Besides Guangdong and Guangxi where the infection rates of CS ranked on the top in national surveys, the infection rates of other provinces in South China were still quite notable as shown in Map 7. In below, situation in each province is presented separately.
(1) Fujian
In Fujian, John Preston Maxwell, the eldest son of J. L. Maxwell, reported in 1921 that he had collected data in the past 20 years in southern Fujian and found the
128 Ge Tao et al., 2003.
129 Cai Lian-shun et al., 2002.
130 Feng Lan-bin et al., 1983.
131 Xu Jing-tian et al., 1998.
132 Gao Ru et al., 2007.
residents were suffered with nine species of parasites, but not CS.133 In 1929-1930, Ishii Shintaro and Cheng De-he conducted fecal examinations for in-patients of Hakuai Hospital in Amoy and found the infection rate was 0.95% (6/634), and five of the six sufferers had travelled to Canton and Hong Kong and ate raw fish there.134
Map 7: The Infection Rate of Clonorchiasis in South China (Except for Guangdong and Guangxi), 1971-2006
In October-November 1989, surveys at four villages in Taining泰寧 County found the infection rate was 0.4% (8/2032).135 In 1999, a hospital in Amoy discovered three cases of infection.136 In 2002, investigations at nine villages around Zhangzhou漳州 found the infection rate was 0.4% (20/4664).137 And in 2005, a group of five tourists from Ningde寧德 visited Nanning, Guangxi, and ate raw fish twice there. After returning they felt unwell and were diagnosed as infected by CS.138 (2) Zhejiang
In 1924, Faust and Balow mentioned that the infection of CS in Zhejiang was
133 Maxwell, 1921.
134 Ishii and Cheng, 1931.
135 Cheng You-zhu et al., 1994.
136 Yang Wen-chuan et al., 2000.
137 Xu Guo-fang et al., 2003.
138 Li Yan-rong et al., 2006.
not as serious as in other provinces of South China.139 In August 1994, a sufferer of Clonorchiasis received treatment at the People’s Hospital in Jiangshan江山 City and thus a survey was conducted at the village where this patient resided. It was found that by intradermal tests the positive rate was 3.0% (4/132) and by fecal examinations the infection rate was 2.9% (1/35). It was also found that the villagers were accustomed to eat half-cooked fish and this was the reason for their infection.140
(3) Jiangsu (including Shanghai)
In Jiangsu, the earliest report by Jeffreys and Day concerning the cases at St.
Luka’s Hospital in Shanghai said that the infection rate was 0.4% (2/500) in 1907.
Day reported again that the infection rate at the same hospital was 1.0% (1/100) in 1908.141 In 1915, it was reported that 128 cases were discovered in Shanghai and the infection rate was 6%.142 In 1935, it was reported that in Shanghai, the infection rate of elementary school pupils was 1.81%, middle school students 2.41%, vocational school students 5.09%, and the restaurant workers 7.18%.143 During 1928-1933, the Pathology Department of Shanghai Medical School performed autopsy on 300 corpses and found CS in 2 Cantonese corpses. During 1939-1943, the infection rate among in-patients of the Red Cross First Hospital in Shanghai was 0.7% (171/23797);
and 90% (155/171) of the sufferers were Cantonese. During 1935-1944, the infection rate of in-patients at the same hospital was 0.72% (355/46517); and 90% of the 355
cases were Cantonese.144 During 1987-1989, the first national parasitic investigation took place at 120
locations of 32 counties in Jiangsu and found the total infection rate of CS was 0.5%
(318/63699); most of the cases were found in Hsuzhou徐州and Huaiyin淮陰 Cities with the infection rate of 1.9% and 0.5% respectively. (Hang Pan-yu et al., 1994) In 1999, the second investigation in 33 counties found the infection rate was 0.12%
(26/21181) and these cases were mostly distributed in Suqian宿遷 and Hsuzhou.145 During 1988-2006, investigations in Xinyi 新沂 City, located in the east of Hsuzhou, found the average infection rate was 1.21% (178/17422). In 2006, random surveys at five villages found the infection rate was 2.10% (56/2667). Moreover, the infection rate of cats was 73.33% (22/30) and that of dogs 60.00% (6/10). The reason of increase was because fish culture developed widely in Xinyi and excrements had
