Prevalence and diversity of avian malaria parasites in illegally traded white-winged parakeets in Peruvian Amazonas

Illegal or poorly regulated wildlife trade may enhance parasite spread worldwide, leading to pathogen outbreaks and the emergence of diseases affecting native wildlife, domestic animals and humans. The order Psittaciformes has the largest proportion of endangered species among all birds worldwide and is one of the most trafficked taxa in the pet trade. However, despite the large number of parrot species commercialized worldwide, the influence of illegally traded wild birds on the introduction of exotic pathogens is still poorly investigated. Here we molecularly examined the prevalence and genetic diversity of haemosporidian parasites in illegally traded white-winged parakeets (Brotogeris versicolurus), one of the most trafficked parrots in South America. We found that 18.5% of parakeets harboured Plasmodium relictum GRW04, a highly invasive malaria parasite provoking population decline and even extinctions in native avifauna when established outside its natural range. We also showed that malaria infected birds have lower body condition than uninfected parakeets, revealing the negative effects of malaria on their avian hosts. These outcomes highlight the risk of malaria spill over and disease outbreak in illegally traded wildlife. Our results also reveal epidemiological key concepts in disease transmission, such as the role of poorly studied parrot species as natural reservoir hosts of haemosporidians. These findings stress the importance of enforcing health control regulations and trade policies to fight wildlife trafficking effectively.