Researchers from the University of Vermont reported that a rare disease is spreading among catfish fry in Memphremagog Lake, located on the border between the state of Vermont in the United States and Quebec in Canada. The study showed that the animals are suffering from a form of skin cancer capable of being transmitted from one fish to another.
The results were published in the journal Nature last Wednesday (the 22nd) after more than ten years of study, which began when fishermen noticed the appearance of dark spots and raised lesions on the lake's fish. Scientists concluded that the tumors share a common origin from a single cancerous cell line.
The study suggests that the disease started with an infected individual whose tumor mass released malignant cells into the water. These cells, it is presumed, reached other individuals, creating a chain of transmission previously unregistered in fish.
The situation drew attention in 2012 when fishermen began noticing catfish fry covered in unusual black growths in Memphremagog Lake. Subsequent assessment by biologists determined that this was melanoma, a type of skin cancer. This phenomenon surprised researchers, as such a type of tumor is considered extremely rare for this species. Nevertheless, over a third of the examined fish had this disease, prompting the team to seek an explanation for the high concentration of cases.
Geneticist Julie Dragon from the University of Vermont participated in the analysis to determine the cause of the problem. Initially, scientists considered hypotheses such as exposure to ultraviolet radiation, environmental pollution from a nearby landfill, or the action of microorganisms capable of causing carcinogenic changes. However, tests did not reveal elevated levels of pollutants or evidence of viruses or bacteria associated with tumor development.
Consequently, the team decided to compare the genetic material of the fish with the DNA present in the cancer cells. The analysis revealed an unexpected pattern: the tumor cells of different fish were genetically very similar to each other but did not match the DNA of the animals carrying the tumors. This result forced scientists to reconsider the initial hypothesis that each fish developed its own cancer. The similarity of the tumors indicated that they might have originated from the same ancestral cancer cell. This pattern persisted when new samples were collected. The team concluded that the fish were not simply developing independent tumors but were receiving cancer cells from another individual.
Before this discovery, transmissible cancers had only been registered in a few groups of animals, including dogs, Tasmanian devils, and some types of mollusks. In dogs, viral transmissible cancer can be transmitted during sexual contact, and genetic studies show that this cancer line originates from one dog that lived thousands of years ago. In Tasmanian devils, face cancer caused by tumor cells transmitted through bites contributed to a severe decline in the species' population. Among mollusks, researchers found leukemia that spreads in seawater.
The case with catfish expands knowledge of this phenomenon, as it is the first registration of transmissible cancer in a freshwater environment. Scientists believe that this discovery may indicate that such events occur more often than previously thought but remain insufficiently studied.
Researchers believe that catfish reproduction may have contributed to the spread of the disease. During spawning, the fish gather in small areas where bites and scratches can occur. These injuries create opportunities for cancer cells present in the water to reach other animals. The environmental dynamics facilitated the transfer of tumor cells between individuals. The team also found signs that similar cases might have occurred in other areas of the northeastern US. Some of this evidence comes from old records of naturalist Henry David Thoreau, who described fish with dark spots in the 19th century.
Scientists involved in the study are now trying to determine if other catfish are suffering from this disease. To do this, they are asking fishermen and biologists to send images of fish with dark tumors and information about the location where the animals were found. Researchers recommend freezing suspicious specimens in case of future analyses. Although there is no evidence that sick fish are unsafe for consumption, specialists advise caution and avoiding the consumption of animals with tumors. Despite the discovery, there is no indication that transmissible cancers circulate among humans. Specialists, however, believe that the new case strengthens the possibility of such phenomena occurring in various species.
A systematic review analyzing data from 2.8 million children across 40 countries identified the main elements linked to the onset of food allergies in early life. Published in the journal JAMA Pediatrics, the study suggests that this condition results from the interaction between genetic predisposition, changes in the skin barrier, early exposure to antibiotics, and environmental influences.
Food allergy manifests when the immune system responds inappropriately to certain proteins found in foods such as milk, egg, peanuts, nuts, or fish. Instead of considering these proteins harmless, the body perceives them as a threat, which can lead to symptoms ranging from mild to severe reactions, such as anaphylaxis. According to pediatric allergist Renata Rodrigues Cocco, the child's immune system is still developing, allowing it to identify food proteins as foreign, triggering the allergic reaction.
