Nobody wore protection, because nobody knew

On 15 February 2020, a patient was admitted to a California hospital. They
denied travel or contact with symptomatic people, so **COVID-19 was not
suspected.**

Over a four-day hospitalisation they were managed **with standard
precautions** and underwent multiple aerosol-generating procedures:
**nebuliser treatments, BiPAP ventilation, endotracheal intubation and
bronchoscopy** — the list of procedures most likely to fill a room with
infectious aerosol.

Several days after transfer to a second hospital, the test came back positive.
It was the first confirmed US case of community-acquired COVID-19.

**Because transmission-based precautions were not in use, no health care
personnel wore personal protective equipment recommended for COVID-19
patient care during contact with the index patient.**

What happened to the staff

Those three were **among the first known cases of probable occupational
transmission of SARS-CoV-2 to health care personnel in the United States.**

All three had unprotected patient contact.

What distinguished them

37 of the tested staff, including all three positives, were interviewed
with a standardised questionnaire. Two kinds of exposure were **more common
among those who became infected**:

• Performing physical examinations
• Exposure during nebuliser treatments

And one quantity: staff with COVID-19 had exposures of longer duration.

Neither of the two is surprising once stated — a physical examination puts a
clinician's face near a patient's for minutes, and a nebuliser aerosolises the
patient's airway into the room — but they were measured here rather than
assumed, in the one situation that could not be arranged deliberately: an
entire ward working with no protection at all.

How staff were handled

Exposed personnel were identified by medical record review, then risk
stratified into high, medium, low and no identifiable risk. **High and
medium risk staff were furloughed and actively monitored**; **low risk staff
self-monitored for 14 days.** Specimens were taken once, from those who
developed symptoms.

Two limits follow from that design and are worth stating: **testing only the
symptomatic** misses asymptomatic infections entirely, and **serologic testing
was not performed**, so nobody was checked afterwards for antibodies. Three is
a floor.

The conclusion

**Early recognition and isolation of patients with possible COVID-19, and use
of recommended PPE**, to **minimise unprotected, high-risk exposures and
protect the health care workforce.**

The hard part is the first clause. This patient denied travel and contact
because they had none to report — which is what community transmission means,
and why "recognise the possible case" had to stop depending on a travel
history.

Source: Centers for Disease Control and Prevention, MMWR.