Wednesday, April 17, 2024

Preprint: Sustained Human Outbreak of a New MPXV Clade I Lineage in Eastern Democratic Republic of the Congo


While the global health emergency for the international spread of a new clade (IIb) of Mpox (formerly Monkeypox) ended nearly a year ago, we continue to see sporadic infections around the globe, while a more dangerous clade I mpox virus continues to rage (>12,000 cases in 2023) in the DRC.

Last month we looked at a report in Eurosurveillance: Ongoing Mpox Outbreak in South Kivu Province, DRC Associated With a Novel Clade I Sub-lineage, which contained the first genomic analysis of samples from a previously unaffected region of the DRC (the city of Kamituga). 

That study revealed a novel clade I sub-linage had emerged - most likely from a zoonotic introduction - with changes that may render current CDC tests unreliable.

The changing epidemiology and genetic evolution of mpox clade I in central Africa has sparked a number of risks assessments over the past few months, including:

Today we have a preprint which further describes the outbreak of Mpox in the city of Kamituga. The authors warn in this 30-page PDF that the potential exists for this novel MPXV clade to eventually spread beyond the DRC, and potentially spark another global mpox outbreak. 

Due to its length I've only posted some excerpts, I'll have a postscript after the break. 
Emmanuel H. Vakaniaki, Cris Kaciat, Eddy Kinganda-Lusamaki, Aine O'Toole, Tony Wawina-Bokalanga, Daniel Mukadi-Bamuleka, Adrienne Amuri Aziza, Nadine Malyamungu-Bubala, Francklin Mweshi-Kumbana, Leandre Mutimbwa-Mambo, Freddy Belesi-Siangoli, Yves Mujula, Edyth Parker, Pauline-Chloe Muswamba-Kayembe, Sabin S. Nundu, Robert S. Lushima, Jean Claude Makangara Cigolo, Noella Mulopo-Mukanya, Elisabeth Pukuta Simbu, Prince Akil-Bandali, Hugo Kavunga, Koen Vercauteren, Nadia A. Sam-Agudu, Edward J Mills, Olivier Tshiani-Mbaya, Nicole A. Hoff, View ORCID ProfileAnne W Rimoin, Lisa E. Hensley, View ORCID ProfileJason Kindrachuk, Ahidjo Ayouba, Martine Peeters, Eric Delaporte, Steve Ahuka-Mundeke, Jean B. Nachega, Jean-Jacques Tamfum Muyembe, Andrew Rambaut, View ORCID ProfileLaurens Liesenborghs, Placide Mbala-Kingebeni


Like all viruses, Monkeypox continues to evolve and diversify, as discussed in the 2014 EID Journal article Genomic Variability of Monkeypox Virus among Humans, Democratic Republic of the Congo, where the authors cautioned:

Small genetic changes could favor adaptation to a human host, and this potential is greatest for pathogens with moderate transmission rates (such as MPXV) (40). The ability to spread rapidly and efficiently from human to human could enhance spread by travelers to new regions.

Which means we shouldn't be surprised if new variants, or subclades, of Mpox appear over time. Especially when very little has been done to curb the spread of the virus in endemic regions like the DRC. 

Complicating matters, recent studies suggest that the protective effects of the JYNNEOS vaccine - at least in those who had not received a smallpox vaccination - wanes over a period of months (see ECCMID 2024 Study: Mpox (monkeypox) Antibodies Wane Within A Year of Vaccination).

While there are no confirmed cases of this new clade outside of the DRC, borders and oceans no longer provide the barrier against the spread of infectious diseases they once did.  

A reminder that an infectious disease threat anywhere in the world is potentially a threat everywhere.