On August 11, 2020, a confirmed case of coronavirus disease 2019 (COVID-19) in a male
correctional facility employee (correctional officer) aged 20 years was reported to
the
Vermont Department of Health (VDH). On July 28, the correctional officer had multiple
brief encounters with six incarcerated or detained persons (IDPs)* while their SARS-CoV-2
test results were pending. The six
asymptomatic IDPs arrived from an out-of-state correctional facility on July 28 and
were
housed in a quarantine unit. In accordance with Vermont Department of Corrections
(VDOC)
policy for state prisons, nasopharyngeal swabs were collected from the six IDPs on
their
arrival date and tested for SARS-CoV-2, the virus that causes COVID-19, at the Vermont
Department of Health Laboratory, using real-time reverse transcription–polymerase
chain reaction (RT-PCR). On July 29, all six IDPs received positive test results.
VDH
and VDOC conducted a contact tracing investigation
†
and used video surveillance footage to determine that the correctional officer
did not meet VDH’s definition of close contact (i.e., being within 6 feet of
infectious persons for ≥15 consecutive minutes)
§
,
¶
; therefore, he continued to work. At the end of his
shift on August 4, he experienced loss of smell and taste, myalgia, runny nose, cough,
shortness of breath, headache, loss of appetite, and gastrointestinal symptoms;
beginning August 5, he stayed home from work. An August 5 nasopharyngeal specimen
tested
for SARS-CoV-2 by real-time RT-PCR at a commercial laboratory was reported as positive
on August 11; the correctional officer identified two contacts outside of work, neither
of whom developed COVID-19. On July 28, seven days preceding his illness onset, the
correctional officer had multiple brief exposures to six IDPs who later tested positive
for SARS-CoV-2; available data suggests that at least one of the asymptomatic IDPs
transmitted SARS-CoV-2 during these brief encounters.
Subsequently, VDH and facility staff members reviewed July 28 quarantine unit video
surveillance footage and standard correctional officer shift duty responsibilities
to
approximate the frequency and duration of interactions between the correctional officer
and infectious IDPs during the work shift (Table). Although the correctional officer
never spent 15 consecutive minutes
within 6 feet of an IDP with COVID-19, numerous brief (approximately 1-minute)
encounters that cumulatively exceeded 15 minutes did occur. During his 8-hour shift
on
July 28, the correctional officer was within 6 feet of an infectious IDP an estimated
22
times while the cell door was open, for an estimated 17 total minutes of cumulative
exposure. IDPs wore microfiber cloth masks during most interactions with the
correctional officer that occurred outside a cell; however, during several encounters
in
a cell doorway or in the recreation room, IDPs did not wear masks. During all
interactions, the correctional officer wore a microfiber cloth mask, gown, and eye
protection (goggles). The correctional officer wore gloves during most interactions.
The
correctional officer’s cumulative exposure time is an informed estimate;
additional interactions might have occurred that were missed during this
investigation.
TABLE
Description, frequency, and duration of close (within 6 ft) interactions
between the ill correctional facility employee and six infectious incarcerated
or detained persons (IDPs) while their SARS-CoV-2 test results were pending
— Vermont, July 28, 2020*
Routine encounter
Description
Typical frequency
Typical duration
Cell door typically
open?†
Estimated no. of exposures
≤6 ft from infectious persons and cumulative employee July 28
exposure time
Recreation room
use
Employees open cell doors to allow IDPs to
access recreation room one at a time. Observed opportunities for
conversation between staff members and IDPs.
Once per 8-hour shift for each IDP
60 seconds
Yes
6 infectious persons x 1 encounter per shift
= 6 encounters x 1 minute per encounter = 6 minutes
Collection of soiled linens
and clothes
Employees collect soiled laundry and provide
clean linens and clothing.
Clothes: twice weekly§;
Linens: once weekly§
30–60 seconds
Yes
6 infectious persons x 1 encounter during
ill employee’s shift = 6 encounters x 45 seconds = 4.5
minutes
Showering or
recreation
Employees open doors for IDPs to leave for
showering or recreation.
