台灣地區2000至2004年腸病毒感染之生態及季節相關

Abstract

中文摘要 背景： 氣候變遷與全球暖化對於生態環境造成莫大的衝擊。極端的氣候型態以及每年溫度的逐漸上升，可能對具有溫度敏感性的病毒造成影響，如非小兒麻痺病毒型的腸病毒(non-polio enterovirus)，也更常發生於一年當中較高溫的季節。由腸病毒感染所引起的手足口病及疱疹性咽唊炎，主要好發於孩童身上，並在夏季及秋季伴隨著較高的發生率。過去在日本有研究指出，由腸病毒感染造成的手足口病及疱疹性咽唊炎，與氣溫及水氣壓之間存在著相關性。然而，目前針對腸病毒感染併發重症的生態及季節相關研究仍很有限。本研究將探討腸病毒併發重症個案、定點醫師通報手足口病與疱疹性咽唊炎之季節與生態相關。 方法： 利用行政院衛生署疾病管制局2000至2004年，腸病毒感染併發重症經病毒檢驗確認個案資料庫、定點醫師通報腸病毒感染個案資料庫，以及病毒實驗室檢驗資料庫，來分析腸病毒感染併發重症之人口學特性，並比較腸病毒重症患者與腸病毒感染患者在全台灣北中南東四個區域的分布情形以及其發生率的差異，進而連結氣象資訊，分析各季節及各月別腸病毒重症發生率、腸病毒感染通報率與季節、氣溫高低、降雨及日照之間的相關性。並利用多變相﹝波以松迴歸, Poisson﹞分析來估算相關潛在危險因子的相對危險性。 結果： 自2000年到2004年間，有1573個腸病毒感染併發重症的患者，其中948個案經確認，病例多好發於5歲以下孩童，佔率高達94%。南部地區的重症發生率為每十萬人口9.13，為最高，北部地區重症發生率則以每十萬人口4.10為最低。季節性變化的分析部分則發現，一般而言六月是一年當中腸病毒重症發生的高峰期，但南部地區則是在十月份達到最高發生率。多變項分析結果顯示，男孩感染腸病毒重症的危險性比女孩高出了43%，1歲的小孩感染腸病毒重症的危險性最高，一歲孩子的相對危險性為5到9歲孩童的28.9倍﹝95%信賴區間為22.0~38.1﹞。而南部地區孩童發生腸病毒重症的危險性比北部地區高出二倍；腸病毒重症的發生有隨氣溫上升而增加的傾向，和二月份別比較，其他月份均有高出的危險。定點醫師的通報則顯示，東部地區腸病毒感染之通報發生率最高，為北部地區約3.5倍；一年當中腸病毒感染通報的危險性以5月份為最高，而通報的危險性也有隨著溫度上升而顯著增加的趨勢。 結論： 台灣地區腸病毒感染有地區差異，其季節差異除與氣候有相關，也可能受到寒暑假的影響。由各地區每個月重症發生率的變化情形顯示，腸病毒的流行可能是由台灣其他地區傳播至南部地區，也可能和南部秋季較不同的氣象型態有關。

Abstract Background: The global warming and climate change have a great impact on the ecology. The temperature-sensitive viruses infection such as non-polio enteroviruses infection appears more frequently in higher temperature seasons. Hand, foot and mouth disease (HFMD) and herpangina are diseases of enteroviral infection occurring mainly in children with high incidence in summer and autumn. The epidemic of HFMD and herpangina has been associated with temperature and vapor pressure. However, studies on the ecological and weather variations of the severe enteroviral cases epidemic remain limited. The present study analyzed the ecological, seasonal and temperature variations associated with severe cases of the enteroviral infection and the HFMD and herpangina cases reported by sentinel physicians at local hospitals and clinics. Methods: We used data obtained from the Centers for Disease Control, Executive Yuan Department of Health to perform the study, including the surveillance data on severe cases of the enteroviral infection, database of HFMD and herpangina cases reported by sentinel physicians, and virology test results provided by virology laboratories. We measured the associations between demographic status and the severe cases, and the HFMD and herpangina cases of enteroviral infection. We also investigated the geographic differences in the incidences of enteroviral infection cases with severe complication, and the reported rates of HFMD and herpangina in Taiwan. Seasonal and monthly incidence rates were measured and the associations with the weather status such as temperature, precipitation, and sunshine were analyzed. Multivariate Poisson regression analysis was used to calculate the relative risk of the enteroviral infection associated with the above potential risk. Results: Severe cases of enteroviral infection occurred mainly in children under 10 years of age, with 94% of cases occurred in children under 5 years of age. The highest incidence rate of enteroviral severe cases was in the southern Taiwan with the rate of 9.13/106, more than two times greater than that for children in the northern area (4.10/106). Results showed an apparent seasonal variation. The epidemic peak of enteroviral severe cases occurred in June in most areas, but a second peak occurred in October in the southern area. The multivariate Poisson regression analysis showed that infants and children of 1-year-old had the highest risk for severe complicated enteroviral infection, with a relative risk (RR) of 28.9 (95% confidence interval (CI) 22.0-38.1) for 1-year-old children compared with children of 5-9 years old. This study also showed that the risk of being severe cases was 43% grater for boys than for girls, 2.02 times grater (95%CI=1.72-2.37) for children in northern region than for children in the southern region. Cases of severe complication increased as the temperature increased, with the lowest rate in February and the highest rate in June. The rate of HFMD and herpangina cases reported by sentinel physicians was 3.5 times greater in the eastern region than in the northern region. In general, the HFMD and herpangina cases reported rates also increased as the temperature increased with the highest rate in May. Conclusion: There was a distinctive seasonal variation in enteroviral infection in Taiwan. The epidemic is associated with not only the weather but also school activities; the risk is decrease when children have no school in the winter and summer breaks. The monthly variations of the incidence by area show that the epidemic may spread from other areas to the south. The elevated incidence in the fall in the southern area is likely associated with the local weather.