The World Health Organization (WHO) has declared the upsurge of mpox in the Democratic Republic of Congo (DRC) and growing number of cases in Africa a Public Health Emergency of International Concern (PHEIC).
Background:
- The World Health Organization (WHO) has declared the upsurge of mpox in the Democratic Republic of Congo (DRC) and growing number of cases in Africa a Public Health Emergency of International Concern (PHEIC).
- This is the second time in the last two years that mpox has been declared as a PHEIC. In July 2022, the multi- country outbreak of mpox was declared a PHEIC, as it spread rapidly via sexual contacts across several countries where the virus had not been seen before. That PHEIC was declared over in May 2023 global cases declined.
- A new virus strain in the DRC, clade I b, which is spreading through sexual networks, and its detection in countries neighbouring the DRC is especially concerning, and one of the main reasons for the declaration of the PHEIC.
Risk for Fraser Health Populations
- As of August 14, 2024, there have been no cases of clade I b mpox virus to date in Canada.
- The risk to the general population in Canada from clade I b mpox is assessed as low at this time.
- While travel associated mpox cases are a possibility, travel by itself without intimate close contact with a confirmed case, is not considered a risk for mpox. Mpox vaccine is not required for travel.
- Some regions of Canada have continued to report cases of clade II mpox, including a recent uptick of cases in the Toronto area. Current reports suggest that clade II mpox is less severe than clade I b.
What are symptoms of mpox?
Symptoms develop 7 to 10 days after being exposed but can begin 3 to 21 days after exposure.
In the first stage, symptoms can include fever, chills, headache, lymphadenopathy, backache, myalgia, fatigue. Less common symptoms can include sore throat, cough, nausea or vomiting, and diarrhea.
The second stage usually starts 1 to 5 days after the first stage. In the second stage, rashes (sores/blisters) develop. They could affect any part of the body, such as the mouth, genitals, perianal area, face, arms and legs, feet, and hands. The rash usually lasts between 14 and 28 days and changes through different stages before finally forming a scab, which later falls off.
Who is at high risk for mpox?
- Most recent cases are happening through close contacts between men having sex with other men.
- In the 2022-23 outbreak in British Columbia, a quarter of all cases had a known contact either with a mpox case, a person with symptoms compatible with mpox symptoms, or with contaminated materials.
- Most subsequent cases in BC have occurred in people who are unvaccinated or partially vaccinated.
What are outcomes from mpox infection?
- Mpox is usually self-limiting. Majority of people recover on their own after a few weeks.
- While complications, hospitalizations, and deaths are uncommon, individuals with immunocompromising conditions (e.g., unsuppressed HIV) may have more severe symptoms and complications.
- People who have had two doses of Imvamune® vaccine may have fewer rashes/lesions.
How does mpox get transmitted?
- From person to person
- Direct contact with sores or an affected mucosal area of a person with mpox. Most cases in the 2022 outbreak were exposed during close, intimate contact during sex.
- Direct contact with items like bedding or towels used by someone with mpox.
- Respiratory droplets during prolonged, close, face-to-face contact, e.g., kissing.
- From infected animals to humans
What are testing considerations for mpox?
- Mpox virus infection can be diagnosed by Polymerase Chain Reaction (PCR) tests. Sensitivity and specificity of PCR for fluid-filled lesions (vesicles, pustules, ulcers) and tissues are over 98%.
- If skin rash or mucosal lesions are present, collect lesion material (roof, crusts, aspirate, exudate, tissue).
- If lesions are present on more than one area of the body, use different swabs for different areas.
- Swab 2 to 3 lesions per area, unroof vesicles, and/or vigorously swab dry or crusted lesions with a single swab.
- Individuals without symptoms do not require testing, even for contacts to a confirmed mpox case, if they remain asymptomatic.
- When testing for mpox
- Consider broad range of differential diagnoses.
- Test for other Sexually Transmitted Infections (STI), including HIV, syphilis, gonorrhea, and chlamydia.
- Use the BCCDC PHL Virology Requisition and indicate "Mpox" in the PATIENT STATUS/TRAVEL HISTORY/EXPOSURE" box.
- For specific testing information, please refer to the PHSA eLab Handbook at http://www.elabhandbook.info/PHSA/Default.aspx, and search for ‘mpox’.
Who is eligible for mpox Vaccine?
- Imvamune® is a live-attenuated, non-replicating vaccine for mpox and smallpox viruses. It is available in specific circumstances for limited group of people, based on their clinical risk.
- Vaccine Eligibility: Two-Spirit and transgender people and men who self-identify as gay or bisexual or who have sex with men AND answer yes to any of the criteria below:
- Has sex with more than one partner, or
- Has sex with a partner, who has more than one partner, or
- Has casual sex (e.g., cruising), or
- Engages in sex work or plans to, either as a worker or a client.
- It may also be offered to individuals exposed to a confirmed mpox case, on a case-by-case basis.
- The vaccine is not indicated for those with signs and symptoms of mpox disease.
- For those who do not meet the eligibility criteria above, the vaccine is not required for travel.
References: 1. Communicable Disease Control Manual. Mpox interim guidance. BC Centre for Disease Control. (February 2024). 2. Statement of the First meeting of the International Health Regulations (2005) Emergency Committee regarding the upsurge of mpox 20 24. World Health Organization (19 August 2024). 3. Virologic and Immunologic Characteristics of Severe Mpox among Persons with Advanced HIV (VIRISMAP). Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Disease, Centers for Disease Control and Prevention (2024). 4. Mpox (monkeypox): Update. Public Health Agency of Canada (16 August 2024).