Absence of natural infection by Schistosoma mansoni in wild rodents captured in endemic areas for schistosomiasis in the State of Alagoas, Brazil

Chieffi, Pedro Paulo; Kloetzel, Kurt; Siqueira, José G. Vergetti de

doi:10.1590/S0036-46651994000400012

SHORT COMMUNICATION

Absence of natural infection by Schistosoma mansoni in wild rodents captured in endemic areas for schistosomiasis in the State of Alagoas, Brazil

Pedro Paulo Chieffi^I; Kurt Kloetzel^II; José G. Vergetti de Siqueira^III

^ITropical Medicine Institute (LIM06) and Preventive Medicine Department (Medicine School University of São Paulo), Brazil

^IISecretary of Health and Hygiene of Santos (State of São Paulo), Brazil

^IIIFederal University of Alagoas, Brazil

^{Correspondence to} Correspondence to: P.P. Chieffi Tropical Medicine Institute Av. Dr. Enéas C. Aguiar 470 05403-000 São Paulo, S P, Brasil

Wild rodents and other small mammals harbouring infection by Schistosoma mansoni have been found in several endemic areas for schistosomiasis in Brazil^{1-5, 8, 11, 13, 14, 16}. In some of these regions certain rodent species - mainly Nectomys squamipes² and Holochilus brasiliensis^{5, 16} - have been stressed as important natural reservoirs of S. mansoni.

In some Caribbean Islands, Rattus rattus specimens have often been found naturally infected by S. mansoni; in addition, S. mansoni strains naturally adapted to both human and rodent hosts have been found^{6, 7, 15}.

In fact, neither the role of non-human vertebrates as S. mansoni natural reservoirs, nor the natural maintenance of this trematode without human participation have been consensually accepted by all the epidemiologists who studied this question.

The municipality of Branquinha, 60 km far from Maceió, capital of the State of Alagoas, is located in a region endemic for schistosomiasis, where high rates of human infection have been found^{9, 10}. In this region we attempted to determine the prevalence of S. mansoni infection in wild rodents caught near human settlements, where schistosomiasis transmission foci for active transmission had been detected^{9, 10}.

Seventy-four wild rodents belonging to five different species (Table 1) were caught alive in special traps and transported to a local laboratory and, under anesthesia, were submitted to portal perfusion with the aim of recovering S. mansoni specimens. Immediately after portal perfusion the liver was sliced, then pressed between two large glass plates, in order to identify S. mansoni specimens not recovered by perfusion as well as eggs trapped within the sinusoidal spaces. Simultaneously, fecal samples from the rodent bowels were examined for S. mansoni eggs.

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The examined rodents did not present any evidence of S. mansoni infection, despite high prevalence rates for human schistosomiasis in the same region. These results suggest that, on the contrary to the situation found in other areas, schistosomiasis transmission in Branquinha depends only on the presence of humans infected by the trematode. Consequently, although in some endemic areas for schistosomiasis in Brazil the infection seems to show a zoonotic behavior as a result of adaptive evolution¹², in Branquinha, S. mansoni should still be considered as an anthroponotic infection.

