1. Institute of Preventive Medicine, National Defense Medical Center, Taipei City, Taiwan
2. Taiwan Centers for Disease Control, Taipei City, Taiwan
3. Kaohsiung Armed Forces General Hospital, Kaohsiung City, Taiwan
4. Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung City, Taiwan
5. Tangshan Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung City, Taiwan