目的 分析生食淡水鱼行为在华支睾吸虫病传播中的定量效应。方法 在广西、广东、黑龙江和吉林等4省（自治区）调查16个县（市、区）,每县分别抽取5个行政村（社区）,每个行政村（社区）整群抽取约200名居民。收集居民的粪样,采用改良加藤厚涂片法（Kato-Katz法,一粪二检）检测华支睾吸虫感染状况;同时收集调查对象生食淡水鱼行为信息。比较各县（市、区）、性别与年龄组的生食淡水鱼者比例和华支睾吸虫感染率,分析其相关性,计算决定系数（R²）。分析生食淡水鱼者和未生食淡水鱼者的华支睾吸虫感染率,计算相对危险度（RR）及95%置信区间（95% CI）。同时计算华支睾吸虫感染的归因危险度（AR）、归因危险度百分比（ARP）、人群归因危险度（PAR）和人群归因危险度百分比（PARP）。结果 4省（自治区）16个县（市、区）共检测16 230人,生食淡水鱼者比例为26.5%（4 295/16 230）,华支睾吸虫感染率为10.8%（1 747/16 230）。各县（市、区）生食淡水鱼者比例和华支睾吸虫感染率呈正向的线性关系（R² = 0.44,P < 0.01）。男性和女性生食淡水鱼者比例分别为31.7%（2 687/8 478）、20.7%（1 608/7 752）,二者差异有统计学意义（P < 0.01）。男性和女性华支睾吸虫感染率分别为13.7%（1 161/8 478）、7.6%（586/7 752）,二者差异有统计学意义（P < 0.01）。男性≤14、15~29、30~44、45~59和≥60年龄组生食淡水鱼者比例和华支睾吸虫感染率分别为1.9%、 19.4%、40.2%、44.5%、36.3%和1.5%、 7.5%、 15.1%、 20.8%、 15.4%;呈正向的线性关系（R² = 0.96,P < 0.01）。女性≤14、15~29、30~44、45~59和≥60年龄组生食淡水鱼者比例和华支睾吸虫感染率分别为2.3%、13.9%、25.3%、29.2%、22.4%和1.2%、6.1%、9.0%、10.4%、8.0%;呈正向的线性关系（R² = 0.99,P < 0.01）。与未生食淡水鱼者相比,生食淡水鱼者感染华支睾吸虫的RR为12.9（95% CI：11.4~14.7）。男性和女性生食淡水鱼者与未生食淡水鱼者相比,感染华支睾吸虫的RR分别为11.8（95% CI：10.0~14.0）、13.4（95% CI：10.9~16.4）。与未生食淡水鱼者相比,各年龄组生食淡水鱼者感染华支睾吸虫的RR为8.2~16.1。生食淡水鱼感染华支睾吸虫的AR为30.9%、ARP为92.3%、PAR为8.2%、PARP为75.9%。男性生食淡水鱼感染华支睾吸虫的AR为33.5%、ARP为91.5%、PAR为10.6%、PARP为77.4%;女性生食淡水鱼感染华支睾吸虫的AR为26.2%、ARP为92.5%、PAR为5.4%、PARP为72.0%。各年龄组的AR为15.6%~34.0%、ARP为87.9%~93.8%、PAR为0.3%~12.7%、PARP为24.1%~79.7%。结论 生食淡水鱼行为是华支睾吸虫病传播的关键因素,生食淡水鱼行为的差异决定了华支睾吸虫病的地区和人群分布差异。

Objective To quantitatively evaluate the relationship between the raw-freshwater fish-eating practice and the infection of Clonorchis sinensis. Methods Total 16 counties were enrolled from 4 provinces highly endemic with clonorchiasis (Guangxi, Guangdong, Heilongjiang and Jilin), and 5 villages were selected from each investigated counties as survey sites. Total 200 residents from each site were recruited for the investigation. The fecal samples were collected from each participant and the eggs of C. sinensis in the feces were examined under microscope using Kato-Katz thick smear method, and the information on eating raw freshwater fish among the participants was collected. The linear relationship between the percentage of participants eating raw freshwater fish and the prevalence of C. sinensis infection was analyzed in people living in different counties, with different genders and age. The parameter of coefficient of determination (R²) was determined accordingly. The relative risk (RR) and 95% confidential intervals (95% CI) were calculated for those with raw-freshwater fish-eating practice compared to those without the practice. Subsequently, attributable risk (AR), attributable risk percent (ARP), population attributable risk (PAR) and population attributable risk percent (PARP) were analyzed. Results A total of 16 230 participants from 16 counties were enrolled in this survey. The percentage of participants with practice of eating raw freshwater fish was 26.5% (4 295/1 6230) and the overall prevalence of C. sinensis infection was 10.8% (1 747/1 6230) with a positive linear association between them in investigated counties (R² = 0.44, P < 0.01). The percentage of eating raw freshwater fish was 31.7% (2 687/8 478) in males and 20.7% (1 608/7 752) in females (P < 0.01), while the corresponding prevalence of C. sinensis infection was 13.7% (1 161/8 478) and 7.6% (586/7 752) (P < 0.01). The percentage of eating raw freshwater fish in males aged ≤14, 15-29, 30-44, 45-59 and ≥60 was 1.9%, 19.4%, 40.2%, 44.5% and 36.3%, respectively, positively correlating with the prevalence of C. sinensis infection of 1.5%, 7.5%, 15.1%, 20.8% and 15.4%, correspondingly (R² = 0.96, P < 0.01). The percentage of eating raw freshwater fish in females aged ≤14, 15-29, 30-44, 45-59 and ≥60 was 2.3%, 13.9%, 25.3%, 29.2% and 22.4%, correspondingly, with positive linear association with, the prevalence of C. sinensis infection of 1.2%, 6.1%, 9.0%, 10.4% and 8.0%, respectively(R² = 0.99, P < 0.01). Compared to those without the practice, RR of C. sinensis infection in those with the practice reached 12.9 (95% CI: 11.4-14.7). RR was 11.8 (95% CI: 10.0-14.0) in males and 13.4 (95% CI: 10.9-16.4) in females between eating raw freshwater fishes and the chance of getting infected. RR ranged from 8.2-16.1 in different age groups. Overall, AR for eating raw freshwater fishes and the infection of C. sinensis was 30.9%, ARP was 92.3%, PAR was 8.2%, and PARP was 75.9%. In males, AR was 33.5%, ARP was 91.5%, PAR was 10.6% and PARP was 77.4%, compared to those in female of 26.2%, 92.5%, 5.4% and 72.0%, respectively. AR ranged between 15.6% and 34.0%, ARP between 87.9% and 93.8%, PAR between 0.3% and 12.7%, and PARP between 24.1% and 79.7% in different age groups. Conclusion Raw-freshwater fish-eating practice is seriously associated with the infection of C. sinensis and the difference in raw-freshwater fish-eating practice determines the different distribution of C. sinensis infection in areas and population in these investigated endemic areas.