A never-before-seen virus has been reported in Peru that causes a disease similar to dengue fever, malaria, and other tropical infectious diseases common in this region. While the infection was a one-off, the novel virus is still likely to be circulating in the jungles of South America somewhere, undetected.
A single case of the mystery virus was seen in a 20-year-old man after he was admitted to Hospital Regional Docente de Medicina Tropical Julio César Demarini Caro in the city of Chanchamayo in Central Peru on June 25, 2019, although it was only reported in a published journal article in September 2023.
The patient sought medical attention after experiencing an array of symptoms, including a high fever, chills, discomfort, muscle pain, joint stiffness, a headache, drowsiness, an intense sensitivity to light, and pain in his eyes.
These symptoms are fairly typical of the many tropical diseases that are relatively common in rural South America, including dengue and malaria. However, lab tests of his blood samples revealed something much stranger: a new phlebovirus variant.
The best-known phlebovirus is the Rift Valley fever virus, a serious pathogen spread by mosquitos that are commonly seen in domesticated animals in sub-Saharan Africa, such as cattle, buffalo, sheep, goats, and camels.
This newly identified phlebovirus is a fairly different thing, though. Genetic analysis suggests that it's an “Echarate” phlebovirus that has naturally picked up genes from a “yet-unidentified phlebovirus” through genetic recombination.
The scientists who studied the case say their findings indicate a novel virus variant is likely to be circulating in the jungles of Central Peru, although it is unclear how common it might be, nor which species may be acting as the natural reservoir of the virus.
"Our findings indicate that a novel ECHV [Echarate virus] variant is circulating in the jungle of central Peru," the study authors conclude.
“Ecologic studies are necessary to determine how widespread the new variant is within this region, to identify potential vectors and reservoirs involved in its transmission, and to support decision-making for keeping service members medically prepared and protected from health and safety threats both on and off duty,” they added.
It appears the risk from this virus is low. It's been several years since the infection occurred and there's been no further reports of its spread.
Nevertheless, the case is a very real reminder that novel pathogens are out there and humanity’s meddling with the natural world means it’s increasingly likely we’ll come into contact with them.
The case study is published in the CDC journal Emerging Infectious Diseases.