Once daily for each IDP during second
shift¶
30 seconds
Yes
6 infectious persons x 1 encounter per shift
= 6 encounters x 30 seconds = 3 minutes
Health
checks
Employees conduct health assessments of
IDPs.
Once per 8-hour shift for each IDP
60 seconds
During approximately one third of the
encounters
6 infectious persons x 1 encounter per shift
x 1/3 of encounters with door open = 2 encounters x 1 minute per
encounter = 2 minutes
Medication
dispensing
Employees deliver medication to IDPs.
Encounters occur through chutes in doors when possible.
As needed; approximately once per 8-hour
shift for each IDP
30–60 seconds
During approximately one third of the
encounters
6 infectious persons x 1 encounter per shift
x 1/3 of encounters with door open = 2 encounters x 45 seconds per
encounter = 1.5 minutes
Safety
checks
Employees visually check on IDPs through door
windows.
Every 15 minutes
<10 seconds
No
None
Meal delivery and
pick-up
Meals are delivered through food chutes in
cell doors; trays are picked up through the same chutes.
Once per 8-hour shift for each IDP
30 seconds
No
None
Total
—
—
—
—
22 encounters; 17 minutes
Abbreviation: COVID-19 = coronavirus disease 2019.
* Standard shift duties and surveillance footage from the quarantine
unit were used to characterize routine opportunities for employees and IDPs to
have close (within 6 ft) interactions. Observed encounters between the
correctional officer and IDPs and typical encounter durations were used to
estimate the ill employee’s cumulative exposure time. One correctional
staff member is assigned to the quarantine unit per shift and is responsible for
performing the tasks described in the table.
† IDPs are not required to wear masks while inside cells.
During health checks and medication dispensing interactions when cell doors were
open but IDPs remained inside, IDPs did not wear masks despite being within 6 ft
of employees without the door as a physical barrier.
§ These activities were observed during the course of the
correctional officer’s shift because these IDPs were new arrivals to the
facility.
¶ Surveillance footage was used to estimate the number of
encounters between the correctional officer and the six quarantined IDPs pending
SARS-CoV-2 test results on July 28.
The correctional officer reported no other known close contact exposures to persons
with
COVID-19 outside work and no travel outside Vermont during the 14 days preceding illness
onset. COVID-19 cumulative incidence in his county of residence and where the
correctional facility is located was relatively low at the time of the investigation
(20
cases per 100,000 persons), suggesting that his most likely exposures occurred in
the
correctional facility through multiple brief encounters (not initially considered
to
meet VDH’s definition of close contact exposure) with IDPs who later received a
positive SARS-CoV-2 test result.
Among seven employees with exposures to the infectious IDPs that did meet the VDH
close
contact definition, one person received a positive test result. Among thirteen employees
(including the correctional officer) with exposures to the infectious IDPs that did
not
meet the VDH close contact definition during contact tracing, only the correctional
officer received a positive SARS-CoV-2 test result.
Data are limited to precisely define “close contact”; however, 15 minutes
of close exposure is used as an operational definition for contact tracing
investigations in many settings. Additional factors to consider when defining close
contact include proximity, the duration of exposure, whether the infected person has
symptoms, whether the infected person was likely to generate respiratory aerosols,
and
environmental factors such as adequacy of ventilation and crowding. A primary purpose
of
contact tracing is to identify persons with higher risk exposures and therefore higher
probabilities of developing infection, which can guide decisions on quarantining and
work restrictions. Although the initial assessment did not suggest that the officer
had
close contact exposures, detailed review of video footage identified that the cumulative
duration of exposures exceeded 15 minutes. In correctional settings, frequent encounters
of ≤6 feet between IDPs and facility staff members are necessary; public health
officials should consider transmission-risk implications of cumulative exposure time
within such settings.