A multivariate analysis of the relationship between work ability and S. japonicum infection in Dongting Lake Region, in China

Yuesheng, Li; Yi, Li; Donbao, Yu; Meng, Xia; Shengqin, Hu; Yang, Xiang; Zhinan, Zhong

doi:10.1590/S0036-46651993000400008

Abstracts

A cross-sectional case-control study on the association between the reduced work ability and S. japonicum infection was carried out in a moderate endemic area for schistosomiasis japonica in the southern part of Dongting lake in China. A total of 120 cases with reduced work ability and 240 controls paired to the case by age, sex, occupation and without reduced work ability, participated in the study. The mean age for individuals was 37.6 years old (21-60), the ratio of male: female was 60:40, the prevalence of S. japonicum in the individuals was 28.3%. The results obtained in this study showed that the infection of S. japonicum in case and control groups was 49.2% (59/120) and 17.9% (43/240), respectively. Odds ratio for reduced work ability among those who had schistosomiasis was 4.34 (95%), confidence interval was 2.58-7.34, and among those who had S. japonicum infection (egg per gram > 100) was up to 12.67 (95%), confidence interval was 3.64-46.39. After odds ratio was adjusted by multiple logistic regression, it was confirmed that heavier intensity of S. japonicum infection and splenomegaly due to S. japonicum infection were the main risk factors for reduced work ability in the population studied.

Schistosomiasis japonica; Work ability; Multivariate analysis; China

Um estudo seccional de casos controles da associação entre a capacidade reduzida para o trabalho e a infecção por S. japonicum foi levada a efeito em região moderadamente endêmica para esquistossomose japônica na parte sul do lago Dongting, China. Um total de 120 casos com redução da capacidade de trabalho e 240 controles pareados no que diz respeito a idade, sexo, ocupação sem redução da capacidade de trabalho. A idade média dos pacientes foi 37,6 anos (21-60) e a relação masculino:feminino foi 60:40. A prevalência do S. japonicum foi de 28,3%. Os resultados obtidos neste estudo mostraram que a infecção nos casos e no grupo controle foi 49,2% (59/120) e 17,9% (43/240) respectivamente. A média para redução da capacidade de trabalho entre aqueles com esquistossomose foi 4,34 (95%) e o intervalo de confiança foi 2,58-7,34 e entre aqueles com infecção por S. japonicum (ovo por grama > 100) foi de 12,67 (95%), com intervalo de confiança de 3,64-46,39. Depois que a média foi ajustada através de regressão logística múltipla, foi confirmado que a maior intensidade de infecção pelo S. japonicum e a esplenomegalia eram os fatores principais de risco para a reduzida capacidade de trabalho da população estudada.

EPIDEMIOLOGY

A multivariate analysis of the relationship between work ability and S. japonicum infection in Dongting Lake Region, in China

Análise multivariada da relação entre capacidade de trabalho e infecção por S. japonicum na região dos lagos de Dongting, China

Li Yuesheng; Li Yi; Yu Donbao; Xia Meng; Hu Shengqin; Xiang Yang; Zhong Zhinan

Human Institute of Parasitic Diseases, WHO Collaborating Centre for Research and Control on Schistosomiasis in Lake Region, Yueyang, Hunan Province, 414000 The People's Republic of China

^{Address for correspondence} Address for correspondence: Li Yuesheng Hunan Institute of Parasitic Diseases Yueyang, Hunan 414000, P.R. of China

SUMMARY

A cross-sectional case-control study on the association between the reduced work ability and S. japonicum infection was carried out in a moderate endemic area for schistosomiasis japonica in the southern part of Dongting lake in China. A total of 120 cases with reduced work ability and 240 controls paired to the case by age, sex, occupation and without reduced work ability, participated in the study. The mean age for individuals was 37.6 years old (21-60), the ratio of male: female was 60:40, the prevalence of S. japonicum in the individuals was 28.3%. The results obtained in this study showed that the infection of S. japonicum in case and control groups was 49.2% (59/120) and 17.9% (43/240), respectively. Odds ratio for reduced work ability among those who had schistosomiasis was 4.34 (95%), confidence interval was 2.58-7.34, and among those who had S. japonicum infection (egg per gram > 100) was up to 12.67 (95%), confidence interval was 3.64-46.39. After odds ratio was adjusted by multiple logistic regression, it was confirmed that heavier intensity of S. japonicum infection and splenomegaly due to S. japonicum infection were the main risk factors for reduced work ability in the population studied.