139 Faust and Barlow, 1924: 69-71.
140 Fan Li-juan et al., 1997.
141 Jefferys and Day, 1908; Day, 1910.
142 Fischer, 1915.
143 Komiyaet al., 1935; Osaka, 1941.
144 Ling and Taur 1949; Lan and Lin, 1949.
145 Sun Fen-hua et al., 2000.
not been well treated before using as fertilizer and thus fish ponds were polluted.146 (4) Anhui
In Anhui, the earliest case of CS infection was found in Wuhu 蕪湖 in 1911 by Miyazaki Ichiro.147 After 1986, data of six investigations are available. (1) In 1986, the SPA-ELISA method was applied to examine residents of three rural townships and elementary school pupils in Huiyuan懷遠 County and found the total positive rate was 10.92% (114/1044); of which Qinji岑集 had 11.05% (42/380), Suji蘇集 11.02%
(14/127), Weizhuang魏庄 15.17% (44/290), and Weiying魏營 elementary school pupils 5.67% (14/247).148 (2) In 1987, fecal examinations of students at three rural townships in Huiyuan County found the infection rate was 4.7% (276/5864).149 (3) In 1986-1989, sample surveys at 102 locations in 24 counties found the average infection rate was 1.44% (784/54392); and the highest rate, 3.55% (644/18141), was found in the plain area of northern Anhui.150 (4) By 1992, the ELISA method was applied to examine residents of a village in Mengcheng蒙城 County and found the positive rate was 27.8% (218/785), and the infection rate by fecal examinations was 10.3% (81/785).151 (5) From 1993, investigations among fishermen and farmers along the Huai River in Huainan淮南 City found the infection rate was 42.3%
(140/274), and there was a difference between male 51.4% (72/140) and female 32.8% (44/134). A random survey of 60 elementary school pupils found the infection rate was 15.0%.152 (6) In 2002-2004, surveys at 27 locations in 10 counties found the infection rate was 0.72% (105/14541); this rate was 46.5% lower than that of 1992.153 In northern Anhui, residents were accustomed to eat half-baked fish, but following the improvement of economic conditions more people could afford to enjoy raw fish at restaurants and thus the infection rate increased.154 Moreover, around 2005, a survey among medical students found the total infection rate was 2.58% (17/659). There was a difference between the students coming from urban area 4.20% (10/238) and those from rural area 1.66% (7/421); the higher infection rate of urban students was due to their habits of eating raw fish and shrimp.155
146 So Ge-hua et al., 2007; Zhang Zhi-cai et al., 2007.
147 Guo Jia et al., 2005.
148 Hu Shou-feng et al., 1988.
149 Zheng Shi-lian et al., 1988.
150 Xu Fu-niu et al., 1992.
151 Zhang Yao-bi, 1994.
152 Zhu Yu-xia et al., 2001.
153 Guo Jian-do et al., 2007.
154 Guo Jia et al., 2005.
155 Yang Qing-gui et al., 2006.
(5) Jiangxi
In Jiangxi, there were 9 cases of Clonorchiasis reported in 1958.156 After 1973, Jiujiang九江, Fuzhou撫州, and Yichun宜春 had also reported some cases. In 1980-1983, endemic areas were found in Yichun City and County, as well as Shanggao 上 高 , Gaoan 高 安 , Fengcheng 豐 城 , Fengxin 奉 新 and Tonggu 銅 鼓 Counties. Surveys in Shanggao, Gaoan, and Yichun City found the infection rate was 4.5% (70/1558); and 62.5% of the sufferers were children.157 In 1988-1989, random surveys of 52,042 persons in 23 counties found the total infection rate was 0.1%; and 43.5% of the sufferers were distributed in 10 counties with the highest rates found in Ruichang 瑞 昌 City (5-20%) in northern Jiangxi. The IHA method (indirect haemagglutination test) was applied to examine elementary school pupils in Ruichang and found the positive rate was 10.95% (5195/47438).158 In 1994, surveys at three villages in Ruichang found the infection rate was 23.5% (122/520). It was also found that infection rates varied with habits of eating fish; those who liked to eat baked raw fish had 32.5% (108/332), those who liked to keep raw fish in mouth had 13.2%
(5/38), and those who liked to eat dry raw fish had 11.4% (9/79).159 (6) Hubei
In 1908, Booth reported that in Hankou the infection rate of CS was 2.16 % (3/139).160 In 1921, Faust and Wassell conducted examinations of parasitic infection at the Church General Hospital in Wuchang and found the infection rate of all parasites was 76.8% (276/359), of which only one case was CS. This patient confessed that he often ate half-cooked dry fish. This report also said that dogs and cats in Middle China were widely infected with CS.161 In 1933, M. N. Andrews reported that human infection rate of CS was 8% in Wu-Han area.162
In the 1970s, the autopsy performed for a child’s corpse in Hanchuan漢川 found more than 10,000 CS in the body, and examinations of 1,848 residents of the county found the infection rate was 0.85%.163 In May 1993, a case of Clonorchiasis appeared at the Public Health Station of Panqiao Village潘橋村, Yangxin陽新 County, and thus from June to November, the improved Kato-Katz method was applied to investigate at 20 locations and found the infection rate was 5.8% (398/6865) and there was a difference between male 7.3% (267/3641) and female 4.1%
