Abbreviations
WHO (World Health Organization)
CDC (Center for Disease Control)
SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2)
COPD (Chronic Obstructive Pulmonary Disease)
To the Editor,
CDC recommends the use of N-95 respirator or surgical mask (if N-95
masks are not available) when taking care of the COVID-19 suspected or
positive patients. N-95 respiratory mask should be used instead of a
face-mask when present or carrying out aerosol-generating procedures
such as intubation, bronchoscopy1. WHO has also
recommended to wear a mask in simple encounters with COVID-19 patients
and reserve the N-95 respirators for aerosol producing
procedures2. CDC reports that the spread of the virus
is mainly from person to person in the form of respiratory droplets when
the infected COVID 19 patient sneezes or coughs3. WHO
reported the transmission of the virus between people through droplets
and contact and not through airborne precautions4.
However, there are recent experimental studies that suggest the
plausibility of aerosol transmission of COVID-19. We describe a case of
an emergency health care worker acquiring COVID-19 in a short encounter
with an index COVID-19 positive patient (patient X) in the hospital
despite the use of a surgical mask and gloves.
A 44-year-old nurse with no significant past medical history took care
of Patient X with the preliminary diagnosis of acute COPD exacerbation
in a non-isolation room, who later was diagnosed to be COVID-19
positive. The total encounter time between the nurse—who was working
as a float nurse—and the patient X lasted approximately 20 minutes.
Patient X was initially at a low suspicion for COVID-19 because there
was no community-acquired case reported in the state at that time.
Patient X and the nurse did not have any history of travel. Patient X
had a surgical mask on but kept on taking it off during the encounter.
The nurse had the gloves and surgical mask on before going into the room
as a general precaution but did not wear the gown. He used 70% alcohol
sanitizer to clean his hands before going in and after going out of the
room. He applied oxygen to the patient’s face. He placed the EKG leads
on Patient X and ran an EKG. Patient X received a bronchodilator
treatment during his emergency room encounter. The nurse was not present
during the treatment but took the nebulizer off the patient X when it
completed. Patient X did not cough or sneeze during the encounter with
the nurse. The nurse had disposed off the gloves and the surgical mask
appropriately (untying from behind without touching his face) after
going out of the room. After going home, he placed aside his scrubs from
the other clothes and took a shower. After Patient X tested positive for
COVID-19, the nurse was instructed to be in-home isolation. The nurse
developed a dry cough with fever and shortness of breath in the next
week after exposure to patient X and was tested positive for COVID-19.
He did not encounter any other COVID-19 positive or person under
investigation patients during this duration besides the index COVID-19
hospitalization. He was admitted to the hospital for observation for a
day. He had crackles on lung exam, but the chest X-ray was clear, and he
was saturating at 96% on room air. His clinical symptoms improved
within a week of its onset. He subsequently tested negative for
COVID-19. Patient X course, however, deteriorated and was admitted into
the ICU. He was empirically treated with remdesivir, hydroxychloroquine,
and lopinavir/ritonavir, however, his COVID-19 test was positive even
after all these therapies. He was pronounced dead after a protracted 22
day-long period of intubation.
Patient X was the index case of community transmission in the state of
Illinois. The nurse had the surgical mask on at all times. The nurse had
gloves on during the encounter and used the 70% alcohol-based sanitizer
after disposing off gloves. He subsequently took a shower and separated
his scrubs after going home, which makes contact-based transmission less
likely. In our case, the nurse took off the nebulizer when it finished.
However, the UK National health sciences guidelines suggest medications
via nebulization does not pose a significant infectious risk as the
aerosol derived from a non-patient source does not carry patient-derived
aerosol particles 5. In a recent study, SARS-CoV-2 RNA
was detected in more than 50% of air samples collected within the room
and in the hallways around the COVID-19 patients6. In
a study from Wuhan China, the researchers proposed the possibility of
aerosol transmission of SARS-CoV-27.The highest
airborne concentration was noted when the patient was receiving oxygen
through a nasal cannula; however, whether the airborne- viral shedding
can cause viral infection is still being studied6. In
another experimental study by Bae et al. on COVID-19 patients, three out
of four patients wearing a surgical mask had detectable virus in the
Petri dishes placed 20cm apart, and all the patients had virus detected
on the outer surface of surgical masks suggesting the ineffectiveness of
surgical mask in COVID-198. They argue assuming the
size of SARS-COV-2 is 0.06 to 0.14μm based on the size measured during
the outbreak in 2002-20049 and that surgical masks can
not filter aerosols measuring 0.9, 2.0, and 3.1 μm in diameter, surgical
masks are unlikely to filter the virus10. Our case
report, coupled with the previous experimental studies, provides
preliminary evidence that surgical masks are unlikely to provide
effective protection against COVID-19.