TABLE 6.
Categorization of LDB samplesa
| Classificationb | Criteria | No. of participants with the indicated characteristics/total no. tested (%) |
|---|---|---|
| Laboratory-confirmed LD | + STTTA result, + PCR result, + culture/PCR of the culture media, or 2 + ELISAs with EM of >5 cm | 82/298 (27) |
| Probable LD | EM lesions of >5 cm, − STTTA result, and – PCR result | 87/298 (29) |
| Suspected LD | EM/annular lesion size of ≤5 cm, − STTTA result, and − PCR result | 41/298 (14) |
| SNL | Symptomatic, − STTTA result, and − PCR result | 88/298 (30) |
| EC (− serology) | − by serology (all serologic tests) | 209/252 (83) |
| EC (+ serology)+ | + by serology (at least 1 + serologic test) | 43/252 (17) |
+, positive; −, negative; STTTA, standard two-tiered testing algorithm; SNL, symptomatic no lesion; EC (+ serology)+, a minimum of 1 positive test result by whole-cell lysate, C6 peptide, or VlsE/pepC10 ELISA, IgM immunoblotting, or IgG immunoblotting.
For the laboratory testing-confirmed category, samples were categorized by positive test results with serology by use of the STTTA (n = 60), positive results by 2 ELISAs with EM lesion size of >5 cm (n = 11), or IgG seroconversion at the convalescent-phase blood draw (n = 7). Tests for direct detection confirmation included culture (n = 2), PCR of culture medium (n = 9), or RT-PCR of whole blood (n = 4). The results for the samples could be confirmed with multiple tests. Participants with probable LD, suspected LD, or SNL had signs or symptoms consistent with early, acute LD that could include skin manifestations (EM/annular lesion), headache, fatigue, fever, chills, or joint or muscle pain but did not meet the criteria for laboratory testing-confirmed LD.