
(Photo: Khalil Ramzi Alkahlut/Anadolu via Getty Images)

Brett Wilkins
Feb 18, 2025

Several recent journalistic investigations—including one published Tuesday by The Associated Press—have deepened the understanding of how Israeli forces are using artificial intelligence and cloud computing systems sold by U.S. tech titans for the mass surveillance and killing of Palestinians in Gaza.

The AP's Michael Biesecker, Sam Mednick, and Garance Burke found that Israel's use of Microsoft and OpenAI technology "skyrocketed" following Hamas' October 7, 2023 attack on Israel.

"This is the first confirmation we have gotten that commercial AI models are directly being used in warfare," Heidy Khlaaf, chief artificial intelligence scientist at the AI Now Institute and a former senior safety engineer at OpenAI, which makes ChatGPT, told the AP. "The implications are enormous for the role of tech in enabling this type of unethical and unlawful warfare going forward."

As Biesecker, Mednick, and Burke noted:
Israel's goal after the attack that killed about 1,200 people and took over 250 hostages was to eradicate Hamas, and its military has called AI a "game changer" in yielding targets more swiftly. Since the war started, more than 50,000 people have died in Gaza and Lebanon and nearly 70% of the buildings in Gaza have been devastated, according to health ministries in Gaza and Lebanon.

According to the AP report, Israel buys advanced AI models from OpenAI and Microsoft's Azure cloud platform. While OpenAI said it has no partnership with the Israel Defense Forces (IDF), in early 2024 the company quietly removed language from its usage policy that prohibited military use of its technology.

The AP reporters also found that Google and Amazon provide cloud computing and AI services to the IDF via Project Nimbus, a $1.2 billion contract signed in 2021. Furthermore, the IDF uses Cisco and Dell server farms or data centers. Red Hat, an independent IBM subsidiary, sells cloud computing services to the IDF. Microsoft partner Palantir Technologies also has a "strategic partnership" with Israel's military.

Google told the AP that the company is committed to creating AI "that protects people, promotes global growth, and supports national security."

However, Google recently removed from its Responsible AI principles a commitment to not use AI for the development of technology that could cause "overall harm," including weapons and surveillance.

The AP investigation follows a Washington Post probe published last month detailing how Google has been "directly assisting" the IDF and Israel's Ministry of Defense "despite the company's efforts to publicly distance itself from the country's national security apparatus after employee protests against a cloud computing contract with Israel's government."

Google fired dozens of workers following their participation in "No Tech for Apartheid" protests against the use of the company's products and services by forces accused of genocide in Gaza.

"A Google employee warned in one document that if the company didn't quickly provide more access, the military would turn instead to Google's cloud rival Amazon, which also works with Israel's government under the Nimbus contract," wrote Gerrit De Vynck, author of the Post report.

"As recently as November 2024, by which time a year of Israeli airstrikes had turned much of Gaza to rubble, documents show Israel's military was still tapping Google for its latest AI technology," De Vynck added. "Late that month, an employee requested access to the company's Gemini AI technology for the IDF, which wanted to develop its own AI assistant to process documents and audio, according to the documents."

Previous investigations have detailed how the IDF also uses Habsora, an Israeli AI system that can automatically select airstrike targets at an exponentially faster rate than ever before.

"In the past, there were times in Gaza when we would create 50 targets per year. And here the machine produced 100 targets in one day," former IDF Chief of Staff Aviv Kochavi told Yuval Abraham of +972 Magazine, a joint Israeli-Palestinian publication, in 2023. Another intelligence source said that Habsora has transformed the IDF into a "mass assassination factory" in which the "emphasis is on quantity and not quality" of kills.



Compounding the crisis, in the heated hours following the October 7 attack, mid-ranking IDF officers were empowered to order attacks on not only senior Hamas commanders but any fighter in the resistance group, no matter how junior. What's more, the officers were allowed to risk up to 20 civilian lives in each strike, and up to 500 noncombatant lives per day. Days later, that limit was lifted. Officers could order any number of strikes as they believed were legal, with no limits on civilian harm.

