Scientists have identified squirrels as a probable animal source of mpox in Africa, marking a major breakthrough in understanding how the virus persists in nature and spreads to humans. Researchers studying a 2026 outbreak in Côte d'Ivoire found compelling evidence that fire-footed rope squirrels transmitted the monkeypox virus to sooty mangabeys, a type of primate, which then spilled over into human populations. This discovery fundamentally changes how experts think about mpox transmission and raises urgent questions about whether the virus could spark another global outbreak. What Makes Squirrels a Dangerous Mpox Reservoir? For years, scientists knew mpox was a zoonotic disease, meaning it jumps from animals to humans, but the exact animal source remained a mystery. The new research from a comprehensive wildlife disease investigation provides several lines of evidence pointing directly to squirrels. Researchers examined samples from fire-footed rope squirrels in Taï National Park and found genetic signatures matching the virus that infected sooty mangabeys and subsequently humans in the region. The significance of this finding lies in understanding transmission pathways. Unlike previous assumptions about mpox sources, squirrels appear to maintain the virus in nature, making them a true reservoir. A reservoir is an animal species that harbors a pathogen and allows it to persist in the environment indefinitely. This means mpox could continue circulating in wildlife populations even if human cases are controlled. How Does Mpox Jump From Squirrels to Humans? The transmission chain typically involves contact with infected animals or their bodily fluids. In West Africa, the wild meat trade plays a critical role in this process. When people hunt, butcher, or prepare wild animals for food, they risk direct contact with infected blood and tissues. The research emphasizes the ongoing risk at the human-animal interface, particularly in regions where hunting and consumption of wild meat remain common practices. The 2022 global mpox outbreak that affected over 100 countries demonstrated how quickly the virus can spread once it reaches human populations. Researchers are now investigating whether the virus has evolved in ways that make it more transmissible between humans or more capable of establishing itself in new animal populations. Why Is Mpox Being Confused With Other Diseases? A surprising discovery during mpox surveillance efforts in Senegal revealed a major diagnostic challenge. When health officials tested 103 patients suspected of having mpox in 2024, they found something unexpected: 30.1% tested positive for varicella-zoster virus, which causes chickenpox, while zero actual mpox cases were detected. This high rate of misdiagnosis highlights a critical public health problem. The confusion occurs because mpox and chickenpox produce remarkably similar symptoms. Both cause fever, skin rash, headache, and muscle pain. Without proper laboratory testing, healthcare workers and patients cannot distinguish between them. The Senegal study revealed that children under 15 years old accounted for 50% of herpesvirus cases, while adults over 30 made up 30.8% of cases. Males were affected at higher rates than females, with a male-to-female ratio of 2.1 among those testing positive for herpesviruses. Phylogenetic analysis of 14 newly sequenced varicella-zoster virus genomes from Senegal showed that circulating strains were closely related to those found in Guinea-Bissau, suggesting regional transmission patterns. Additionally, researchers identified viral and bacterial coinfections in some patients, meaning people had multiple infections simultaneously, which may have contributed to skin lesions initially suspected to be mpox. Steps to Improve Mpox Detection and Prevention - Enhanced Laboratory Diagnostics: Implement molecular testing via qPCR (quantitative polymerase chain reaction) to definitively distinguish mpox from chickenpox and other infections that cause similar symptoms, reducing misdiagnosis rates. - Targeted Public Health Interventions: Develop region-specific surveillance programs that account for local disease patterns, such as the high circulation of varicella-zoster virus in West Africa, to guide appropriate resource allocation. - Differential Diagnostic Testing: Train healthcare workers to order comprehensive testing panels for patients with rash and fever rather than assuming a single diagnosis, particularly in areas where multiple viruses circulate simultaneously. - Wildlife Contact Risk Reduction: Educate communities about safe handling practices during hunting and butchering of wild animals, including use of protective equipment and proper food preparation techniques to minimize exposure to infected tissues. Could Mpox Spread Globally Again? The discovery of squirrels as a natural reservoir raises a critical question: will mpox go global again? Researchers are actively investigating how the virus managed to spread worldwide in 2022 and what conditions might enable another international outbreak. The virus appears to be evolving in curious ways, according to recent research, though scientists are still working to understand the exact nature of these changes. The key difference between the 2022 outbreak and current African cases is transmission efficiency. The 2022 outbreak spread rapidly through human-to-human contact, particularly among specific populations. Current outbreaks remain largely localized to Africa, with occasional cases appearing elsewhere. However, the identification of squirrels as a persistent animal source means the virus has a stable reservoir that could potentially fuel future human outbreaks if transmission conditions change. Public health experts emphasize that understanding animal reservoirs is essential for long-term mpox control. Unlike diseases that only spread human-to-human, mpox cannot be eliminated simply by vaccinating or treating infected people. As long as the virus circulates in wildlife, the risk of spillover events persists. This reality underscores why researchers are racing to understand mpox evolution and transmission dynamics before another global emergency emerges.
