Serological studies in Nectomys squamipes demonstrate the low sensitivity of coprological exams for the diagnosis of schistosomiasis.
The existence of wild rodents naturally infected by Schistosoma mansoni is a drawback for schistosomiasis control programs. As a consequence, it is necessary to have a precise diagnosis of S. mansoni infection in wild rodents (water rats; Nectomys squamipes), the species seemingly involved in the transmission of schistosomiasis at Sumindouro, Rio de Janeiro, Brazil. A total of 78 specimens of N. squamipes was captured in an endemic area at Vale do Pamparrão and Porteira Verde, Sumidouro, Brazil; 5 more were born in captivity and experimentally infected. The sensitivity and specificity of the coprological method of Kato-Katz and serological methods, i.e., enzyme-linked immunosorbent assay (ELISA) and western blot (WB), were compared. The rodents were subsequently killed and necropsied to confirm infection. The prevalences observed using ELISA (48%) and WB (41%) were equivalent to those found at necropsy (41%). The ELISA showed a sensitivity of 97% and a specificity of 87%, whereas the WB showed a sensitivity of 87% and a specificity of 89%. The Kato-Katz method exhibited 50% sensitivity and 100% specificity. The differences found among the ELISA, WB, and necropsy, when compared with Kato-Katz, may be related to the low sensitivity of the coprological method. Serological methods should be used for more reliable epidemiological information.
Peralta
Regina H S
RH
Departamento de Patologia, Faculdade de Medicina, Universidade Federal Fluminense, Av. Marques do Paraná, 303, Niterói 24030-210, RJ, Brazil. peralta@micro.ufrj.br
Melo
Daniel G S
DG
Gonçalves
Margareth M L
MM
D'Andrea
Paulo S
PS
Rey
Luis
L
Machado-Silva
José R
JR
Peralta
José M
JM
D000818:Animals; D000835:Animals, Wild; D000909:Antibodies, Helminth / Q000096:biosynthesis / Q000097:blood*; D001344:Autopsy / Q000662:veterinary; D015153:Blotting, Western / Q000662:veterinary; D001938:Brazil / Q000453:epidemiology; D004197:Disease Reservoirs; D019353:Endemic Diseases; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005243:Feces / Q000469:parasitology; D007700:Kinetics; D051379:Mice; D015995:Prevalence; D011817:Rabbits; D012376:Rodent Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000469:parasitology; D012550:Schistosoma mansoni / Q000276:immunology* / Q000302:isolation & purification; D012555:Schistosomiasis mansoni / Q000175:diagnosis / Q000453:epidemiology / Q000662:veterinary*; D012680:Sensitivity and Specificity; D016205:Sigmodontinae / Q000469:parasitology*
D000909:Antibodies, Helminth