First molecular detection of astrovirus and rotavirus in Brazilian neotropical felids
Wild felids in Brazil have now yielded the first molecular evidence of astrovirus and rotavirus infection in Neotropical species, a finding that matters because these animals move through fragmented habitats where contact with domestic animals, invasive prey, and human-altered environments is increasingly common. The study screened 50 felids drawn from both free-ranging and captive settings across multiple Brazilian biomes, including the Amazon Forest, Atlantic Forest, Caatinga, and Cerrado. Fifty animals may sound modest, but in wildlife virology, a cohort that spans several species and ecosystems can expose pathogen circulation that would otherwise remain invisible.
One animal carried an astrovirus without obvious illness. Another harbored rotavirus in intestinal tissue after a roadkill event.
Those two detections do not establish disease burden, transmission direction, or clinical severity across felids. They do establish something more basic and more consequential for conservation medicine: these RNA viruses are present in wild Neotropical cats, and the ecological routes that place them there deserve scrutiny.
Viral screening across species, settings, and sample types
The animals studied included 19 ocelots, 12 pumas, seven jaguarundis, six southern tiger cats, three margays, and three jaguars. Samples came from blood, oral swabs, rectal swabs, and frozen tissues, allowing investigators to look across respiratory, gastrointestinal, and systemic compartments rather than relying on a single specimen type. RT-PCR was used for astrovirus detection, while real-time RT-PCR was used for rotavirus and cardiovirus, followed by sequencing to confirm what had been amplified.
That design matters in wildlife surveillance because viral shedding is not uniform across tissues. A rectal swab can reveal gastrointestinal passage when blood is negative, while frozen intestinal tissue can capture a pathogen present at death even when a carcass is too degraded for classic histopathology. In this study, autolysis limited morphologic interpretation of the rotavirus-positive puma, which is a familiar obstacle in field-based pathology. Roadkill specimens are often the only available window into disease in elusive carnivores, yet they arrive with a built-in penalty: tissue degradation can erase the histologic details needed to determine whether the virus was incidental, contributory, or merely passing through.
What the positive findings actually showed
The astrovirus detection came from the rectal swab of a healthy captive southern tiger cat. The animal was not described as ill, and there was no indication from the screened material that the virus had produced overt clinical disease at the time of sampling. The rotavirus finding came from the intestine of a roadkill puma and was identified as genotype G3P[3] Rotavirus A, formally described as a Rotavirus alphagastroenteritidis strain. Cardiovirus was not found in any felid sample.
In practical terms, the positive results are narrow but important. Astroviruses and rotaviruses are widely distributed among humans, domestic mammals, and wildlife, and both groups of viruses are known for environmental resilience. That resilience increases the likelihood of fecal-oral spread through contaminated surfaces, prey species, or shared ecological interfaces. In felids that hunt rodents or wild boars, pathogen exposure may be influenced by prey ecology as much as by direct contact with other carnivores. The study’s introduction places that risk in context: jaguars and pumas in Brazil consume wild boars, while smaller Neotropical felids often rely on rodents, many of which are recognized reservoirs for viral pathogens.
Ecological pressure, prey interfaces, and spillover risk
The detection of these viruses in wild felids should be read against the background of habitat fragmentation, environmental degradation, and increasing overlap between domestic, human, and wild animal populations. Those pressures do not merely alter movement patterns. They reshape pathogen traffic. When prey communities change and carnivores feed closer to human-dominated landscapes, viral exchange becomes more plausible, especially for agents capable of surviving outside the host long enough to bridge ecological gaps.
Astroviruses are single-stranded RNA viruses divided into avian and mammalian genera, and mammalian astroviruses have been reported in many host species. Rotaviruses are likewise broadly distributed and are recognized causes of enteric disease across mammalian populations. In felids, the biological question is not just whether the virus can be detected, but whether the host supports replication, shedding, and onward transmission. Molecular positivity alone cannot answer that, yet it is the first necessary step before more detailed epidemiology can begin.
The captive astrovirus-positive southern tiger cat adds a separate layer of concern. Captive wildlife can sit at the intersection of free-ranging exposure, enclosure contamination, and human handling, so a positive result in a managed animal should prompt attention to biosafety, sanitation, and screening protocols within conservation facilities. A single positive sample does not prove an outbreak. It does show that captive status is not a barrier to exposure.
Why negative cardiovirus results still matter
No cardiovirus signal appeared in any of the felid samples. In a surveillance study, a negative result is not an empty result; it narrows the set of agents currently documented in the host population and helps calibrate future testing priorities. It also suggests that, within the specimen types and animals sampled here, cardiovirus was not molecularly detectable at the time of collection.
The absence of cardiovirus should not be overread. Molecular surveillance is constrained by timing, tissue choice, and viral load. If shedding is intermittent, low-level, or tissue-specific, a negative screen may reflect sampling limits rather than true absence. Even so, the clean separation between the two positives and the cardiovirus-negative cohort strengthens the central message: selected RNA viruses are present in Brazilian Neotropical felids, but the detectable pattern is sparse and species-specific rather than widespread across the sampled group.
Conservation surveillance now has a clearer target
This study provides the first molecular detection of astrovirus and rotavirus in Neotropical wild felid species. The result does not support alarmism, and it does not justify assigning disease causality where pathology was unavailable or inconclusive. It does justify broader surveillance in both wild and captive settings, especially where carnivores live near invasive rodents, wild boars, domestic animals, and degraded habitats.
Future work will need larger sample sets, better-preserved tissues, and paired ecological data if investigators want to move from presence to transmission dynamics. For now, the most defensible clinical and conservation reading is simple: viral circulation in wild Brazilian felids is real, and the boundary between wildlife health and ecosystem change is already thin enough for molecular traces to appear in rectal swabs and intestine alike.