Objective To understand the situation of soil-transmitted nematode infection in China in 2020 and provide support for evaluating the development of surveillance on soil-transmitted nematodiasis in various provinces/municipalities/autonomous regions, and improving and perfecting the control strategies. Methods Surveillance was carried out in 408 national surveillance sites (counties) in 31 provinces (municipalities, autonomous regions) in China in 2020. With the county as unit, each site was divided into 5 areas geographically: east, west, south, north, and central part, followed by selecting one township (town), and therein one administrative village was selected from wherein, 200 permanent residents over the age of 3 were sampled. A total of 1 000 people were surveyed at each surveillance site. Fecal samples were collected from the sampled villagers, and examined by using the modified Kato-Katz thick smear method (two slide-reading for each sample) for infection of hookworm, Ascaris lumbricoides, Trichuris trichiura and Enterobius vermicularis, to calculate the infection rate and intensity, respectively. In addition, soil samples were collected from fields or vegetable gardens of each village in the survey site, and examined for hookworm larvae using 5% saline at 45 ℃, and for Ascaris eggs by saturated sodium nitrate flotation method. Results In 2020, the overall infection rate of soil-transmitted nematode in residents was 0.84% (3 485/415 672) in 408 surveillance sites of 31 provinces (municipalities/autonomous regions), with the highest found in Hainan (6.34%, 199/3 141), followed by Yunnan (5.80%, 963/16 616) and Sichuan (3.66%, 592/16 168); infection rate in females was 0.91% (1 944/213 591), which was higher than that of 0.76% in males (1 541/202 081) (χ² = 27.20, P < 0.01). The soil-transmitted nematode infection rate was the highest in the age group ≥ 60-years-old, which is 1.26% (1 376/109 251). The difference between each age group was statistically significant (χ² = 382.28, P < 0.01). The infection rates of hookworm, A. lumbricoides, T. trichiura were 0.51% (2 016/415 672), 0.19% (805/415 672) and 0.16% (673/415 672), respectively. Among them, hookworm and T. trichiura had only mildly infected cases. The proportions of mild and moderate A. lumbricoides infections were 99.25% (799/805) and 0.75% (6/805), respectively. In 2020, 2 604 soil samples were examined and found that the positive rate of Ascaris eggs and hookworms was 3.07% (80/2 604) and 2.42% (63/2 604), respectively. Conclusion In 2020, the infection rate of soil-transmitted nematode in China remains at a low level in general, but the regional differences are still significant, and the areas with high infection rates still exist. At the same time, it is necessary to strengthen the control measures for the key groups of people over age of 60, women and children, and carry out health education.

After more than 70 years of effective control programme, China has made remarkable achievements in the control of key parasitic diseases, and is moving towards the goal of control and elimination. This paper analyzes the epidemic status and challenges of schistosomiasis, malaria, echinococcosis, leishmaniasis, clonorchiasis and soil-transmitted helminthiasis in recent years, and puts forward the future directions and key tasks of those diseases, in order to provide reference for accelerating the control and elimination programmes on key parasitic diseases in China.

Toxoplasma gondii is an obligate intracellular parasite that widely distributes in the world and causes zoonotic toxoplasmosis. In recent years, parasite infection in the brain has been paid more and more attention. T. gondii can cause central nervous system damage, often manifested as depression, schizophrenia, epilepsy and other symptoms. In this paper, the process and mechanism of T. gondii establishing chronic infection through blood-brain barrier, causing central nervous system injury and disease are reviewed.

Zoonotic diseases pose a serious threat to human health and ecological security. Climate change facilitates the crossover and spread of zoonotic diseases by affecting pathogens, hosts, vectors, and human activities, therefore threatening global public health. This article summarizes the impact of climate change on the spread of zoonotic diseases and explores the effective strategies based on the One Health approach to protect human health and safety.

Antimalarial drug resistance presents the biggest challenge for treatment against malaria. Plasmodium parasites have developed different degrees of resistance to common traditional antimalarial drugs including artemisinin. Therefore, the improvement of traditional drugs and the research and development of new drugs are urgently needed. This paper discusses the malaria control strategies based on a systematic review of the resistance mechanisms against traditional antimalarial drugs, the improvement strategies and optimisation achievements based on traditional drugs, and the research advances of new antimalarial drugs.