Key words: Schistosomiasis japonica; Work ability; Multivariate analysis; China.

RESUMO

Um estudo seccional de casos controles da associação entre a capacidade reduzida para o trabalho e a infecção por S. japonicum foi levada a efeito em região moderadamente endêmica para esquistossomose japônica na parte sul do lago Dongting, China. Um total de 120 casos com redução da capacidade de trabalho e 240 controles pareados no que diz respeito a idade, sexo, ocupação sem redução da capacidade de trabalho. A idade média dos pacientes foi 37,6 anos (21-60) e a relação masculino:feminino foi 60:40. A prevalência do S. japonicum foi de 28,3%. Os resultados obtidos neste estudo mostraram que a infecção nos casos e no grupo controle foi 49,2% (59/120) e 17,9% (43/240) respectivamente. A média para redução da capacidade de trabalho entre aqueles com esquistossomose foi 4,34 (95%) e o intervalo de confiança foi 2,58-7,34 e entre aqueles com infecção por S. japonicum (ovo por grama > 100) foi de 12,67 (95%), com intervalo de confiança de 3,64-46,39. Depois que a média foi ajustada através de regressão logística múltipla, foi confirmado que a maior intensidade de infecção pelo S. japonicum e a esplenomegalia eram os fatores principais de risco para a reduzida capacidade de trabalho da população estudada.

Full text available only in PDF format.

Texto completo disponível apenas em PDF.

ACKNOWLEDGEMENTS

The work described was a part of the project (ID 890179) which received a financial support from de UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases. The data analysis of this work was completed in Centro de Pesquisas "Rene Rachou'', Brasil, while the investigator was in receipt of a training grant from the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases. Authors are grateful to Dr. Peter Jordan and Dr. Marcel Tanner for reviewing the design of the study and Dr. Naftale Katz and Dr. Henrique L. Guerra for statistical and epidemiological assistance in this manuscript.

