CDC EID Journal: Clade I–Associated Mpox Cases Associated with Sexual Contact, DRC - ECDC Risk Assessment Dec 5th

[Michael Coston]

CDC EID Journal: Clade I–Associated Mpox Cases Associated with Sexual Contact, the Democratic Republic of the Congo


Credit WHO
#17,788

Last week, in WHO Reports 1st Confirmed Cluster Of Sexually Transmitted MPXV Clade 1 in the DRC, we looked at the first confirmed clusters of MPXV Clade 1 spread by sexual transmission in the DRC.

Compared to the milder Clade IIb MPXV - which was recognized as spreading internationally in early 2022 - Clade I infections are far more severe, more disfiguring, and can have a significant (≅ 10%) fatality rate.​

Over the past decade we've seen a number of cautionary reports warning of Clade I's evolution and growing transmissibility, including:

WHO: Modelling Human-to-Human Transmission of Monkeypox​

EID Journal:Extended H-2-H Transmission during a Monkeypox Outbreak​

Genomic Variability of Monkeypox Virus among Humans, Democratic Republic of the Congo​

This newly discovered ability to transmit sexually could open the door for Clade I MPXV to follow in Clade IIb's footsteps, and begin spreading outside of the endemic regions of central Africa.

This decidedly unwelcome news comes on the heels of reports of growing (antiviral) Tecovirimat Resistance in Mpox Patients, and some uncertainties over the effectiveness of the JANNEOS Mpox vaccine against the more virulent Clade I virus.​

This morning the CDC's EID Journal has published dispatch from the team in the DRC that discovered these clusters. I've only posted some excerpts, so follow the link to read it in its entirety. I'll have a bit more after the break.

Dispatch

Clade I–Associated Mpox Cases Associated with Sexual Contact, the Democratic Republic of the Congo

Emile M. Kibungu, Emmanuel H. Vakaniaki, Eddy Kinganda-Lusamaki, Thierry Kalonji-Mukendi, Elisabeth Pukuta, Nicole A. Hoff, Isaac I. Bogoch, Muge Cevik, Gregg S. Gonsalves, Lisa E. Hensley, Nicola Low, Souradet Y. Shaw, Erin Schillberg, Mikayla Hunter, Lygie Lunyanga, Sylvie Linsuke, Joule Madinga, Martine Peeters, Jean-Claude Makangara Cigolo, Steve Ahuka-Mundeke, Jean-Jacques Muyembe, Anne W. Rimoin1, Jason Kindrachuk1 , Placide Mbala-Kingebeni1 , Robert S. Lushima1, and International Mpox Research Consortium​

Abstract

We report a cluster of clade I monkeypox virus infections linked to sexual contact in the Democratic Republic of the Congo. Case investigations resulted in 5 reverse transcription PCR–confirmed infections; genome sequencing suggest they belonged to the same transmission chain. This finding demonstrates that mpox transmission through sexual contact extends beyond clade IIb.


Human mpox, caused by monkeypox virus (MPXV), is an emerging zoonotic viral disease first identified in the Democratic Republic of the Congo (DRC) (1). MPXV is endemic in multiple regions of Central and West Africa (2,3). The virus is subclassified into 2 clades: clade I, formerly Congo Basin (Central Africa) clade, and clade II, formerly West African clade. Clade II is further subdivided into 2 subclades, IIa and IIb; subclade IIb was responsible for the 2022 global epidemic (4; https://www.who.int/news/item/12-08-2022-monkeypox--experts-give-virus-variants-new-namesExternal Link).​

Clade I infections are associated with greater disease severity and more pronounced rash and had demonstrated increased human-to-human transmission compared with
clade II before the global emergence of clade IIb (5). Those difference are likely influenced by factors such as clade-specific genomic differences in host response modifier proteins, exposure type and dose, and vaccination status (https://www.who.int/news/item/12-08-2022-monkeypox--experts-give-virus-variants-new-namesExternal Link). Travel-related and animal importation–related cases have been reported in nonendemic regions (6). In 2022, rapid spread of MPXV to new geographic regions resulted in >86,000 confirmed infections in nonendemic regions and declaration of a public health emergency of international concern by the World Health Organization (7).

