Epidemiological characteristics of imported Plasmodium ovale malaria in Jiangsu Province from 2012 to 2020 / 中国血吸虫病防治杂志

ABSTRACT

Objective To analyze the epidemiological characteristics of imported cases with Plasmodium ovale infections in Jiangsu Province from 2012 to 2020, so as to provide insights into the development of the imported malaria control strategy in the province. Methods All data pertaining to cases with definitive diagnosis of P. ovale malaria in Jiangsu Province from 2012 to 2020 were captured from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China, including the date of going abroad and returning to China, time of malaria infections overseas, date of malaria onset, initial diagnosis and definitive diagnosis. All data pertaining to epidemic status were descriptively analyzed. Results A total of 347 cases of P. ovale malaria were reported in Jiangsu Province from 2012 to 2020, with the highest number seen in 2015 (71 cases). All cases were laboratory-confirmed overseas imported malaria cases, accounting for 14.32% of all reported malaria cases in Jiangsu Province during the period from 2012 to 2020. The 5 cities with the highest number of imported P. ovale malaria cases included Lianyungang City (53 cases, 15.27%), Nantong City (44 cases, 12.68%), Huai’an (44 cases, 12.68%), Taizhou City (44 cases, 12.68%) and Yangzhou City (36 cases, 10.37%). The highest number of imported P. ovale malaria cases was reported in October (39 cases, 11.24%), and the lowest number was seen in December (21 cases, 6.05%). P. ovale infections mainly occurred in were Equatorial Guinea (97 cases, 37.95%), Angola (60 cases, 17.29%) and Nigeria (40 cases, 11.53%). The median duration between returning to China and malaria onset was 64 (144) days, and 7.49% (26/347) of all cases developed malaria one year after returning to China. The initial diagnosis of P. ovale malaria was mainly made at county-level medical institutions (117 cases, 33.72%), and the definitive diagnosis was mainly made at city-level medical institutions (122 cases, 35.16%). The correct rate of initial diagnosis of P. ovale malaria increased from 0 in 2012 to 78.26% in 2020, appearing a tendency towards a rise year by year (χ2 = 50.90, P < 0.01). Conclusions Imported P. ovale malaria cases were reported in Jiangsu Province each year from 2012 to 2020, and P. ovale infections predominantly occurred in Africa. Initial and definitive diagnoses of P. ovale malaria were mainly made at city- and county-level medical institutions. Training on the detection ability of malaria parasites is recommended among grassroots microscopists to improve the diagnostic ability of P. ovale malaria, and consolidate the achievements of malaria elimination in Jiangsu Province.