WHO initiates enhanced global surveillance in response to acute
respiratory syndrome in China, Vietnam, and Hong Kong, special administrative
region (SAR) of China
In response to recent developments in southern China, Vietnam,
and Hong Kong, the World Health Organization (WHO) has initiated global surveillance
of cases with acute respiratory syndrome of unknown etiology (1) and provided
the following case definition for hospital based surveillance:
A person presenting to a health care facility after 23 February 2003 with
all of the following:
- sudden onset of high fever (>38 oC)
- one or more respiratory symptoms (cough, sore throat, shortness of breath,
AND one or more the following:
- history of travel to mainland China, Hong Kong, Special Administrative
Region of China, or Hanoi within two week of symptom onset
- history of having cared for, having lived with, having had face-to-face
contact with, or having had contact with respiratory secretions of, a
- a suspect case with,
- chest x-ray findings of pneumonia or Adult Respiratory Distress Syndrome
WHO asks for every suspect and probable case to be reported to national
Public Health authorities and then to WHO on a daily basis: fax (+41 22
791 1397) or email (email@example.com).
Until further information on these episodes is available, WHO recommends
that any patient presenting with atypical pneumonia and possibly related
to these outbreaks be isolated and cared for using barrier nursing techniques.
On 11 February 2003, WHO was notified by the Chinese Ministry of Health
of an outbreak of acute respiratory syndrome in Guangdong Province (China)
(2). From 16 November until 9 February, 305 cases, including five deaths
were reported in six of the municipalities of the province. The syndrome
was described as an atypical pneumonia, with non-specific symptoms, including
fever, headache, joint ache, and overall fatigue and weariness. Two of the
cases were diagnosed with Chlamydia pneumoniae infection, but no
cause has been confirmed in the other cases. Investigation of this outbreak
In late February 2003, a Hong Kong resident became ill with a pneumonic
illness shortly after arriving in Hanoi, Vietnam. He was initially cared
for in a hospital in Hanoi and was then evacuated to a hospital in Hong
Kong. Approximately twenty hospital staff involved in his care, in Hanoi,
have subsequently developed a similar illness. In Hong Kong, an outbreak
of a similar respiratory illness has occurred among hospital workers in
another hospital (not the hospital in which the Hong Kong resident from
Hanoi was cared for).
Despite intensive investigation, no cause for these outbreaks has, so far,
been determined other than the two cases of C. pneumoniae infection
in the Guangdong outbreak. Influenza virus infection has not been demonstrated.
No clear epidemiological link between these three separate outbreaks has
been identified, nor any link with the earlier outbreak of influenza due
to the avian influenza A H5N1 in Hong Kong reported in February 2003 (3).
The signs and symptoms of the illness in Hanoi, most commonly, include
an initial influenza-like illness (rapid onset of high fever followed by
muscle aches, headache, and sore throat). In some cases, but not all, this
is followed by bilateral pneumonia and occasionally acute respiratory distress
requiring assisted breathing on a respirator. Some patients are recovering
but others remain critically ill. Laboratory findings may include thrombocytopenia
(low platelet count) and leucopenia (low white cell count).
A Global Alert Response Network/WHO team is assisting with investigation,
clinical and laboratory management, and outbreak control in Hanoi.