Bundibugyo ebolavirus

The species Orthoebolavirus bundibugyoense belongs to the genus Orthoebolavirus in the family Filoviridae.^[11] The species has a single virus member, Bundibugyo virus (BDBV).^[6] The members of the species are called Bundibugyo ebolaviruses.^[6] The virus's name is derived from Bundibugyo, the name of the chief town of the Ugandan Bundibugyo District, where Bundibugyo virus was first discovered.^[6]

Bundibugyo virus (abbreviated BDBV) was first described in 2008 as a single member of a suggested new species Bundibugyo ebolavirus, which was suggested to be included into the genus Ebolavirus, family Filoviridae, order Mononegavirales.^[12] A formal proposal to accept this species into virus taxonomy was submitted in 2010^[13] and was accepted by the ICTV in 2011.^[14] In 2023, the species was renamed Orthoebolavirus bundibugyoense and the genus Orthoebolavirus.^[15]

A virus of the genus Orthoebolavirus is a member of the species Orthoebolavirus bundibugyoense if:^[6]

• it is endemic in Uganda
• it has a genome with three gene overlaps (VP35/VP40, GP/VP30, VP24/L)
• it has a genomic sequence different from Zaire ebolavirus by ≥30%, but different from that of Bundibugyo virus by <30%

A virus of the species Orthoebolavirus bundibugyoense is a Bundibugyo virus if it has the properties of Bundibugyo ebolaviruses and if its genome diverges from that of the prototype Bundibugyo ebolavirus, Bundibugyo virus variant #811250 (BDBV/#811250), by ≤10% at the nucleotide level.^[6]

Bundibugyo virus was first introduced as Bundibugyo ebolavirus in 2008, albeit without differentiating this name from the suggested species Bundibugyo ebolavirus.^[12] Another name introduced at the same time was Uganda ebolavirus.^[16] Later publications also referred to the virus as a novel "strain" of Zaire ebolavirus^[7] or as Bundibugyo Ebola virus.^[17] The abbreviations BEBOV (for Bundibugyo ebolavirus) and UEBOV (for Uganda ebolavirus)^[16] were briefly used before BDBV was established as the abbreviation for Bundibugyo virus.^[6]

BDBV is one of four ebolaviruses that causes Ebola virus disease (EVD) in humans (also referred to as Ebola hemorrhagic fever, EHF). Symptoms of EVD due to BDBV infection are similar to EVD caused by other ebolaviruses,^[7][17] which is why infections by all ebolaviruses are presented together as Ebola virus disease. BDBV was first seen on August 1 of 2007, when a viral hemorrhagic fever outbreak began in the Bundibugyo and Kikyo townships of Bundibugyo District in western Uganda. Blood samples from suspect cases were sent to the US Centers for Disease Control and Prevention, where the presence of an ebolavirus was confirmed on November 29, 2007. In-depth analysis revealed that the ebolavirus was a relative, but not identical, to the other four ebolaviruses known at the time.^[12][7] The outbreak was declared over on February 20, 2008.^[7]

A second outbreak was reported by the WHOTooltip World Health Organization on August 17, 2012, suspected to have infected 15 and killed 10 including three health care workers in Isiro, Pawa and Dungu, Province Orientale, DRC.^[18] Two of the cases have been confirmed to be BDBV.^[19] It is reported that bushmeat was the source.^[20] By September 3, the number of cases had risen to 28, with 8 confirmed, 6 probable and 14 suspected, including 14 deaths,^[8] and as of 12 September, it had spread to Viadana and a total of "41 cases (9 laboratory confirmed, and 32 probable) have been reported from Haut-Uélé district in Province Orientale. Of these cases, 18 have been fatal. (5 confirmed and 13 probable). 18 healthcare workers are included among the probable cases. 28 suspected cases have also been reported and are being investigated.”^[21] The Democratic Republic of Congo announced a final tally of 77 cases (36 confirmed, 17 probable and 24 suspect) with 36 deaths.^[22]

On May 15, 2026, a third outbreak was reported in Uganda and the Democratic Republic of the Congo, and the WHO declared the epidemic was a public health emergency of international concern two days later.^[10] As of 10 July, there were reports of eight laboratory-confirmed cases, 1981 suspected cases and over 600 suspected deaths in Ituri Province, DRC.^[10]

The ecology of BDBV is currently unclear, and no reservoir host has yet been identified. Therefore, it remains unclear how BDBV was introduced into the human population. Bats are suspected to harbor the virus because infectious Marburg virus (MARV) and Ravn virus (RAVV), two distantly related filoviruses, have been isolated from bats,^[12] and because traces (but no infectious particles) of the more closely related Zaire ebolavirus (EBOV) were found in bats as well.^[24]

BDBV is basically uncharacterized on a molecular level. However, its genomic sequence, and with it the genomic organization and the conservation of individual open reading frames, is similar to that of the other four known ebolaviruses (58-61% nucleotide similarity).^[12]

A United States patent with multinational collaborative recognition was applied for on 10/26/2009, and published 10/4/2012, for the rights to BDBV.^[25] The patent is listed under six different numbers, including one assigned a US appellation, as well as one Canadian (CA), two European Patent Office (EP), and two World Intellectual Property Organization (WO) designations.

• US 20120251502 A1
• CA 2741523 A1
• EP 2350270 A2
• EP 2350270 A4
• WO 2010048615 A2
• WO 2010048615 A3

It is openly noted in the Deposit Statement of the patent application (Section [0002]) that the virus sample was deposited to the CDC in Atlanta, GA, on November 26, 2007, not to an International Depository Authority (IDA), which was the accepted method as established under the Budapest Treaty on the International Recognition of the Deposit of Microorganisms for Purposes of Patent Procedure.^[25] According to the same section, the "deposited organism" was also admittedly, "not acceptable by American Type Culture Collection." This sample was painstakingly researched and led to the patent application.^[25]

Section [0037] of the patent explains its purpose as having “utility in design of diagnostic assays to monitor Ebola HF [Hemorrhagic Fever] disease in humans and animals, and develop effective antivirals and vaccines.”^[25] Further, to avoid limiting the extent and reach of the patent, Section [0036] states that:

It is to be understood that the present invention is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.^[25]