(SNIP)​

Conclusions

We describe a cluster of clade I MPXV–associated infections in DRC related to sexual contact, which has previously only been described for clade II MPXV. Of note, MPXV transmission through sexual contact is not exclusive to clade IIb and can occur during heterosexual and same-sex contact.​

This study demonstrates that MPXV infections can occur through additional exposure routes in MPXV-endemic regions and that the current understanding of mpox burden in clade I–endemic regions is based on classical transmission exclusively; recognizing those factors is critical. Our findings highlight additional considerations for MPXV circulation and transmission containment in endemic areas. Thus, increased MPXV surveillance, diagnostic testing access, and equitable access to both vaccines and therapeutics for persons at increased risk for infection are needed for ongoing mitigation strategies.​

Given the increased disease severity associated with clade I MPXV, the potential implications of sexual transmission on broadening geographic distribution for MPXV across clades I and II must be considered. In addition, long-term immunity to mpox inferred by vaccination is unknown, including the role of mucosal immunity against clade I MPXV infections. This report highlights multiple critical global health considerations that must be addressed. Ongoing support for community engagement and educational efforts focusing on mpox recognition and reporting, including within sexual networks and for specific groups who might suffer from lack of care or experience stigma when seeking care.​

Our findings highlight historically unrecognized MPXV transmission through sexual contact and indicate the need for increased routine screening in sexual health clinics in mpox-endemic and nonendemic regions. Population movement and previously unreported routes of transmission could exacerbate global distribution of MPXV, which could be compounded by the lack of routine diagnostic testing or inadequate access to rapid point-of-care testing. In view of this investigation, epidemiologic and genomic surveillance for MPXV, in both endemic and nonendemic regions, should be improved and strengthened.​

Dr. Kibungu is a senior expert epidemiologist with a primary research interest in emerging infectious diseases, including response and containment efforts from the Ministry of Public Health, Hygiene and Prevention, Democratic Republic of the Congo. His primary research interests are emerging infectious diseases, including response and containment efforts.​

Last year's emergence and global spread of the Mpox virus had been long predicted, but we arguably got lucky when it turned out to be the milder Clade II virus that began its world tour.

Although international spread of Clade I has not been reported, the Clade IIb virus had probably been spreading globally for quite some time before it was finally detected in the UK in May of 2022.​

Another reason why we should be strengthening our global surveillance and reporting systems, not dismantling them, as we've seen over the past couple of years.
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https://afludiary.blogspot.com/2023/11/cdc-eid-journal-clade-iassociated-mpox.html

 

[sharon sanders]

Please see:

DRC - Mpox (monkeypox) outbreak 2023
​​

 

[Michael Coston]

ECDC Risk Assessment On Transmission & Spread of Clade I Mpox From The DRC

#17,800

Just over 10 days ago the WHO Reported the 1st Confirmed Cluster Of Sexually Transmitted MPXV Clade 1 in the DRC. Clade 1 Mpox is considered far more dangerous than clade IIb, which is currently spreading outside of Africa.

After presenting the evidence, the WHO warned that `The risk of mpox further spreading to neighbouring countries and worldwide appears to be significant.' and that it poses `. . . an additional risk of mpox outbreaks with potentially more severe consequences than the one which has been affecting the world since 2022.'. ​

Last week, in CDC EID Journal: Clade I–Associated Mpox Cases Associated with Sexual Contact, the Democratic Republic of the Congo, we looked at dispatch from the team in the DRC that discovered these clusters. They wrote:

Population movement and previously unreported routes of transmission could exacerbate global distribution of MPXV, which could be compounded by the lack of routine diagnostic testing or inadequate access to rapid point-of-care testing. In view of this investigation, epidemiologic and genomic surveillance for MPXV, in both endemic and nonendemic regions, should be improved and strengthened.​

While obviously a concern, so far we've not seen any evidence of clade I transmission outside of the endemic regions of central Africa. To be fair, however, clade IIb was probably circulating internationally long before surveillance first identified it in the UK in May of 2022.

Today the ECDC has published a Risk Assessment for the EU on the spread of Clade I Mpox outside of Africa, where the currently set the overall risk for MSM with multiple sexual partners stemming from this outbreak in the DRC is low. The overall risk for the general population is also assessed as low.

First, the ECDC news release, followed by the Executive Summary and a link to the full risk assessment.

