Schistosomiasis mansoni in an area of low transmission: I. impact of control measures

Marçal Júnior, Oswaldo; Patucci, Rosa Maria de Jesus; Dias, Luiz Candido de Souza; Hotta, Luiz Koodi; Etzel, Arnaldo

doi:10.1590/S0036-46651991000200001

Abstracts

This work was undertaken in the municipality of Pedro de Toledo (São Paulo State, Brazil) in 1987, to clarify aspects related to the transmission levels of Schistosoma mansoni in a human population where the snail host is Biomphalaria tenagophila. Since 1980 a control programme has been undertaken in this municipality. Urban and rural populations (4,719 subjects) were submitted to faecal examinations (Kato-Katz method). The overall prevalence rate was 4.8% being higher in males (6.2%) and also in the rural zone (5.8%). The geometric mean of S. mansoni eggs was 35.1 eggs per gramme of faeces (epg). Approximately 80.0% of the carriers presented less than 100 epg and only 20 individuals (9.0%) eliminated more than half of total eggs. The highest index of potencial contamination (IPC) was in the age group of 5 to 20 years (57.6%). Two thirds of the investigated patients (207) were autochthonous of Pedro de Toledo. The geographical distribution of the carriers showed a clear aggregation of the autochthonous cases and a close association between human contact sites and breeding places of B. tenagophila. This study shows that schistosomiasis subjects were not randomly aggregated, the youngsters should be the main target in the prophylaxis, and the efficacy of the control programme.

Schistosomiasis transmission; Schistosoma mansoni; Biomphalaria tenagophila

Este trabalho foi realizado no município de Pedro de Toledo, no Estado de São Paulo, Brasil, em 1987 para esclarecer aspectos sobre níveis de transmissão ao homem de Schistosoma mansoni, quando o hospedeiro intermediário é Biomphalaria tenagophila. Desde 1980 vem sendo desenvolvido um programa de controle neste município. Foram submetidos a exames de fezes (método de Kato-Katz) 4.719 indivíduos das zonas rural e urbana. A taxa de prevalência foi de 4,8%, sendo maior nos homens (6,2%) e também na zona rural (5,8%). Foi de 35,1% a média de ovos de S. mansoni por grama de fezes (epg). Cerca de 80,0% dos portadores apresentavam menos de 100 epg e somente 20 indivíduos (9,0%) eliminavam mais do que metade do total de ovos. Os mais altos índices de potencial de contaminação (IPC) ocorreram nos grupos etários de 5 a 20 anos (57,6%). Dois terços dos pacientes investigados (207) eram autóctones de Pedro de Toledo. A distribuição geográfica dos portadores demonstrou evidente agregação dos casos autóctones, assim como uma íntima associação entre locais de contato da população com os criadouros de B. tenagophila. Este estudo demonstra que os portadores de S. mansoni não estão agregados ao acaso, que os jovens devem ser o principal objetivo na profilaxia, e que o programa de controle foi eficaz.

ORIGINAL ARTICLES

Schistosomiasis mansoni in an area of low transmission. I. Impact of control measures

Esquistossomose mansoni em área de baixa transmissão. I. Impacto das medidas de controle

Oswaldo Marçal Júnior^I,(¹⁾; Rosa Maria de Jesus Patucci^II; Luiz Candido de Souza Dias^I; Luiz Koodi Hotta^I; Arnaldo Etzel^II

^IUniversidade Estadual de Campinas. Campinas, SP, Brazil

^IISuperintendência de Controle de Endemias. São Paulo, SP, Brazil

SUMMARY

This work was undertaken in the municipality of Pedro de Toledo (São Paulo State, Brazil) in 1987, to clarify aspects related to the transmission levels of Schistosoma mansoni in a human population where the snail host is Biomphalaria tenagophila. Since 1980 a control programme has been undertaken in this municipality. Urban and rural populations (4,719 subjects) were submitted to faecal examinations (Kato-Katz method). The overall prevalence rate was 4.8% being higher in males (6.2%) and also in the rural zone (5.8%). The geometric mean of S. mansoni eggs was 35.1 eggs per gramme of faeces (epg). Approximately 80.0% of the carriers presented less than 100 epg and only 20 individuals (9.0%) eliminated more than half of total eggs. The highest index of potencial contamination (IPC) was in the age group of 5 to 20 years (57.6%). Two thirds of the investigated patients (207) were autochthonous of Pedro de Toledo. The geographical distribution of the carriers showed a clear aggregation of the autochthonous cases and a close association between human contact sites and breeding places of B. tenagophila. This study shows that schistosomiasis subjects were not randomly aggregated, the youngsters should be the main target in the prophylaxis, and the efficacy of the control programme.

