ALERT:1st Monkeypox-like disease in USA
This morning (Sunday, June 8th) Pro-MED published on their website (www.promedmail.org) the news that for the first time in the Western Hemisphere a Monkeypox virus-like illness has been diagnosed in 19 persons, 17 of whom are in Wisconsin, with the others in Illinois and Indiana.
Photos related to the index patient in Wisconsin and the mother and father of this patient can be viewed on the Marshfield Clinic (Wisconsin) website at: http://research.marshfieldclinic.org/crc/prairiedog.asp. If the clinical photos cannot be seen at that site, copies may be available at the BEPAST website.
Transmission of the virus to humans may have occurred from prairie dogs, which may possibly have been infected by a Gambian rat. Both prairie dogs and a Gambian rat may be linked to a pet store distributor in the Midwest USA.
**Bioterrorism is not being implicated at this time.
In a 1996-1997 monkeypox outbreak in Africa, 3 of 19 Gambian rats were reported to have been infected with monkeypox virus (Hutin Y et al. Emerging Infectious Disease Journal 2001; Vol 7. No. 3 May-June issue. This journal ("EID Journal") can be found online at the bottom left corner of the CDC homepage, or at www.cdc.gov/ncidod/eid/vol7no3/hutin.htm).
The CDC issued a Press Release dated June 7th that is on their website (under "In the News" and on their homepage near the top) titled:
"Public Health Investigation Uncovers First Outbreak of Human Monkeypox Infection in the Western Hemisphere".
More information on the CDC website, and sent to us via their new 'ListServ for Bioterrosim and Emerging Diseases' for Clinicians and Public Health Officials will certainly follow shortly given the recent excellent CDC Response to SARS in March.
The June 7 CDC Press release on "Human Monkeypox Infection" states:
"CDC has also issued interim recommendations for infection control calling for health care personnel attending hospitalized patients to follow standard precautions for guarding against airborne or contact illness. Veterinarians examining...exotic pets such as prairie dogs or Gambian rats are advised to use...gloves, surgical mask or N-95 respirator, and gowns".
Our understanding of this statement is that an N-95 mask and the other precautions should definitely be used when evaluating a patient with any rash resembling monkeypox or smallpox, as part of "airborne precautions".
A few other brief facts and references about monkeypox may prove helpful for local and regional preparedness training:
1. Monkeypox virus belongs to the Orthopoxviruses, as does the smallpox virus (variola virus) and the related smallpox vaccine virus (vaccinia virus).
2. This monkeypox-like virus in the USA IS NOT SMALLPOX.
3. However, the spectrum of evolving skin lesions of monkeypox can closely resemble those skin lesions of smallpox (including being on the palms, soles, and face). See Figure 1 online in the reference below by Breman and DA Henderson NEJM Aug 20, 1998 (pages 556-559) of skin lesions due to monkeypox).
a. Notably, a key difference between the two diseases is that monkeypox causes lymphadenopathy (swollen glands in non-medical jargon), but smallpox does not. (Include neck (cervical) and inguinal lymph node exams).
4. "Smallpox vaccine protects against monkeypox..." This statement occurs in the superb article on Monkeypox and Smallpox by Joel Breman (now at NIH and a DC resident) and DA Henderson (now back at Hopkins) in the NEJM 1998; Aug 20th; Vol 339: 556-559. You can read this online at www.nejm.org.
a. Also, the WHO website (www.who.int) has an alphabetically ordered list of diseases archived under "disease outbreaks". Click on "Monkeypox" and you will find 5 references for 1997. Under 14 April 1997 is the statement:
"Monkeypox, a disease which closely resembles smallpox, is preventable by the vaccination against smallpox".
5. Monkeypox can spread from person-to-person and can be fatal. Historically it has not spread as readily or for as long as smallpox, and the case-fatality rate has been less with monkeypox. Still it is high (especially in young children) and is a serious concern.
6. Previously, human monkeypox has occurred in West and Central Africa, and never in the Americas.
a. Monkeypox was discovered in 1970. Distinct monkeypox isolates and "clades" are known to exist (see Figure 2 online in the above referenced Emerging Infectious Disease Journal paper May-June 2001 by Hutin et al).
7. "The incubation period is about 12 days" (June 7 CDC Press release). "Incubation period" is the time between infection with this virus and the onset of illness symptoms. The average incubation period for smallpox is also ~12-13 days.
8. Monkeypox causes fever, muscle pain, headache, cough, and an evolving rash like smallpox (vesicles or pustules, umbilications or confluence, eventual crusting. As with smallpox look on the FACE and ask to see PALMS and later soles as part of the rapid clinical triage evaluation). Look for lymphadenopathy with monkeypox. (Monkeypox was the final diagnosis for the disease on the TV show "ER" last year when a family returned from central Africa and a ("smallpox") panic occurred when they presented to the US Midwest hospital featured on this TV show ("Er")).
9. NO FDA-licensed antiviral drug exists for monkeypox, but the antiviral "cidofovir" may be active and is apparently already being tested by CDC against this virus isolated from patients in the US Midwest. Cidofovir has severe side effects an dmust be given with alot of fluids and probenecid to decrease side effects (e.g. kidney damage).
10. Please consider circulating this initial preliminary information, websites with photos, and medical journal references to your respective medical and public health organizations within your region. This information will be accessible along with that on SARS and other regional threats on our website: www.bepast.org.
a. An Emergency Department algorithm for Monkeypox-like virus disease would likely initially resemble those already in place in the DC region and nationally for smallpox, as documented in the CDC color-photo website poster for smallpox and "Acute, Generalized Vesicular or Pustular Rash Illness Protocol".
Thank you very much. As with SARS, the anthrax attack of 2001, and smallpox vaccination issues in 2002-2003, let us be in contact with one another across our region in the coming days as more informaiton becomes available.
Daniel R. Lucey, MD, MPH
Director, Center for Biologic Counterterrorism & Emerging Diseases
Washington Hospital Center
ID Consultant to: DC DOH, DC Hospital Association, Medical Society of DC
cell: 614-226-2643