Wetland Virus (WELV) Emerges as a New Threat
A newly discovered “wetland virus” (WELV) in China, transmitted through tick bites, can lead to neurological symptoms, including fever, headaches, and brain infections. First identified in 2019, researchers found that 2% of collected ticks in northern China carried the virus. Though patients recovered, lab tests show WELV may cause lethal infections, especially affecting the nervous system, raising global health concerns.
First case in Jinzhou city
The virus was first identified in June 2019 in a 61-year-old patient from Jinzhou city. The patient fell ill five days after being bitten by ticks in the wetlands of Inner Mongolia. According to a report published in The New England Journal of Medicine, the patient exhibited symptoms of fever, headache, and vomiting, which were resistant to antibiotic treatments.
Similarities to other tick-borne viruses
WELV is part of a group of viruses known for being transmitted by ticks, akin to the Crimean-Congo hemorrhagic fever virus, which can cause severe illness in humans. Following this initial discovery, researchers conducted an extensive investigation across northern China, collecting nearly 14,600 ticks from various locations. Approximately 2% of these ticks tested positive for WELV genetic material, predominantly from the species Haemaphysalis concinna.
Symptoms and treatment
WELV RNA has also been detected in a range of animals, including sheep, horses, pigs, and a type of rodent known as Transbaikal zokor. The virus showed cytopathic effects in human umbilical-vein endothelial cells and caused lethal infections in animal models.
Researchers analyzed blood samples from forest rangers in the region, discovering antibodies to WELV in 12 out of 640 individuals.They also screened patients from four northeastern Chinese hospitals, focusing on those who developed fevers after tick bites. Out of hundreds tested, 20 patients were positive for the virus, with three showing co-infections. The rest exhibited symptoms like fever, dizziness, headaches, nausea, and signs of tissue damage and blood clotting, pointing to WELV infections. One patient even entered a coma due to elevated white blood cell counts in the brain and spinal fluid.
Although all patients recovered after treatment, laboratory experiments on mice indicated that WELV could cause lethal infections and potentially affect the nervous system. This suggests that while WELV can be mild in some cases, it possesses the potential to cause severe health issues, particularly those involving the brain.
The discovery of WELV highlights the ongoing need for vigilance and research in the field of infectious diseases, especially those transmitted by vectors such as ticks.
As scientists continue to investigate the virus, the global health community remains on alert for any new developments.