156 Zhou Xian-min et al., 1994.
157 Yi Ming-hua, 1983.
158 Pan Bing-rong et al., 1994.
159 Jiang Wei-sheng et al., 1995.
160 Booth, 1909.
161 Faust and Wassell, 1921.
162 Osaka, 1941.
163 Wu Zhi-xu et al., 1995.
(131/3215).164 In July 1998, sample surveys at five villages in Icheng宜城 City found the infection rate was 2.4% (11/468). The locations investigated this time had many ditches and ponds with fishes and snails propagated thus provided suitable conditions for the infection of CS.165 Moreover, from March 2003 to December 2004, an investigation at Xianning咸寧 City found the infection rate of male was 17.5%
and that of female 11.6%. It was also found that sufferers were mostly youngsters from hilly area and they liked to eat half-baked small fish and shrimp.166
(7) Hunan
In Hunan, several investigations during 1971-1990 were conducted in Yongxing 永興, Wugang武岡, Shaoyang邵陽, Lianyuan漣源, and Guiyang桂陽, altogether the infection rate was 7.5% (3036/40569) and there was a difference between male 12.9%
(105/814) and female 8.8% (75/857). Individually, the infection rates available were as follows: Yongxing had 27.4% (88/321) in 1971 and 27.5% (61/222) in 1990;
Lianyuan had 5.8% (122/2108) in 1972; Guiyang had 29.6% (94/318) in 1976;
Wugang had 2.1% (696/33828) in 1973-1981; Xiangtan湘潭 had 5.3% (23/434) in 1980 and 9.8% (26/266) in 1989; Qiyang祁陽 had 85.2% (1820/2136) in 1980-1984;
Lixian澧縣 had 3.2% (83/627) in 1982; Shaoyang had 14.1% (13/92) in 1984; and Yuanjiang沅江 had 4.6% (10/217) in 1984. In general, these investigations found that residents in Hunan did not eat raw fish, except for the people in rural area of Qiyang and children there liked to catch fish and play by keeping fish in the mouth.167
During 1996-1999, examinations of 342 residents and elementary school pupils along the west bank of Xiang湘 River at Yuelu岳麓 district in Changsha長沙 did not discover any infection.168 In 2002, surveys at three villages of three townships in Yongxing County found the total infection rate was 3.6% (55/1546). In 2005, surveys at two villages of Xiangyindu Town湘陰渡鎮 found the infection rate was 3.1%
(14/446). These rates were much lower than that in 1990. The reduction of infection rate was because residents of Yongxing had changed their habit and a new method of fish culture was adopted to prevent pollution of water and thus mitigated the infections of intermediate hosts.169
