Monkeypox Virus - Credit CDC PHIL
#16,804
With the news on Friday (see Helen Branswell's report) that at least two genetically distinct variants of Monkeypox have been detected in American cases, and international case counts nearing 1,000 (likely, a huge under-count), it is becoming increasingly apparent that this orthopox virus has been spreading unnoticed in humans for quite some time.
While Monkeypox doesn't have anywhere near the pandemic potential of COVID or influenza, the longer it circulates in humans, the greater the chance that it will `adapt' to its new host (see 2014 EID Journal article Genomic Variability of Monkeypox Virus among Humans, Democratic Republic of the Congo) with unpredictable results.
The `window of opportunity' for containing this outbreak is likely small, and after the less-than-stellar initial response to COVID early in 2020, public health agencies are being far more proactive. A few recent examples include:
MMWR: Monkeypox Outbreak — Nine States, May 2022
WHO Statement Monkeypox in the European Region: What We Know So Far And How We Need To Respond
UKHSA Announces 71 Additional Monkeypox Cases - Issues New Guidance
UK HAIRS (Human Animal Infections & Risk Surveillance) Group Risk Assessment On Monkeypox
Yesterday, and for the second time in a week, the World Health Organization published a lengthy Situation Update on Monkeypox. You'll note that this edition contains an expanded risk assessment which warns that the . . . public health risk could become high if this virus exploits the opportunity to establish itself in non-endemic countries as a widespread human pathogen.
Due to its length I've only reproduced some excerpts, so follow the link to read it in its entirety.
Multi-country monkeypox outbreak: situation update
4 June 2022The current publication of Disease Outbreak News is an update to the previously published Disease Outbreak News of 29 May and also provides short summaries of guidance, including on vaccination.
Outbreak at a glanceSince 13 May 2022, and as of 2 June 2022, 780 laboratory confirmed cases of monkeypox have been reported to or identified by WHO from 27 Member States across four WHO regions that are not endemic for monkeypox virus. Epidemiological investigations are ongoing. Most reported cases so far have been presented through sexual health or other health services in primary or secondary health care facilities and have involved mainly, but not exclusively, men who have sex with men (MSM).While the West African clade of the virus has been identified from samples of cases so far, most confirmed cases with travel history reported travel to countries in Europe and North America, rather than West or Central Africa where the monkeypox virus is endemic. The confirmation of monkeypox in persons who have not travelled to an endemic area is atypical, and even one case of monkeypox in a non-endemic country is considered an outbreak. While most cases are not associated with travel from endemic areas, Member States are also reporting small numbers of cases in travelers from Nigeria, as has been observed before.The sudden and unexpected appearance of monkeypox simultaneously in several non-endemic countries suggests that there might have been undetected transmission for some unknown duration of time followed by recent amplifier events.WHO assesses the risk at the global level as moderate considering this is the first time that many monkeypox cases and clusters are reported concurrently in non-endemic and endemic countries in widely disparate WHO geographical areas.WHO continues to receive updates on the situation in endemic countries.
(SNIP)
In addition to the cases reported from or identified in non-endemic countries, WHO continues to receive updates on the status of ongoing monkeypox outbreaks in endemic countries[1] in the African region through established surveillance mechanisms (Integrated Disease Surveillance and Response). From January to 1 June 2022, 1408 suspected and 44 confirmed cases including 66 deaths were reported from seven endemic countries (Table 2).
[1] Monkeypox endemic countries are: Cameroon, the Central African Republic, the Democratic Republic of the Congo, Gabon, Ghana (identified in animals only), Cote d’Ivoire, Liberia, Nigeria, the Republic of the Congo, and Sierra Leone. Benin and South Sudan have documented importations in the past. Countries currently reporting cases of the West African clade are Cameroon and Nigeria.
The situation is evolving and WHO expects that there will be more cases of monkeypox identified as the outbreak progresses and as surveillance expands in both endemic and non-endemic countries.
(SNIP)
WHO risk assessment
Currently, the public health risk at the global level is assessed as moderate considering this is the first time that many monkeypox cases and clusters are reported concurrently in non-endemic and endemic countries in widely disparate WHO geographical areas.
Cases were initially and mainly identified amongst men self-identified as part of extended sexual networks. The sudden appearance and wide geographic scope of many cases that initially appeared to be sporadic cases indicate that extended human-to-human transmission was facilitated by frequent encounters between persons in close proximity and/or with physical contact. Some countries are reporting that new generations of cases are no longer appearing only among known contacts of previously confirmed cases, suggesting that chains of transmission are being missed through undetected circulation of the virus.
Additionally, as epidemiological and laboratory information are still limited, the actual number of cases is likely an underestimate. This may in part be due to the lack of early clinical recognition of an infection previously known to occur mostly in West and Central Africa, limited surveillance, and a lack of widely available diagnostics in some countries. Given the number of countries across several WHO regions reporting cases of monkeypox, it is highly likely that other countries will identify cases and there will be further spread of the virus.
Human-to-human transmission occurs through close proximity or direct physical contact (e.g., face-to-face, skin-to-skin, mouth-to-mouth, mouth-to-skin contact including during sex) with skin or mucous membranes that may have recognized or unrecognized infectious lesions such as mucocutaneous ulcers, respiratory droplets (and possibly short-range aerosols), or contact with contaminated materials (e.g., linens, bedding, electronics, clothing).
Although the current risk to human health and for the general public remains low, the public health risk could become high if this virus exploits the opportunity to establish itself in non-endemic countries as a widespread human pathogen. There is also a risk to health workers if they are not using adequate infection prevention and control (IPC) measures or wearing appropriate personal protective equipment (PPE) when necessary, to prevent transmission.
Though not reported in this current outbreak, the risk of health care associated infections has been documented in the past in both endemic and non-endemic areas.
There is the potential for increased health impact with wider dissemination in vulnerable groups, as the risk of severe disease and mortality is recognized to be higher among children and immunocompromised individuals. There is limited data among people living with HIV, but those who take antiretrovirals and have a robust immune system have not reported a more severe course; those people living with HIV who are not on treatment or remain immunosuppressed may have a more severe course, as documented in the literature. Infection with monkeypox in pregnancy is poorly understood, although limited data suggest that infection may lead to adverse outcomes for the foetus.
The early confidence expressed by some public health officials - that this orthopoxvirus could be rapidly contained - has diminished sharply as more information about the size, scope, and nature of this outbreak emerges.
The good news is, this isn't Nipah, avian H5N6, Lassa Fever, MERS-CoV, or even the Congo Basin clade of Monkeypox - all which produce considerably higher mortality than the West African MPXV.
The bad news is, there is little to prevent one or more of this rogue's gallery of viruses from embarking on a world tour of their own.
