The ''Nairobi sheep disease orthonairovirus'' (NSDV), also known as ''Ganjam virus'' is a species in the genus ''

Orthonairovirus ''Orthonairovirus'' is a genus of viruses in the family ''Nairoviridae'' of the order Bunyavirales that include viruses with circular, RNA virus#Group V - negative-sense ssRNA viruses, negative-sense single stranded RNA. It got its name from th ...

'' belonging to the Nairobi sheep disease serogroup. NSDV is

enzootic Enzootic is the non-human equivalent of endemic and means, in a broad sense, "belonging to" or "native to", "characteristic of", or "prevalent in" a particular geography, race, field, area, or environment; native to an area or scope. It also has t ...

, becoming

epizootic In epizoology, an epizootic (from Greek: ''epi-'' upon + ''zoon'' animal) is a disease event in a nonhuman animal population analogous to an epidemic in humans. An epizootic may be restricted to a specific locale (an "outbreak"), general (an "epi ...

when denser populations of susceptible animals are exposed to infection. NSDV's known hosts belong to the hard

tick Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...

family

Ixodidae The Ixodidae are the family of hard ticks or scale ticks, one of the three families of ticks, consisting of over 700 species. They are known as 'hard ticks' because they have a scutum or hard shield, which the other major family of ticks, the 'sof ...

, including ''

Rhipicephalus appendiculatus ''Rhipicephalus appendiculatus'', the brown ear tick, is a hard tick found in Africa where it spreads the parasite ''Theileria parva'', the cause of East Coast fever East Coast fever, also known as theileriosis, is a disease of cattle which o ...

'', and '' Amblyomma variegatum'', and afflict

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals 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 domesticated s ...

and

goat The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the a ...

s naturally. The virus is in the family

Nairoviridae ''Nairoviridae'' is a family of viruses in the order ''Bunyavirales ''Bunyavirales'' is an order of segmented negative-strand RNA viruses with mainly tripartite genomes. Member viruses infect arthropods, plants, protozoans, and vertebrates. I ...

and order

Bunyavirales ''Bunyavirales'' is an order of segmented negative-strand RNA viruses with mainly tripartite genomes. Member viruses infect arthropods, plants, protozoans, and vertebrates. It is the only order in the class ''Ellioviricetes''. The name ''Bunyavir ...

Symptoms

Symptoms of an animal infected with NSDV may include fever, reduction in white blood cells, rapid respiration, anorexia, profound depression, diarrhea, drop in body temperature, premature abortion, and eventually death.

History

NSDV was first recognised in 1917 as the causative agent of a disease that was affecting sheep transported from the

Maasai Maasai may refer to: * Maasai people *Maasai language * Maasai mythology * MAASAI (band) See also * Masai (disambiguation) * Massai Massai (also known as: Masai, Massey, Massi, Mah–sii, Massa, Wasse, Wassil or by the nickname "Big Foot" Mas ...

region of

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

for sale in the

Nairobi Nairobi ( ) is the capital and largest city of Kenya. The name is derived from the Maasai phrase ''Enkare Nairobi'', which translates to "place of cool waters", a reference to the Nairobi River which flows through the city. The city proper ha ...

livestock markets, where a 70% mortality rate was recorded for local breeds sheep, but a lower rate for European breeds. Another mortality rate of 90% has been reported, affecting highly susceptible populations.

Species affected

Sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals 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 domesticated s ...

and

s are

natural reservoir In infectious disease ecology and epidemiology, a natural reservoir, also known as a disease reservoir or a reservoir of infection, is the population of organisms or the specific environment in which an infectious pathogen naturally lives and rep ...

s for NSDV and Ganjam, but fatal cases have also been reported among

blue duiker The blue duiker (''Philantomba monticola'') is a small antelope found in central, southern and eastern Africa. It is the smallest duiker. The species was first described by Swedish naturalist Carl Peter Thunberg in 1789. 12 subspecies are ident ...

s in zoos or in the wild. High morbidity and mortality are seen in both sheep and goats, although goats tend to have less severe clinical signs than sheep. African field rats, langur monkeys and

Bonnet macaque The bonnet macaque (''Macaca radiata''), also known as zati,Chambers English Dictionary is a species of macaque endemic to southern India. Its distribution is limited by the Indian Ocean on three sides and the Godavari and Tapti Rivers, along wi ...

s have been experimentally inoculated with NSDV and Ganjam virus, with the macaques not becoming viremic as result.

Genome

The genome is composed a single strand of negative sense RNA in three parts—small (S), medium (M) and large (L).Yadav PD, Vincent MJ, Khristova M, Kale C, Nichol ST, Mishra AC, Mourya DT (2011) Genomic analysis reveals Nairobi sheep disease virus to be highly diverse and present in both Africa, and in India in the form of the Ganjam virus variant. Infect Genet Evol

References

{{Taxonbar, from1=Q29002589 Nairoviridae Sheep and goat diseases