The onyongnyong virus (ONNV) was first isolated by researchers at the Uganda Virus Research Institute in Entebbe, Uganda, during a large outbreak of a disease in 1959 that resembled dengue fever. ONNV is a togavirus (family Togaviridae), genus Alphavirus,  is closely related to the chikungunya and Igbo Ora viruses, and is a member of the Semliki Forest antigenic complex. The name was given to the disease by the Acholi tribe during the 1959 outbreak. The name comes from the Nilotic language of Uganda and Sudan and means “weakening of the joints". The virus can infect humans and may cause disease. Signs and symptoms
Common symptoms of infection with the virus are polyarthritis, rash and fever. Other symptoms include eye pain, chest pain, lymphadenitis and lethargy. The disease is self-limiting. No fatalities due to infection are known. Cause
Strains
ONNV has at least three major subtypes, or strains, the genomic sequences of which are currently available on genome databases. Transmission
ONNV is transmitted by bites from an infected mosquito. It is the only virus whose primary vectors are anopheline mosquitoes (Anopheles funestus and Anopheles gambiae). Epidemiology
There have been two epidemics of o’nyong’nyong fever. The first occurred from 1959 to 1962, spreading from Uganda to Kenya, Tanzania, Zaire (Democratic Republic of the Congo), Malawi and Mozambique, and affecting over two million people, one of the largest arbovirus epidemics ever recorded.
Statistics
Many of those affected during a thunderstorm asthma outbreak may have never experienced an asthma attack before.It has been found 95% of those that were affected by thunderstorm asthma had a history of hayfever, and 96% of those people had tested positive to grass pollen allergies, particularly rye grass. A rye grass pollen grain can hold up to 700 tiny starch granules, measuring 0.6 to 2.5 μm, small enough to reach the lower airways in the lung. Prevention
Patients with a history of grass allergies should be tested for asthma and treated for the grass allergies and asthma if also present. Patients with known asthma should be treated and counseled on the importance of adherence to preventative medication protocols. Preventative treatment found useful for severe asthma includes Allergen immunotherapy (AIT) particularly sublingual immunotherapy (SLIT). Significant events
6 July 1983 (1983-07-06) – 7 July 1983 (1983-07-07): Birmingham, England
8 November 1987 (1987-11-08): Melbourne, Australia
29 November 1989 (1989-11-29) – 30 November 1989 (1989-11-30): Melbourne, Australia
24 July 1994 (1994-07-24) – 25 July 1994 (1994-07-25): London, England
30 October 1997 (1997-10-30): Wagga Wagga, Australia
4 June 2004 (2004-06-04): Naples, Italy
25 November 2010 (2010-11-25): Melbourne, Australia
2 November 2013 (2013-11-02): Ahvaz, Iran
21 November 2016 (2016-11-21): Melbourne, Australia
1 December 2016 (2016-12-01): Kuwait and Riyadh, Saudi Arabia


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