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Revista do Instituto de Medicina Tropical de São Paulo

On-line version ISSN 1678-9946

Rev. Inst. Med. trop. S. Paulo vol.29 no.1 São Paulo Jan./Feb. 1987

http://dx.doi.org/10.1590/S0036-46651987000100001 

ARTIGOS ORIGINAIS

 

Water-contact patterns and schistosoma mansoni infection in a rural community in northeast Brazil (1)

 

Padrões de contato com a água e infecção por Schistosoma mansoni em comunidade rural do Nordeste Brasileiro

 

 

Eduardo MotaI; Adrian C. SleighII

IDepartamento de Medicina Preventiva, Faculdade de Medicina, Universidade Federal da Bahia. Rua Padre Feijó, 29 - 4.° andar, Canela. 40000 Salvador, Bahia, Brasil
IIDepartment of Tropical Public Health, Harvard School of Public Health, Boston, Massachusetts, USA

 

 


SUMMARY

We evaluated the influence of water-related human activities, contaminative behaviour, house location, education and socio-economic status on endemic Schistosoma mansoni infection. The study was conducted in a hilry non-irrigated area of rural northeast Brazil amongst a defined population of subsistence farmers, of whom 93% were infected by age 20. The area was mapped, water bodies were surveyed, and a detailed questionnaire was performed on each household. Infection was assessed by duplicate stool examinations using the sensitive Bell technique to quantify egg excretion. For each household, and index of intensity of infection was computed by grouping individual log-transformed egg counts as an age-sex adjusted Z score. Few households had a sanitary installation or a domestic water supply. However, neither water-contact nor contaminative behavior were indiscriminate. The people made considerable effort to defaecate far from a water source, to obtain household drinking water from the cleanest source, and to bathe only at certain sites where privacy is assured. Land ownership and literacy correlated poorly with the household index of intensity of infection. The key influence on infection status was the relative location of the house and snail-free or snail colonized water sources. In this area, a safe domestic water supply is the critical input needed to achieve definitive control of endemic Schistosomiasis.

Key words: Schistosoma mansoni - infection; Schistosomiasis - rural community; Transmission - water contact.


RESUMO

Este estudo analisa a relação entre as ca racterísticas da infecção por S. mansoni e o padrão de contato com água, os hábitos de higiene, a localização do domicílio, o nível educacional e as condições sócio-econômicas, em uma população definida residente na zona endêmica de Castro Alves, Bahia, Brasil. A área de estudo é típica de zonas rurais do Nordes te, com relevo acidentado e sua população dedica-se à lavoura não irrigada de fumo e mandioca. Após o mapeamento da área e um inquérito malacológico completo, foi aplicado um questionário para cada família com questões referentes às atividades de contato com água, tempo de exposição, condições de habitação e características sócio-econômicas. A prevalência e a intensidade de infecção por S. mansoni foram obtidas usando-se a técnica de Bell para a contagem de ovos nas fezes. A análise dos dados incluiu o cálculo de um índice de infecção da família utilizando-se a contagem de ovos por grama de fezes de cada indivíduo. Poucas casas tinham instalações sanitárias ou fonte de água para uso doméstico, entretanto, os hábitos de defecação e de contato com água não eram indiscriminados, observando-se que os indivíduos dispendiam esforço considerável em busca de água mais limpa para beber e para tomar banho, evitando defecar próximo às fontes de água. A propriedade da terra e o nível educacional não mostraram-se correlacionados com o índice de infecção. O fator que pareceu influenciar a maior ou menor prevalência de infecção por S. mansoni foi a localização das casas em relação à distância de uma fonte de água não colonizada por Biomphalaria glabrata.


 

 

Texto completo disponível apenas em PDF.

Full text available only in PDF format.

 

 

ACKNOWLEDGMENTS

This study was a collaborative project involving the Federal University of Bahia, The Fundação Oswaldo Cruz, and the Harvard School of Public Health. Field work was supported by Antonio Celso Batista and Tome Silva Oliveira. Technical support in the laboratory was provided by Vera Lúcia Menezes, Roberto Magalhães, and Tereza Maisk de Paiva. At Harvard the faculty and staff of the Department of Tropical Public Health furnished logistical, secretarial, and technical assistance; Dr. Thomas H. Weller provided administrative support and scientific advice throughout the study. Dr. Oto Oliveira and Dr. Reinaldo Rosa furnished vital local assistance.

