Abstract:

In order to understand the work progress in nationwide control of echinococcosis, data related to echinococcosis prevention and control in 2021 were collected and analyzed. As of the end of 2021, echinococcosis was found endemic in 370 counties (city, district, banner) covering 30 421 endemic villages in China. There were 47 584 117 permanent residents living in endemic townships. In 2021, 26 773 echinococcosis cases were documented in endemic counties (cities, districts, banners), with an average prevalence 0.06% (26 773/47 584 117), among them, 16 625 cases were of cystic, and 8 327 cases alveolar echinococcosis, 311 cases mixed infection, 1 510 cases unclassified. A total of 1 346 cases were newly diagnosed in 2021, including 1 075 cases of cystic echinococcosis, 86 cases of alveolar echinococcosis, 7 cases of mixed infection, and 178 cases of unclassified. In 2021, population screening by abdominal ultrasound scanning was performed in all endemic provinces (autonomous regions) for 4.471 7 million person/times, of them, 0.871 5 million person/examinations were for people under age of 12, 3.600 2 million person/times for permanent residents aged ≥ 12; serological examination was carried out for 11 358 person/times. Recorded from 370 surveillance sites in 2021, positive rate of ultrasound detection in people under age of 12 was 0.02% (72/336 959), of which 58.33% (42/72) were newly diagnosed. The positive rate of ultrasound imaging in permanent residents aged ≥ 12 was 0.26% (922/355 006) in type Ⅰ, Ⅱ endemic counties (city, district, banner), and the newly diagnosed patients accounted for 10.52% (97/922) of the detected patients. In 2021, 19 552 people received drug treatment, 14 440 people received liver and kidney function tests or treatment of adverse reactions. A total of 1 792 patients received surgical treatment, among them cystic echinococcosis accounted for 71.15% (1 275/1 792) and alveolar echinococcosis accounted for 23.66% (424/1 792). In 2021, the follow-up results showed that 3 063 cases were cured, 22 660 cases responded to the treatment, 2 356 cases failed in the treatment, 359 cases died (the cause of death was not echinococcosis), 285 cases were excluded, 301 cases were lost in follow-up, 312 cases had not completed the follow-up, and 146 cases migrated to other places. In 2021, there were 2 626 679 dogs in endemic townships (towns) nationwide, of which 2 389 828 were registered and documented. In 35 019 villages, deworming was conducted for dogs, with 25 844 226 deworming for domestic dogs and 131 315 deworming drug sites were distributed for wild canines. A total of 555 688 fecal samples from domestic dogs were collected and tested, of which 2 614 were found Echinococcus coproantigen positive, with a positive rate of 0.47% (2 614/555 688). Of wild canidae, 54 266 field fecal samples were collected and tested, among which, 422 were found Echinococcus coproantigent positive, with a positive rate of 0.78%. A total of 222 844 slaughtered livestock were randomly examined, among which 1 408 were positive, with a positive rate of 0.63% (1 408/222 844); and 56 124 field rodents were examined, of which 599 were found positive, with a positive rate of 1.07% (599/56 124). The epidemic state of echinococcosis has been basically controlled, but there are still many difficulties and challenges in the control and prevention. It is noted that there may be flaws in the control of the source of infection in some endemic areas, and it is likely that there might exist transmission chain in wild environment. It is imperative to continuously advance the comprehensive intervention areas as gripper to explore and optimize the control strategy, enhance the capacity of primary disease control institutions for control of echinococcosis, carry out pilot trial for controlling echinococcosis transmission in wild field, strengthen the surveillance-early warning system to further curb the epidemic of echinococcosis.

Key words: Echinococcosis, Cystic echinococcosis, Alveolar echinococcosis, Epidemiology, China