Schistosomiasis mansoni in an area of low transmission: II. Risk factors for infection

Marçal Júnior, Oswaldo; Hotta, Luiz Koodi; Patucci, Rosa Maria de Jesus; Glasser, Carmen Moreno; Dias, Luiz Candido de Souza

doi:10.1590/S0036-46651993000400005

Abstracts

Risk factors for Schistosoma mansoni infection were identified using a 1:1 matched case-control design. The work was conducted in the municipality of Pedro de Toledo, São Paulo State, Brazil, an area where the snail host is Biomphalaria tenagophila. Information on water contact patterns, knowledge, attitudes and pratices (kap), socioeconomic and sanitary conditions were obtained by mean of questionnaires. The crude odds ratio estimates and the adjusted odds ratio estimates using the logistic regression model are presented. Most of the examined individuals admitted recent water contacts (90.6% of the cases). The most frequent reason for contact was swimming, playing and fishing and the preferential site of contact was the river. According to the logistic regression technique, the main risk factors for infection were: a) water contact through swimming, playing and fishing; b) fording; c) bad hygiene. We concluded that recreational activities are the main reasons for schistosomiasis transmission in Pedro de Toledo and leisure alternatives should be offered to the local population.

Schistosomiasis transmission; Schistosoma mansoni; Risk factors; Water contact pattern

A partir de um estudo de caso-controle por pareamento (1:1) foram determinados os fatores de risco para infecção por Schistosoma mansoni. O trabalho foi desenvolvido no município de Pedro de Toledo, São Paulo, Brasil, área onde Biomphalaria tenagophila é o hospedeiro intermediário. Por meio de questionários foram obtidas informações sobre o padrão de contato com águas naturais; percepção da doença e condições sanitárias e socio-econômicas. Os fatores de risco foram estimados individualmente e através de modelo logístico. A maioria dos pesquisados admitiu contatos recentes com águas naturais (90,6% dos casos). O motivo mais freqüente para estes contatos foi nadar, brincar e pescar. O rio representou o principal local de contato com águas naturais. De acordo com a técnica de regressão logística, os principais fatores de risco foram: a) contato com água para nadar, brincar, pescar; b) vadear; c) más condições de higiene. Concluímos que as atividades recreativas são as principais responsáveis pela transmissão da esquistossomose em Pedro de Toledo e alternativas de lazer devem ser oferecidas a esta população.

ORIGINAL ARTICLES

Schistosomiasis mansoni in an area of low transmission. II. Risk factors for infection

Esquistossomose mansônica em área de baixa transmissão. II. Fatores de risco para infecção

Oswaldo Marçal Júnior^I; Luiz Koodi Hotta^I; Rosa Maria de Jesus Patucci^II; Carmen Moreno Glasser^II; Luiz Candido de Souza Dias^I

^IUniversidade Estadual de Campinas (UNICAMP). Campinas, S. Paulo, Brasil

^IISuperintendência de Controle de Endemias de S. Paulo (SUCEN)

^{Address for correspondence} Address for correspondence: Dr. Oswaldo Marçal Júnior Universidade Federal de Uberlandia, Centro de Ciências Biomédicas, Departamento de Biociências. Campus Umuarama Caixa Postal 593 CEP 38.400, Uberlândia, MG, Brasil

SUMMARY

Risk factors for Schistosoma mansoni infection were identified using a 1:1 matched case-control design. The work was conducted in the municipality of Pedro de Toledo, São Paulo State, Brazil, an area where the snail host is Biomphalaria tenagophila. Information on water contact patterns, knowledge, attitudes and pratices (kap), socioeconomic and sanitary conditions were obtained by mean of questionnaires. The crude odds ratio estimates and the adjusted odds ratio estimates using the logistic regression model are presented. Most of the examined individuals admitted recent water contacts (90.6% of the cases). The most frequent reason for contact was swimming, playing and fishing and the preferential site of contact was the river. According to the logistic regression technique, the main risk factors for infection were: a) water contact through swimming, playing and fishing; b) fording; c) bad hygiene. We concluded that recreational activities are the main reasons for schistosomiasis transmission in Pedro de Toledo and leisure alternatives should be offered to the local population.

Key words: Schistosomiasis transmission; Schistosoma mansoni; Risk factors; Water contact pattern.

RESUMO

A partir de um estudo de caso-controle por pareamento (1:1) foram determinados os fatores de risco para infecção por Schistosoma mansoni. O trabalho foi desenvolvido no município de Pedro de Toledo, São Paulo, Brasil, área onde Biomphalaria tenagophila é o hospedeiro intermediário. Por meio de questionários foram obtidas informações sobre o padrão de contato com águas naturais; percepção da doença e condições sanitárias e socio-econômicas. Os fatores de risco foram estimados individualmente e através de modelo logístico. A maioria dos pesquisados admitiu contatos recentes com águas naturais (90,6% dos casos). O motivo mais freqüente para estes contatos foi nadar, brincar e pescar. O rio representou o principal local de contato com águas naturais. De acordo com a técnica de regressão logística, os principais fatores de risco foram: a) contato com água para nadar, brincar, pescar; b) vadear; c) más condições de higiene. Concluímos que as atividades recreativas são as principais responsáveis pela transmissão da esquistossomose em Pedro de Toledo e alternativas de lazer devem ser oferecidas a esta população.