Key words: Schistosomiasis transmission; Schistosoma mansoni; Biomphalaria tenagophila.

RESUMO

Este trabalho foi realizado no município de Pedro de Toledo, no Estado de São Paulo, Brasil, em 1987 para esclarecer aspectos sobre níveis de transmissão ao homem de Schistosoma mansoni, quando o hospedeiro intermediário é Biomphalaria tenagophila. Desde 1980 vem sendo desenvolvido um programa de controle neste município. Foram submetidos a exames de fezes (método de Kato-Katz) 4.719 indivíduos das zonas rural e urbana. A taxa de prevalência foi de 4,8%, sendo maior nos homens (6,2%) e também na zona rural (5,8%). Foi de 35,1% a média de ovos de S. mansoni por grama de fezes (epg). Cerca de 80,0% dos portadores apresentavam menos de 100 epg e somente 20 indivíduos (9,0%) eliminavam mais do que metade do total de ovos. Os mais altos índices de potencial de contaminação (IPC) ocorreram nos grupos etários de 5 a 20 anos (57,6%). Dois terços dos pacientes investigados (207) eram autóctones de Pedro de Toledo. A distribuição geográfica dos portadores demonstrou evidente agregação dos casos autóctones, assim como uma íntima associação entre locais de contato da população com os criadouros de B. tenagophila. Este estudo demonstra que os portadores de S. mansoni não estão agregados ao acaso, que os jovens devem ser o principal objetivo na profilaxia, e que o programa de controle foi eficaz.

Full text available only in PDF format.

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ACKNOWLEDGEMENTS

We are thankful to Dr. Antonio Guilherme de Souza for support given throughout all stages of the study, and to Prof. Dr. Sérgio Furtado dos Reis and Prof. Dr. Arício Xavier Linhares for suggestions in the English version of the manuscript.

Recebido para publicação em 16/11/1990.

Aceito para publicação em 17/4/1991.

Supported by SUCEN, FAPESP and CNPq.

