WHO coordinated
virtual conference (
http://www.who.int/csr/sars/cliniciansconference/en/)
On 26 March 80 clinicians from 13 countries participated in an electronic
"grand round" on clinical features and treatment for patients
with Severe Acute Respiratory Syndrome (SARS) (1). Their discussion, organised
by the World Health Organization (WHO) network of clinicians focused on
features of the disease at presentation, treatment and progression of the
disease, prognostic indicators and discharge criteria. No therapy demonstrated
any particular effectiveness. Clinicians agreed that a subset of SARS patients,
perhaps 10%, decline and need mechanical assistance to breathe. These patients
often have other illnesses which complicates their care, and in this group,
mortality is high.
Disease presentation:
All of the clinicians described presentations of SARS patients and a general
consensus is agreed that presentation is relatively consistent across all
nations. Presentation is of a prodromal illness with a sudden onset of high
fever. In a great number of cases this sudden, high fever is associated
myalgia, chills, rigors, and nonproductive cough. At presentation (which
is often three to four days after onset of symptoms), a large proportion
of patients have characteristic changes on chest radiographs.
Disease progression:
Following presentation, chest radiographs continue to worsen and most patients
demonstrate bilateral changes with interstitial infiltrations. These infiltrations
produce radiographs with a characteristic cloudy appearance. Patients then
fall into one of two groups. Most patients (80-90%) show improvement in
signs and symptoms at day six or seven. A second smaller group, progress
to a more severe form of SARS, many of whom develop acute respiratory distress
syndrome and require mechanical ventilatory support. Mortality associated
with the more severe group is high, however, a number of patients have remained
on ventilator support for prolonged periods of time. Mortality in the severe
group appears to be linked to a patient's other illnesses (comorbid factors).
Prognostic indicators:
Generally, patients over 40 with other illnesses are more likely to progress
to the severe form of the disease.
Therapy:
Numerous antibiotic therapies have been tried to date with little clear
effect. Ribavirin with or without use of steroids has been used in an increasing
number of patients. But in the absence of clinical indicators, its effectiveness
has not been proven. Currently the most appropriate management measures
are general supportive therapy, insuring the person is hydrated and treated
for subsequent infections.
What next:
Planning these grand rounds regularly. The clinicians involved in establishing
management guidelines (treatment, management of patients and contacts, discharge).
The participants agreed to "meet" regularly using electronic communications
and to rapidly develop international guidelines for the care of SARS patients.
MMWR Dispatch (http://www.cdc.gov/mmwr/preview/mmwrhtml/m2d321.htm)
As of 21 March 2003, most patients identified as having SARS have been
adults aged 25-70 years who were previously healthy. Few suspected cases
of SARS have been reported among children aged <15 years.
The incubation period for SARS is typically 2-7 days; although, isolated
reports have suggested an incubation period as long as 10 days. The illness
begins generally with a prodrome of fever (>100.4°F (>38.0°C)), which
is often high, and sometimes associated with chills and rigors. It may be
accompanied by other symptoms, including headache, malaise, and myalgia.
At the onset of illness, some persons have mild respiratory symptoms. Typically,
rash and neurological or gastrointestinal findings are absent; but some
patients have reported diarrhoea during the febrile prodrome.
After 3-7 days, a lower respiratory phase begins with the onset of a dry,
nonproductive cough or dyspnea, which might be accompanied by or progress
to hypoxaemia. In 10-20% of cases, the respiratory illness is severe enough
to require intubation and mechanical ventilation. The case fatality rate
among persons with illness meeting the current WHO case definition of SARS
is approximately 3%.
Chest radiographs may be normal during the febrile prodrome and throughout
the course of illness. However, in a substantial proportion of patients
the respiratory phase is characterised by early focal interstitial infiltrates
progressing to more generalised, patchy, interstitial infiltrates. Some
chest radiographs from patients in the late stages of SARS have shown areas
of consolidation.
Early in the course of disease, the absolute lymphocyte count is often
decreased. Overall, white blood cell counts have generally been normal or
decreased. At the peak of the respiratory illness, approximately 50% of
patients have leukopenia and thrombocytopenia or low to normal platelet
counts (50 000-150 000/µL). Early in the respiratory phase, elevated creatine
phosphokinase concentrations (as high as 3000 IU/L) and hepatic transaminases
(two to six times the upper limits of normal) have been noted. In most patients,
renal function has remained normal.
The severity of illness might be highly variable, ranging from mild illness
to death. Although a few close contacts of patients with SARS have developed
a similar illness, most have remained well. Some close contacts have reported
a mild, febrile illness without respiratory signs or symptoms, suggesting
the illness may not always progress to the respiratory phase.
Treatment regimens have included several antibiotics for presumptive treatment
of known bacterial agents of atypical pneumonia. In several locations, treatment
has also included antiviral agents such as oseltamivir or ribavirin. Steroids
have also been administered orally or intravenously to patients, in combination
with ribavirin and other antimicrobials. At present, the most efficacious
treatment regimen, if any, is unknown.
Clinicians who suspect cases of SARS are requested to report such cases
to their local public health authorities. Updates on the developing situation
are also available from WHO, on ProMED, and at the websites of various national
public health organisations, including CDC, Health Canada, and the Public
Health Laboratory Service in the UK.
Eurosurveillance Weekly reproduces these reports here in the interests
of disseminating the information more widely.