The researchers examined 190 studies and evaluated 342 potential factors. The main conclusion points to the relevance of atopic dermatitis (eczema) in the first year of life, late introduction of allergenic foods (such as egg and peanuts), antibiotic use in the first months, and family history of allergies. Although smaller correlations were noted with Cesarean delivery, male sex, and being the firstborn, these aspects had less impact.
Renata Cocco comments that today it is understood that food allergy does not have a single cause, and it is classified as a disease characteristic of contemporary life. She adds that factors such as alterations in the microbiome, diets rich in ultra-processed foods, pollution, and other environmental elements can increase mucosal permeability, causing the immune system to begin treating food proteins as dangerous.
One of the most significant findings of the review is the link between atopic dermatitis and the appearance of food allergies. Babies who presented with eczema in the first year of life showed three to four times higher risk of developing allergies. This is due to the protective role of the skin. The specialist explains that atopic dermatitis is seen as a warning sign, part of the so-called 'atopic march,' a sequence that can progress from eczema to food allergies and subsequently to rhinitis and asthma.
Another crucial point addressed by the study is the timing of food introduction. It was found that offering peanuts only after 12 months of age more than doubles the chance of the child developing a food allergy. This data corroborates recent pediatric guidelines, which discourage delaying potentially allergenic foods as a preventive measure.
Renata Cocco advises that exclusive breastfeeding should be maintained until six months, starting gradual food introduction from this period, including all food groups, such as egg, fish, and peanuts, according to child development and under pediatric guidance. The study also established a connection between antibiotic use, especially in the first month of life, and an elevated risk of food allergies. The most plausible hypothesis for this lies in the effect of these medications on the microbiome, the collection of microorganisms essential for the development and strengthening of the child's immune system.
Additionally, genetic predisposition is a relevant factor, as children whose parents or siblings are allergic have a higher probability of developing the condition. However, the doctor emphasizes that the genetic component is not the sole cause, but rather the combination of genetics and environmental factors that seems to favor the development of allergies.
The work also correlated food allergies with low birth weight, post-term birth, partial breastfeeding, maternal diet during pregnancy, and gestational stress. However, the specialist advises caution in interpreting these results, mentioning important methodological limitations related to stress and nutrition during pregnancy. She concludes by stating that there is already more solid evidence that restricting allergenic foods during pregnancy does not prevent the emergence of allergies in the child.
OpenAI has made the availability of ChatGPT Health, its health and wellness focused assistant, public for all adults residing in the United States. This launch occurred this week and is accessible in both free and paid versions, on both the web interface and iOS devices.
This move comes one day after a lawsuit filed by a Florida pastor. He alleged that he received advice from the artificial intelligence that could be fatal, as he was advised not to seek specialized medical assistance.
The tool's functionality is based on cross-analysis of clinical records and metrics obtained from healthy living applications, utilizing the computational model GPT 5.6-Luna. The system registered an impressive volume of 300 million requests every seven days.
Due to the high volume of use, the system has been updated to allow diagnoses and dietary habits to be consolidated in any conversation section within the ecosystem, expanding its applicability beyond the restricted dashboard previously used only by volunteers in tests.
The ecosystem's infrastructure allows for the unification of databases from large hospital networks, such as Epic and Oracle Health, in addition to integrating services like One Medical, Apple Health, Function, and MyFitnessPal.
The developer emphasized that any private data entered into the dashboard is not used to train its algorithms. Furthermore, she highlighted the continuous participation of medical professionals in refining the responses provided.
Although the GPT 5.6-Luna model demonstrated superior performance compared to the GPT 5.5 version metrics in the HealthBench test, the corporation reiterated in its terms of use that the mechanism does not have the capacity to issue diagnoses or prescribe treatments for diseases. The company's advisory informed the press that it strongly recommends confirming any guidance with human specialists.
Recent academic research indicates inconsistencies in virtual robots when offering clinical diagnoses. However, this scenario of uncertainty has not prevented the advancement of large technology companies, as competitors such as Google and Anthropic continue to invest in developing similar tools aimed at human health.
A source close to the politician's defense informed the Lusa agency by phone from Lisbon that the opposition figure has gone to Portugal to receive medical assistance.
Simões Pereira has been under pre-trial detention since July 10. He is accused by military courts of participating in an alleged coup attempt that occurred in October 2025.