Recebido para publicação em 08/04/1994

Aceito para publicação em 25/05/1994

1. AMORIM, J.P. - Infeccçăo do homem e de roedores silvestres pelo Schistosoma mansoni em localidades do muniicípio de Viçosa (Estado de Alagoas, Brazil). Arq. Hig. Saúde públ., 27: 335-339, 1962.
2. ANTUNES, C.M.F.; MILWARD DE ANDRADE, R.; KATZ, N.; COELHO, P.M.Z. & PELLEGRINO, J. - Role of Nectomys squamipes in the epidemiology of Schistosoma mansoni infection. Ann. trop. Med. Parasit., 67: 67-73, 1973.
3. CARVALHO, O.S.; MILWARD DE ANDRADE, R. & CORTĘS, M.I.N. - Roedores silvestres na epidemiología da esquitossomose mansônica no Lago da Pampulha, Belo Horizonte, Minas Gerais (Brasil). Rev. Soc. bras. Med. trop., 9: 27-35, 1975.
4. COELHO, P.M.Z.; DIAS, M.; MAYRINK, W.; MAGALHĂES, P; MELLO, M.N. & COSTA, C.A. - Wild reservoirs of Schistosoma mansoni from Caratinga, an endemic shistosomiasis area of Minas Gerais State, Brazil. Amer. J. trop. Med. Hyg., 28: 163-164, 1979.
5. DIAS, L.C.S.; ÁVILA-PIRES, F.D. & PINTO, A.C.M. - Parasitological and ecological aspects of schistosomiasis mansoni in the valley of the Paraiba do Sul River (Săo Paulo State, Brazil). 1. Natural infection of small mammals with Schistosoma mansoni. Trans. roy. Soc. trop. Med. Hyg., 72: 496-500, 1978.
6. IMBERT-ESTABLET, D. - Approche expérimentale du role de Rattus rattus et de Rattus norvegicus dans les foyers de Schistosoma mansoni de Guadaloupe. Ann. Parasit. hum. comp., 57: 271-284, 1982.
7. JOURDANE, J. & IMBERT-ESTABLET, D. - Étude expérimentale de la permissivité du rat sauvage (Rattus rattus) de Guadaloupe ŕ l'égard de Schistosoma mansoni. Hypothése sur le rôle de cet hôte dans la dynamique des foyers naturales. Acta trop. (Basel), 37: 41-51, 1980.
8. KAWAZOE, U. & PINTO, A.C.M. - Importância epidemiológica de alguns animais silvestres na esquistossomose mansônica. Rev. Saúde públ. (S. Paulo), 17: 345-366, 1983.
9. KLOETZEL, K.; CHIEFFI, P.P. & SIQUEIRA, J.G.V. - Repeated mass treatment of schistosomiasis mansoni: experience in hyperendemic areas of Brazil. 3. Techiques of assessment and surveillance. Trans. roy. Soc. trop. Med. Hyg., 84: 74-79, 1990.
10. KLOETZEL, K. & SCHUSTER, N.H. - Repeated mass treatment of schistosomiasis mansoni: experience in hyperendemic areas of Brazil. 1. Parasitological effects and morbidity. Trans. roy. Soc. trop. Med. Hyg., 81: 365-370, 1987.
11. LUZ, E.; LIMA, E.C. & GUSOLIN, J. - Reservatórios silvestres de S mansoni numa área endęmica de esquistossomose no Estado do Paraná. An. Fac. Med. Univ. Fed. Paraná, 9/10: 113-120, 1966-67.
12. PICOT, H. - Holochilus brasiliensis and Nectomys squamipes (Rodentia, Cricetidae) natural hosts of Schistosoma mansoni. Mem. Inst. Oswaldo Cruz, 87 (suppl.): 255-260, 1992.
13. PIVA, N. & BARROS, P.R.C. - Infecçăo natural de animais silvestres e domésticos pelo Schistosoma mansoni em Sergipe. Rev. bras. Malar., 18: 221-223, 1966.
14. RODRIGUES, D.C. & FERREIRA, C.S. - Primeiro encontro de roedor (Nectomys squamipes) naturalmente infestado pelo Schistosoma mansoni, no Estado de Săo Paulo (Brasil). Rev. Inst. Med. trop. S. Paulo, 11: 306-308, 1969.
15. THÉRON, A. - Early and late shedding patterns of Schistosoma mansoni cercariae: ecological significance in transmission to human and murine hosts. J. Parasit., 70: 652-655, 1984.
16. VEIGA-BORGEAUD, T.; NETO, R.C.L.; PETER, F. & BASTOS, O.C. - Constataçőes sobre a importância dos roedores silvestres (Holochilus brasiliensis nanus Thomas, 1897), na epidemiología da esquistossomose mansônica própria da pré-Amazônia, Maranhăo - Brasil. Cad. pesq. Săo Luís, 2: 86-89, 1986.

Correspondence to:

P.P. Chieffi

Tropical Medicine Institute

Av. Dr. Enéas C. Aguiar 470

05403-000 São Paulo, S P, Brasil

Publication Dates

Publication in this collection
20 Sept 2006
Date of issue
Aug 1994

History

Received
08 Apr 1994
Accepted
25 May 1994

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

[1] 1. AMORIM, J.P. - Infeccçăo do homem e de roedores silvestres pelo Schistosoma mansoni em localidades do muniicípio de Viçosa (Estado de Alagoas, Brazil). Arq. Hig. Saúde públ., 27: 335-339, 1962.

[2] 2. ANTUNES, C.M.F.; MILWARD DE ANDRADE, R.; KATZ, N.; COELHO, P.M.Z. & PELLEGRINO, J. - Role of Nectomys squamipes in the epidemiology of Schistosoma mansoni infection. Ann. trop. Med. Parasit., 67: 67-73, 1973.

