J S M Peiris, C M Chu, V C C Cheng, K S Chan, I F N Hung, L L M Poon, K
I Law, B S F Tang, T Y W Hon, C S Chan, K H Chan, J S C Ng, B J Zheng, W L Ng, R
W M Lai, Y Guan, K Y Yuen, and members of the HKU/UCH SARS Study Group
Summary
Background We investigated the temporal progression of the
clinical, radiological, and virological changes in a community outbreak of
severe acute respiratory syndrome (SARS).
Methods We followed up 75 patients for 3 weeks managed with a
standard treatment protocol of ribavirin and corticosteroids, and assessed the
pattern of clinical disease, viral load, risk factors for poor clinical outcome,
and the usefulness of virological diagnostic methods.
Findings Fever and pneumonia initially improved but 64 (85%)
patients developed recurrent fever after a mean of 8·9 (SD 3·1) days, 55 (73%)
had watery diarrhoea after 7·5 (2·3) days, 60 (80%) had radiological worsening
after 7·4 (2·2) days, and respiratory symptoms worsened in 34 (45%) after 8·6
(3·0) days. In 34 (45%) patients, improvement of initial pulmonary lesions was
associated with appearance of new radiological lesions at other sites. Nine
(12%) patients developed spontaneous pneumomediastinum and 15 (20%) developed
acute respiratory distress syndrome (ARDS) in week 3. Quantitative
reverse-transcriptase (RT) PCR of nasopharyngeal aspirates in 14 patients (four
with ARDS) showed peak viral load at day 10, and at day 15 a load lower than at
admission. Age and chronic hepatitis B virus infection treated with lamivudine
were independent significant risk factors for progression to ARDS (p=0·001).
SARS-associated coronavirus in faeces was seen on RT-PCR in 65 (97%) of 67
patients at day 14. The mean time to seroconversion was 20 days.
Interpretation The consistent clinical progression, shifting
radiological infiltrates, and an inverted V viral-load profile suggest that
worsening in week 2 is unrelated to uncontrolled viral replication but may be
related to immunopathological damage.
