@article{oai:nagasaki-u.repo.nii.ac.jp:00002094,
 author = {Vuong, Nguyen Lam and Manh, Dao Huy and Mai, Nguyen Thi and Phuc, Le Hong and Luong, Van Thuy and Quan, Vo Duy and Thuong, Nguyen Van and Lan, Nguyen Thi Phuong and Nhon, Cao Thi My and Mizukami, Shusaku and Doan, Nguyen Ngoc and Huong, Vu Thi Que and Huy, Nguyen Tien and Hirayama, Kenji},
 journal = {Tropical Medicine and Health},
 month = {May},
 note = {Introduction: Dengue is a viral disease that spreads rapidly in the tropic and subtropic regions of the world and causes 22,000 deaths annually. In 2009, the World Health Organization (WHO) released a new classification of dengue infections, which divided them into three categories: dengue without warning sign (D), dengue with warning sign (DWS), and severe dengue (SD). However, researchers have been using different criteria to define persistent vomiting; therefore, we aimed to evaluate the ability of the number of vomiting times in early prediction of SD development among D/DWS patients. Method: A hospital-based cohort study was conducted in Ben Tre-south of Vietnam. We enrolled confirmed dengue patients with D and DWS at admission. The final classification was determined on the discharged day for every patient based on the classification of WHO 2009 without using vomiting symptom, using the receiver operating characteristic (ROC) curve to evaluate the ability of the number of vomiting times in early prediction of SD development among D/DWS patients. Result: The prevalence of vomiting symptom was higher in SD group than D/DWS group (92 versus 46 %, p = 0.006), and the median of the number of vomiting times was higher in SD group than D/DWS group (2.5 versus 0, p = 0.001). To distinguish SD from D/DWS, the ROC curve of the number of vomiting episodes showed that the area under the curve was 0.77; with the cut point of two, the sensitivity and specificity were 92 and 52 %, respectively. Conclusion: The number of vomiting times could be a good clinical sign which can early predict SD from the group of D/DWS. We suggest the definition of persistent vomiting should be vomiting two times or more per day., Tropical Medicine and Health, 44, 14; 2016},
 title = {Criteria of “persistent vomiting” in the WHO 2009 warning signs for dengue case classification},
 volume = {44},
 year = {2016}
}