Senior IDF commanders sometimes approved strikes they knew could kill more than 100 civilians if the target was deemed important enough. In one AI-aided airstrike targeting one senior Hamas commander, the IDF dropped multiple U.S.-supplied 2,000-pound bombs, which can level an entire city block, on the Jabalia refugee camp in October 2023. According to the U.K.-based airstrike monitor Airwars, the bombing killed at least 126 people, 68 of them children, and wounded 280 others. Hamas' Qassam Brigades said four Israeli and three international hostages were also killed in the attack.

Then there's the mass surveillance element. Independent journalist Antony Loewenstein recently wrote for Middle East Eye that "corporate behemoths are storing massive amounts of information about every aspect of Palestinian life in Gaza, the occupied West Bank, and elsewhere."



"How this data will be used, in a time of war and mass surveillance, is obvious," Loewenstein continued. "Israel is building a huge database, Chinese-state style, on every Palestinian under occupation: what they do, where they go, who they see, what they like, what they want, what they fear, and what they post online."

"Palestinians are guinea pigs—but this ideology and work doesn't stay in Palestine," he said. "Silicon Valley has taken note, and the new Trump era is heralding an ever-tighter alliance among Big Tech, Israel, and the defense sector. There's money to be made, as AI currently operates in a regulation-free zone globally."

"Think about how many other states, both democratic and dictatorial, would love to have such extensive information about every citizen, making it far easier to target critics, dissidents, and opponents," Loewenstein added. "With the far right on the march globally—from Austria to Sweden, France to Germany, and the U.S. to Britain—Israel's ethno-nationalist model is seen as attractive and worth mimicking.

 

Are we trusting AI too much? New study demands accountability in Artificial Intelligence

University of Surrey

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Are we putting our faith in technology that we don't fully understand? A new study from the University of Surrey comes at a time when AI systems are making decisions impacting our daily lives—from banking and healthcare to crime detection. The study calls for an immediate shift in how AI models are designed and evaluated, emphasising the need for transparency and trustworthiness in these powerful algorithms. 

As AI becomes integrated into high-stakes sectors where decisions can have life-altering consequences, the risks associated with 'black box' models are greater than ever. The research sheds light on instances where AI systems must provide adequate explanations for their decisions, allowing users to trust and understand AI rather than leaving them confused and vulnerable. With cases of misdiagnosis in healthcare and erroneous fraud alerts in banking, the potential for harm – which could be life-threatening - is significant. 

Surrey's researchers detail the alarming instances where AI systems have failed to adequately explain their decisions, leaving users confused and vulnerable. With misdiagnosis cases in healthcare and erroneous fraud alerts in banking, the potential for harm is significant. Fraud datasets are inherently imbalanced - 0.01% are fraudulent transactions – leading to damage on the scale of billions of dollars. It is reassuring for people to know most transactions are genuine, but the imbalance challenges AI in learning fraud patterns. Still, AI algorithms can identify a fraudulent transaction with great precision but currently lack the capability to adequately explain why it is fraudulent. 

 

Dr Wolfgang Garn, co-author of the study and Senior Lecturer in Analytics at the University of Surrey, said: 

"We must not forget that behind every algorithm’s solution, there are real people whose lives are affected by the determined decisions. Our aim is to create AI systems that are not only intelligent but also provide explanations to people - the users of technology - that they can trust and understand." 

The study proposes a comprehensive framework known as SAGE (Settings, Audience, Goals, and Ethics) to address these critical issues. SAGE is designed to ensure that AI explanations are not only understandable but also contextually relevant to the end-users. By focusing on the specific needs and backgrounds of the intended audience, the SAGE framework aims to bridge the gap between complex AI decision-making processes and the human operators who depend on them. 

In conjunction with this framework, the research uses Scenario-Based Design (SBD) techniques, which delve deep into real-world scenarios to find out what users truly require from AI explanations. This method encourages researchers and developers to step into the shoes of the end-users, ensuring that AI systems are crafted with empathy and understanding at their core. 

