Monkeypox: What you need to know

Compiled by Dr. Heidi Munchenberg and Prof. Laurie Walsh from the ADA Infection Control Committee  Summary of current guidance.

Monkeypox is not highly infectious and requires close contact with lesions, body fluids, respiratory droplets and contaminated materials such as bedding. Monkeypox is infectious from the onset of the prodrome until the vesicles have scabbed over and the scabs have fallen off.
 
Monkeypox can clinically present similar to other viral rash illnesses such as measles and chickenpox. Caution is warranted if a patient has signs and symptoms that are consistent with a viral rash illness, i.e.:

- Fever
- Fatigue
- Rash (including vesicles)
 
If a patient has presented to the clinic and a suspicion of infectious monkeypox, measles or chicken pox has been formed while reviewing the patient’s presenting condition and medical history, staff should delay any non-urgent treatment until a doctor confirms that the patient is no longer infectious.

If urgent treatment is required for a patient with a viral rash illness, while on the premises the patient should: 

- Be isolated from other patients and staff 
- Perform hand hygiene
- Wear a standard surgical mask when not being evaluated/treated
- Be instructed to cover their mouth and nose when coughing or sneezing.

In this situation, the dental team should: 

- Adopt transmission based precautions (contact and droplet precautions), including (but not limited to) the use of a fit-tested (ideally) and fit-checked particulate filter respirator (PFR) – P2/N95 or equivalent and single use fluid resistant gown. Please see page 98 of the NHMRC Guidelines 2020 for further information about contact and droplet precautions.

- Avoid coming into close contact with the patient if not immune to measles/chicken pox.

As part of appropriate environmental management, surfaces that the patient came into contact with (including reception areas/common areas) must be cleaned with either: 

- Diluted neutral detergent followed by a disinfectant solution (2-step clean)

- Combined detergent/disinfectant solution/wipe (2-in-1 clean)
 
For clients who are no longer infectiousno specific infection prevention and control precautions are required.
 

Further information about Monkeypox

Monkeypox (MPX) is a rare but potentially serious viral zoonotic disease, endemic to Central and West African tropical rainforest areas (especially Nigeria). Since 13 May 2022, cases have been reported in other countries through people with no established travel links to endemic areas. The first  case was reported in Australia on 20 May 2022. It was declared a public health emergency by WHO on 23 July 2022.

The Monkeypox virus (MPXV) is similar to the Variola virus that causes smallpox (same genus). (Note that WHO is considering renaming the MPX virus). 

MPX is spread through (A) close contact with an infected animal (either by being scratched or bitten by the animal or by preparing or eating meat or using products from an infected animal); (B) Contact with material contaminated with the virus, and (C) close contact with an infected person. Monkeypox can spread from the time symptoms start until the rash has fully healed and a fresh layer of skin has formed. People who do not have monkeypox symptoms cannot spread the virus to others. The amount of time between being infected and showing symptoms (incubation period) of MPX is typically between 7 and 14 days, but can range from 5 to 21 days.

Human-to-human transmission of monkeypox can occur through (A) Direct contact with the infectious rash, scabs, or body fluids; (B) Close contact with lesions on the skin, including during sexual contact; (C) Fomites, such as contaminated linen, clothing, or towels that previously touched the infectious rash or body fluids, and (D) Contact with respiratory particles and respiratory secretions, containing infectious material, e.g. during prolonged, face-to-face contact, or during intimate physical contact, such as kissing, cuddling, or sex.

Transmission via respiratory particles usually requires prolonged face-to-face contact, which may put dental health care workers, household members and other close contacts of active cases at greater risk.

The clinical presentation typically starts with fever and swollen lymph nodes and may also include headache, muscle aches, joint pain and back pain. Some 1-3 days after fever starts, a distinctive rash appears. The rash lesions typically begin to develop at the same time on any part of the body, including the mouth, eyes and genitalia. The lesions may on one part of the body or all over the body. The rash may appear on the: face (95% of cases); palms of the hands and soles of the feet (75% of cases); inside of the mouth (70% of cases); genitalia (30% of cases); and eyes (20% of cases). The number of lesions varies from a few to several thousand.