ECDC assesses risk associated with ongoing mpox epidemic in the Democratic Republic of the Congo​

News story​

5 Dec 2023

An outbreak of mpox is ongoing in the Democratic Republic of the Congo (DRC), with 12 569 cases reported between 1 January and 12 November 2023. The vast majority of infections are caused by Monkeypox virus (MPXV) clade I, which is generally considered to be more virulent than MPXV clade II, which has been driving the multi-country epidemic of mpox in 2022-23.

Currently, there is no evidence that MPXV clade I is circulating outside certain central African countries and available MPXV sequences do not suggest circulation in the EU/EEA. 

According to ECDC, the likelihood of infection for the general EU population from the ongoing epidemic of mpox due to MPXV clade I is very low, while the impact from such infection is assessed as low, resulting in an overall low risk.  

The likelihood of infection with clade I virus for the population of men who have sex with men (MSM) with multiple sexual partners in the EU/EEA is considered higher than that of the general population. However, it is still estimated as low, as immunity in this population due to prior infection with MPXV Clade II and/or vaccination in 2022-23 will probably decrease both the likelihood and the impact of such an infection. Therefore, the overall risk for MSM with multiple sexual partners stemming from this outbreak in the DRC is low. The overall risk for the general population is also assessed as low.

Public health authorities should continue efforts to increase awareness among clinicians about mpox. Contact tracing, testing and sequencing of samples from detected mpox cases should continue, along with sharing the detected sequences. In the event of mpox cases with increased severity and/or the detection of a MPXV clade I infection, the event should be promptly communicated at the EU level via EpiPulse - an online portal for European public health authorities and partner organisations to share disease and viral sequence data.​

Implications for the EU/EEA of the outbreak of mpox caused by Monkeypox virus clade I in the Democratic Republic of the Congo
Assessment
5 Dec 2023

An outbreak of mpox is ongoing in the Democratic Republic of the Congo (DRC), with 12 569 cases reported between 1 January and 12 November 2023.

Executive summary​

• The vast majority of infections are caused by Monkeypox virus (MPXV) clade I, which is generally considered to be more virulent than MPXV clade II.
• A cluster of mpox cases from March 2023 was recently documented as the first detection of sexually transmitted MPXV clade I infections. The presumed index case of this cluster is a European traveller who reportedly developed mpox soon after his arrival in DRC.
• Currently, there is no evidence that MPXV clade I is circulating outside certain central African countries and available MPXV sequences do not suggest circulation in the EU/EEA.
• The likelihood of infection from the ongoing epidemic mpox due to MPXV clade I is assessed as very low for the general EU population and the impact from such an infection is assessed as low. The overall risk is assessed as low.
• The overall risk for men who have sex with men (MSM) with multiple sexual partners in the EU/EEA from this outbreak in the DRC is low. Although the likelihood of infection with clade I virus for this population is considered higher than that of the general population, it is still estimated as low, as it is attenuated by the immunity in this population due to prior infection with MPXV clade II and/or vaccination in 2022-23. The impact from such infection is also estimated to be low, also influenced by increased immunity and availability of vaccines and therapeutics in the EU/EEA.
• Public health authorities should continue efforts to increase awareness among clinicians about mpox.
• Contact tracing, testing and sequencing of samples from detected mpox cases should continue, along with sharing the detected sequences. In the event of mpox case(s) with increased severity and/or the detection of a MPXV clade I infection, the event should be promptly communicated at the EU-level via EpiPulse.

Download

Implications for the EU/EEA of the outbreak of mpox caused by Monkeypox virus clade I in the Democratic Republic of the Congo - EN - [PDF-383.79 KB]​

While reassuring, in the summer of 2021 - roughly 1 year before clade IIb Mpox began its world tour - the ECDC issued a risk assessment following a family cluster of Monkeypox cases in the UK (index case imported from Nigeria).

ECDC assessment ​

The likelihood for further spread of the virus is very low due to the moderate transmissibility of the virus. However, infections among close contacts cannot be excluded, as demonstrated by the infections described above.​

A perfectly reasonable assessment given the facts available at the time. But it does remind us that all risk assessments have a shelf life, and as the virus changes, so do the risks.


https://afludiary.blogspot.com/2023/12/ecdc-risk-assessment-on-transmission.html
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