Full text available only in PDF format.

Texto completo disponível apenas em PDF.

ACKNOWLEDGMENT

We are thankful to Dr. Antonio Guilherme de Souza for support given to the study, to SUCEN field staff for its invaluable participation, to Prof. Dr. José F. de Carvalho for this important contributions to the project, to Prof. Dr. Aricio Xavier Linhares for reviewing the manuscripts and to the people of Pedro de Toledo.

Recebido para publicação em 13/3/1992

Aprovado para publicação em 3/5/1993

This project was supported by SUCEN, FAPESP and CNPq.

1. BRESLOW, N.E. & DAY, M.E. Statistical methods in cancer research: the analysis of case control studies IARC scientific. Lion, International Agency for Research on Cancer, 1980. (Publication n.ş 32)
2. COX, D.R. - Two further applications of a model for binary regression. Biometrika, 45: 562-565, 1958.
3. DALTON, P.R. - A socioecological aprroach to the control of Schistosoma mansoni in St. Lucia. Bull. Wld. Hlth. Org., 54: 587-595, 1976.
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. & ISHIHATA, 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. FAROOQ, M. & MALLAH, M.B. - The behavioural patterns of social and religious water-contact activities in the Egypt-49 Bilharziasis Project Area. Bull. Wld. Hlth. Org., 35: 377-387, 1966.
7. FIGUEIREDO, A.C. - Study of biological and morphological characteristics of Schistosoma mansoni strain from the Ribeira Valley. Rev. Soc. bras. Med. trop., 24: 125-126, 1991.
8. FIGUEIREDO, A.C.; DIAS, L.C.S. & MARQUES, E.H.F. - Biological and morphological characteristics of Schistosoma mansoni from Ribeira Valley, State of Săo Paulo, Brazil. I - Susceptibility of Biomphalaria tenagophila snail to sympatric S. mansoni strain. Rev. Inst. Med. trop. S. Paulo, 34: 199-203, 1992.
9. HOLFORT, T.R.; WHITE, C. & KELSEY, J.C. - Multivariate analysis from matched case-control studies. Amer. J. Epidem., 107: 245-256, 1978.
10. HUSTING, E.L. - Sociological patterns and their influence on the transmission of bilharziasis. Cent. Afr. J. Med., 16 (suppl.): 5-10, 1970.
11. JORDAN, P. & WEBBE, G. - Schistosomiasis: epidemiology, treatment and control. London, William Heinemann Medical Book, 1982.
12. KRAUS, A.S. - Comparison of a group with disease and a control group from the same families, in the search for possible etiologic factors. Amer. J. publ. Hlth., 50: 303-311, 1960.
13. LIMA E COSTA, M.F.; MAGALHĂES, M.A.; ROCHA, R.S.; ANTUNES, C.M.F. & KATZ, N. - Water-contact patterns and socio-economic variables in the epidemiology of schistosomiasis mansoni in an endemic area in Brazil. Bull. Wld. Hlth. Org., 65: 57-66, 1987.
14. LIMA E COSTA, M.F.; ROCHA, R.S.; LEITE, M.L.C.; CARNEIRO, R.G.; COLLEY, D.; GAZZINELLI, G. & KATZ, N. A multivariate analysis of socio-demographic factors, water contact patterns and Schistosoma mansoni infection in an endemic area in Brazil. Rev. Inst. Med. trop. S. Paulo, 33: 58-63, 1991.
15. LIPES, J.K. & HIATT, R.A. - Determinants of human water contact patterns in urban Puerto Rico with special reference to schistosomiasis. Bol. Asoc. méd. P. Rico, 69: 35-44, 1977.
16. MARÇAL JÚNIOR, O.; PATUCCI, R.M.J.; DIAS, L.C.S.; HOTTA, L.K. & ETZEL, A. - Schistosomiasis in an area of low transmission. I Impact of control measures. Rev. Inst. Med. trop. S. Paulo, 33: 83-90, 1991.
17. MOTTA, E. & SLEIGH, A.C. - Water-contact patterns and Schistosoma mansoni infection in a rural community in northeast Brazil. Rev. Inst. Med. trop. S. Paulo, 29: 1-8, 1987.
18. PIMENTEL, D.; GERHARDT, C.E.; WILLIANS, E.R.; WHITE, P.C. & FERGUSSON, F.F. - Aspects of schistosomal endemicity in three Puerto Rican watersheds. Amer. J. trop. Med. Hyg., 10: 523-529, 1961.
19. SCHLESSELMAN, J.J. - Case-control studies: design, conduct, analysis. Oxford, Oxford University Press, 1982.
20. WARREN, K.S. - Regulation of the prevalence and intensity of schistosomiasis in man: Immunology or Ecology? J. infect. Dis., 127: 595-609, 1973.
²¹
WORLD HEALTH ORGANIZATION Workshop on the role of human/water contact in schistosomiasis transmission. Document. Geneve, 1979. (TDR/SER-HWC/79.3).