Objective To analyze the genotype and sequence polymorphisms of mitochondrial cytochrome oxidase 1（co1）and NADPH dehydrogenase subunit 1 (nd1) in Echinococcus granulosus from Yunnan Province. Methods Echinococcus of animal origin was collected from cysts isolated from liver or lung lesions of cattle, sheep and free-range pigs at slaughterhouses in Shangri-La, Daguan, Eryuan, Lushui and Weixi counties of Yunnan Province. Echinococcus of human origin was obtained from the focal tissues surgically removed from hospitals in Jianchuan, Yunlong, Longyang and Yulong Counties, then the E. granulosus was selected after pathogenic identification, and used to extract genomic DNA with a DNA extraction kit, followed by PCR amplification and sequencing of co1 and nd1 genes. The sequence homology and single nucleotide polymorphisms were analyzed using BLAST aligment. Phylogenetic trees based on co1 and nd1 were constructed by the neighbor-joining method using MEGA-X software. Results A total of 62 samples of Echinococcus were collected, 36 of which were pathogenically confirmed as E. granulosus. A total of 32 gene co1 sequences were successfully sequenced, of which 15 were type G1 and 17 were type G5, with a length of 824 bp and 807 bp, respectively. After submitting to GenBank database, the login numbers obtained were OP413393-OP413402, OP413498-OP413506 and OP420520. A total of 34 nd1 genes were sequenced successfully, of which 11 were type G1 and 23 were type G5, with lengths of 882 bp and 888 bp, respectively. The entry numbers obtained by submitting the GenBank database were OP471626-OP471638. The results of sequence polymorphism analysis showed that 1.94% (16/824) mutation sites in the co1 type G1 sequence and 3.10% (25/807) mutation sites in the G5 type sequence were found. In the nd1, 0.45% (4/882) and 2.93% (26/888) mutation sites were found in the type G1 sequence and the G5 type sequence, respectively. The results of multiple genotypic sequence comparison showed that there were 6 homologous sequences of the co1 gene, 4 of which were type G1, the genetic distances of homologous sequences were 0.000 0-0.001 1, 0.000 0-0.000 6, and 0.000 0-0.001 7, respectively. Also included two G5 types. The genetic distances of homologous sequences were 0.000 0-0.002 5 and 0.000 0-0.001 2, respectively. There were 3 homologous sequences in nd1 gene, of which 1 was type G1, and the genetic distance was 0.000 0-0.001 1, 2 of which were type G5, genetic distance was 0.000 0 and 0.000 0-0.001 1. Phylogenetic tree analysis showed that the phylogenetic tree based on co1 and nd1 genes formed two branches of type G1 and type G5, type G1 was closely related to the gene sequences of central and western China (Qinghai, Ningxia, Gansu, Sichuan), Bhutan, Iran and Jordan in the Middle East (GenBank entry number AF297617.1, KJ628328.1, EU072106.1, MW138946.1, AB688602.1). The G5 Type was closely related to Vietnam, China's Guangxi, the United Kingdom, Poland, Zambia, France, Pakistan, Brazil, Kenya and Namibia (GenBank login numbers MW558412.1, MN058591.1, KU378107.1, MZ322608.1, KU743915.1, KU743919.1, MN886291.1, KX010903.1, KU743918.1 and KX138068.1). Conclusion The prevalent isolate of E. granulosus in Yunnan Province are of genotype G1 and G5, and both co1 and nd1 gene reveals single nucleotide polymorphisms.

The individual malaria case investigation forms in 31 provinces/municipalities/autonomous regions (excluding Taiwan, Hong Kong and Macao) and Xinjiang Production and Construction Corps of China in 2023 were collected and sorted from “The Information System for Infectious Disease Surveillance”. The epidemiological characteristics were analyzed. In 2023, 2 488 malaria cases were reported, showing an increase of 194.4% compared to 2022 (845). Among them, there were 2 487 imported cases, 1 case of blood transfusion infection; 1 561 falciparum malaria cases (62.7%, 1 561/2 488), 615 vivax malaria (24.7%, 615/2 488), 234 ovale malaria (9.4%, 234/2 488), 66 malariae malaria (2.7%, 66/2 488) and 12 cases with mixed-infection (0.5%, 12/2 488). In the reported, 2 313 cases were of Chinese nationality (93.0%, 2 313/2 488) and 175 cases foreign nationality (7.0%, 175/2 488); the male-to-female ratio was 11.6∶1; the highest number of cases (29.1%, 725/2 488) was seen at the age group of 30-39 years showed. The malaria cases were reported from all the 31 provinces/municipalities/autonomous regions and Xinjiang Production and Construction Corps, with the top 5 provinces of Yunnan (398 cases), Henan (234 cases), Guangxi (195 cases), Shandong (178 cases) and Guangdong (174 cases) accumulately, a total of 1 179 cases (47.4%, 1 179/2 488) reported. Of the reported, 85 were severe cases (3.4%, 85/2 488) and 12 deaths (0.5%, 12/2 488). Although no local transmitted primary malaria cases have been reported in China for seven consecutive years, the risk of imported cases and re-transmission. It is imperative to continuousely strengthen the surveillance and response, find the cases timely and deliver standardized treatment, so as to reduce severe cases and death, preventing local re-transmission.

