Ongoing Assessment of the Molecular Evolution of Peste Des Petits Ruminants Virus Continues to Question Viral Origins

Abstract

Understanding the evolution of viral pathogens is critical to being able to define how viruses emerge within different landscapes. Host susceptibility, which is spread between different species and is a contributing factor to the subsequent epidemiology of a disease, is defined by virus detection and subsequent characterization. Peste des petits ruminants virus is a plague of small ruminant species that is a considerable burden to the development of sustainable agriculture across Africa and much of Asia. The virus has also had a significant impact on populations of endangered species in recent years, highlighting its significance as a pathogen of high concern across different regions of the globe. Here, we have re-evaluated the molecular evolution of this virus using novel genetic data to try and further resolve the molecular epidemiology of this disease. Viral isolates are genetically characterized into four lineages (I−IV), and the historic origin of these lineages is of considerable interest to the molecular evolution of the virus. Our re-evaluation of viral emergence using novel genome sequences has demonstrated that lineages I, II and IV likely originated in West Africa, in Senegal (I) and Nigeria (II and IV). Lineage III sequences predicted emergence in either East Africa (Ethiopia) or in the Arabian Peninsula (Oman and/or the United Arab Emirates), with a paucity of data precluding a more refined interpretation. Continual refinements of evolutionary emergence, following the generation of new data, is key to both understanding viral evolution from a historic perspective and informing on the ongoing genetic emergence of this virus.

Retrospective Characterization of Initial Peste des petits ruminants Outbreaks (2008–2012) in the Democratic Republic of the Congo

“…Cross-border transmissions between the DRC and Gabon might be incriminated, given the frequent illegal movements and commercial transactions in these areas that are traditionally shared by close tribes. At the continental level, it is established that all four lineages of PPRV have been circulating in Africa for several years [9,28]. Therefore, based on the data generated in this study and other previous reports [13], the DRC is currently harboring three lineages of PPRV: II and III (2016−2018 outbreaks, reported in 2019), and IV (this study) (Table 2).…”

Peste Des Petits Ruminants in the Middle East: Epidemiological Situation and Status of Control and Eradication Activities after the First Phase of the PPR Global Eradication Program (2017–2021)

“…Lineage II is present in West and Central Africa, while lineage III has been reported only in East Africa and in the southern part of the Arabian Peninsula [ 13 ]. Lastly, lineage IV, after a probable origin in West Africa, spread eastward and became endemic to large parts of Asia and the Middle East, but is now thought to have become the dominant lineage in Africa as well [ 4 , 14 ].…”

Peste des Petits Ruminants in Central and Eastern Asia/West Eurasia: Epidemiological Situation and Status of Control and Eradication Activities after the First Phase of the PPR Global Eradication Programme (2017–2021)

“…PPRV is an enveloped virus with a single-stranded, negative-sense RNA genome. Its genetic variability is comparable to that of most RNA viruses, with a substitution rate in the order of 10 −3 /10 −4 substitutions per site per year [ 10 , 16 , 17 ]. There are four different PPRV lineages (I–IV), which can be discriminated based on a portion of the N gene [ 18 ].…”

“…There are four different PPRV lineages (I–IV), which can be discriminated based on a portion of the N gene [ 18 ]. Historically, lineages I–II have been mostly detected in West Africa, while lineage III has circulated in the Middle East and East Africa [ 16 , 19 ]. After its likely origin in West Africa [ 10 , 16 ], lineage IV spread eastward and became the predominant lineage across Asia; it then re-emerged in Africa, where it now seems to be the prevalent lineage as well [ 19 ].…”