天津市传染性非典型肺炎流行特点及主要控制措施效果评价

目的：分析天津市传染性非典型肺炎严重急性呼吸综合征(SARS)]流行病学特征，对主要控制措施的效果进行初步评价。方法：采用自行设计的病例报告表，全市统一的流行病学个案调查表及病例接触者、密切接触者树状分布图，深入病房、家庭、社区、团体等对病例及接触者进行调查。结果：以发病时间计算，自2003年4月13日至5月8日，包括输入病例在内发病175例，发病率为1．9／10万，其中死亡14例，病死率达8．O％。整个流行过程不足1个月，流行特点：1例“超级传播者”直接或间接传染了全市94．3％的病例；呈现以A、B、C 3家医院聚集发病为特点的爆发性流行，占全市病例的68．6％，3家医院外的家庭聚集发病占全市病例的14．3％，同事间传播为2．3％，散发者为9．1％，这些散发者未造成接触者感染；早期医务人员发病较多，占总病例数的38．2％，流行全过程参加SARS救治工作的1975名医护人员的总感染率为3．4％；全部流行过程传染源明确，传染链清晰，全市仅3例患者未找到传染源，占病例总数的2％；在10例源头病例中仅“超级传播者”和另一病例传染了其接触者，其他传染源由于及时隔离未造成任何传播。结论：SARS是严重急性呼吸系统传染病，如能及时准确地掌握传染链并进行范围适当、及时有效的封闭及隔离措施，以科学的方法提高全民的警觉度，传染链可能在较短时间内被切断，从而控制传播。

Epidemiological characteristics of severe acute respiratory syndrome in effectiveness on measures of control

OBJECTIVE: To analyze the epidemiologic characteristics of severe acute respiratory syndrome (SARS) and to evaluate the effectiveness on its major control measures in Tianjn. METHODS: Adopting two case reports 1 and 2, designed by the Tianjin Centers for Disease Control and Prevention to develop a unified case-tracing table including the map of the distribution of close contacts to SARS patients. With those methods, investigation on patients and their close contacts at hospital wards, families, communities and institutions of the patients were carried out. RESULTS: From April 13 through May 8, 2003, there were 175 SARS cases including imported ones, were identified with an incidence rate of 1.9 cases per 100,000. Among them, 14 died with a fatality of 8.0%. The whole process of epidemic in Tianjin was less than one month with the following features: (1) 93.7% of the total SARS cases in Tianjin were directly or indirectly transmitted by a super-spreader. (2) 68.6% of the total SARS patients were concentrated in 3 hospitals A, B and C which was menifastated in 'clustering'. Through study on the rest of the SARS patients, results showed that 16.8% of them were transmitted through family close contact and 2.3% due to contact to colleagues. However, 12.6% of the patients were not able to show evidence that they had any contact to a diagnosed SARS patient. At the early stage of the epidemic, a number of medical practitioners were infected, taking up 38.2% of the total SARS cases. Among the total number of 1 975 medical workers who participated in the SARS medical cares and treatments, 3.4% of them got infected. During the outbreak, all index cases and chains of transmission seemed to be clear, with only 3 patients not able to be traced for the source of infection, taking up 2% of the total SARS patients in Tianjin. Among the 10 index cases, only the super spreader and another one index case transmitted the virus to their contacts but the rest of index cases did not cause any secondary infection. CONCLUSION: Though SARS is clinically severe and can be spreaded quickly, the epidemic can be under control within a short period of time if chains of SARS transmission are broken down and effective measures as isolation and quarantine against patients as well as underscoring awareness among the publics in a scientific way, being carried out.