[Comparison of demographical characteristics of malaria cases from malaria control to elimination in China]

[[[ Objective: ]]] To further identify the high-risk population at malaria elimination phase, and to provide the scientific evident for targeted prevention and control measures, we compared the demographical feature and its change trend for malaria cases between malaria control stage and elimination stage in China. [[[ Methods: ]]] The data of individual case (probable and confirmed) and population during 2007-2014 were collected from China National Notifiable Infectious Disease Reporting Information System, and the data of epidemiological investigation for malaria case (imported and indigenous) during 2011-2014 were collected from China Parasite Disease Prevention and Control Information System. All of the data didn’t include China’s Hongkong, Macao, Taiwan and foreign cases. We described the demographic features of malaria cases, e.g. sex, age, occupation and mobility, to compare the differences of cases between malaria control stage (2007-2010) and the elimination phase (2011-2014). [[[ Results: ]]] From 2007 to 2014, a total of 108 076 malaria cases were reported nationwide, which 13 355 cases were reported at the elimination stage. The proportion of male cases considerably increased from 65.1% (6 1625 cases) at the control stage to 91.4% (12 209 cases) at the elimination phase, with the cases aged 15-64 years among male cases dramatically rose from 74.3% (45 793 cases) to 97.2% (11 870 cases). In terms of occupation, the proportion of children and students decreased from 17.8% (16 891 cases) to 2.7% (356 cases), while the percentage of migrant workers, workers and other professional cases increased from 8.5% (8 031 cases), 3.5% (3 319 cases) and 3.6% (3 435 cases) to 13.1% (1 757 cases), 11.5% (1 534 cases) and 11.4% (1 517 cases), respectively. During the elimination stage,P. faliparium cases have higher proportion of male (96.4%, 7 179 cases) and adult aged 15-64 year (99.4%, 7 399 cases) than that of P. vivax cases , 83.9% (4 344 cases) and 90.3% (4 679 cases), respectively. Moreover, the proportion of imported cases rose from 63.6% (2 599 cases) in 2011 to 97.7% (2 854 cases) in 2014, and the proportion of the migrants in indigenous cases also showed an increasing trend from 13.5% (201 cases) in 2011 to 28.4% (19 cases) in 2014. [[[ Conclusion: ]]] Compared with the control stage, great changes of demographical characteristics of malaria cases occurred at the elimination stage. Male adults aged 15-64 year-old, imported cases and domestic migrants were the high-risk population for targeted control and prevention at the malaria elimination stage.