References

1. BARBOSA, F.S. Cross-sectional studies on Schistosoma mansoni infection in northeast Brazil. Ann. trop. Med. Parasit., 69: 207-216, 1975.
2. BLISS, C. I. Statistics in biology: statistical methods for research in the natural sciences. New York, Mc Graw-Hill, 1967. v. 1.
3. COUTINHO, B.; GOUVĘA, L. & LUCENA, D. Estudos sobre a esquistossomose em Pernambuco. Brasil. Mem. Inst. Oswaldo Cruz, 35: 207-230, 1940.
4. DIAS, L.C.S.; GLASSER, C.M.; ETZEL, A.; KAWAZOE, U.; HOSHINO-SHIMIZU, S.; KANAMURA, H.E.; CORDEIRO, J.A.; MARÇAL Jr., O.; CARVALHO, J.F.; GONÇALVES Jr., F.L. & PATUCCI, R. The epidemiology and control of schistosomiasis mansoni where Biomphalaria tenagophila is the snail host. Rev. Saúde públ. (S. Paulo), 22: 462-463, 1988.
5. DIAS, L.C.S.; KAWAZOE, U.; GLASSER, C.M.; HOSHINO-SHIMIZU, S.; KANAMURA, H.Y.; CORDEIRO, J.A.; GUARITA, O.F. & ISHINATA, G.J. Schistosomiasis mansoni in the municipality of Pedro de Toledo (Săo Paulo, Brazil) where the Biomphalaria tenagophila is the snail host: I Prevalence in human population. Rev. Inst. Med. trop. S. Paulo, 31: 110-118, 1989.
6. DOUMENGE, J.P.; MOTT, K.E.; CHEUNG, C.; VILLENAVE, D.; CHAPUIS, O.; PERRIN, M. F. & REAUD-THOMAS, G. Atlas de la repartition mondiale des schistosomiases. Talence, CEGET-CNRS; GENĘVE, OMS/WHO; TALENCE, PUB, 400 p., fig. 47 tabl., 49 cartes en coul., bibliogr., 1987.
7. FAROOQ, M.; NIELSEN, J.; SAMAAN, S.A.; MALLAH, M.B. & ALLAMY, A.A. The epidemiology of Schistosoma haematobium and S. mansoni infection in the Egypt-49 Project Area: 2. Prevalence of bilharziasis in relation to personal attributes and habits. Bull. Wld. Hlth. Org., 35: 293-318, 1966.
8. FAROOQ, M. & SAMAAN, S.A. The relative potencial of different age-groups in the transmission of schistosomiasis in the Egypt-49 Project Area. Ann. trop. Med. Parasit., 61: 315-320, 1966.
9. FRÓES, E.; PIZA, J.T.; RAMOS, A.S.; PINTO, A.C.M. & DIAS, L.C.S. Aspectos da epidemiologia e profilaxia da esquistossomose mansoni em Săo José dos Campos. Hospital (Rio de Janeiro), 77: 153-164, 1970.
10. HIATT, R.A. & GEBRE-MEDHIN, M. Morbidity from Schistosoma mansoni infection: an epidemiologic study based on quantitative analysis of egg excretion in Ethiopian children. Amer. J. trop. Med. Hyg., 26: 473-481, 1977.
¹¹ IBGE. Anuário Estatístico do Brasil, 1985. Rio de Janeiro, 1986.
12. JORDAN, P.; CHRISTIE, J.D. & UNRAU, G.O. Schistosomiasis transmission with particular reference to possible ecological and biological methods of control: a review. Acta trop. (Basel), 37: 95-135, 1980.
13. JORDAN, P. & WEBBE, G. Schistosomiasis: epidemiology treatment and control. London, Willian Herneman Medical Book, 1982.
14. KATZ, N.; CHAVES, A. & PELLEGRINO, J. A simple device for quantitative stool thick-smear technique in schistosomiasis mansoni. Rev. Inst. Med. trop. S. Paulo, 14: 397-400, 1972.
15. KLOOS, H.; SIDRAK, W.; MICHAEL, A.A.M.; MOAHAMED, E.W. & HIGASHI, G.I. Disease concepts and treatment pratices relating to schistosomiasis haematobium in upper Egypt. J. trop. Med. Hyg., 85: 99-107, 1982.
16. LEHMANN, E.L. Nonparametrics: statistical methods based on Ranks. San Francisco, Holden Day, 1975.
17. LEHMAN Jr., J.S.; MOTT, K.E.; MORROW Jr., R.H.; MUNIZ, T.M. & BOYER, M.H. The intensity and effects of infection with schistosoma mansoni in a rural community in northeast Brazil. Amer. J. trop. Med. Hyg., 25: 285-294, 1976.
18. POLDERMAN, A.M. Transmission dynamics of endemic schistosomiasis. Trop. geogr. Med., 31: 465-475, 1979.
19. SAS Institute Inc. SAS user guide: statistics, Version 5th. ed. Cary, NC, USA, 1985.
20. SMITH, D.H.; WARREN, K.S. & MAHMOUD, A.A.F. Morbidity of schistosomiasis mansoni in relation to intensity of infection: study of a community in Kisumi, Kenya. Amer. J. trop. Med. Hyg., 28: 220-229, 1979.
21. SNEDECOR, G.W. & COCHRAN, W.G. Statistical methods. 7th. ed. Ames, Iowa State University Press, 1980.
²² SUCEN Situação da esquistossomose no Estado de São Paulo. II Encontro sobre Esquistossomose. Novembro de 1982 (Relatório).

(1

) Present address: Universidade Federal de Uberlândia, Centro de Ciências Biomédicas, Departamento de Biociências, CEP 38400 Uberlândia, MG, Brazil.

Publication Dates

Publication in this collection
12 Sept 2006
Date of issue
Apr 1991

History

Accepted
17 Apr 1991
Received
16 Nov 1990

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

[1] 1. BARBOSA, F.S. Cross-sectional studies on Schistosoma mansoni infection in northeast Brazil. Ann. trop. Med. Parasit., 69: 207-216, 1975.

[2] 2. BLISS, C. I. Statistics in biology: statistical methods for research in the natural sciences. New York, Mc Graw-Hill, 1967. v. 1.

[3] 3. COUTINHO, B.; GOUVĘA, L. & LUCENA, D. Estudos sobre a esquistossomose em Pernambuco. Brasil. Mem. Inst. Oswaldo Cruz, 35: 207-230, 1940.

[4] 4. DIAS, L.C.S.; GLASSER, C.M.; ETZEL, A.; KAWAZOE, U.; HOSHINO-SHIMIZU, S.; KANAMURA, H.E.; CORDEIRO, J.A.; MARÇAL Jr., O.; CARVALHO, J.F.; GONÇALVES Jr., F.L. & PATUCCI, R. The epidemiology and control of schistosomiasis mansoni where Biomphalaria tenagophila is the snail host. Rev. Saúde públ. (S. Paulo), 22: 462-463, 1988.