(8) Sichuan
In 1943, it was reported that in Chengdu成都 cats were infected seriously with
164 Chen Si-li et al., 1996.
165 Xu Zheng-min et al., 2002.
166 Chen Si-li et al., 2006.
167 Wang Jun-hua et al., 1994.
168 Liu Nian-meng et al., 2000.
169 Liao Guo-le et al., 2006.
CS but dogs were not.170 In 1947, it was found that the infection rate among residents in Chengdu was 0.7% (9/1176); and of the nine sufferers, three came from Guangdong.171
After 1988, investigations revealed that Chongqing重慶 area had the highest infection rate of CS in Sichuan. As mentioned above, the infection rate of Chongqing ranked the fifth in the second national investigation in 2001-2004. The total infection rate of Chongqing was 4.1% (982/23738) during 1988-2002 and individual rates within its jurisdiction were as follows: Tongnan潼南 15.9% (289/1815), Dianjiang墊 江 10.0% (413/4112), Changshou長壽 5.1% (86/1686), Shapingba沙坪壩 4.9%
(98/2006), Hechuan合川 4.1% (47/1134), Ronchang榮昌 3.0% (27/900), Tongliang 銅梁 1.2% (5/422), Jiangjin江津 0.8% (7/869), Yongchuan永川 0.6% (2/333), Bishan璧山 0.5% (8/1515), and no infection was found in Wanzhou萬州, Liangping 梁平, Yunyang雲陽, Kaixian開縣, Wushan巫山, Fuling涪陵, and Fengdu豐都.172 Within the jurisdiction of Chongqing, the highest infection rate was found in Tongnan, where the Qiong琼and the Fu涪 Rivers run through with an abundant resource of fish at the Qiong River Basin. During 1978-2002, surveys at three villages of the upper, middle and lower reaches along the Qiong River found the total infection rate was 18.3% (386/2105). During 1978-1980, consecutive surveys at the three villages found the infection rate at the upper village was 30.5% (231/758), the middle village 16.3% (111/681), and the lower village 6.6% (44/666). In 1986-1989, surveys at Lingjiang Village臨江村 found the infection rate in 1986 before curing was 24.2%
(342/1414), and after curing, it was 6.7% (84/1254) in 1987 and 0.2% (3/1231) in 1989. In October 2002, the three villages at upper, middle and lower reaches were investigated again and found the total infection rate was 2.8% (42/1508) and individual rates were 4.4% (22/502), 3.6% (18/506) and 0.4% (2/500) respectively.
The decreasing rates reflected the effect of curing. (Zhou Zi-lun et al., 2003) In 2004-2006, a survey at Changshou Village長壽村, located at the upper Qiong River, found the infection rate was 11.4% (22/197) in 2004, 4.3% (19/447) in 2005, and 3.3% (12/367) in 2006, and the total rate was 5.2% (53/1011), which was much lower than the 24.2% (342/1414) in 1986. The reduction also indicated the effect of curing.173
The next highest infection rate was found in Dianjiang where measures of control were adopted at Jixiang Village吉祥村 in 1982-1986 and the infection rate decreased from 15.2% to 0.9%. In September 1995, both fecal examinations and Dot-ELISA serum tests were applied to examine residents and elementary school
170 Kuo and Kiang, 1943.
171 Hsu Kuo-Chin, 1947.
172 Jiang Shi-guo et al., 2003.
173 Jiang Shi-guo et al., 2007.
pupils at this village; the serum tests found the positive rate was 6.2% (14/226) for residents and 3.8% (17/445) for pupils; the fecal examinations found the infection rates were 1.3% (3/228) and 1.0% (4/419) respectively. These results showed little difference from those found in 1986.174
In 1987-1991, measures of control were adopted at Zhijiadian Village支家店村 in Zhongjiang County. As a result, the infection rate was reduced from 20.9%
(230/1103) in 1987 to 4.5% (51/1139) in 1991 and further to 0.3% (2/628) in 1995.
The experience of Zhijiadian Village demonstrated that proper measures and health education for the people within a limited area could bring this food borne infection under efficient control. During 1990-1992, surveys at elementary and middle schools in Zhongjiang, Anyue安岳, and Lezhi樂至 Counties found the infection rates as follows: in Zhongjiang, the rate of middle school students was 12.3% (70/570) and that of elementary school pupils 3.6% (21/584); in Anyue, the rate of middle school students was 9.4% (13/139) and the pupils had no infection; in Lezhi, middle school students had 9.9% (14/142) and elementary school pupils 2.4% (3/124). These results showed that middle school students had a higher infection rate. Although economic and public health conditions had been improved in rural area, youngsters still lack of awareness to protection themselves and still like to eat half-baked small fish when they play along streams.175
In 1978-1990, investigations at 28 locations in Chengdu found the infection rate was 6.0% (894/14865). Investigations at four villages in Pengxi蓬溪 County found the infection rate was 2.7% (71/2606). In 1989, investigations at five locations in Jiajiang夾江 County found two sufferers at Ganlu Rural Township甘露鄉 and the infection rate was 0.07% (2/2703). Because the two sufferers had never traveled outside of the village, this finding proved that Clonorchiasis existed in this village for the first time.176
In addition to provinces discussed above, a report in 2007 concerning the situation of parasitic infection in southeastern Guizhou mentioned CS but the infection rate was not clear.177