Monkeypox Case Investigation — Cook County Jail, Chicago, Illinois, July–August 2022

Chicago, Illinois, July-August 2022

Liesl M. Hagan, MPH; Amy Beeson, MD; Sarah Hughes, MPH; Rashida Hassan, MSPH; Lauren Tietje, MPH; Ashley A. Meehan, MPH; Hillary Spencer, MD; Janice Turner, MPH; Morgan Richardson, MFA; Jourdan Howard, MPH; Anne Schultz, MPH; Salma Ali, MPH; Margaret Mary Butler, MSN; Diana Arce Garza, MS; Clint N. Morgan, MS; Chantal Kling; Nicolle Baird, PhD; Michael B. Townsend, PhD; William C. Carson; David Lowe, PhD; Nhien T. Wynn, MS; Stephanie R. Black, MD; Janna L. Kerins, VMD; Josh Rafinski, MBA; Andrew Defuniak, MD; Priscilla Auguston, MD; Emily Mosites, PhD; Isaac Ghinai, MBBS; Chad Zawitz, MD


Morbidity and Mortality Weekly Report. 2022;71(40):1271-1277. 

In This Article

Investigation and Results

CCJ houses approximately 6,000 residents in cell-based and dormitory-based units across 16 buildings. The monkeypox case occurred in a resident who was booked into jail in mid-July 2022 (investigation day 1) and assigned to two congregate dormitories used for intake (dormitories A and B) during the 7 days preceding his isolation for suspected monkeypox. On day 7, the resident placed a written request for health services, reporting swollen genitals, and CCJ health care personnel ordered a sexually transmitted infection laboratory panel. On day 8, health care administrators received a call from one of the patient's family members alerting them to the possibility that the patient might have monkeypox; he was then evaluated in person and isolated. Lesion swab specimens collected for nonvariola Orthopoxvirus (NVO) testing on day 9 returned a positive result on day 11. During evaluation, the patient reported first noticing a localized rash on day 2, which subsequently spread over much of his body and was accompanied by fatigue and body aches before he was isolated. IDPH requested a CDC deployment team to assist with the investigation. This activity was reviewed and approved by CDC and conducted consistent with applicable federal law and CDC policy.§

Fifty-seven other residents were housed with the patient for 1–7 nights (median = 5 nights) before he was isolated (Table) (Figure). Although CCJ policy required indoor mask use as a COVID-19 prevention strategy during the period of this investigation, enforcing mask use 24 hours per day in correctional facilities is challenging and mask usage is often low; the patient and other residents were not observed wearing masks consistently during this time. The patient reported during an interview that he had had no skin-to-skin or sexual contact with other residents, and no such contact between the patient and other residents was observed during review of security video footage. Because of the difficulty in ascertaining whether each resident sharing a dormitory with the patient met criteria for intermediate-risk exposure versus lower-risk exposure (simply entering the living space of a person with monkeypox), all 57 residents were conservatively categorized as having had intermediate-risk exposure.


Follow-up of 57 residents potentially exposed to Monkeypox virus — Cook County Jail, Chicago, Illinois, July–August 2022
Abbreviation: PEP = postexposure prophylaxis.

On investigation day 15, serologic testing was offered to the 36 potentially exposed residents who were still in detention. One week later, on investigation day 22, serologic testing was again offered to those who had declined the first offer. Among all 36 residents still in detention, a total of 14 (39%) consented to testing. Specimens were tested by enzyme-linked immunosorbent assay for anti-Orthopoxvirus immunoglobulin (Ig) M (a transient marker of acute infection or recent vaccination) and IgG (a long-lived marker generated during infection or vaccination).[1] None of the specimens tested positive for IgM. Specimens from three residents tested positive for IgG; all three were old enough to have received routine childhood smallpox vaccination, although their previous smallpox vaccination history could not be confirmed.**

On investigation day 8, after the patient was isolated, CCJ resident-workers cleaned and disinfected dormitories A and B. To evaluate the extent of remaining surface contamination, 54 environmental samples were collected from both dormitories on investigation day 21, which was 18 days after the patient had been in dormitory A and 13 days after he had been in dormitory B.†† One dormitory B sample, collected from a vertical, painted concrete slab at the head of the patient's bed, tested positive for NVO DNA by real-time polymerase chain reaction (PCR) and was confirmed by Clade II MPXV-specific PCR; viral culture was negative§§.[2]

To identify possible exposure patterns in the dormitories and to assess residents' knowledge about monkeypox, 16 potentially exposed residents were interviewed individually.¶¶ The majority of residents (12) reported washing their clothes in communal showers or sinks in the dormitory. Some residents reported sharing personal hygiene items (five) or eating utensils (four) with other residents, engaging in physical altercations (four), sitting on other residents' beds (three), or sharing or touching other residents' linens (two). None reported sexual contact with others while in CCJ. The majority (13) also reported hearing about monkeypox for the first time while detained in CCJ. Residents' knowledge about monkeypox symptoms, transmission modes, and exposure risks varied but was generally low.

Dormitories A and B are each 2,950 ft2 with 10.5-ft high ceilings and a congregate bathroom with five combination toilet-sink units and five shower stalls. Each has 39 fixed single bed platforms spaced a minimum of 3 ft apart. During the investigation period, the ventilation system typically provided five to six air changes per hour for both dormitories; when outdoor air temperature was >90°F (>32°C) for brief periods on 2 days, three to four air changes per hour occurred. During the period when the patient with monkeypox was housed in dormitories A and B, residents were served meals at communal tables inside the dormitories and spent an average of 20–24 hrs per day in the dormitories.
§45 C.F.R. part 46, 21 C.F.R. part 56; 42 U.S.C. Sect. 241(d); 5 U.S.C. Sect. 552a; 44 U.S.C. Sect. 3501 et seq.
**One resident had an equivocal IgM result 7 days after last potential exposure to the patient but reported no symptoms at the time of specimen collection or during his 21-day incubation period. Because he received PEP, repeat serologic testing was not performed; seroconversion in progress cannot be definitively ruled out.
††Surfaces included painted concrete bed platforms, desks, and stools in the spaces assigned to the patient before he was isolated, as well as metal toilet rims and flush buttons, metal sink and shower buttons, and plastic telephone receivers shared in communal spaces.
§§Polyester-tipped applicator swabs were prewetted with phosphate buffered saline (PBS) solution before swabbing environmental surfaces, then stored and transported in 300 μL of PBS solution and kept frozen until processing using the swab extraction tube system (Roche); DNA was extracted from the swab eluate before PCR testing.
¶¶Residents were asked about their monkeypox knowledge (including transmission modes, prevention, and symptoms) and the types of contact they had with other persons in the jail or with shared objects. The identity of the patient with monkeypox was not disclosed; thus, questions about contact with others in the jail did not specify whether it occurred with the patient versus with other persons in the dormitory.