Dr Wolfgang Garn continued: 

"We also need to highlight the shortcomings of existing AI models, which often lack the contextual awareness necessary to provide meaningful explanations. By identifying and addressing these gaps, our paper advocates for an evolution in AI development that prioritises user-centric design principles. It calls for AI developers to engage with industry specialists and end-users actively, fostering a collaborative environment where insights from various stakeholders can shape the future of AI. The path to a safer and more reliable AI landscape begins with a commitment to understanding the technology we create and the impact it has on our lives. The stakes are too high for us to ignore the call for change." 

The research highlights the importance of AI models explaining their outputs in a text form or graphical representations, catering to the diverse comprehension needs of users. This shift aims to ensure that explanations are not only accessible but also actionable, enabling users to make informed decisions based on AI insights. 

The study has been published in Applied Artificial Intelligence. 

[ENDS] 

Journal

Applied Artificial Intelligence

DOI

10.1080/08839514.2024.2430867 

Method of Research

Observational study

Article Title

Real-World Efficacy of Explainable Artificial Intelligence using the SAGE Framework and Scenario-Based Design

New AI framework aims to remove bias in key areas such as health, education, and recruitment

Researchers at the University of Navarra present this new prediction methodology that could help governments and companies eliminate algorithmic discrimination and ensure fairness in critical decision-making

Universidad de Navarra

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Caption: From left to right: Alberto García Galindo, Marcos López De Castro and Rubén Armañanzas Arnedillo

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Credit: Manuel Castells

Researchers from the Data Science and Artificial Intelligence Institute (DATAI) of the University of Navarra (Spain) have published an innovative methodology that improves the fairness and reliability of artificial intelligence models used in critical decision-making. These decisions significantly impact people's lives or the operations of organizations, as occurs in areas such as health, education, justice, or human resources. 

The team, formed by researchers Alberto García Galindo, Marcos López De Castro and Rubén Armañanzas Arnedillo, has developed a new theoretical framework that optimizes the parameters of reliable machine learning models. These models are AI algorithms that transparently make predictions, ensuring certain confidence levels. In this contribution, the researchers propose a methodology able to reduce inequalities related to sensitive attributes such as race, gender, or socioeconomic status.

Machine Learning, one of the leading scientific journals in artificial intelligence and machine learning, presents this study. It combines advanced prediction techniques (conformal prediction) with algorithms inspired by natural evolution (evolutionary learning). The derived algorithms offer rigorous confidence levels and ensure equitable coverage among different social and demographic groups. Thus, this new AI framework provides the same reliability level regardless of individuals' characteristics, ensuring fair and unbiased results.

"The widespread use of artificial intelligence in sensitive fields has raised ethical concerns due to possible algorithmic discriminations," explains Armañanzas Arnedillo, principal investigator of DATAI at the University of Navarra. "Our approach enables businesses and public policymakers to choose models that balance efficiency and fairness according to their needs, or responding to emerging regulations. This breakthrough is part of the University of Navarra's commitment to fostering a responsible AI culture and promoting ethical and transparent use of this technology.”

Application in real scenarios

Researchers tested this method on four benchmark datasets with different characteristics from real-world domains related to economic income, criminal recidivism, hospital readmission, and school applications. The results showed that the new prediction algorithms significantly reduced inequalities without compromising the accuracy of the predictions. "In our analysis, we found, for example, striking biases in the prediction of school admissions, evidencing a significant lack of fairness based on family financial status," notes Alberto García Galindo, DATAI predoctoral researcher at the University of Navarra and first author of the paper. "In turn, these experiments demonstrated that, on many occasions, our methodology manages to reduce such biases without compromising the model's predictive ability. Specifically, with our model, we found solutions in which discrimination was practically completely reduced while maintaining prediction accuracy." The methodology offers a 'Pareto front' of optimal algorithms, "which allows us to visualize the best available options according to priorities and to understand, for each case, how algorithmic fairness and accuracy are related".

According to the researchers, this innovation has vast potential in sectors where AI must support reliable and ethical critical decision-making. Garcia Galindo points out that their method "not only contributes to fairness but also enables a deeper understanding of how the configuration of models influences the results, which could guide future research in the regulation of AI algorithms." The researchers have made the code and data from the study publicly available to encourage further research applications and transparency in this emerging field.

