Louping-ill () is an acute viral disease primarily of

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to d ...

that is characterized by a biphasic

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 ...

, depression,

ataxia Ataxia (from Greek α- negative prefix+ -τάξις rder= "lack of order") is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in e ...

muscular MUSCULAR (DS-200B), located in the United Kingdom, is the name of a surveillance program jointly operated by Britain's Government Communications Headquarters (GCHQ) and the U.S. National Security Agency (NSA) that was revealed by documents release ...

incoordination,

tremor A tremor is an involuntary, somewhat rhythmic muscle contraction and relaxation involving neural oscillations, oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements and can affect the h ...

s, posterior

paralysis Paralysis (: paralyses; also known as plegia) is a loss of Motor skill, motor function in one or more Skeletal muscle, muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory d ...

coma A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to Nociception, respond normally to Pain, painful stimuli, light, or sound, lacks a normal Circadian rhythm, sleep-wake cycle and does not initiate ...

, and death. Louping-ill is a

tick Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks a ...

-transmitted disease whose occurrence is closely related to the distribution of the primary vector, the sheep tick ''

Ixodes ricinus ''Ixodes ricinus'', the castor bean tick, is a chiefly European species of hard-bodied tick. It may reach a length of when engorged with a blood meal, and can transmit both bacterial and viral pathogens such as the causative agents of Lyme disea ...

''. It also causes disease in

red grouse The red grouse (''Lagopus scotica'') is a medium-sized bird of the grouse family which is found in Calluna, heather moorland in Great Britain and Ireland. It was formerly classified as a subspecies of the willow ptarmigan (''Lagopus lagopus'') ...

, and can affect humans. The name 'louping-ill' is derived from an old Scottish word describing the effect of the disease in sheep whereby they 'loup' or spring into the air.

Cause

Louping ill is caused by

RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

virus called Louping ill virus. Louping ill virus belongs to genus ''

Flavivirus ''Flavivirus'', renamed ''Orthoflavivirus'' in 2023, is a genus of positive-strand RNA viruses in the family ''Flaviviridae''. The genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, Zika viru ...

'', family Flaviviridae. There are four subtypes: British, Irish, Spanish and Turkish.

Prevention

According to a

ProMED Program for Monitoring Emerging Diseases (also known as ProMED-mail, abbreviated ProMED) is among the largest publicly available emerging diseases and outbreak reporting systems in the world. The purpose of ProMED is to promote communication amon ...

article, disease in sheep has been controlled in the UK by a vaccine (

ATCvet The Anatomical Therapeutic Chemical (ATC) Classification System is a drug classification system that classifies the active ingredients of drugs according to the organ or system on which they act and their therapeutic, pharmacological and chemica ...

code: QI04AA01), originally developed by Scotland's

Moredun Research Institute The Moredun Research Institute is a scientific research institution based at the Pentlands Science Park, in the Bush Estate area of Midlothian, Scotland. It conducts research into diseases of farm livestock and the promotion of animal health and ...

by Prof John Russell Greig. In 2009, however, a shortage of vaccine combined with an increase in the number of ticks found in sheep pasture areas cause an increased risk of this disease.

Louping ill in humans

Although predominantly a sheep disease, Louping ill infections have also been reported in humans, and hence is a zoonotic disease. The first reported human case of louping ill occurred in 1934. The clinical symptoms in humans include influenza-like illness (fever, headache, and muscle stiffness), biphasic encephalitis (initial flu-like symptoms followed by neurological signs such as severe headache, vomiting, and neck stiffness), poliomyelitis-like illness (paralysis ranging from mild to severe), and in rare cases hemorrhagic fever. Certain groups are at higher risk of infection due to occupational exposure. These include laboratory personnel working with the virus, farmers, shepherds, or butchers handling infected sheep or animal tissues, as well as individuals exposed to tick bites in endemic areas.

References

* *

External links

Moredun Research Institute vaccine article
* WHO vaccine listing: ) {{Taxonbar, from1=Q614279, from2=Q19838288 Sheep and goat diseases Animal viral diseases Viral encephalitis Flaviviridae Tick-borne diseases Zoonotic viral diseases