 

REFERENCES

1. BARBOSA, F. S.; PINTO, R. & SOUZA, O. A. - Con-rol of Schistosomiasis mansoni in a small Northeast Brazilian community. Trans, roy. Soc. trop. Med. Hyg., 65: 206-213, 1971.         [ Links ]

2. BARRETO, M. L.; FRANÇA, J. T.; MOTT, K. E.; LEHMAN, J. S. - Stability of faecal egg excretion in Schistosoma mansoni infection. Trans, roy. Soc. trop. Med. Hyg., 72: 181-187, 1978.         [ Links ]

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

4. DALTON, P. R. & POLE, D. - Water-contact patterns in relation to Schistosoma hematobium infection. Bull. Wld. Hlth. Org., 56: 417-426, 1978.         [ Links ]

5. FARROQ, M. & MALLAH, M. G. - Patterns of Scoial and Religious water-contact activities in the Egypt-49 Bilharziasis Project Area. Bull. Wld. Hlth. Org., 35: 277-387, 1966.         [ Links ]

6 JOBIN, W. R. & RUIZ-TIBEN, E. - Bilharzia and patterns of human contact with water in Puerto Rico. Bol. Asoc. med. P, Rico, 60: 279-284, 1968.         [ Links ]

7. JORDAN, P. - Epidemiology and control of schistosomiasis. Brit. med. Bull., 28: 55-59, 1972.         [ Links ]

8,  JORDAN, P.; WOODSTOCK, L.; UNRAU, G. O. & COOK, J. A. - Control of Schistosoma mansoni transmission by provision of domestic water supplies. Bull. Wld Hlth. Org., 52: 9.20, 1975.         [ Links ]

9. JORDAN, P.; UNRAU, G. O.; BARTHOLOMEW, R. K.; COOK, J. A. & GRIST, E. - Value of individual household water supplies in the maintenance phase of schistosomiasis control programme in St Lucia, after chemotherapy. Bull. Wld. Hlth. Org., 60: 583-588, 1982.         [ Links ]

10. LEHMAN, J. S.; MOTT, K. E.; SOUZA, C. A. M.; LEBOREIRO, O. & MUNIZ, T. M. - The associaton of Schistosomiasis mansoni and proteinuria in an endemic area. Amer. J. trop. Med. Hyg., 24: 616-618, 1975.         [ Links ]

11. LEHMAN, J. S.; MOTT, K. E.; MORROW, 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: 552-562, 1976.         [ Links ]

12. MACHADO, P. A. - Brazil's special schistosomiasis control program: the model. Bull. Wld. Hlth. Org., 13: 33-45, 1979.         [ Links ]

13. McCULLOUGH, F. S.; EYAKUZE, V. M.; MSINDE, J. & NDITI, H. - Water resources and bilharziasis transmission in the Misungwi area, Mwanza District, North-east Tanzania. E. Afr. med. J., 45: 295-308, 1968.         [ Links ]

14. MICHELSON, E. H. & DuBOIS, L. - Susceptibility of Bahia populations of Biomphalaria glabrata to an allopathic strain of Schistosoma mansoni. Amer. J. trop. Med. Hyg.t 27: 782.786, 1978.

15. MICHELSON, E. H. & MOTA, E. - Malacological observations bearing on the epidemiology of schistosomiasis in a rural Bahian community. Rev. Inst. Med. trop. S. Paulo, 24: 75-82, 1982.         [ Links ]

16. MOTT, K. E.; LEHMAN, J. S.; HOFF, R.; MORROW, R. H.; MUNIZ, T. M.; SHERLOCK, I. & DRAPER, C C - PUGLIESE, C; GUIMARÃES, A. C. The epidemiology and household distribution of seroreacti-vity to Trypanosoma cruzi in a rural community in northeast Brazil. Amer. J. trop. Med. Hyg., 25: 552-562, 1976.         [ Links ]

17. PIMENTEL, D.; GERHARDT, C E.; WILLIAMS, E. R.; WHITE JR., P. C. & FERGUSON, F. F. - Aspects of schistosomal endemicity in three Puerto Rican Watersheds. Amer. J. trop. Med. Hyg., 10: 523-529, 1961.         [ Links ]

18. SLEIGH, A. C; MOTT, K. E.; FRANÇA, J. T.; MUNIZ, T. M.; MOTA, E. A.; BARRETO, M. L.; HOFF, R.; MAGUIRE, J. H.; LEHMAN, J. S. & SHERLOCK, I. - A three year follow-up of chemotherapy with oxara. niquine in a Brazilian community with endemic Schistosomiasis mansoni. Trans, roy. Soc. trop. Med. Hyg., 75: 234-238, 1981.         [ Links ]

19. SLEIGH, A.; HOFF, R.; MOTT, K. E.; BARRETO, M. L.; PIVA, T. M.; PEDROSA, J. S. & SHERLOCK, I. - Comparison of filtration staining (Bell) and thick smear (Kato) for the detection and quantitation of Schistosoma mansoni eggs in faeces. Trans, roy. Soc, trop. Med. Hyg., 76: 403-406, 1982.         [ Links ]

20. SLEIGH, A. C; MOTT, K. E.; HOFF, R.; BORRETO, M. L.; MOTA, E. A.; MAGUIRE, J. H.; SHERLOCK, I. .& WELLER, T. H. - Three-year prospective study of the evolution of Manson's schistotomiasis in North east Brazil. Lancet, 2: 63-66, 1985.         [ Links ]

21. UNRAU, G. O. - Individual household water supplios as a control measure against Schistosoma mansoni. A study in rural St Lucia. Bull. Wld. Hlth. Org., 52: 1-8, 1975.         [ Links ]

 

 

Recebido para publicação em 29/1/86.

 

 

(1)  Presented at the XVI Congresso da Sociedade Brasileira de Medicina Tropical, Natal, Rio Grande do Norte, Brazil, 3-8 February, 1980

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