A newly discovered tick-borne virus in China, dubbed Wetland Virus (WELV), has raised concerns among scientists due to its potential to cause neurological disease in humans. The virus, belonging to the orthonairovirus family, was first identified in a 61-year-old patient in Jinzhou, China, in June 2019. The patient, who had visited a wetland park in Inner Mongolia, experienced symptoms like fever, headache, and vomiting after being bitten by ticks.
While the initial investigation focused on the patient, researchers subsequently conducted extensive investigations in northern China, including the wetland park. They collected nearly 14,600 ticks and analyzed them for the presence of WELV. The virus was found in approximately 2% of the tick batches, with the species *Haemaphysalis concinna* showing the highest infection rate. The virus was also detected in a small percentage of sheep, horses, pigs, and Transbaikal zokor (a type of rodent).
Interestingly, although WELV wasn’t found in dogs or cattle, antibodies against the virus were detected in their blood, indicating past exposure and immune response. Further investigation revealed that 12 out of 640 apparently healthy forest rangers also had antibodies against WELV.
To understand the extent of WELV infection, researchers screened hundreds of patients at four hospitals in northeastern China who had experienced fever after a tick bite within a month. They found 20 patients positive for WELV, three of whom were co-infected with other tick-borne diseases. The remaining 17 patients presented with common symptoms like fever, dizziness, headache, malaise, back pain, nausea, vomiting, and diarrhea. Lab results showed signs of tissue damage and blood clotting in many of these patients, with one case even leading to a coma. Fortunately, all patients recovered after receiving treatment.
However, laboratory experiments injecting WELV into mice revealed a concerning outcome. The virus caused deadly infections in mice, spreading to various organs, including the brain. This finding supports the notion that WELV can potentially lead to serious neurological complications in humans.
The researchers concluded that WELV is a newly identified pathogen that circulates among humans, ticks, and various animals in northeastern China. They emphasized the importance of improving surveillance and detection efforts for emerging orthonairoviruses to better understand their impact on human health. The discovery of WELV highlights the continuous emergence of new infectious diseases and the need for vigilance in monitoring and responding to potential threats.
