Table I.

Seroprevalence of Anti–TSSA-I and Anti–TSSA-II Abs in Populations from Distinct Geographical Origins

Percentage of reactive sera
OriginSerum panelnConventional serology
 (IHA, IFI, ELISA)
 reactivity (%)EpEx CL-ELISAareactivity (%)HemocultureAnti–TSSA-IbAnti–TSSA-II
ArgentinaChagasic66100NDND3.095.4
Non-Chagasic100NDND00
BrazilChagasicc11210098.2ND5.482.1
Chagasicd48100100+0100
Chagasice75100100+2.7100
Non-Chagasic12600ND00
ChileChagasicc23NDf100ND8.787.0
  • a EpEx CL-ELISA, chemiluminescent ELISA test using an epimastigote (Tulahuén strain) preparation as antigen (reference 25).

  • b Positive sera showed very low reactivity against TSSA-I, with reading (absorbance or relative luminescent unit) values close to the cutoff value for the specific test. Sera reactive for TSSA-I were also positive for TSSA-II, with reading values for the latter higher than those observed for the former (see also Fig. 6 C).

  • c Potentially Chagasic patients.

  • d Confirmed Chagasic patients.

  • e Confirmed Chagasic patients coinfected with HIV.

  • f ND, not determined.

  • Sera were grouped according to the country of origin and diagnosis criteria and tested at 1:200 dilution for TSSA-I and TSSA-II reactivity by ELISA (Argentinean samples) and/or CL-ELISA (Brazilian and Chilean samples).