As shown in Table 1, the mean age was not significantly
different between seropositive and negative subjects. No
association was observed with gender (P = 0.56) or time of
residence in the household. Prior Leptospira infection was
not associated with the planting of rice or other crops, the
growing of sugar cane, and care of livestock or milking goats
or cows. Of the 240 people who engaged in farming, 237
(98.8%) did not use protective clothing or footwear during
work-related activities. In children and adolescents under
the age of 15 (n = 66), 63.6% of those who played in waters
near the rice plantations had a prior infection (P = 0.08). The
majority of subjects (85.7%) reported sighting domestic rats
in their household environments. Among 250 subjects who
engaged in agricultural work, 91 (36.4%) reported sighting
‘red’ rats (rato vermelho) in their working environment.
Subjects did not report sighting other types of wild or domestic
rats in this setting. However, significant associations were
not found between serologic evidence for prior Leptospira
infection and the presence of rats in the household or workplace
environments or with the presence of dogs (P = 0.83)
or cattle (P = 0.33) in the household area.