Clinical progression and viral load in a community outbreak of coronavirus-associated SARS pneumonia: a prospective study

Dong

et al. 2004

Clin Vaccine Immunol

The sensitivities and specificities of an immunofluorescence assay and an enzyme immunoassay for detection of antibodies specific for severe acute respiratory syndrome coronavirus (SARS-CoV) were compared for 148 laboratory-confirmed SARS cases. The appearance and persistence of SARS-CoV-specific antibodies were assessed, with immunoglobulin G detected in 59% of samples collected within 14 days and persisting for 60 to 95 days after the onset of illness. (2-4, 7, 9, 10), although data on the performance of various antibody detection assays and the persistence of SARS-CoV-specific antibodies are lacking.The first aim of this study was to compare the sensitivities and specificities of a commercial immunofluorescence assay (IFA; Euroimmun AG, Lübeck, Germany) and a recombinant double-nucleocapsid antigen sandwich enzyme-linked immunosorbent assay (ELISA; Wantai Biological Pharmacy Enterprise Company, Ltd., Beijing, China) for SARS-CoV-specific immunoglobulin G (IgG) and IgM in patients for whom SARS-CoV RNA had been detected by reverse transcriptase PCR (RT-PCR). The second aim was to assess the timing of the appearance and persistence of SARS-CoV-specific antibodies after the onset of disease.Three hundred four patients fitting the SARS clinical case definition (fever of 38°C or higher, cough or shortness of breath, new pulmonary infiltrates on chest radiography, and close contact with a person with a suspected or probable case) were hospitalized at Ditan Hospital, Beijing, China, between 26 March and 31 May 2003. Probable cases were regarded as laboratory confirmed if SARS-CoV-specific IgG and/or IgM was detected by IFA within 3 weeks of the onset of illness and/or SARS-CoV RNA was detected by RT-PCR within 2 weeks. SARS-CoV infection was laboratory confirmed in 271 of 304 (89.1%) cases, with 33 individuals testing SARS-CoV negative (10.9%; 27 of these had alternative laboratory diagnoses). The mean age of the 271 individuals with laboratoryconfirmed cases was 36 Ϯ 16 years, and they included 92 (33.9%) health care workers and 32 patients with significant underlying illnesses. SARS acquisition in the hospital setting, in either health care workers, inpatients, or hospital visitors, occurred in 112 (41.3%) cases, and a further 62 individuals acquired SARS following exposure at home to family members or friends with hospital-acquired infections. The clinical features were similar to those reported elsewhere (data not shown) (1,3,5,10,11).Comparison of IFA and ELISA for detection of SARS-CoVspecific IgG and IgM. Testing was performed for 148 patients for whom SARS-CoV was detected in respiratory or fecal samples by RT-PCR. SARS-CoV IgM was detected for 117 (79%) people and SARS-CoV IgG was detected for 145 (98%) people by IFA, while IgM was detected for 133 (90%) people and IgG was detected for 120 (82%) people by ELISA. Controls included 105 asymptomatic close contacts of individuals with SARS cases (medical workers) and 90 individuals with chronic hepatitis B (30 cases), hepatitis C (30 cases), or human immunodef...

supporting

confidence: 69%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Kinetics of Severe Acute Respiratory Syndrome (SARS) Coronavirus-Specific Antibodies in 271 Laboratory-Confirmed Cases of SARS

Dong

et al. 2004

Clin Vaccine Immunol

“…These samples were primarily collected early in the outbreak when the recommendation for convalescent-phase serum collection was set for >21 days after exposure. Evidence from other studies shows that most case-patients case will seroconvert by day 20 ( 13 ). Although this ELISA is currently used as a standard criterion and has unknown sensitivity, a similar assay has been reported to have an estimated sensitivity of approximately 93%, based on clinical case definitions for probable SARS ( 13 ).…”

Section: Discussionmentioning

confidence: 97%

“…In Singapore, five patients were identified early in the epidemic who had infected > 10 contacts each ( 10 ). The timing of exposure to ill patients also is critical; patients may be most infectious in the second week of illness, as some data suggest peak viral shedding occurs at day 10 ( 13 ). Additionally, descriptive data suggest that severely ill patients may spread virus more efficiently, particularly if they are coughing or vomiting ( 12 ).…”

Section: Discussionmentioning

confidence: 99%

Lack of SARS Transmission among Healthcare Workers, United States

Park

Peck

Kuehnert

et al. 2004

Emerg. Infect. Dis.

Healthcare workers accounted for a large proportion of persons with severe acute respiratory syndrome (SARS) during the worldwide epidemic of early 2003. We conducted an investigation of healthcare workers exposed to laboratory-confirmed SARS patients in the United States to evaluate infection-control practices and possible SARS-associated coronavirus (SARS-CoV) transmission. We identified 110 healthcare workers with exposure within droplet range (i.e., 3 feet) to six SARS-CoV–positive patients. Forty-five healthcare workers had exposure without any mask use, 72 had exposure without eye protection, and 40 reported direct skin-to-skin contact. Potential droplet- and aerosol-generating procedures were infrequent: 5% of healthcare workers manipulated a patient’s airway, and 4% administered aerosolized medication. Despite numerous unprotected exposures, there was no serologic evidence of healthcare-related SARS-CoV transmission. Lack of transmission in the United States may be related to the relative absence of high-risk procedures or patients, factors that may place healthcare workers at higher risk for infection.

Arch Otolaryngol Head Neck Surg

Initial Otolaryngological Manifestations of Severe Acute Respiratory Syndrome in Taiwan

Chen¹,

Young²,

Luo³

et al. 2003