Recebido para publicação em 22/12/1992

Aceito para publicação em 15/03/1993

1. ARMITAGE, P. & BERRY, G. - Statistical methods in medical research. Oxford, Blackwell Scientific Publications, 1987.
2. BARBOSA, F.S. & PEREIRA, D.P. - Incapacitating effects of schistosomiasis mansoni on the productivity of sugar-cane cutters in north-eastern Brazil. Amer. J. Epidem., 114: 102-111, 1981.
3. BRESLOW, N.E. & DAY, N.E. - Statistical methods in cancer research: the analyses of case control studies. Lyon, International Agency for Research on Cancer, 1980.
4. CHEN, M.G. & MOTT, K.E. - Progress in assessment of morbidity due to S. japonicum infection. Trop. Dis. Bull., 85(6): R1-R45, 1988.
5. COSTA, M.F.F.; ROCHA, R.S.; MAGALHĂES, M.H.A. & KATZ, N. - A clinical epidemiological survey of schistosomiasis mansoni in a hyperendemic area in Minas Gerais state. I. Differences in the manifestations of schistosomiasis in the town centre and the environs. Trans. roy. Soc. trop. Med. Hyg., 79: 539-545, 1985.
6. COSTA, M.F.F.; MAGALHĂES, M.H.A.; ROCHA, R.S.; ANTUNES, C.M.F. & KATZ, N. - Water-contact patterns and socioeconomic variables in the epidemiology of schistosomiasis mansoni in an endemic area in Brazil. Bull. Wld. Hlth. Org., 65: 57-66, 1987.
7. FENWICK, A. & FIGENSCHOU, B.M. - The effect of S. mansoni infection on the productivity of cane cutters on a sugar estate in Tanzania. Bull. Wld. Hlth. Org., 47: 567-572, 1972.
8. FOSTER, R. - Schistosomiasis on an irrigated estate in East Africa. III. Effects of asymptomatic infection on health and industrial efficiency. J. trop. Med. Hyg, 70: 185-195, 1967.
9. 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.
10. LI, Y.S. - A report on the expectant life of residents in an endemic area for schistosomiasis japonica. J. Control Schistos., 38: 84-87, 1983. (in Chinese)
11. LI, Y.S.; YU, D.B.; LI, Y. & XIANG, Y. - A study on 245 deads due to advanced schistosomiasis japonica in Hunan. Hunan Med., 8: 56-59, 1991. (in Chinese)
12. MOTT, K.E. - Schistosomiasis new goals. Wld. Hlth., 12: 3, 1984.
13. OLVEDA, R.M.; FEVIDAL, P.; VEYRE, F.D.; ICATALO, F.C. & DOMINGO, E.O. - Relationship of prevalence and intensity of infection to morbidity in schistosomiasis japonica: a study of three communities in Leyte, Philippines. Amer. J. trop. Med. Hyg., 32: 1312-1321, 1983.
14. SMITH, P.G. & MORROW, R.H. - Methods for field trials of interventions against tropical diseases: "a toolbox". New York, Oxford University Press, 1991.
15. TAN, D.L. - An analysis of the endemicity of schistosomiasis japonica in Hunan. Sci. Technol. Schistos., 65: 112-118, 1991. (in Chinese)
16. TANNER, M. - Evaluation of public health of schistosomiasis. Trop. Med. Parasit., 40: 143-148, 1989.
17. VAN, E.J.H. & POLDERMAN, A.M. - Physiological performance and work capacity of tin mine labourers infected with schistosomiasis in Zaire. Trop. geogr. Med., 36: 259-266, 1984.
18. WANG, Z.H. - Study on chemotherapy with pyguition in control of schistosomiasis japonica. Chin. J. Schistos. Control, 1: 19-24, 1989. (in Chinese)
19. WARREN, K.S.; SU, D.L.; XU, Z.Y.; YUAN, H.C.; PETERS, P.A.; COOK, J.A.; MOTT, K.E. & HOUSER, H.B. - Morbidity on schistosomiasis japonica in relation to intensity of infection: a study of two rural brigades in Anhui province, China. New Engl. J. Med., 307: 1553-1559, 1983.
20. WEISBROD, B.A. & HELMINIAK, T.W. - Parasitic diseases and agricultural labor productivity. Econ. Dev. Cult. Change, 25: 505-522, 1977.
21. WU, Z.W.; ZHUO, S.J. & PU, K.M. - The prevalence of human behaviours to the endemicity and control of schistosomiasis japonica in Dongting lake region. Chin. J. Schistos. Control, 3: 7-12, 1991. (in Chinese)
22. YIXIN, H. & MANDERSON, L. - Schistosomiasis and the social patterning of infection. Acta trop. (Basel), 51: 175-194, 1992.
23. YU, D.B.; LI, Y.S.; LI, Y. & XIANG, Y. - Morbidity of schistosomiasis japonica in three villages of the Dongting lake region, China. Chin. J. Schistos. Control, 4(5): 17-19, 1992. (in Chinese)

Address for correspondence:

Li Yuesheng

Hunan Institute of Parasitic Diseases

Yueyang, Hunan 414000, P.R. of China

Publication Dates

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

History

Accepted
15 Mar 1993
Received
22 Dec 1992

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

[1] 1. ARMITAGE, P. & BERRY, G. - Statistical methods in medical research. Oxford, Blackwell Scientific Publications, 1987.

[2] 2. BARBOSA, F.S. & PEREIRA, D.P. - Incapacitating effects of schistosomiasis mansoni on the productivity of sugar-cane cutters in north-eastern Brazil. Amer. J. Epidem., 114: 102-111, 1981.

[3] 3. BRESLOW, N.E. & DAY, N.E. - Statistical methods in cancer research: the analyses of case control studies. Lyon, International Agency for Research on Cancer, 1980.

[4] 4. CHEN, M.G. & MOTT, K.E. - Progress in assessment of morbidity due to S. japonicum infection. Trop. Dis. Bull., 85(6): R1-R45, 1988.

