Abstract
Emerging infectious diseases in general, and zoonotic diseases of viral origin in particular, are experiencing an acceleration in the frequency of epidemics and pandemics. This increase in the frequency of epidemics is undoubtedly exacerbated by anthropocenic activities. Thus, between 2005 and 2024, the World Health Organization was led to raise its alert to the maximum level by declaring a Public Health Emergency of International Concern (PHEIC) nearly 8 times. The last one in progress was declared for mpox on August 14, 2024. With this declaration, mpox joined the Ebola virus disease, another zoonosis with high epidemic potential, in the batch of emergences that led to the declaration of PHEIC twice.These two diseases share several common points including their viral origin, the first human detections in the Democratic Republic of Congo (between 1970 and 1980), their reservoir not yet elucidated and the major challenges in their diagnosis and treatment, especially at the places of emergence.They also require rapid control wherever they emerge in order to secure local communities and spare global systems from multifaceted crises such as those caused by covid-19. Effective control requires the ability to detect and characterize the pathogenWe have developed a serological test and have integrated multiplex serology into the investigation of epidemics such as the one in Masimanimba. We also carried out a retrospective survey on serum samples, which allowed us to increase the positivity rate by 14.5%, when PCR and/or seropositivity are considered for the detection of positive cases, demonstrating that several epidemics would probably go unnoticed.In addition, in the face of the growing number of cases, high-throughput sequencing has been integrated in addition to epidemiological investigations. Thus, we were able to characterize clade Ia, which circulates mainly in the country. We have described cases associated with sexual transmission in Kwango province, co-circulation with Swinepox in Tshuapa, a proprice context for cross-border transmission around the Ubangi River and introductions in urban areas such as the cities of Kisangani or Kinshasa. In addition, we documented the emergence of the Clade Ib-related outbreak in the Kamituga Health Zone in the east of the country, showing more molecular signals of adaptation to humans, and which quickly spread to the cities of Bukavu, Goma and Kinshasa. This dual paradigm, on the one hand clade Ia linked to zoonotic (interspecies) transmissions in a predominant way, and on the other hand clade Ib characterized by sustained human-to-human transmission could evolve, especially because of clade Ia and clade Ib corcirculations, as in Kinshasa.For the Ebola epidemic in Ecuador in 2020, the use of genomics made it possible to detect the co-circulation of 2 variants were discovered that were co-circulating, namely the one responsible for declaring the 2020 epidemic and the one that circulated in 2018 (9th EVD epidemic, Tumba strain). And a more global view of the epidemic has been obtained despite the fact that not all the chains of transmission have been elucidated.Thus, the insights from the responses to some of the observations relating to the epidemics of mpox and Ebola virus diseases, reveal other mysteries to be explored in order to anticipate the health problems that these threats could cause at any time. Our thesis results further demonstrate how crucial is the integration of the "one health" approach associating several disciplines to address the health challenges posed by zoonotic diseases that are more difficult to eradicate.