[5] 5. DIAS, L.C.S.; KAWAZOE, U.; GLASSER, C.M.; HOSHINO-SHIMIZU, S.; KANAMURA, H.Y.; CORDEIRO, J.A.; GUARITA, O.F. & ISHINATA, G.J. Schistosomiasis mansoni in the municipality of Pedro de Toledo (Săo Paulo, Brazil) where the Biomphalaria tenagophila is the snail host: I Prevalence in human population. Rev. Inst. Med. trop. S. Paulo, 31: 110-118, 1989.

[6] 6. DOUMENGE, J.P.; MOTT, K.E.; CHEUNG, C.; VILLENAVE, D.; CHAPUIS, O.; PERRIN, M. F. & REAUD-THOMAS, G. Atlas de la repartition mondiale des schistosomiases. Talence, CEGET-CNRS; GENĘVE, OMS/WHO; TALENCE, PUB, 400 p., fig. 47 tabl., 49 cartes en coul., bibliogr., 1987.

[7] 7. FAROOQ, M.; NIELSEN, J.; SAMAAN, S.A.; MALLAH, M.B. & ALLAMY, A.A. The epidemiology of Schistosoma haematobium and S. mansoni infection in the Egypt-49 Project Area: 2. Prevalence of bilharziasis in relation to personal attributes and habits. Bull. Wld. Hlth. Org., 35: 293-318, 1966.

[8] 8. FAROOQ, M. & SAMAAN, S.A. The relative potencial of different age-groups in the transmission of schistosomiasis in the Egypt-49 Project Area. Ann. trop. Med. Parasit., 61: 315-320, 1966.

[9] 9. FRÓES, E.; PIZA, J.T.; RAMOS, A.S.; PINTO, A.C.M. & DIAS, L.C.S. Aspectos da epidemiologia e profilaxia da esquistossomose mansoni em Săo José dos Campos. Hospital (Rio de Janeiro), 77: 153-164, 1970.

[10] 10. HIATT, R.A. & GEBRE-MEDHIN, M. Morbidity from Schistosoma mansoni infection: an epidemiologic study based on quantitative analysis of egg excretion in Ethiopian children. Amer. J. trop. Med. Hyg., 26: 473-481, 1977.

[11] ¹¹ IBGE. Anuário Estatístico do Brasil, 1985. Rio de Janeiro, 1986.

[12] 12. JORDAN, P.; CHRISTIE, J.D. & UNRAU, G.O. Schistosomiasis transmission with particular reference to possible ecological and biological methods of control: a review. Acta trop. (Basel), 37: 95-135, 1980.

[13] 13. JORDAN, P. & WEBBE, G. Schistosomiasis: epidemiology treatment and control. London, Willian Herneman Medical Book, 1982.

[14] 14. KATZ, N.; CHAVES, A. & PELLEGRINO, J. A simple device for quantitative stool thick-smear technique in schistosomiasis mansoni. Rev. Inst. Med. trop. S. Paulo, 14: 397-400, 1972.

[15] 15. KLOOS, H.; SIDRAK, W.; MICHAEL, A.A.M.; MOAHAMED, E.W. & HIGASHI, G.I. Disease concepts and treatment pratices relating to schistosomiasis haematobium in upper Egypt. J. trop. Med. Hyg., 85: 99-107, 1982.

[16] 16. LEHMANN, E.L. Nonparametrics: statistical methods based on Ranks. San Francisco, Holden Day, 1975.

[17] 17. LEHMAN Jr., J.S.; MOTT, K.E.; MORROW Jr., R.H.; MUNIZ, T.M. & BOYER, M.H. The intensity and effects of infection with schistosoma mansoni in a rural community in northeast Brazil. Amer. J. trop. Med. Hyg., 25: 285-294, 1976.

[18] 18. POLDERMAN, A.M. Transmission dynamics of endemic schistosomiasis. Trop. geogr. Med., 31: 465-475, 1979.

[19] 19. SAS Institute Inc. SAS user guide: statistics, Version 5th. ed. Cary, NC, USA, 1985.

[20] 20. SMITH, D.H.; WARREN, K.S. & MAHMOUD, A.A.F. Morbidity of schistosomiasis mansoni in relation to intensity of infection: study of a community in Kisumi, Kenya. Amer. J. trop. Med. Hyg., 28: 220-229, 1979.

[21] 21. SNEDECOR, G.W. & COCHRAN, W.G. Statistical methods. 7th. ed. Ames, Iowa State University Press, 1980.

[22] ²² SUCEN Situação da esquistossomose no Estado de São Paulo. II Encontro sobre Esquistossomose. Novembro de 1982 (Relatório).

Schistosomiasis mansoni in an area of low transmission: I. impact of control measures

Esquistossomose mansoni em área de baixa transmissão: I. impacto das medidas de controle

Abstracts

References

Publication Dates

History