Pangolin Disease Ecology: What Science Reveals About Zoonotic Research and Wildlife Health

When SARS-CoV-2 emerged in late 2019, pangolins were thrust into a global spotlight they never asked for. Headlines named them as a possible intermediate host for the virus that caused COVID-19. Five years later, the scientific picture is far more nuanced than those early reports suggested. Pangolin disease ecology has become a legitimate field of study, and the findings carry implications not just for human health but for pangolin conservation itself.

This article examines what researchers have actually found, separates established science from speculation, and explains why disease monitoring has become an essential component of pangolin protection programmes.

The Coronavirus Question: What the Evidence Shows

In February 2020, researchers at the South China Agricultural University announced they had found coronaviruses in Sunda pangolins (Manis javanica) seized from illegal trade in Guangdong province. The receptor-binding domain of these pangolin coronaviruses showed 97% amino acid similarity to SARS-CoV-2, sparking intense media attention and the hypothesis that pangolins could be an intermediate host.

Subsequent analysis complicated that narrative considerably. The overall genome similarity between pangolin coronaviruses and SARS-CoV-2 was only 85–92% — a gap that represents decades of evolutionary divergence. Multiple independent studies published between 2020 and 2025 concluded that horseshoe bats (Rhinolophus spp.) remain the most probable original reservoir of SARS-CoV-2, with bat coronaviruses such as RaTG13 and BANAL-52 showing closer overall genomic similarity.

Critically, the pangolins in which coronaviruses were detected were not wild-caught animals sampled in their natural habitat. They were confiscated from illegal trade operations where animals from multiple species and geographic origins were held together in cramped, unhygienic conditions. This distinction matters enormously for interpreting the results.

Viruses Found in Pangolins: A Broader Picture

Coronavirus research drew global attention, but it represents only one strand of pangolin virology. Systematic pathogen screening studies conducted since 2020 have identified a wider range of viruses in pangolins:

• Parainfluenza virus 5 (PIV5) — detected in Sunda pangolins seized in Vietnam. PIV5 is a paramyxovirus known to infect multiple mammalian species, typically causing mild respiratory symptoms.
• Sendai virus (SeV) — identified in Chinese pangolins. Sendai virus is a well-characterised paramyxovirus primarily associated with rodents, suggesting cross-species transmission in wildlife markets.
• Pestivirus — a novel pestivirus was isolated from Sunda pangolins in China in 2020, the first detection of this virus group in any pangolin species.
• Coltiviruses and picobirnaviruses — detected in faecal samples from pangolins in rehabilitation, indicating a diverse enteric virome that has only begun to be characterised.

None of these findings represent confirmed instances of pangolin-to-human transmission. However, they establish that pangolins, like most mammals, carry a diverse viral community, and that the conditions of illegal trade — stress, crowding, multi-species contact — significantly increase pathogen loads compared to wild populations.

Why the Illegal Trade Creates Spillover Risk

The single most important insight from pangolin disease ecology is that the zoonotic risk comes not from pangolins themselves but from the conditions of the illegal wildlife trade. Wild pangolins are solitary, nocturnal animals that encounter very few other species during their normal lives. A Temminck’s ground pangolin foraging in the South African bushveld has virtually zero opportunity to exchange viruses with a bat from a cave system in Yunnan province.

The illegal trade changes that equation entirely. Animals are captured, transported in sacks or crates alongside other wildlife, held in wet markets where dozens of mammalian species share airspace, body fluids, and waste. These conditions create a viral mixing bowl that does not exist in nature. A 2023 study published in Nature Communications demonstrated that pangolins held in captive trade conditions showed significantly higher viral diversity and pathogen loads than animals sampled in the wild.

The wildlife trade is not just a conservation problem. It is a public health infrastructure failure that creates novel pathogen recombination opportunities that would never occur in natural ecosystems.

Disease Monitoring in Pangolin Conservation

For the pangolins themselves, disease ecology research has immediate practical applications. Rehabilitation centres across Africa and Asia now incorporate health screening protocols that did not exist a decade ago. The African Pangolin Working Group in South Africa, the Save Vietnam's Wildlife centre in Cuc Phuong, and the Carnivore and Pangolin Conservation Programme in Zimbabwe all conduct veterinary assessments that include pathogen screening before release.

Common Health Issues in Trafficked Pangolins

Pangolins confiscated from the illegal trade present with a consistent pattern of health problems that reflects the physical trauma of trafficking:

• Severe dehydration and starvation — pangolins cannot eat in captivity without specialised insect-based diets. Most trafficked individuals have gone days or weeks without adequate food or water.
• Parasitic infections — intestinal nematodes are common, and pentastomid parasites (tongue worms) are frequently found in lung tissue during post-mortem examination.
• Respiratory infections — bacterial pneumonia is a leading cause of death in confiscated pangolins, exacerbated by stress-induced immunosuppression.
• Organ failure — renal failure from prolonged dehydration is common. Liver damage from toxin exposure (some traffickers inject pangolins with substances to increase weight) has been documented.
• Scale and skin damage — physical injuries from rough handling, wire snares, and confinement in mesh cages cause scale loss and secondary bacterial infections.

Mortality rates among confiscated pangolins remain high despite improvements in veterinary care. Estimates from Asian rehabilitation centres suggest that 30–70% of confiscated Sunda pangolins die within the first two months of rescue, depending on condition at intake. In South Africa, where Temminck’s ground pangolins are the species most commonly encountered, rehabilitation success rates are somewhat higher due to better-established protocols, but still require months of intensive care per individual.

The Conservation Argument for Disease Research

Disease ecology supports pangolin conservation through three distinct channels. First, pre-release health screening ensures that rehabilitated pangolins are not inadvertently introducing pathogens into wild populations. This biosecurity function is especially critical for genetically distinct populations where a novel pathogen could cause disproportionate damage.

Second, pathogen surveillance in wild populations provides a proxy indicator for ecosystem health. Elevated parasite loads or viral diversity in a given population may signal environmental stressors such as habitat fragmentation, reduced prey availability, or increased human encroachment.

Third, and perhaps most strategically, the link between the illegal wildlife trade and zoonotic disease risk provides a powerful argument for policy action. The economic cost of the COVID-19 pandemic — estimated at over $16 trillion globally — dwarfs the investment required to shut down illegal wildlife markets and strengthen anti-trafficking enforcement. Framing pangolin protection as pandemic prevention gives conservation advocates access to public health funding streams and political will that pure wildlife arguments alone may not generate.

What Remains Unknown

Pangolin disease ecology remains a young field with significant knowledge gaps. The baseline pathogen ecology of wild pangolins is almost entirely undescribed for six of the eight species. No long-term epidemiological monitoring programme exists for any wild pangolin population. The enteric virome — the community of viruses in the gut — has been characterised in only a handful of individuals. Whether pangolins play any natural role in coronavirus ecology in the wild, as opposed to acquiring infections in trade conditions, remains an open question.

What is clear is that the narrative of pangolins as dangerous disease vectors is both scientifically inaccurate and counterproductive. Stigmatising pangolins as plague carriers undermines conservation efforts and misdirects attention from the actual source of zoonotic risk: the illegal trade itself. The science points unambiguously toward a conclusion that serves both human and pangolin interests. Ending the illegal wildlife trade reduces pandemic risk and protects the world’s most trafficked mammal simultaneously.