[3] 3. CARVALHO, O.S.; MILWARD DE ANDRADE, R. & CORTĘS, M.I.N. - Roedores silvestres na epidemiología da esquitossomose mansônica no Lago da Pampulha, Belo Horizonte, Minas Gerais (Brasil). Rev. Soc. bras. Med. trop., 9: 27-35, 1975.

[4] 4. COELHO, P.M.Z.; DIAS, M.; MAYRINK, W.; MAGALHĂES, P; MELLO, M.N. & COSTA, C.A. - Wild reservoirs of Schistosoma mansoni from Caratinga, an endemic shistosomiasis area of Minas Gerais State, Brazil. Amer. J. trop. Med. Hyg., 28: 163-164, 1979.

[5] 5. DIAS, L.C.S.; ÁVILA-PIRES, F.D. & PINTO, A.C.M. - Parasitological and ecological aspects of schistosomiasis mansoni in the valley of the Paraiba do Sul River (Săo Paulo State, Brazil). 1. Natural infection of small mammals with Schistosoma mansoni. Trans. roy. Soc. trop. Med. Hyg., 72: 496-500, 1978.

[6] 6. IMBERT-ESTABLET, D. - Approche expérimentale du role de Rattus rattus et de Rattus norvegicus dans les foyers de Schistosoma mansoni de Guadaloupe. Ann. Parasit. hum. comp., 57: 271-284, 1982.

[7] 7. JOURDANE, J. & IMBERT-ESTABLET, D. - Étude expérimentale de la permissivité du rat sauvage (Rattus rattus) de Guadaloupe ŕ l'égard de Schistosoma mansoni. Hypothése sur le rôle de cet hôte dans la dynamique des foyers naturales. Acta trop. (Basel), 37: 41-51, 1980.

[8] 8. KAWAZOE, U. & PINTO, A.C.M. - Importância epidemiológica de alguns animais silvestres na esquistossomose mansônica. Rev. Saúde públ. (S. Paulo), 17: 345-366, 1983.

[9] 9. KLOETZEL, K.; CHIEFFI, P.P. & SIQUEIRA, J.G.V. - Repeated mass treatment of schistosomiasis mansoni: experience in hyperendemic areas of Brazil. 3. Techiques of assessment and surveillance. Trans. roy. Soc. trop. Med. Hyg., 84: 74-79, 1990.

[10] 10. KLOETZEL, K. & SCHUSTER, N.H. - Repeated mass treatment of schistosomiasis mansoni: experience in hyperendemic areas of Brazil. 1. Parasitological effects and morbidity. Trans. roy. Soc. trop. Med. Hyg., 81: 365-370, 1987.

[11] 11. LUZ, E.; LIMA, E.C. & GUSOLIN, J. - Reservatórios silvestres de S mansoni numa área endęmica de esquistossomose no Estado do Paraná. An. Fac. Med. Univ. Fed. Paraná, 9/10: 113-120, 1966-67.

[12] 12. PICOT, H. - Holochilus brasiliensis and Nectomys squamipes (Rodentia, Cricetidae) natural hosts of Schistosoma mansoni. Mem. Inst. Oswaldo Cruz, 87 (suppl.): 255-260, 1992.

[13] 13. PIVA, N. & BARROS, P.R.C. - Infecçăo natural de animais silvestres e domésticos pelo Schistosoma mansoni em Sergipe. Rev. bras. Malar., 18: 221-223, 1966.

[14] 14. RODRIGUES, D.C. & FERREIRA, C.S. - Primeiro encontro de roedor (Nectomys squamipes) naturalmente infestado pelo Schistosoma mansoni, no Estado de Săo Paulo (Brasil). Rev. Inst. Med. trop. S. Paulo, 11: 306-308, 1969.

[15] 15. THÉRON, A. - Early and late shedding patterns of Schistosoma mansoni cercariae: ecological significance in transmission to human and murine hosts. J. Parasit., 70: 652-655, 1984.

[16] 16. VEIGA-BORGEAUD, T.; NETO, R.C.L.; PETER, F. & BASTOS, O.C. - Constataçőes sobre a importância dos roedores silvestres (Holochilus brasiliensis nanus Thomas, 1897), na epidemiología da esquistossomose mansônica própria da pré-Amazônia, Maranhăo - Brasil. Cad. pesq. Săo Luís, 2: 86-89, 1986.