Lesions look like the blisters in varicella (chickenpox), but larger. They typically start in the head and neck region rather than centrally in most patients. Direct skin contact may lead to blisters at the site of contact (skin spots or rash).

The disease is usually self-limiting with symptoms resolving within 2-4 weeks. Most cases will be managed in the community rather than in hospital. Severe illness can develop in a small percentage of cases, and fatal outcomes can occur (up to 10% has been reported in the literature, when medical care is limited). A key resource is the CDNA Monkeypox Virus Infection Case and Contact Management Guidelines https://health.gov.au/resources/publications/cdna-monkeypox-virus-infection-case-and-contactmanagement-guidelines. 

People presenting to any health care setting with a rash or monkeypox-like symptoms, should be assessed for clinical or epidemiological risk factors. i.e. travel to country with endemic MPX or established community MPx spread, contact with a known MPX case while infectious.
 

Some key actions to consider based on an assessment of risk

- If a patient presenting for care at health care facility is suspected of having monkeypox, inform the local public health unit immediately. 

- Consider signage in health care facilities to enhance awareness of the symptoms and transmission of monkeypox virus, to the general public.

- Implementing Transmission based precautions for suspected or confirmed cases

- Hand hygiene for patients using TGA approved alcohol-based hand rubs (60-80% alcohol).

- Separate suspected cases from other patients and staff (when not donned in appropriate PPE).

- Identify high patient touch surfaces for environmental cleaning and disinfection 

- Staff involved in care of a suspect or known case: Staff who have received smallpox vaccination in the past are preferred when caring for a suspected, probable, or confirmed monkeypox patient. Avoid allocation of immunocompromised staff to any patient with suspected, probable, or confirmed monkeypox.

- Consider the use of dedicated patient equipment, or single use equipment, to limit disease spread associated with reuse of shared patient equipment. 

- Treating patients infected with MPXV requires contact and droplet precautions.

Environmental surfaces

Clean with a detergent based product then apply a TGA approved hospital-grade disinfectant with activity against viruses (according to the label and product information), OR use a TGA-listed 2-in-1 (single step) combined cleaning and disinfection product with activity against viruses may also be used, such as a combined detergent/disinfectant wipe or solution. When using disposable wipes, ensure an adequate number of wipes are used for the area and surfaces being cleaned and disinfected. The manufacturer’s instructions for contact time needs to be adhered to. Remove PPE worn during the patient interaction and apply a new set of PPE before cleaning and disinfecting the room.

Personal Protective Equipment (PPE)
Ideally, a fit-tested particulate filter respirator (PFR) – P2/N95 or equivalent should be worn. A fit check should be performed each time the PFR is applied. Eye protection using a face shield should be adopted. Disposable fluid resistant gown should be used and disposed of after treating the patient and before treating any other patients.

PEP and vaccines
Vaccines using the vaccinia virus are likely to be effective against MPX. For guidance on post-exposure vaccination and vaccination as pre-exposure prophylaxis for monkeypox, refer to advice from the Australian Technical Advisory Group on Immunisation (ATAGI) https://health.gov.au/resources/publications/atagi-clinical-guidance-on-vaccination-against-monkeypox

Note that these vaccines are live viruses and give around 85% protection. Different vaccines have different periods before protection is developed e.g. 4 weeks for Vaccinia vaccination (ACAM2000™). The vaccination sites must remain covered.

Antiviral treatment
Tecovirimat is the preferred treatment for severe monkeypox virus infection. This is held in the National Medical Stockpile (NMS). Another antiviral of possible use is Cidofovir, but this has a considerable adverse events profile. Evidence for the use of antiviral agents for post exposure prophylaxis is limited. Vaccinia Immunoglobulin (VIG) may also have some value. Little human evidence is available on whether combination therapy of an antiviral agents plus VIG is superior to an antiviral agent alone. Because most infections are mild in the current outbreak, most patients will not require antiviral treatment. If needed these agents will be prescribed by an infectious diseases physician and/or a sexual health physician involved in case management. 

Guidance above has been based on (A) the CDNA Monkeypox virus infection case and contact management Guidelines 6 July 2022, (B) the Infection Prevention and Control Expert Group Interim Guidance on Monkeypox for Health Workers, 24 June 2022, and (C) the Australian Human Monkeypox Treatment Guidelines 24 June 2022.