Table 1

Numbers and percentages of confirmed cases using paired samples from time points 0 (time of diagnosis) and 3 months based on IFAT IgG phase II, ELISA IgG phase II, and CFT phase II (n = 62)

AssayNo. (%) testing positivea at month 0P valueb at month 0No. (%) testing positivea at month 3P valueb at month 3No. (%) of confirmed casesc at month 3P valueb of confirmed casesc at month 3
IFAT, IgG phase II9 (14.5)0.020 (IFAT vs ELISA)62 (100)0.250 (IFAT vs ELISA)62 (100)0.025 (IFAT vs ELISA)
ELISA, IgG phase II2 (3.2)1.000 (ELISA vs CFT)59 (95.2)0.250 (ELISA vs CFT)59 (95.2)1.000 (ELISA vs CFT)
CFT, phase II3 (4.8)0.030 (CFT vs IFAT)62 (100)NAd (CFT vs IFAT)60 (96.8)0.500 (CFT vs IFAT)
  • a “Positive” is defined as an IgG phase II titer of ≥32 (IFAT), a positive extinction (ELISA), or a phase II titer of ≥8 (CFT).

  • b McNemar exact test (binomial distribution).

  • c Based on IgG phase II seroconversion between month 0 and 3 (negative IgG phase I at month 0 and positive IgG phase I at month 3) or a 4-fold rise in the IgG phase II titer.

  • d NA, not applicable (no discordant pairs).