Background A pilot clonorchiasis control project was implemented to evaluate the efficacies of various chemotherapy strategies on prevalence, incidence and re-infection in Heilongjiang Province, China. Methods and Findings Seven intervention groups (14,139 residents, about 2000 in each group) in heavily or moderately endemic areas were subjected to repeated praziquantel administration from 2001 to 2004. In the selective chemotherapy groups, residents were examined for fecal eggs, and those who tested positive were treated with three doses of 25 mg/kg praziquantel at 5-hour-intervals in one day. However, all residents were treated in the mass chemotherapy groups. In heavily endemic areas, two mass treatments of all residents in 2001 and 2003 reduced the prevalence from 69.5% to 18.8%, while four annual mass treatments reduced the prevalence from 48.0% in 2001 to 8.4% in 2004. Selective annual treatments for egg-positive subjects reduced the egg-positive rates from 54.9% in 2001 to 15.0% in 2004 or from 73.2% in 2001 to 12.3% in 2004. Selective treatments every 6 months significantly reduced the prevalence from 59.5% in 2001 to 7.5% in 2004. All of the repeated treatments reduced EPG (eggs per gram of feces) significantly. The annual mass treatment and selective treatment every 6 months produced lower prevalence and re-infection rates and higher egg reduction rate than annual selective treatments did. In the moderate endemic areas, egg positive rates were 24.8% and 29.7% in 2001 but were 1.9% and 1.3% after 2 or 3 selective treatments. The prevalence, incidence, re-infection rates in a moderately endemic area were significantly lower than those of heavy endemic areas. Conclusions Repeated mass treatment or selective treatment with praziquantel every 6 to 12 months is highly effective for clonorchiasis control in heavily endemic areas. In contrast, one or two selective treatments with health education is effective in moderately endemic areas.
References
[1]
Lun ZR, Gasser RB, Lai DH, Li AX, Zhu XQ, et al. (2005) Clonorchiasis: a key foodborne zoonosis in China. Lancet Infect Dis 5: 31–41. doi: 10.1016/S1473-3099(04)01252-6
[2]
Rim HJ (2005) Clonorchiasis: an update. J Helminthol 79: 269–281. doi: 10.1079/JOH2005300
[3]
Hong ST (2003) Clonorchis sinensis. In: Miliotis MD, Bier JW, editors. International Handbook of Foodborne Pathogens. New York, Basel: Marcel Dekker, Inc. pp. 581–592.
[4]
Choi BI, Han JK, Hong ST, Lee KH (2004) Clonorchiasis and cholangiocarcinoma: etiologic relationship and imaging diagnosis. Clin Microbiol Rev 17: 540–552. doi: 10.1128/CMR.17.3.540-552.2004
[5]
Choi D, Lim JH, Lee KT, Lee JK, Choi SH, et al. (2006) Cholangiocarcinoma and Clonorchis sinensis infection: a case-control study in Korea. J Hepatol 44: 1066–1073. doi: 10.1016/j.jhep.2005.11.040
[6]
Bouvard V, Baan R, Straif K, Grosse Y, Secretan B, et al. (2009) A review of human carcinogens–Part B: biological agents. Lancet Oncol 10: 321–322. doi: 10.1016/S1470-2045(09)70096-8
[7]
Cho SH, Lee KY, Lee BC, Cho PY, Cheun HI, et al. (2008) Prevalence of clonorchiasis in southern endemic areas of Korea in 2006. Korean J Parasitol 46: 133–137. doi: 10.3347/kjp.2008.46.3.133
[8]
Sriamporn S, Pisani P, Pipitgool V, Suwanrungruang K, Kamsa-ard S, et al. (2004) Prevalence of Opisthorchis viverrini infection and incidence of cholangiocarcinoma in Khon Kaen, Northeast Thailand. Trop Med Int Health 9: 588–594. doi: 10.1111/j.1365-3156.2004.01234.x
[9]
Rim HJ, Lyu KS, Lee JS, Joo KH (1981) Clinical evaluation of the therapeutic efficacy of praziquantel (Embay 8440) against Clonorchis sinensis infection in man. Ann Trop Med Parasitol 75: 27–33.
[10]
Hong ST, Yoon K, Lee M, Seo M, Choi MH, et al. (1998) Control of clonorchiasis by repeated praziquantel treatment and low diagnostic efficacy of sonography. Korean J Parasitol 36: 249–254. doi: 10.3347/kjp.1998.36.4.249
[11]
Tinga N, De N, Vien HV, Chau L, Toan ND, et al. (1999) Little effect of praziquantel or artemisinin on clonorchiasis in Northern Vietnam. A pilot study. Trop Med Int Health 4: 814–818. doi: 10.1046/j.1365-3156.1999.00499.x
[12]
Hong ST, Rim HJ, Min DY, Li X, Xu J, et al. (2001) Control of clonorchiasis by repeated treatments with praziquantel. Korean J Parasitol 39: 285–292. doi: 10.3347/kjp.2001.39.4.285
[13]
Hong ST, Choi MH, Kim CH, Chung BS, Ji Z (2003) The Kato-Katz method is reliable for diagnosis of Clonorchis sinensis infection. Diagn Microbiol Infect Dis 47: 345–347. doi: 10.1016/S0732-8893(03)00113-5
[14]
Choi MS, Choi D, Choi MH, Ji Z, Li Z, et al. (2005) Correlation between sonographic findings and infection intensity in clonorchiasis. Am J Trop Med Hyg 73: 1139–1144.
[15]
Benjamini Y, Hochberg Y (1995) Controlling the false discovery rate - A practical and powerful approach to multiple testing. Journal of the Royal Statistical Society Series B (Methodological) 57: 289–300.
[16]
Choi MH, Ge T, Yuan S, Hong ST (2005) Correlation of egg counts of Clonorchis sinensis by three methods of fecal examination. Korean J Parasitol 43: 115–117. doi: 10.3347/kjp.2005.43.3.115
[17]
Molyneux DH (2007) Control of human parasitic diseases: contexts and overview. In: Molyneux DH, editor. Control of Human Parasitic Diseases. Oxford: Elsevier Ltd. pp. 1–45.
[18]
Rangsin R, Mungthin M, Taamasri P, Mongklon S, Aimpun P, et al. (2009) Incidence and risk factors of Opisthorchis viverrini infections in a rural community in Thailand. Am J Trop Med Hyg 81: 152–155.
[19]
Upatham ES, Viyanant V, Brockelman WY, Kurathong S, Lee P, et al. (1988) Rate of re-infection by Opisthorchis viverrini in an endemic northeast Thai community after chemotherapy. Int J Parasitol 18: 643–649. doi: 10.1016/0020-7519(88)90099-9
[20]
Shen C, Choi MH, Bae YM, Yu G, Wang S, et al. (2007) A case of anaphylactic reaction to praziquantel treatment. Am J Trop Med Hyg 76: 603–605.