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Journal

Machine Learning

DOI

10.1007/s10994-024-06721-w 

Method of Research

Meta-analysis

Subject of Research

Not applicable

Article Title

Fair prediction sets through multi-objective hyperparameter optimization

US tariffs threat a 'shock' to Canadian businesses

Agence France-Presse
February 18, 2025 

A truck prepares to enter the United States at a border crossing in Blackpool, Canada, a country which has vowed to hit back if Washington goes ahead with 25 percent tariffs on Canadian imports. (AFP)

by Anne-Marie PROVOST

Donald Trump's threats of import tariffs have sent shockwaves through Canada, forcing businesses to question their dependence on the United States -- a reassessment that is creating headaches for many sectors.

"It was an absolute shock," Matthew Holmes, vice president of the Canadian Chamber of Commerce, told AFP. "There's an incredible anxiety that comes from the unpredictability and the uncertainty."

"It got everybody talking in Canada about (how) we can't trust this partnership anymore," he added.

Earlier this month US President Trump announced 25 percent tariffs on Canadian and Mexican imports, then granted a 30-day reprieve.

The pause, however, has done little to reassure Canadian businesses that send more than 75 percent of Canada's exports to the United States, and who worry that a trade war would lead to a recession and hundreds of thousands of job losses.

Canada must prepare for the tariffs by removing barriers to trade between provinces and diversify its export markets, Holmes said. "We need to be ready and have the infrastructure and relationships and start building those out now."

Otherwise, he said, Canadian businesses will be "really, really screwed."

- 'No quick fix' -

According to a recent survey, nine out of 10 Canadians agree on the need to lessen Canada's trade reliance on the United States.

Prime Minister Justin Trudeau recently hosted a summit in Toronto that brought business leaders together to discuss ways of growing the Canadian economy, including removing internal trade barriers, diversifying export markets and boosting productivity.

Provincial governments and business leaders, he told delegates, must "step up and push hard" to make Canada more competitive, while acknowledging that it has been easy to just sell to the country's southern neighbor.

But that may be easier said than done, according to Robert Gillezeau, an economics professor at the University of Toronto.
"The two economies are extremely interconnected with over a trillion dollars in trade between the two countries," he told AFP, pointing to their close proximity and "longstanding good relations" for how ties developed.

"For some sectors, it'll be a little bit easier" to disentangle from the United States, Gillezeau said.

For others, "it's going to be a mess," he added. "You can't just snap your fingers and take that integrated industry and have it work with someone else or have it become fully domestic... There is no quick fix."

The food industry is a case in point.

"We've frozen our purchases of some American goods and we're looking elsewhere for alternatives," explains Mike Bono of Can-Am Food Services.

But it is not possible for the company -- which is one of the largest distributors of fruits and vegetables in Quebec and Ontario with nearly 3,000 customers including restaurants and hotels -- to find substitutes for all of its American offerings.
- Interprovincial trade barriers -

The removal of interprovincial trade barriers was flagged in a report as a way to boost Canada's economy as far back as 1940.

Ottawa led efforts to dismantle them in 2017 but hundreds of exceptions were kept in an agreement signed by the provinces.

Removing these barriers would improve productivity and increase Canadian GDP, but "would take a level of effort and coordination that we rarely see in the federation," Gillezeau said.

Internal Trade Minister Anita Anand, who wants to see these barriers abolished as soon as possible, believes that "in the face of Donald Trump's repeated threats, we must choose Canada."

She explained that removing the barriers -- such as alcohol sales restrictions, different labelling rules, varying professional licensing certifications, and independent dairy marketing boards in each province -- could lower prices by 15 percent, boost productivity and inject up to Can$200 billion into the economy.

Some are also calling for east-west oil and gas pipeline projects to be revived in order to lessen dependency on US infrastructure. Oil from western Alberta, for example, is currently shipped via a pipeline that dips into the United States before emerging in Ontario.

