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Zhu R, Gray DJ, Thrift AP, Williams GM, Zhang Y, Qiu DC, Zheng F, Li YS, Guo J, Zhu HQ, Wu WP, Li RS, McManus DP. A 5-year longitudinal study of schistosomiasis transmission in Shian village, the Anning River Valley, Sichuan Province, the Peoples' Republic of China. Parasit Vectors 2011; 4:43. [PMID: 21429229 PMCID: PMC3072348 DOI: 10.1186/1756-3305-4-43] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 03/24/2011] [Indexed: 11/10/2022] Open
Abstract
Background Schistosoma japonicum is a major public health concern in the Peoples' Republic of China (PRC), with over one million people infected and another 50 million living in areas at risk of infection. Based on ecological, environmental, population genetic and molecular factors, schistosomiasis transmission in PRC can be categorised into four discrete ecosystems or transmission modes. It is predicted that the Three Gorges Dam (TGD) will impact upon the transmission of schistosomiasis in the PRC, with varying degree across the four transmission modes. We undertook longitudinal surveillance from 2002 to 2006 in sentinel villages both above and below the TGD across five provinces (Hunan, Jiangxi, Hubei, Anhui and Sichuan) to determine whether there was any impact of the TGD on schistosomiasis transmission during its construction. Here we present the results from a schistosomiasis-endemic village located above the dam in Sichuan Province. Results Baseline results showed a human S. japonicum prevalence of 42.0% (95% CI: 36.6-47.5). At follow-up, results showed that the incidence of S. japonicum infection in the selected human cohort in Shian decreased by three quarters from 46% in 2003 to 11.3% in 2006. A significant (P < 0.01) downward trend was also evident in the yearly adjusted (for water contact) odds ratios. Over the four years of follow-up, the incidence of S. japonicum infection in bovines declined from 11.8% in the first year to zero in the final year of follow-up. Conclusions The substantial decrease in human (75%) and bovine (100%) incidence observed in Shian village can probably be attributed to the annual human and bovine PZQ treatment of positives; as seen in drug (PZQ) intervention studies in other parts of PRC. If an increase in schistosome transmission had occurred as a result of the TGD, it would be of negligible size compared to the treatment induced decline seen here. It appears therefore that the construction of the TGD had virtually no impact on schistosomiasis transmission in Shian village over the period of study. Furthermore, contrary to previous reports from Sichuan downplaying the role of animals in human schistosome transmission, bovines may indeed play a role.
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Affiliation(s)
- Rong Zhu
- National Institute of Parasitic Disease, Chinese Centre for Disease Control and Prevention, Shanghai, PR China
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de Melo NI, Magalhaes LG, de Carvalho CE, Wakabayashi KAL, de P. Aguiar G, Ramos RC, Mantovani ALL, Turatti ICC, Rodrigues V, Groppo M, Cunha WR, Veneziani RCS, Crotti AEM. Schistosomicidal activity of the essential oil of Ageratum conyzoides L. (Asteraceae) against adult Schistosoma mansoni worms. Molecules 2011; 16:762-73. [PMID: 21245809 PMCID: PMC6259589 DOI: 10.3390/molecules16010762] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 01/11/2011] [Accepted: 01/17/2011] [Indexed: 12/02/2022] Open
Abstract
The in vitro schistosomicidal effects of the essential oil of Ageratum conyzoides L. (Ac-EO) against adult worms of Schistosoma mansoni is reported in this paper. Concerning this activity, Ac-EO was considered to be active, but less effective than the positive control (praziquantel, PZQ) in terms of separation of coupled pairs, mortality, decrease in motor activity, and tegumental alterations. However, Ac-EO caused an interesting dose-dependent reduction in the number of eggs of S. mansoni. Precocene I (74.30%) and (E)-caryophyllene (14.23%) were identified as the two major constituents of Ac-EO. These compounds were tested individually and were found to be much less effective than Ac-EO and PZQ. A mixture of the two major compounds in a ratio similar to that found in the Ac-EO was also less effective than Ac-EO, thus revealing that there are no synergistic effects between these components. These results suggest that the essential oil of A. conyzoides is very promising for the development of new schistosomicidal agents.
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Affiliation(s)
- Nathalya I. de Melo
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
| | - Lizandra G. Magalhaes
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
| | - Carlos E. de Carvalho
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
| | - Kamila A. L. Wakabayashi
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
| | - Gabriela de P. Aguiar
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
| | - Rafael C. Ramos
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
| | - Andre L. L. Mantovani
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
| | - Izabel C. C. Turatti
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, CEP 14040-903 Ribeirão Preto, SP, Brazil; E-Mail: (I.C.C.T.)
| | - Vanderlei Rodrigues
- Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, CEP 14049-900 Ribeirão Preto, SP, Brazil; E-mail: (V.R.)
| | - Milton Groppo
- Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, CEP 14040-901 Ribeirão Preto, SP, Brazil; E-mail: (M.G.)
| | - Wilson R. Cunha
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
| | - Rodrigo C. S. Veneziani
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
| | - Antônio E. M. Crotti
- Núcleo de Pesquisas em Ciências Exatas e Tecnológicas, Universidade de Franca, CEP 14404-600, Franca, SP, Brazil; E-Mails: (N.I.M.); (L.G.M.); (C.E.C.); (K.A.L.W); (G.P.A); (R.C.R.); (A.L.L.M.); (W.R.C.); (R.C.S.V.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +55-16-3711-8871; Fax: +55-16-3711-8871
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