RESUMEN
[Objective] To obtain the genetic information on Necator americanus and to search for the purpose genes.[Methods] Mrna was isolated from the third stage larvae of Necator americanus maintained in hamsters.Double strand Cdna was synthesized and ligated to ΛzapⅡ vector to construct the Cdna library.Expresed se-quence tages (ESTs) were obtained by single pass sequencing of randomly isolated Cdna clones from the es-tablished library.[Results] A Cdna librazy of N.americanus was successfully constructed with high recombi-nant efficiency.The titer of unamplified library was 1×107.The insert size was about 750～3000bp.Of 11 ESTs obtained from the library,7 have a significant homology with certain functional genes.[Conclunsion]A high quality and high representative Cdna library of N.americanus was constructed at the first time and ome functional genes were identified from the library by ESTs.
RESUMEN
A cross-sectional study in Itagua, Paraguay tested 192 people for the presence, intensity and species of hookworm infection. Fifty-nine percent of these individuals were found to be infected. Intensity of infection was determined on 92 per cent of infected individuals by quantitative egg counts. The high intensity hookworm infections, which cause the greatest morbidity, were clustered between the ages of five and 14 years. No differences were seen between genders. The species of hookworm was determined for parasites reared from 72 per cent of infected individuals. Both Necator americanus and Ancylostoma duodenale were identified, although the former species predominated. We conclude that hookworm infection continues to be a public health problem in Paraguay, particularly among children and adolescents who suffer from high intensity infections. A. duodenale continues to persist in the Western Hemisphere and has not been completely displaced by N. americanus.