The study attempted to mimic the virus being deposited
onto everyday surfaces in a household or hospital setting by
an infected person through coughing or touching objects,
for example. The scientists then investigated how long the
virus remained infectious on these surfaces.
The study’s authors are from UCLA, the National Institutes
of Health’s National Institute of Allergy and Infectious
Diseases, the Centers for Disease Control and Prevention,
and Princeton University. They include Amandine Gamble,
a UCLA postdoctoral researcher in Lloyd-Smith’s laboratory.
In February, Lloyd-Smith and colleagues reported in the
journal eLife that screening travelers for COVID-19 is not very
effective. People infected with the virus — officially named
SARS-CoV-2 — may be spreading the virus without knowing
they have it or before symptoms appear. Lloyd-Smith said
the biology and epidemiology of the virus make infection
extremely difficult to detect in its early stages because the
majority of cases show no symptoms for five days or longer
after exposure.
“Many people won’t have developed symptoms yet,”
Lloyd-Smith says. “Based on our earlier analysis of flu
pandemic data, many people may not choose to disclose
if they do know.”
The new study supports guidance from public health
professionals to slow the spread of COVID-19:
● ● Avoid close contact with people who are sick.
● ● Avoid touching your eyes, nose and mouth.
● ● Stay home when you are sick.
● ● Cover coughs or sneezes with a tissue, and dispose
of the tissue in the trash.
● ● Clean and disinfect frequently touched objects and
surfaces using a household cleaning spray or wipe.
COVID-19: The Clinical Imperatives
Klompas (2020) says that it is “apparent that severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2) is optimized
to spread widely. It causes mild but prolonged disease, infected
persons are contagious even when minimally symptomatic or
asymptomatic, the incubation period can extend beyond 14
days, and some patients seem susceptible to reinfection. These
factors make it inevitable that patients with respiratory viral
syndromes that are mild or nonspecific will introduce the virus
into hospitals, leading to clusters of nosocomial infections. The
signs and symptoms of coronavirus disease 2019 (COVID-19)
are largely indistinguishable from those of other respiratory
virus infections. Less than one half of patients with confirmed
disease have fever on initial presentation. The sensitivity of a
single nasopharyngeal swab early during disease is only 70
percent. Multiple reports already exist of delayed diagnoses
leading to nosocomial transmissions.
How bad will it be? As Klompas (2020) emphasizes,
“Characterizing the morbidity rate of COVID-19 is challenging
because case detection in the early stages of an outbreak
is biased toward severe disease. An initial series reported
a mortality rate of 15 percent. A subsequent analysis that
included patients who were less sick reported a mortality
rate of 2.3 percent, but this is still likely an overestimate.
Mortality rates are substantially lower outside than inside
Hubei province, where the outbreak began (114 deaths
among 13,152 patients [0.9 percent] vs. 2,986 deaths among
24
67,707 patients [4.4 percent] as of March 8, 2020). This is
presumably because of Hubei’s initial focus on patients with
severe disease, constraints on the province’s testing and care
capacity, and the passage of more time since the outbreak
began in Hubei versus other provinces allowing more time
for patients to declare themselves. More to the point,
current mortality estimates minimally account for patients
with mild or asymptomatic infections, an important aspect
of this epidemic. Case detection is still primarily focused
on identifying patients with fever, cough, or shortness of
breath; this focus leads to underestimation of the number
of infected persons, overestimation of the mortality rate,
and ongoing spread of disease.”
Regarding what can be done to prevent further spread of
infection, Klompas (2020) observes, “We have to be more
aggressive about case detection. Current screening is still
focused on identifying patients with foreign travel or contacts
with known cases. Both of these foci no longer reflect the
current status of this epidemic given increasing evidence of
community spread. We need to be able to test patients with
milder syndromes regardless of travel or contact history. The
Centers for Disease Control and Prevention has updated its
‘person under investigation’ criteria to permit this, but there
is still a severe shortage of readily available tests.”
Klompas (2020) adds, “More broadly, however, the best
way to protect hospitals against COVID-19 is to bolster our
approach to routine respiratory viruses (that is, influenza,
respiratory syncytial virus, parainfluenza, adenovirus, human
metapneumovirus, and “conventional” coronaviruses). This
will simultaneously improve care for current patients, make
work safer for clinicians, and help prevent the incursion
of occult COVID-19 into hospitals. We underestimate the
contagiousness and seriousness of routine respiratory viruses.
We underappreciate that 30 percent to 50 percent of cases of
community-acquired pneumonia are caused by viruses, that
nosocomial transmission of respiratory viruses is common,
and that “routine” respiratory viruses cause substantial
morbidity and mortality that may not differ much from
those caused by SARS-CoV-2 once minimally symptomatic
COVID-19 is accounted for. Respiratory viruses infect millions
of persons each year (about 10 percent of the population)
and cause tens of thousands of deaths in the United States
alone. They can cause severe pneumonia, predispose patients
to bacterial superinfection, and exacerbate cardiac and
pulmonary conditions up to and including death.”
Most hospitals, however, manage respiratory viruses
passively, Klompas (2020) asserts, adding, “We rely on signs
alone to deter visitors with upper respiratory tract infections
from visiting, we isolate patients in private rooms only if they
test positive for influenza virus (even though many other
viruses can cause influenza-like syndromes that are equally
morbid), we discontinue precautions in patients with acute
respiratory tract syndromes if they test negative for viruses
(even though viral tests have variable and imperfect sensi-
tivity), we consider masks alone to be adequate protection
(even though viruses can be transmitted via fomites and
eye contact as well as mouth and nose contact), and we
tolerate health care workers coming to work with upper
respiratory tract infections so long as they are not febrile.
Our halfhearted approach to endemic respiratory viruses is a
april 2020 • www.healthcarehygienemagazine.com