Food-borne parasitic diseases caused by ingesting food and water containing infective parasites are still common parasitic diseases that are easily misdiagnosed and mistreated in clinical practice. With the participation of multi-disciplinary experts, and in the light of the latest research results at home and abroad, based on factors other than the quality of evidence (economics, patient preferences and values, trade-offs, accessibility, fairness, acceptability, etc.), the level of recommendation and the quality of evidence in evidence-based medicine were assessed using the World Health Organization-recommended evidence quality classification and strength of recommendation system, and a consensus of 24 items was reached to guide and improve the comprehensive diagnosis and treatment of food-borne parasitic diseases for clinical medical staff.

To understand the work progress in nationwide control of echinococcosis, we summarize the experience and find the existing problems through descriptive analysis on the national control data in 2022. As of the end of 2022, there were 370 echinococcosis endemic counties (city, district, banner) covering 29 926 villages in China, having a total of 25 227 echinococcosis cases with an average prevalence of 58.35 per 100 000 （25 227/43 232 609), among them, 15 554 cases were of cystic echinococcosis, 8 169 cases alveolar echinococcosis, 255 mixed infection, and 1 249 cases pending; 1 270 cases were newly found, including 991 cases of cystic echinococcosis, 89 alveolar echinococcosis, 5 mixed infection, and 185 pending; revealing 102 cases were at age < 12, and 1 168 case were of age ≥ 12. In 2022, population screening by abdominal ultrasound scanning was performed in all endemic provinces (autonomous regions) for 3 576 121 person/times. Of them, 751 440 person/examinations were performed for the residents younger than 12, and 2 824 681 person/times were performed for residents older than 12. The serological examination was carried out for the suspected individuals for 17 404 person/times. According to data from 370 surveillance sites in 2022, the prevalence in residents younger than 12 was 0.02% (60/287 437) by ultrasound screening, with 40.00% (24/60) newly diagnosed cases. The prevalence in the residents older than 12 was 0.29% (772/270 407) in type Ⅰ and type Ⅱ endemic counties (city, district, banner). The newly diagnosed cases accounted for 8.29% (64/772) of the detected patients. In 2022, 18 354 patients received drug treatment, of which 16 625 patients received liver and kidney function tests or management against adverse reactions. A total of 1 418 patients received surgical treatment, including 69.82% (990/1 418) for cystic echinococcosis, and 26.52% (376/1 418) for alveolar echinococcosis. In 2022, the follow-up results showed that 999 cases were cured, 20 599 cases responded to the treatment, 2 546 cases failed in the treatment, 374 cases died (the causes of the deaths were not echinococcosis), 239 cases were excluded, 372 cases were lost in follow-up, 884 cases had not completed the follow-up, and 170 cases migrated to other places. In 2022, there were 2 478 608 dogs in the endemic townships (towns) nationwide, of which 2 250 694 were registered for management. Deworming work was conducted for dogs in 34 646 villages, with 24 289 457 deworming times. Wild canines were demormed by delivering 119 473 drug doses. A total of 394 851 fecal samples from domestic dogs were collected and detecteded, of which 1 756 were found positive for Echinococcus coproantigen, with a positive rate of 0.44% (1 756/394 851). Of the wild canines, 62 884 field fecal samples were collected and detected, among which 1 201 were found positive for Echinococcus coproantigen, with a positive rate of 1.91% (1 201/62 884). A total of 117 303 slaughtered livestock were randomly examined, among which 1 038 were diseased, with a prevalence of 0.88%. A total of 43 705 field rodents were examined, among which 403 were diseased, with a prevalence of 0.92%. Although the endemic of echinococcosis in China has been essentially controlled, there remain many difficulties and challenges in control work. It is imperative to continuously strengthen the prevention and control measures for echinococcosis, raise the disease prevention awareness, explore optimizing the control strategy, exert the role of regional joint prevention and control mechanisms and fully implement comprehensive measures to further control the prevalence of echinococcosis.

