To the Editor: Since its emergence early in 2003, the epidemic of severe acute respiratory
syndrome (SARS) has been characterized by its rapid spread among healthcare workers.
August 14, 2003, the World Health Organization (WHO) issued an alert concerning SARS
and recommended a staged approach to surveillance (1). Because occupational transmission
has been a feature of the SARS outbreak, WHO recommends surveillance for clusters
of alert cases among healthcare workers in low-risk areas (i.e., cases not reported,
only imported cases reported, or local cases with limited transmission potential reported).
A SARS alert is identified when two or more healthcare workers in the same healthcare
unit meet the clinical case definition of SARS with onset of illness in the same 10-day
To determine the value of routinely collecting worker absence data as part of this
kind of surveillance and to assess a threshold level of possible alert cases, directors
of six major Italian hospitals were asked for the number of cases that fit the alert
definition in 2003. (In Italy, the hospital director is a physician who is in charge
of nosocomial and occupational infection control.) The facilities involved were three
general hospitals, two university hospitals, and one research hospital; each has an
infectious and respiratory tract diseases unit. Three of four patients with imported
cases of probable SARS observed in Italy during the 2003 epidemic (2) were treated
in two of these hospitals.
No hospitals were able to immediately provide the requested data; in all hospitals
in Italy, information on sickness certificates is recorded only for administrative
purposes, and certificates are not generally used for medical surveillance. The European
Union Council Directive 89/391 directs all participating countries to introduce measures
to improve worker safety and health and to provide a designated service that will
protect workers, prevent occupational risks, including hazards from biological agents,
and conduct health surveillance. In the hospital, these activities are coordinated
by the hospital director. When a worker has a transmissible disease, the attending
physician for the infected patient recommends that the patient stay home from work
for the duration of the infectivity period. If the illness is included in the list
of notifiable infectious diseases, the case must be reported to the local public health
authority so infection control measures can be implemented. However, neither the attending
physician nor public health personnel usually supervise home isolation, and adherence
to the recommendations relies on the patient.
Sickness certificates are generally provided by the physician and sent by the worker
to the hospital administration within 3 days of illness onset. The certificate indicates
the prognosis (i.e., recommended number of days absent from work) but does not report
the diagnosis because of privacy concerns. In case of hospital admission, the worker
can send the hospital certificate (attesting to the duration of the hospital stay),
followed by a physician's certificate for the recommended length of convalescence,
To determine how the sickness certification system in other European Union countries
operates and assesses the feasibility of the WHO alert surveillance, we interviewed
specialists in infectious diseases or public health in France (seven imported cases
of SARS, two in healthcare workers), Spain (one case), and Denmark (no cases) (2)
by electronic mail. According to their answers, the situation in those countries is
not substantially different from that in Italy.
In view of the increasing concern related to the emergence and reemergence of transmissible
diseases, surveillance efforts focused on groups likely to be first affected by the
reemergence of SARS have been strongly encouraged (3,4). Possible alternatives similar
to the SARS alert system have been proposed, based on healthcare workers' sickness
absenteeism, when other illnesses are concerned. For example, the effectiveness of
enforced monitoring of pneumonia in healthcare workers requiring hospitalization should
be evaluated in the context of a wider syndromic surveillance strategy (5).
Although the current healthcare worker sickness reporting system cannot be fully representative
and generalizable, Italy and several other European Union countries (e.g., France,
Spain, and Denmark) do not support initiating the WHO recommendation and do not have
the capacity to detect and respond to SARS, should it reemerge. To overcome barriers
to early detection of cases and clusters of severe unexplained respiratory infections
that might signal the reemergence of SARS, regulatory changes are necessary, and efforts
should be made to balance the need for protecting the privacy of persons with the
need for an effective surveillance system.
To identify clusters of occupational diseases among healthcare workers and provide
prompt response to any alert, an expanded sickness information system should be implemented.
For example, an active confidential assessment of diagnosis could be performed in
selected circumstances when healthcare workers are absent. We plan to evaluate the
feasibility of this kind of surveillance by focusing on workers with absences with
longer than a week and on workers with onset of illness in the same 10-day period.