Table 1: Clinical manifestations, exposure levels, and socio-demographic findings of subjects.

Clinical statusSexExposure level (2)
AgeMaleFemaleHighMediumLow
NMean95% CIN%N%N%N%N%

Case (1)
 Pneumonia943.333.3–53.491009100
 Flu-like symptoms939.427.9–50.991009100
 Asymptomatic1546.438.4–54.4151001387213
Noncase735.123.7–46.634341002291144100

Total403643334

(1) A case is considered when IgG  ≥  200 and IgM  ≥  80.
(2) Exposure level estimated according to workplace, distance to the workshop, and time spent at the workshop.
N: number of subjects; 95% CI: 95% Confidence Interval.