Address for correspondence:

Dr. Oswaldo Marçal Júnior

Universidade Federal de Uberlandia, Centro de Ciências Biomédicas, Departamento de Biociências. Campus Umuarama

Caixa Postal 593

CEP 38.400, Uberlândia, MG, Brasil

Publication Dates

Publication in this collection
21 July 2006
Date of issue
Aug 1993

History

Accepted
03 May 1993
Received
13 Mar 1992

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

[1] 1. BRESLOW, N.E. & DAY, M.E. Statistical methods in cancer research: the analysis of case control studies IARC scientific. Lion, International Agency for Research on Cancer, 1980. (Publication n.ş 32)

[2] 2. COX, D.R. - Two further applications of a model for binary regression. Biometrika, 45: 562-565, 1958.

[3] 3. DALTON, P.R. - A socioecological aprroach to the control of Schistosoma mansoni in St. Lucia. Bull. Wld. Hlth. Org., 54: 587-595, 1976.

[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. & ISHIHATA, 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. FAROOQ, M. & MALLAH, M.B. - The behavioural patterns of social and religious water-contact activities in the Egypt-49 Bilharziasis Project Area. Bull. Wld. Hlth. Org., 35: 377-387, 1966.

[7] 7. FIGUEIREDO, A.C. - Study of biological and morphological characteristics of Schistosoma mansoni strain from the Ribeira Valley. Rev. Soc. bras. Med. trop., 24: 125-126, 1991.

[8] 8. FIGUEIREDO, A.C.; DIAS, L.C.S. & MARQUES, E.H.F. - Biological and morphological characteristics of Schistosoma mansoni from Ribeira Valley, State of Săo Paulo, Brazil. I - Susceptibility of Biomphalaria tenagophila snail to sympatric S. mansoni strain. Rev. Inst. Med. trop. S. Paulo, 34: 199-203, 1992.

[9] 9. HOLFORT, T.R.; WHITE, C. & KELSEY, J.C. - Multivariate analysis from matched case-control studies. Amer. J. Epidem., 107: 245-256, 1978.

[10] 10. HUSTING, E.L. - Sociological patterns and their influence on the transmission of bilharziasis. Cent. Afr. J. Med., 16 (suppl.): 5-10, 1970.

[11] 11. JORDAN, P. & WEBBE, G. - Schistosomiasis: epidemiology, treatment and control. London, William Heinemann Medical Book, 1982.

[12] 12. KRAUS, A.S. - Comparison of a group with disease and a control group from the same families, in the search for possible etiologic factors. Amer. J. publ. Hlth., 50: 303-311, 1960.

[13] 13. LIMA E COSTA, M.F.; MAGALHĂES, M.A.; ROCHA, R.S.; ANTUNES, C.M.F. & KATZ, N. - Water-contact patterns and socio-economic variables in the epidemiology of schistosomiasis mansoni in an endemic area in Brazil. Bull. Wld. Hlth. Org., 65: 57-66, 1987.

[14] 14. LIMA E COSTA, M.F.; ROCHA, R.S.; LEITE, M.L.C.; CARNEIRO, R.G.; COLLEY, D.; GAZZINELLI, G. & KATZ, N. A multivariate analysis of socio-demographic factors, water contact patterns and Schistosoma mansoni infection in an endemic area in Brazil. Rev. Inst. Med. trop. S. Paulo, 33: 58-63, 1991.

[15] 15. LIPES, J.K. & HIATT, R.A. - Determinants of human water contact patterns in urban Puerto Rico with special reference to schistosomiasis. Bol. Asoc. méd. P. Rico, 69: 35-44, 1977.

[16] 16. MARÇAL JÚNIOR, O.; PATUCCI, R.M.J.; DIAS, L.C.S.; HOTTA, L.K. & ETZEL, A. - Schistosomiasis in an area of low transmission. I Impact of control measures. Rev. Inst. Med. trop. S. Paulo, 33: 83-90, 1991.

[17] 17. MOTTA, E. & SLEIGH, A.C. - Water-contact patterns and Schistosoma mansoni infection in a rural community in northeast Brazil. Rev. Inst. Med. trop. S. Paulo, 29: 1-8, 1987.

[18] 18. PIMENTEL, D.; GERHARDT, C.E.; WILLIANS, E.R.; WHITE, P.C. & FERGUSSON, F.F. - Aspects of schistosomal endemicity in three Puerto Rican watersheds. Amer. J. trop. Med. Hyg., 10: 523-529, 1961.

[19] 19. SCHLESSELMAN, J.J. - Case-control studies: design, conduct, analysis. Oxford, Oxford University Press, 1982.

[20] 20. WARREN, K.S. - Regulation of the prevalence and intensity of schistosomiasis in man: Immunology or Ecology? J. infect. Dis., 127: 595-609, 1973.

[21] ²¹
WORLD HEALTH ORGANIZATION Workshop on the role of human/water contact in schistosomiasis transmission. Document. Geneve, 1979. (TDR/SER-HWC/79.3).

Brasil