 

Novel insights from 26 years of monitoring highlights how moth abundances impact birds in boreal forests

University of Oulu, Finland

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A Pied Flycatcher having a lepidopteran larva in its beak - Photo by Sami Kivelä - University of Oulu

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Credit: Photo by Sami Kivelä - University of Oulu

A new study explored how changes in moth abundance affect insect-eating birds in Finland. The findings reveal that the impact of moths as a food source varies between bird groups and is generally stronger in northern areas. 

The study found a positive association between the abundance of moths (Lepidoptera) overwintering as eggs or adults and the abundance of resident or long-distance migrating forest birds, which are reliant on caterpillars as food source during their breeding season in the spring. The results indicate that early-season moth abundance significantly influences bird abundance, and particularly in the north-boreal zone. This highlights how species interactions depend on their environment and suggests that declines in insect populations could lead to declines in their bird predators.

However, a similar dependency of bird abundance on moth abundance was not found in southern and central parts of Finland, or for moths that are available for the birds later in the season.

“The reason why moth abundance affected bird abundance only in northern Finland is that in the north bird breeding seasons are short, food webs are relatively simple, and temporal moth abundance fluctuations from year to year are naturally strong. Therefore, abundance changes of a particular group of insect prey more likely reflect in bird abundance in northern Finland than in central or southern Finland”, explains Mahtab Yazdanian, the lead author and doctoral researcher at the University of Oulu. “In other words, birds in the north are more reliant on moth preys compared to birds in the central and southern regions of Finland.”

The study drew on 26 years of monitoring data. “This study highlights the value of long-term monitoring programmes. We are fortunate in Finland to have detailed abundance data for both moths and birds, which our study combines in full for the first time.”, explains Tuomas Kankaanpää, a postdoctoral researcher at the University of Oulu.

Such comprehensive temporal and spatial datasets are rare worldwide. “Complexities in the ecosystem, the food web, and the insect populations' fluctuations cascading effects on higher trophic levels like birds are really difficult to systematically study in nature where everything affects everything”, Yazdanian explains. One of the difficulties is that temporal moth abundance fluctuations from year to year are naturally strong. Large variations in abundance of insect prey are needed to reveal its importance for bird survival and reproduction.” Finland’s exceptional long-term monitoring schemes have provided this study with valuable data on almost 80 bird and 400 moth species dating back to 1993.

Deeper insights into ecological dynamics are gained, and the complexities of natural systems are better understood through the investigation of these datasets. The new study demonstrates that using long-term data in combination with information on birds’ migratory strategies and seasonal availability of different moth species facilitates uncovering regional differences in interactions between moths and their bird predators.

“Further investigations of insect abundance effects on bird populations are needed, especially in areas where insect numbers are declining”, Kankaanpää continues. The next research, currently underway at the University of Oulu, aims to identify which moth species are more important as a food source for specific bird species. Technological advances in DNA meta-barcoding helps to identify multiple species from a mixed sample, for example in diet analyses, currently ongoing by another research group at Ecology and Genetics Unit.

The outcomes of the new study address the concern of insect declines and their cascading impact on ecosystems amidst global changes. The results suggest that conservation strategies should consider the entire food web, including the preservation of insect populations, to support bird conservation efforts.

The research team was led by the University of Oulu and included experts from Finnish Environment Institute (SYKE), Finnish Museum of Natural History (LUOMUS), University of Lapland, and Vrije Universiteit Brussel.

The research article Evidence for bottom-up effects of moth abundance on forest birds in the north-boreal zone alone was published in the highly esteemed Ecology Letters journal in December 2024.

