Field trial in Ceiba Norte of epidemiological tests for operational evaluation of schistosomiasis control in Puerto Rico
Negrón Aponte, H.; Ramos-Morales, F.; Jobin, W.R.
Boletin de la Asociacion Medica de Puerto Rico 70(9): 298-307
1978
ISSN/ISBN: 0004-4849 PMID: 358998 Document Number: 700009
The prevalence of Schistosoma mansoni infection in 272 schoolchildren 4 to 15 years old in Puerto Rico was 27.9%, as determined by 5 faecal examinations using a modification of the formol-ether concentration method. Only 204 children cooperated by giving faeces at the 3rd examination and only 92 at the 5th. The true prevalence rate was estimated to be 28.5%. Prevalence as determined by the skin test in 249 children was 22.5%, by the fluorescent antibody test in 214 children it was 64.0% and by the slide flocculation test in 215 children it was 53.0%. The sensitivities and specificities of the different tests were compared in 186 children. It is concluded that the skin test was unsatisfactory for diagnosing S. mansoni infection in the individual, but the authors chose it for the best estimate of true prevalence of infection under local conditions.