Wetland virus or WELV is a tick borne ''

Orthonairovirus ''Orthonairovirus'' is a genus of viruses in the family '' Nairoviridae'' of the order '' Hareavirales'' which includes viruses with circular, negative-sense single stranded RNA. The name is derived from the Nairobi sheep disease which affect ...

'' which can infect humans. It can produce fever, headache, dizziness, malaise, arthritis and less commonly

petechia A petechia (; : petechiae) is a small red or purple spot ( 1 cm in diameter) and purpura (3 to 10 mm in diameter). The term is typically used in the plural (petechiae), since a single petechia is seldom noticed or significant. Causes Physical t ...

e, localized

lymphadenopathy Lymphadenopathy or adenopathy is a disease of the lymph nodes, in which they are abnormal in size or consistency. Lymphadenopathy of an inflammatory type (the most common type) is lymphadenitis, producing swollen or enlarged lymph nodes. In c ...

. Complications may include neurological symptoms.

Virology

The Wetland virus orthonairovirus (WELV) is a member of the genus ''

'', family ''

Nairoviridae ''Nairoviridae'' is a family of viruses in the order '' Hareavirales''. Its name derives from Nairobi sheep disease, caused by the member ''Nairobi sheep disease orthonairovirus Nairobi sheep disease virus (NSDV), also known as Ganjam virus, i ...

'' of

RNA viruses ''Orthornavirae'' is a kingdom of viruses that have genomes made of ribonucleic acid (RNA), including genes which encode an RNA-dependent RNA polymerase (RdRp). The RdRp is used to transcribe the viral RNA genome into messenger RNA (mRNA) and t ...

. It was first identified in 2019 in a Chinese person in

Jinzhou Jinzhou (, zh, s= , t=錦州 , p=Jǐnzhōu), formerly Chinchow, is a coastal prefecture-level city in central-west Liaoning province, China. It is a geographically strategic city located in the Liaoxi Corridor, which connects most of the la ...

Liaoning province ) , image_skyline = , image_alt = , image_caption = Clockwise: Mukden Palace in Shenyang, Xinghai Square in Dalian, Dalian coast, Yalu River at Dandong , image_map = Liaoning in China (+all claims hatched).svg , ...

Northeast China after a visit to a wetland park in

Yakeshi Yakeshi (; zh, c=牙克石) is a county-level city of Hulunbuir, Inner Mongolia, China. Yakeshi has a population of 391,627 and an area of . It is situated next to the Hailar River east of Hailar District, the seat of Hulunbuir, and on the nor ...

, Inner Mongolia. Three different strains were identified one from the patient and two from ticks. Its sequence is most similar to the

Tofla virus Tofla virus (''Orthonairovirus japonicum'') is a species of virus in the genus ''Orthonairovirus'' belonging to the Crimean-Congo hemorrhagic fever serogroup. It was isolated in 2016 from ''Ixodid'' in Japan. See also * Wetland virus Wet ...

from Japan.

Hosts and transmission

The Wetland virus was found in mice, sheep, pigs, and horses, but not dogs or cattle. It was found in about 2% of 14,500 different ticks in Northeast China with the highest prevalence (6%) in '' Haemaphysalis concinna''. Experimental infection showed that WELV caused lethal disease even in immunocompetent mice, unlike the remainder of the viruses in Nairoviridae family.

Signs and symptoms

Symptoms of infection with the Wetland virus are

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

, headache, dizziness,

malaise In medicine, malaise is a feeling of general discomfort, uneasiness or lack of wellbeing and often the first sign of an infection or other disease. It is considered a vague termdescribing the state of simply not feeling well. The word has exist ...

, myalgia (muscle pain),

arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...

, and back pain. Less commonly there are

e and localized

. One person also had severe

neurological symptoms Neurological disorders represent a complex array of medical conditions that fundamentally disrupt the functioning of the nervous system. These Disorder of consciousness, disorders affect the brain, spinal cord, and nerve networks, presenting unique ...

, but all recovered without sequelae. Symptoms and signs resemble those of Crimean–Congo hemorrhagic fever, and the differential diagnosis includes

severe fever with thrombocytopenia syndrome Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infection caused by '' Dabie bandavirus'' also known as the SFTS virus, first reported between late March and mid-July 2009 in rural areas of Hubei and Henan provinces in Central ...

and

spotted fever A spotted fever is a type of tick-borne disease which presents on the skin. They are all caused by bacteria of the genus '' Rickettsia''. Typhus is a group of similar diseases also caused by ''Rickettsia'' bacteria, but spotted fevers and typhus a ...

References

Nairoviridae Unaccepted virus taxa {{virus-stub