Monkeypox: Safety Considerations for Clinical Labs

Adhering to biosafety protocols should be the highest priority when testing possible monkeypox specimens

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Morgana Moretti, PhD
Photo portrait of morgana moretti

Morgana Moretti, PhD, is a scientist and medical writer with more than 60 articles published in peer-reviewed biomedical literature. She holds a doctoral degree in biochemistry and has expertise in the study of brain alterations in neurodegenerative diseases and psychiatric disorders.

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Published:Oct 17, 2022
|4 min read
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Monkeypox was first detected in the US in May, and as of October 13, 2022, the Centers for Disease Control and Prevention (CDC) is tracking more than 72,000 confirmed cases in 100 countries where the disease is not regularly found. In July 2022, the World Health Organization (WHO) declared monkeypox a Public Health Emergency of International Concern, a designation meant to coordinate international response to control the disease spread and protect communities.

While monkeypox is not expected to reach the scale of the COVID-19 pandemic, clinical labs must implement response actions to prevent its transmission. Aligned with international efforts to stop the onward spread of monkeypox, this article provides information about the disease and outlines key biosafety considerations to maximize the safety of laboratory personnel when testing specimens from confirmed or suspected monkeypox patients.

Monkeypox: The pathogen

Monkeypox virus belongs to the Orthopoxvirus genus, which also includes species like variola virus (which causes smallpox), vaccinia virus (used in the smallpox vaccine), and cowpox virus.

"Currently, the CDC recommends that only people with a skin rash consistent with monkeypox should be tested."

Patients with monkeypox usually present flu-like symptoms and a skin rash that can affect the face, inside of the mouth, hands, feet, genital or anal area, and other parts of the body. The skin rash, similar in appearance to smallpox, can cause irritation, discomfort, and pain. Symptoms typically start within two weeks of exposure to the virus and last from two to four weeks.

In the current outbreak, monkeypox is primarily spreading through contact with the sores, scabs, respiratory droplets, or oral fluids of an infected person, usually through close contact, like hugging, cuddling, kissing, or sex. According to the CDC, laboratory exposures to the virus occur primarily through needle-stick injuries, direct contact with the specimen, or aerosols that laboratory procedures may generate.

A PCR test on a viral swab taken from lesions or lesion crusts is used to diagnose monkeypox. Currently, the CDC recommends that only people with a skin rash consistent with monkeypox should be tested.

Biosafety considerations for lab personnel working with monkeypox

Specimen collection

Because of the contagious nature of the virus, patients with suspected or diagnosed monkeypox should be isolated in accordance with CDC recommendations for health care settings. Personal protective equipment (PPE) used by health care personnel who enter the patient’s room should include a gown, gloves, eye protection, and a NIOSH-approved particulate respirator equipped with N95 filters or higher.

Effective communication between specimen collection teams and laboratory staff and a labeling system that clearly identifies suspected monkeypox samples are essential to ensure safety during specimen manipulation. This is especially relevant in hospital laboratories that routinely process specimens from patients with infectious or noninfectious conditions.

Specific protocols for specimen collection are available on the CDC monkeypox website. The Laboratory testing for the monkeypox virus: Interim guidance is another excellent resource that provides information and guidance on monkeypox specimen collection.

Sample handling

 When manipulating possible monkeypox specimens, clinical lab workers should use a certified Class II biological safety cabinet (BSC). In the absence of a BSC, clinical lab employees can lower their risk of exposure to monkeypox by combining PPE and physical containment devices like centrifuge safety cups or sealed rotors.

"When manipulating possible monkeypox specimens, clinical lab staff should use a certified Class II BSC."

Clinical laboratories can also encourage their staff to use higher levels of respiratory protection, including powered air-purifying respirators and non-powered respirators with N, R, or P100 filters. These respirators can be used if the vaccination status of staff is not confirmed or if disposable particulate respirators do not fit personnel.

Immunization for health care workers

Although recommended, vaccination is not an absolute requirement for handling specimens from suspected or confirmed monkeypox patients.

According to the CDC, employees vaccinated within the past three years can conduct routine chemistry, hematology, microbiology, and urinalysis of non-lesion specimens in Biosafety Level 2 (BSL-2) facilities. Lesion specimens from patients who are suspected of having monkeypox must also be managed in BSL-2 laboratory facilities, following biosafety guidelines for BSL-2 according to site-specific and activity-specific risk assessments.

If staff are unvaccinated, specimen processing from suspected or confirmed monkeypox patients may be handled in BSL-2 facilities, but with more stringent BSL-3 work practices.

Culture-based testing for the monkeypox virus should be limited to laboratories whose staff have been properly trained and vaccinated.

Don’t forget clinical lab biosafety basics

While all laboratories should perform site- and activity-specific risk assessments to determine the most appropriate safety measures for particular circumstances, some biosafety principles can be reinforced to reduce the risk of occupational exposure to the monkeypox virus. These include the following:
  • Wearing appropriate PPE
  • Hand washing after removing gloves and especially before touching the eyes or mucosal surfaces
  • Avoiding procedures that could generate infectious aerosols
  • Decontaminating work surfaces after completing work or at the end of the day
  • Decontaminating cultures, stocks, and other regulated waste before disposal by using an approved method, such as autoclaving

Key takeaways on monkeypox for clinical laboratory leaders 

Although monkeypox is rarely fatal in its current form and unlikely to reach the pandemic spread of COVID-19, laboratory leaders must continue to monitor guidance from the CDC, WHO, OSHA, and other relevant agencies and provide updates as appropriate.

Employers must be proactive in communicating risk, providing guidance to lab staff, and promoting engagement activities to increase awareness of the growing monkeypox outbreak. In addition, they must be vigilant and encourage careful adherence to infection control precautions.

"Monkeypox can spread to anyone."

Laboratory leadership must ensure that workers with monkeypox follow recommended isolation practices. Moreover, leaders may consider reinstituting or maintaining some of the controls previously implemented to manage the COVID-19 pandemic, such as flexible work policies.

The infection control response must encourage vaccination and avoid stigmatizing men who have sex with men (currently the most affected patient population) by reminding employees that monkeypox can spread to anyone. Employers may also want to review their discrimination, harassment, and retaliation prevention policies and monitor workplace interactions to anticipate and address potential conflicts or misunderstandings about virus transmission.

Increased detection will advance our understanding of the current outbreak epidemiology, help categorize risk factors for severe disease, and improve our approach to monkeypox prevention. Currently, the most important measures to control the spread of the monkeypox virus in clinical laboratory settings are to avoid close contact with infected individuals and strictly adhere to biosafety protocols.

Top Image:
As of October 13, the CDC is tracking more than 72,000 confirmed cases of monkeypox.
iStock, anilakkus