Read also

Light pollution has adverse effects on the overwintering of moths – new study could in part explain the decline in insect populations

Global change impacts on northern animal communities: from mechanisms to ecosystem-level implications

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Journal

Ecology Letters

DOI

10.1111/ele.14467 

Subject of Research

Animals

Article Title

Evidence for bottom-up effects of moth abundance on forest birds in the north-boreal zone alone

 

Landmark study of Chagas disease in Paraguay supports use of rapid tests to improve access to diagnosis

Combining rapid diagnostic tests with conventional serology proves to be a useful strategy for diagnosing Chagas disease in an indigenous community in the Paraguayan Chaco

Barcelona Institute for Global Health (ISGlobal)

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Rapid tests could be used to diagnose Chagas disease in resource-limited areas, according to a study led by the Barcelona Institute for Global Health (ISGlobal), a centre supported by ”la Caixa” Foundation. The results of this research, published in PLOS Neglected Tropical Diseases, show that the prevalence of Chagas in an indigenous community in Paraguay is six times higher than in the country's capital.

Chagas disease, caused by the parasite Trypanosoma cruzi, is a serious public health problem in the Americas. Between six and seven million people suffer from the disease, which is mainly transmitted by insect vectors. Under-diagnosis is one of the main obstacles in the fight against the parasite, reflected in the fact that less than 1% of those affected receive treatment. Chagas is primarily diagnosed by serological techniques—the detection of antibodies to T. cruzi in the blood—during the chronic phase of the disease. To improve diagnostic access, Paraguayan health authorities proposed a new algorithm for resource-limited settings: a combination of rapid diagnostic tests (RDTs) followed by conventional serological tests, such as enzyme-linked immunosorbent assay (ELISA).

"In July 2023, we conducted a two-week screening campaign in the endemic community of Casanillo (an indigenous community in the Paraguayan Chaco), involving 999 people," explains Sofía Ardiles Ruesjas, ISGlobal researcher and first author of the study. "We were able to verify the effectiveness of the combination of RDTs and serological tests compared to the standard method recommended by PAHO and WHO, which relies solely on conventional serological tests," she adds.

 

The potential of rapid tests

Although they have good sensitivity and specificity, conventional serological tests require specialised personnel and equipment, which are often in short supply in endemic regions. Even when these resources are available, access to health centres can be a challenge for local people.

The use of rapid diagnostic tests offers a new approach: they are easy to use, require only a minimal sample volume (blood from a finger prick), do not require special equipment, and ensure rapid delivery of results. The algorithm validated in the study suggests using RDTs for an initial screening of at-risk individuals in endemic areas, thereby reducing the need for serological testing to confirm positive results.

“Each participant underwent a rapid diagnostic test (RDT), and those with a positive result were confirmed using two different serological techniques (recombinant ELISA and lysate ELISA),” explains the ISGlobal researcher.

 

Variability in the prevalence of Chagas among communities

The study results of the study showed a seroprevalence (percentage of people with antibodies against T. cruzi) of 12.6% in the community of Casanillo, a figure significantly higher than the 2.1% estimated from blood banks in Asunción. This highlights the health inequalities between urban and rural areas.

The algorithm using rapid diagnostic tests (RDTs) showed high agreement with the standard algorithm, with a sensitivity of 94.6% and a specificity of 98.6%. These results are crucial for public health initiatives, as they validate the combined use of RDTs and conventional serology, an algorithm proposed by Paraguayan health authorities for resource-limited settings.

“The results obtained are particularly relevant in the context of a global re-evaluation of guidelines for the diagnosis and treatment of Chagas disease,” says Irene Losada, coordinator of the Chagas Initiative at ISGlobal and senior author of the study. “The adoption of RDT-based algorithms adapted to each region could improve access to diagnosis for thousands of people in remote areas,” she concludes.

 

Reference

Ardiles-Ruesjas, S., Lesmo, V., González-Romero, V., Cubilla, Z., Chena, L., Huber, C., Rivas, M. J., Saldaña, P., Carrascosa, A., Méndez, S., Sanz, S., Becker, S. L., Alonso-Padilla, J., & Losada, I. (2025). Prevalence and diagnostic accuracy of different diagnostic tests for Chagas disease in an indigenous community of the Paraguayan Chaco. PLoS Neglected Tropical Diseases, 19(2), e0012861. https://doi.org/10.1371/journal.pntd.0012861

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Journal

PLOS Neglected Tropical Diseases

DOI

10.1371/journal.pntd.0012861 

Method of Research

Observational study

Subject of Research

People