Louping-ill is an acute viral disease primarily of sheep that is characterized by a biphasic fever

Fever

Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...

, depression, ataxia

Ataxia

Ataxia is a neurological sign and symptom that consists of gross lack of coordination of muscle movements. Ataxia is a non-specific clinical manifestation implying dysfunction of the parts of the nervous system that coordinate movement, such as the cerebellum...

, muscular incoordination, tremor

Tremor

A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving to-and-fro movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the...

s, posterior paralysis

Paralysis

Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...

, coma

Coma

In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...

, and death. Louping-ill is a tick

Tick

Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...

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

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 disease and tick-borne encephalitis.-Description:In common...

. It also causes disease in red grouse

Red grouse

The Red Grouse is a medium sized bird of the grouse family which is found in heather moorland in Great Britain and Ireland. It is usually classified as a subspecies of the Willow Grouse but is sometimes considered to be a separate species Lagopus scoticus...

, 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.

Etiology

Louping ill is caused by RNA

RNA

Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....

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

Flavivirus

Flavivirus is a genus of the family Flaviviridae. This genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, and several other viruses which may cause encephalitis....

, family Flaviviridae.

Prevention

According to a ProMED

ProMED-mail

The Program for Monitoring Emerging Diseases is among the largest of publicly available emerging disease and outbreak reporting systems in the world....

 article, disease in sheep has been controlled in the UK by a vaccine (ATCvet code: QI04AA01), originally developed by the Moredun Research Institute. 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.

External links

• Moredun Research Institute vaccine article
• WHO vaccine listing: )