ANALYSIS OF AN IMPORTATION OUTBREAK AND CASE DIAGNOSIS AFTER MALARIA ELIMINATION IN LIYANG CITY,JIANGSU PROVINCE
Objective To analyze the imported malaria epidemic and case diagnoses after eliminating malaria in Liyang,and also provide data for formulating strategies to prevent malaria re-transmission.Methods Data on malaria epidemic status,etiological detection,case epidemiological investigation reports,and case review reports in Liyang from 2013 to 2022 were collected and SPSS software(version 22.0)was used for statistical analysis.Results From 2013 to 2022,a total of 54 imported malaria cases were reported in Liyang City,including 40 cases of falciparum malaria(74.07%),10 cases of vivax malaria(18.52%)and four cases of tertian malaria(7.41%).All but one case originated in Africa,comprising 53 male cases aged 15-59 years and 74.07%of the victims are farmers.These malaria cases occur in all seasons,with a high prevalence in January,and are distributed in all 10 towns/streets.Notably,four tertiary malaria cases were reported in Licheng Street(2 cases),Daibu Town and Shangxing Town.The main clinical symptoms were fever(n=54,100.00%)and chills(n=41,75.93%).The median time from onset of illness to confirmation of diagnosis was one day.The rates of initial correct diagnosis were 100.0%in the Centre for Disease Control and Prevention(CDC)(19/19)and 76.19%(16/21)in district hospitals.The CDC confirmed 30 malaria cases and the district hospitals confirmed 23 cases.Of the 54 confirmed cases,49 were diagnosed by morphological observations on blood smears under the microscopes.Thirty-nine cases were diagnosed by both morphological observation and Rapid Detection Tips(RDT).There was no statistically significant difference between the two test methods(x2=0.16,P>0.05).The concordance rates of malaria species identification and diagnosis at the county level were 94.44%and 96.30%,respectively,with those re-qualified by the provincial department.Although Liyang City has entered the post-elimination phase of the malaria epidemic,there is still a potential risk of recurrence of endemic malaria caused by these imported P.vivax in the city.Conclusion Therefore,the current focus for malaria prevention and control is on strengthening malaria case management practices,improving rapid detection accuracy in health facilities,and increasing health education among key populations.Particular emphasis should be placed on imported malaria cases to safeguard our malaria elimination gains.