Efficiency of the quarantine system during the epidemic of severe acute respiratory syndrome in Beijing, 2003 / 中华流行病学杂志

<p><b>OBJECTIVE</b>An epidemic of severe acute respiratory syndrome (SARS) hit Beijing, China, between March and July 2003 with an attack rate of 1.9 per 10 thousand. (2,521 cases). To control the epidemic of SARS, a total of 30,173 residents were quarantined either in their residence or in quarantine sites. In order to understand the personal need of being quarantined and to estimate the risk of developing SARS during the quarantine period, a survey on the quarantined residents of Haidian District, Beijing, China was carried out.</p><p><b>METHODS</b>33 precincts in Haidian District divided into five groups (7 in north, 6 in south, 7 in west, 6 in east and 7 in central of Haidian District) according to the location of the precincts were involved. The director of Center of Disease Control and Prevention of Haidian District was asked to select 1 precinct from each group according to the workload of the precinct quarantine officers. From those 5 precincts we obtained lists of all quarantined persons from the precinct quarantine officers. All quarantinees were asked to complete a self-administered questionnaire. The SARS patients were diagnosed and verified according to the diagnosis criteria released by Chinese Ministry of Health which was equivalent to the SARS 'probable case' definition of WHO. All SARS cases had been reported to the relative authorities.</p><p><b>RESULTS</b>By May 23, 2003, 5,186 persons had been quarantined in Haidian district, accounting for 0.23% of all residents. 1,028 of sampled quarantined residents completed the questionnaire. Of those who completed the questionnaire, 2.3% (95% CI: 1.5% - 3.5%) developed SARS while under quarantine. The median quarantine period was 14 days (range 1 day to 28 days). 61% of the quarantinees had a direct contact history with SARS patients, and all secondary SARS patients developed through contact to these quarantinees. The remaining 39% quarantinees who did not have a direct contact history with SARS patients had not developed SARS during the period under quarantine. 37% of the quarantees had direct contact during original patients' symptomatic period with an AR of 6.3%. Persons who looked after the illed SARS patient(s) during their symptomatic period, had an highest attack rate of 31% (95% CI: 20% - 44%). 63% (95% CI: 60% - 66%) of the total quarantined persons did not have direct contact with a SARS patient during his/her symptomatic period, with an attack rate of 0% (95% CI: 0% - 0.73%).</p><p><b>CONCLUSION</b>Only those persons having direct contact with ill SARS patients need to be under quarantine. The overall cost for quarantine on SARS prevention could be reduced by as much as 63% if the quarantine program was limited to this group. No evidence was found that SARS patient was infective during the incubation period.</p>

Epidemiological characteristics of 403 patients with severe acute respiratory syndrome in Haidian district, Beijing / 中华流行病学杂志

<p><b>OBJECTIVE</b>To analyze epidemiological features of severe acute respiratory syndrome (SARS) in Haidian district, Beijing.</p><p><b>METHODS</b>Each SARS case was interviewed by trained investigator using standardized questionnaire followed a descriptive analysis.</p><p><b>RESULTS</b>Four hundred and three SARS cases were identified and 27 of them died from March 18 and May 31, 2003. The incidence rate of SARS was 18.0/100,000 with case fatality rate as 6.7% in Haidian district, Beijing. Seventy-four percent of patients were adults with higher risk in age group of 20 - 29 year. SARS patients were scattered around in 32 out of 33 streets and villages in this district. The disease appeared to be sporadic but the case of outbreaks in family or university only seen in three streets. The course of SARS epidemic in this district could be divided into three phases: initial-which last for days, peak-21 days and then rapid decline-for 26 days. Number of patients having had a history of close contact to other SARS were gradually decreasing along with the process of the epidemics (trend chi(2) = 8.800, P = 0.003). Seventy-two point seven percent of the SARS cases had been exposed to the injection in the hospital settings. When the epidemics came to a rapid decline, 85.7% of the patients diagnosed during that period could be traced down to have had the history of contacting SARS cases within their own families. The distribution of occupation was also showed significantly different in the three respective stages (chi(2) = 36.41, P < 0.01). Among the patients who could not be identified as having confirmed contact history, 26.6% having had outward activities and 47.6% of them visited hospitals, especially during the peak stage.</p><p><b>CONCLUSION</b>The intensity of SARS epidemic among the residents of Haidian district was recognized as similar to the other parts of Beijing. Nosocomial infection in hospital settings was most important cause responsible for the transmission of SARS in this district.</p>