Infectious Disease Alert Updates
May 1, 2023
Related Articles
By Carol A. Kemper, MD, FIDSA
Medical Director, Infection Prevention, El Camino Hospital, Palo Alto Medical Foundation
Occupational Mpox in Healthcare Workers
SOURCE: Alarcón J, Kim M, Balanji N, et al. Occupational monkeypox virus transmission to a healthcare worker, California, USA, 2022. Emerg Infect Dis 2023;29:435-437.
Mpox virus (monkeypox, MPXV) infection has been reported with some frequency in healthcare workers (HCWs), but most cases cannot be convincingly attributed to occupational exposure. As of Aug. 22, 2022, 256 cases of MPXV infection in HCWs had been reported to the Centers for Disease Control and Prevention (CDC), although only three were confirmed as occupational. Rare cases of MPXV infection in HCWs in other countries were suspected to be related to contaminated environmental surfaces or specimen collection. Surveys of HCWs providing care for suspect or confirmed cases suggested the majority do not wear full personal protective equipment (PPE) as recommended, but, nonetheless, occupational infection has been infrequent.
The Morbidity and Mortality Weekly Report reports a case of occupationally acquired non-needlestick MPXV infection in a 40-year-old female physician in Los Angeles. She was working in two outpatient clinics that served the LGBTQ+ community and human immunodeficiency virus (HIV)-infected individuals and, last summer, directly worked with patients with suspected or confirmed MPXV infection. She routinely wore full PPE with N95, gloves, gown, and eye protection when around patients with suspected symptoms or confirmed infection. Remarkably, she had a history of rheumatoid arthritis and was receiving etanercept (a tumor necrosis factor blocker).
In August 2022, she developed a prodromal illness for two days and then developed a single umbilicated lesion on her left middle finger, which gradually ulcerated. Nine to 10 days later, she developed transient fever, cough, and sore throat, and 10 additional skin lesions occurred throughout her body. She was treated with tecovirimat and fully recovered, although appended photos suggest it took 30 days for the finger lesion to heal completely. No secondary cases occurred, and 5/23 clinic staff received post-exposure prophylaxis with Jynneos vaccine.
Investigation identified two patients who had escaped recognition at triage with symptoms suggestive of MPXV infection and who were initially seen in examination rooms by the physician without full PPE. Twenty-nine days prior to the onset of her own symptoms, the physician spent 15 minutes with one patient wearing a surgical mask and gloves; and about four days prior to the onset of her own symptoms, she spent five minutes with a second patient wearing a surgical mask and gloves. This latter patient subsequently tested positive for MPXV infection. In both cases, she left the room and donned full PPE before obtaining specimens.
Another 159 patient visits had been conducted in the 21 days prior to her symptom onset — three were tested for MPXV and only one was positive, although all of that person’s lesions had healed by the time of the visit four days prior to onset of her own symptoms. Exam rooms were fully cleaned and sanitized with Cavicide between visits. Patients and staff shared two gender-neutral bathrooms that were cleaned at night by janitorial services.
The mode of transmission in this HCW remains unknown, and virus samples were not available for genetic comparison in order to confirm nosocomial transmission. The patient had no other known risk factors for MPXV infection. The fact that the lesion first appeared on a digit suggests that contamination occurred during specimen collection or bagging, doffing of gown and gloves, or possibly environmental exposure from the room or the bathroom. It seems likely the etanercept contributed to her vulnerability to MPXV infection.
An earlier MMWR report in August 2022 described the first occupationally acquired MPXV infection in the United States, which occurred in an emergency room nurse exposed to MPXV through a needlestick injury while obtaining a swab specimen in a suspected case. Despite receiving the first of two doses of Jynneos vaccine within 15 hours for post-exposure prophylaxis, she developed a single skin lesion at the site of the needlestick injury on her finger about 10 days later. No further skin lesions or symptoms occurred. Despite the apparent rarity of infection in HCWs, the CDC continues to recommend full PPE, including N95, for close contact with suspected MPXV cases. And HCWs and janitorial staff working in areas providing care for patients at risk for MPXV infection now are eligible for vaccination against MPXV infection.
Homeless People at Risk for Mpox
SOURCE: Waddell CJ, Filardo TD, Prasad N, et al. Possible undetected mpox infection among persons accessing homeless services and staying in encampments – San Francisco, California, October-November 2022. MMWR Morbid Mortal Wkly Rep 2023;72:227-231.
