Contact Tracing and Exposure Investigation in Response to the First Case of Monkeypox Virus Infection in the United States During the 2022 Global Monkeypox Outbreak.

BACKGROUND: In May 2022, the first case of monkeypox virus (MPXV) infection in the United States in the current global outbreak was identified. As part of the public health and health care facility response, a contact tracing and exposure investigation was done. OBJECTIVE: To describe the contact tracing, exposure identification, risk stratification, administration of postexposure prophylaxis (PEP), and exposure period monitoring for contacts of the index patient, including evaluation of persons who developed symptoms possibly consistent with MPXV infection. DESIGN: Contact tracing and exposure investigation. SETTING: Multiple health care facilities and community settings in Massachusetts. PARTICIPANTS: Persons identified as contacts of the index patient. INTERVENTION: Contact notification, risk stratification, and symptom monitoring; PEP administration in a subset of contacts. MEASUREMENTS: Epidemiologic and clinical data collected through standard surveillance procedures at each facility and then aggregated and analyzed. RESULTS: There were 37 community and 129 health care contacts identified, with 4 at high risk, 49 at intermediate risk, and 113 at low or uncertain risk. Fifteen health care contacts developed symptoms during the monitoring period. Three met criteria for MPXV testing, with negative results. Two community contacts developed symptoms. Neither met criteria for MPXV testing, and neither showed disease progression consistent with monkeypox. Among 4 persons with high-risk exposures offered PEP, 3 elected to receive PEP. Among 10 HCP with intermediate-risk exposures for which PEP was offered as part of informed clinical decision making, 2 elected to receive PEP. No transmissions were identified at the conclusion of the 21-day monitoring period, despite the delay in recognition of monkeypox in the index patient. LIMITATION: Descriptions of exposures are subject to recall bias, which affects risk stratification. CONCLUSION: In a contact tracing investigation involving 166 community and health care contacts of a patient with monkeypox, no secondary cases were identified. PRIMARY FUNDING SOURCE: None.

Epidemiologic and Clinical Characteristics of Monkeypox Cases - United States, May 17-July 22, 2022.

Monkeypox, a zoonotic infection caused by an orthopoxvirus, is endemic in parts of Africa. On August 4, 2022, the U.S. Department of Health and Human Services declared the U.S. monkeypox outbreak, which began on May 17, to be a public health emergency (1,2). After detection of the first U.S. monkeypox case), CDC and health departments implemented enhanced monkeypox case detection and reporting. Among 2,891 cases reported in the United States through July 22 by 43 states, Puerto Rico, and the District of Columbia (DC), CDC received case report forms for 1,195 (41%) cases by July 27. Among these, 99% of cases were among men; among men with available information, 94% reported male-to-male sexual or close intimate contact during the 3 weeks before symptom onset. Among the 88% of cases with available data, 41% were among non-Hispanic White (White) persons, 28% among Hispanic or Latino (Hispanic) persons, and 26% among non-Hispanic Black or African American (Black) persons. Forty-two percent of persons with monkeypox with available data did not report the typical prodrome as their first symptom, and 46% reported one or more genital lesions during their illness; 41% had HIV infection. Data suggest that widespread community transmission of monkeypox has disproportionately affected gay, bisexual, and other men who have sex with men and racial and ethnic minority groups. Compared with historical reports of monkeypox in areas with endemic disease, currently reported outbreak-associated cases are less likely to have a prodrome and more likely to have genital involvement. CDC and other federal, state, and local agencies have implemented response efforts to expand testing, treatment, and vaccination. Public health efforts should prioritize gay, bisexual, and other men who have sex with men, who are currently disproportionately affected, for prevention and testing, while addressing equity, minimizing stigma, and maintaining vigilance for transmission in other populations. Clinicians should test patients with rash consistent with monkeypox,† regardless of whether the rash is disseminated or was preceded by prodrome. Likewise, although most cases to date have occurred among gay, bisexual, and other men who have sex with men, any patient with rash consistent with monkeypox should be considered for testing. CDC is continually evaluating new evidence and tailoring response strategies as information on changing case demographics, clinical characteristics, transmission, and vaccine effectiveness become available.§.