Imported Malaria Cases--China,2012–2018

Introduction:In 2017,no indigenous malaria cases were reported in China,but imported malaria was a challenge for the elimination program.This study analyzed the status and trends of imported malaria in China from 2012 to 2018 to provide evidence for further strategies and adjustments to current interventions.Methods:Data on individuals were collected from the Parasitic Diseases Information Reporting Management System(PDIRMS)from 2012 to 2018.Plasmodium species,case classification,temporal distribution,spatial distribution,and source of imported cases were analyzed to investigate imported malaria characteristics.Results:In total,21,376 malaria cases were recorded in the PDIRMS from 2012 to 2018.Among them,20,938(98.0%)cases were imported malaria cases(IMCs).The number and proportion of IMCs increased from 2012(n=2,474,91.0%)to 2018(n=2,511,99.7%).IMCs consisted of 13,510(64.5%)P.falciparum,4,803(22.9%)P.vivax,1,725(8.2%)P.ovale,376(1.8%)P.malariae,2(0.01%)P.knowlesi,348(1.7%)mixed infections,and 174(0.8%)clinically-diagnosed cases.The proportion of imported P.falciparum cases increased from 2012(n=1403,57.4%)to 2018(n=1655,66.0%),while imported P.vivax cases showed a decreasing trend from 2012(n=901,43.7%)to 2018(n=352,14.0%).IMCs were mainly reported in Yunnan(n=2,922,14.0%),Guangxi(n=2,827,13.5%),and Jiangsu(2,067,9.9%).IMCs were reported throughout the entire year,and the highest number of IMCs was reported in June 2013.IMCs originated from 67 countries from 4 continents,and the largest proportion were from Myanmar(n=3,081,14.7%)and Ghana(n=2,704,12.9%).Conclusion and Implications for Public Health Practice:The total number of IMCs increased in China.Therefore,two actions are needed to continue the elimination of malaria in China:prevent reestablishment caused by imported P.vivax because Anopheles sinensis is still widely distributed;and ensure timely diagnosis and appropriate treatment to avoid fatal cases caused by imported P.falciparum.