The current (waning) multinational outbreak of mpox virus (monkeypox, MPXV) began in May 2022, and by August 2022, the United States Food and Drug Administration granted Emergency Use Authorization for Jynneos vaccine for post-exposure prophylaxis (PEP) for exposed persons and for pre-exposure prophylaxis (PrEP) of adult healthcare workers (HCWs) at high risk for occupational exposure. Later, as supplies of vaccine became more available, PrEP vaccination was offered to gay and bisexual men who have sex with men and their female contacts, especially human immunodeficiency virus (HIV)-infected persons at risk. More recently, in February 2023, the Centers for Disease Control and Prevention (CDC) emphasized the need to focus PrEP efforts on adolescents at higher risk for MPXV infection.
Those experiencing homelessness generally have not been considered at risk for MPXV infection and have not been included in the recommendations for PrEP. Although, when you think about MPXV transmission, homeless shelters and encampments are essentially higher-risk congregate living situations with crowded living conditions, poor sanitation, and higher rates of HIV infection and drug use. In such conditions, individuals are known to trade sex for food, drugs, and shelter. An official Department of Housing and Urban Development (HUD) report from Oct. 26, 2022, described how the MPXV outbreak had disproportionately affected the homeless and those with HIV infection — with one survey finding 81% of MPXV-infected adults were HIV-positive and 23% were homeless.
In October-November 2022, a CDC field team performed a serosurvey of homeless persons staying in shelters, encampments, or supportive housing in San Francisco. Sixteen different sites were visited, and 209 participants agreed to respond to a 15-minute survey and provide a blood sample. Among those who had not received smallpox or MPXV vaccination nor had previous MPXV infection, 2/80 (2.5%) had alphaorthopoxvirus immunoglobulin G (IgG) antibodies detected, suggesting prior occult infection. In addition, 1/73 (1.4%) persons who did not report MPXV infection had detectable immunoglobulin M (IgM) antibody. These results suggest that at least three MPXV infections had gone undetected in these homeless individuals.
Several urban areas have expanded their wastewater surveillance to include human MPXV, in addition to SARS-CoV-2, influenza and other respiratory viruses, polio, drug-resistant bacteria, and even Candida auris (as well as a variety of opiates) to monitor disease activity in their areas. I recall how our county announced last summer they had detected MPXV deoxyribonucleic acid (DNA) in the wastewater in two of four sewer systems in Santa Clara County — although the corresponding cases were not clinically recognized. This kind of real-time data serves as an important tool for public health officials when tracking patterns of disease transmission and as an early warning system.1 It would be good if these data were made publicly available in real time as well.
REFERENCE
- Boehm AB, Hughes B, Duong D, et al. Wastewater concentrations of human influenza, metapneumovirus, parainfluenza, respiratory syncytial virus, rhinovirus, and seasonal coronavirus nucleic-acids during the COVID-19 pandemic: A surveillance study. Lancet Microbe 2023;S2666-5247(22)00386-X.
PRIORIX Is Interchangeable with MMRII
SOURCE: Krow-Lucal E, Marin M, Shepersky L, et al. Measles, Mumps, Rubella Vaccine (PRIORIX): Recommendations of the Advisory Committee on Immunization Practices – United States, 2022. MMWR Morb Mortal Wkly Rep 2022;71:1465-1469.
Since 1978, only one vaccine, MMRII, has been available for vaccination against measles, mumps, and rubella — until now. In June 2022, the United States Food and Drug Administration approved a second measles, mumps, and rubella (MMR) vaccine, PRIORIX. PRIORIX vaccine includes three attenuated live viruses that are genetically similar or identical to those of MMRII.
The Advisory Committee on Immunization Practices wants it understood that they regard the two vaccines as “fully interchangeable,” and PRIORIX may be used for all of the same on- and off-label purposes as MMRII. Similar to the MMRII vaccine, PRIORIX comes as a single-dose vial without a preservative and is given as a subcutaneous injection. It can be administered at different anatomic sites with other live and nonlive childhood vaccines, although other live vaccines not administered on the same day should be delayed by 28 days or more.
Importantly, if there is uncertainty as to which vaccine was used initially, or if one or the other vaccine is not available, a second dose of vaccine should not be deferred or delayed. For example, for international travel, infants 6-11 months of age should receive a single dose of either MMR vaccine and those 12 months of age or older who have not yet received MMR vaccine should receive two doses at least 28 days apart — and the vaccines do not need to be from the same manufacturer.
Occupational Mpox in Healthcare Workers; Homeless People at Risk for Mpox; PRIORIX Is Interchangeable with MMRII
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