[5] 5. COSTA, M.F.F.; ROCHA, R.S.; MAGALHĂES, M.H.A. & KATZ, N. - A clinical epidemiological survey of schistosomiasis mansoni in a hyperendemic area in Minas Gerais state. I. Differences in the manifestations of schistosomiasis in the town centre and the environs. Trans. roy. Soc. trop. Med. Hyg., 79: 539-545, 1985.

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

[7] 7. FENWICK, A. & FIGENSCHOU, B.M. - The effect of S. mansoni infection on the productivity of cane cutters on a sugar estate in Tanzania. Bull. Wld. Hlth. Org., 47: 567-572, 1972.

[8] 8. FOSTER, R. - Schistosomiasis on an irrigated estate in East Africa. III. Effects of asymptomatic infection on health and industrial efficiency. J. trop. Med. Hyg, 70: 185-195, 1967.

[9] 9. 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.

[10] 10. LI, Y.S. - A report on the expectant life of residents in an endemic area for schistosomiasis japonica. J. Control Schistos., 38: 84-87, 1983. (in Chinese)

[11] 11. LI, Y.S.; YU, D.B.; LI, Y. & XIANG, Y. - A study on 245 deads due to advanced schistosomiasis japonica in Hunan. Hunan Med., 8: 56-59, 1991. (in Chinese)

[12] 12. MOTT, K.E. - Schistosomiasis new goals. Wld. Hlth., 12: 3, 1984.

[13] 13. OLVEDA, R.M.; FEVIDAL, P.; VEYRE, F.D.; ICATALO, F.C. & DOMINGO, E.O. - Relationship of prevalence and intensity of infection to morbidity in schistosomiasis japonica: a study of three communities in Leyte, Philippines. Amer. J. trop. Med. Hyg., 32: 1312-1321, 1983.

[14] 14. SMITH, P.G. & MORROW, R.H. - Methods for field trials of interventions against tropical diseases: "a toolbox". New York, Oxford University Press, 1991.

[15] 15. TAN, D.L. - An analysis of the endemicity of schistosomiasis japonica in Hunan. Sci. Technol. Schistos., 65: 112-118, 1991. (in Chinese)

[16] 16. TANNER, M. - Evaluation of public health of schistosomiasis. Trop. Med. Parasit., 40: 143-148, 1989.

[17] 17. VAN, E.J.H. & POLDERMAN, A.M. - Physiological performance and work capacity of tin mine labourers infected with schistosomiasis in Zaire. Trop. geogr. Med., 36: 259-266, 1984.

[18] 18. WANG, Z.H. - Study on chemotherapy with pyguition in control of schistosomiasis japonica. Chin. J. Schistos. Control, 1: 19-24, 1989. (in Chinese)

[19] 19. WARREN, K.S.; SU, D.L.; XU, Z.Y.; YUAN, H.C.; PETERS, P.A.; COOK, J.A.; MOTT, K.E. & HOUSER, H.B. - Morbidity on schistosomiasis japonica in relation to intensity of infection: a study of two rural brigades in Anhui province, China. New Engl. J. Med., 307: 1553-1559, 1983.

[20] 20. WEISBROD, B.A. & HELMINIAK, T.W. - Parasitic diseases and agricultural labor productivity. Econ. Dev. Cult. Change, 25: 505-522, 1977.

[21] 21. WU, Z.W.; ZHUO, S.J. & PU, K.M. - The prevalence of human behaviours to the endemicity and control of schistosomiasis japonica in Dongting lake region. Chin. J. Schistos. Control, 3: 7-12, 1991. (in Chinese)

[22] 22. YIXIN, H. & MANDERSON, L. - Schistosomiasis and the social patterning of infection. Acta trop. (Basel), 51: 175-194, 1992.

[23] 23. YU, D.B.; LI, Y.S.; LI, Y. & XIANG, Y. - Morbidity of schistosomiasis japonica in three villages of the Dongting lake region, China. Chin. J. Schistos. Control, 4(5): 17-19, 1992. (in Chinese)

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