The questionnaire covered family
information, exposures, and handwashing
habits. For the one-time or
rare exposures, we asked about the exposure
of case-children during the
week before onset of the first symptom
of HFMD or herpangina. For controlchildren,
we asked about the entire
8-week outbreak period. We recruited
and trained public health doctors from
community health centers to conduct
in-person interviews of parents (or
other caregivers). If the interviewee
was not at home, 1 revisit was attempted.
We (Mr Ruan, Mr Yang, and
Ms Jin) monitored the progress of
each interviewer and checked all questionnaires
for inconsistencies and
missing data at the end of each day