#18,607
Amid the growing concerns over avian flu, a raging flu season, and fresh outbreaks of hemorrhagic fever (Marburg & Ebola Sudan) in Africa, we are also monitoring the progress of a recently emerging clade (Ib) of Mpox in Africa, and its slow, but steady, international spread.
Last August WHO declared the Mpox outbreak in Central Africa to constitute a PHEIC (Public Health Emergency of International Concern) after reports that a new clade of the virus had begun to spread outside of the DRC (see More African Nations Reporting Mpox - Africa CDC Mpox Update (Jul 30th)).
This Ib clade is reportedly more virulent, and potentially more transmissible, than the clade II mpox virus which began its world tour in the spring of 2022. Last December, the WHO published a new, updated risk assessment, which put the risk of national and international spread as HIGH.
So far, we've seen 11 non-African nations report imported cases of this Mpox Ib clade; Sweden, Thailand, India, Germany, the United Kingdom of Great Britain and Northern Ireland, the United States of America, Canada, Pakistan, Belgium, China, and France.
Several countries, including China, Belgium, Germany, France and the UK have reported limited secondary transmission. The UK has reported the most cases (n=9), while the United States - until yesterday - had only reported 2 (1 in California, 1 in Georgia).
Yesterday the New Hampshire DHHS reported the third case identified in the United States (h/t Shiloh & Sharon Sanders on FluTrackers). While listed as clade I, this is most likely clade Ib.
First the announcement, after which I'll have a bit more.
Press Release
Date: February 07, 2025
Contact
Public Information Office
(603) 271-9389 | PIO@dhhs.nh.gov
DHHS Identifies New Hampshire Resident with Clade I Mpox
Risk to Public Is Low
Concord, NH – The New Hampshire Department of Health and Human Services (DHHS), Division of Public Health Services (DPHS) has identified an adult from Merrimack County with clade I mpox. The individual recently traveled to Eastern Africa, where there is an ongoing outbreak of clade I mpox, and is currently self-isolating and recovering at home. The individual’s illness poses no current risk to the public.
The individual’s illness is likely related to their recent travel, and there is no evidence that clade I mpox is spreading from person-to-person in New Hampshire or within the United States. This is the first clade I mpox diagnosis in New Hampshire and the third clade I mpox diagnosis in the United States.
DHHS is conducting a disease investigation to identify anyone who may have had close contact with the individual. There have been no public locations identified where exposure may have occurred. The Department will facilitate appropriate care for anyone identified during the investigation.
“The mpox virus is spread primarily through direct physical contact with someone who has mpox and has developed an infectious skin rash,” said State Epidemiologist Dr. Benjamin Chan. “Public Health is working to identify and notify people who had close contact with the individual, so we can connect them with preventive vaccination and help them to monitor for symptoms of mpox.”
Mpox is a disease caused by two different genetic types of the mpox virus, called clade I and clade II. Clade II mpox has continued to circulate at low levels in the United States since a widespread outbreak occurred in 2022. More recently, clade I mpox has been causing outbreaks in Central and Eastern Africa. Both types of the virus spread primarily through direct physical contact with a symptomatic person with mpox or through contact with used items contaminated with the mpox virus. The mpox virus is not spread through the air.
People with mpox develop an infectious rash that changes over time as a person’s illness progresses. The rash can look like pimples or blisters that are painful or itchy. Over time, the rash can spread, and then slowly the skin lesions develop a scab or crust before going away over several weeks. Other symptoms of mpox can include fever, chills, headache, exhaustion, muscle aches, sore throat, or swollen lymph nodes. A person with mpox can spread the virus starting when they first develop symptoms, and they remain contagious until their rash has fully healed and a fresh layer of skin has formed.
If you are traveling to Central or Eastern Africa or if you believe you might have a risk factor for mpox, talk to your healthcare provider about whether the JYNNEOS vaccine is recommended for you.
If you have questions about mpox, please contact DPHS at 603-271-4496. For more information about mpox, visit the DHHS mpox webpage.
While the clade Ib variant of Mpox is new, concerns over the international spread of Mpox (both clade I & II) go back decades.
In 2003 we saw a rare multi-state (Illinois, Indiana, Kansas, Missouri, Ohio, and Wisconsin) outbreak when a Texas animal distributor imported hundreds of small animals from Ghana, which in turn infected prairie dogs that were subsequently sold to the public (see MMWR Update On Monkeypox 2003).
By the time that outbreak was quashed, the U.S. saw 37 confirmed, 12 probable, and 22 suspected human cases. Among the confirmed cases 5 were categorized as being severely ill, while 9 were hospitalized for > 48 hrs; although no patients died (cite).
Throughout the second half of the last decade we saw repeated exported cases turning up in places like the UK, Singapore, and even Israel (see ECDC: RRA On Imported Monkeypox Cases From Nigeria). The first case imported into the United States was via a traveler from Nigeria in 2021.
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.
As our collective immunity from the smallpox vaccine - which was discontinued in the late 1970s - wanes, there will be increased opportunities for emerging pox viruses to make a comeback. We ignore them at considerable risk to global public health.
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