Objective To analyze the epidemiological characteristics of visceral leishmaniasis cases in Longnan City, Gansu Province from 2005 to 2021, to provide scientific basis for formulating prevention and control strategy for visceral leishmaniasis. Methods The information on the visceral leishmaniasis cases residing at the current address in Longnan City, reported by the National Infectious Disease Surveillance Reporting and Management System from 2005 to 2021, was collected. A database was established using Microsoft Excel 2013. Three-dimentional distribution characteristics of visceral leishmaniasis cases were analyzed with descriptive epidemiological method. The distribution map of reported cases was plotted by Arc GIS 10.2. Statistical analysis was performed using SPSS 25.0 software. Results From 2005 to 2021, a total of 1 109 cases of visceral leishmaniasis were reported in Longnan City,among them, 577 cases were of clinical diagnosis, and 532 confirmed cases. The annual average incidence rate was reported at 2.49/100 000, showing a low prevalence status. The incidence rate reached 2.76/100 000 in 2005, rose to 4.53/100 000 in 2009, and gradually dropped to 0.46/100 000 in 2021, indicating a trend of first increase and then decrease (χ² = 267.561, P < 0.01). The visceral leishmaniasis cases were mainly distributed in Wudu District (606 cases), Wenxian County (323 cases) and Tanchang County (148 cases), accounting for 97.11% of reported cases (1 077/1 109). In some villages/towns of endemic counties, a cluster of high incidence was found. There were 633 male cases and 476 female cases, and the sex ratio was 1.33∶1; the incidence rates in males and females were 2.73/100 000 and 2.23/100 000, respectively (χ² = 2.699, P > 0.05). The number of reported cases in the 0-4 age group accounted for 50.50% (560/1 109) of the total number of reported cases, with the highest incidence rate of 19.62/100 000. The second is the 5-9 age group, with the number of reported cases accounting for 12.80% (142/1 109) of the total number of reported cases, and the incidence rate is 4.84/100 000. It indicated that the incidence rate tends to decrease with age (χ² = 14.942, P < 0.01). The first incidence rate was occupied in children of scattered living, accounting for 41.12% (456/1 109), and the second in peasants, accounting for 24.71% (274/1 109). Conclusion In Longnan City of Gansu Province, visceral leishmaniasis remains at a low prevalent status. The reported cases are mainly of children. There is a recurgence trend in historically endemic counties.

Objective To investigate the parasitic infection in domestic dogs in Da Hinggan Ling area, and provide reference for the prevention and control of local zoonotic parasitic diseases. Methods In September 2020, fresh domestic dog feces were collected from dog owner’s household yard of 6 natural villages including Jiabei Village, Baihua Village, Dongshan Village, Tuqiang Town, Xingfu Village and Guyuan Town in the Da Hinggan Ling area, and total DNA was extracted from the fecal samples. PCR amplification was conducted using 13 pairs of parasite universal primers targeting 8 taxonomy groups including Apicomplexa, Amoeba, Diplomonadida, Kinetoplastida, Parabasalia, Nematoda, Platyhelminthes and Microsporidia, and the target gene fragments were obtained after high-throughput sequencing of the amplified products. The product sequences were compared and analyzed in the NCBI database to identify the parasite species, and the detection rate of parasites in domestic dog feces was calculated. Results Parasite DNA were detected in 37 of 202 domestic dog feces, and the total detection rate was 18.31%. A total of 19 species of parasites which belongs to 15 families from 7 phyla were detected, and the detection rate of different species were significantly different (χ² = 69.488, P < 0.05). Thirteen protozoa species and 6 helminth species were detected. The detection rate of Parabodo caudatus in the family Parabodonidae was the highest at 6.44% (13/202). Among the 37 samples in which parasite DNA was detected, the mixed positive ratio was 32.43% (12/37), of which 72.97% (27/37) detected 1 type of parasite, and 2 types, 3 kinds and 4 kinds accounted for 27.03% (10/37), 0.27% (1/37) and 0.27% (1/37) respectively. Jiabei Village had the highest detection rate of parasite DNA in domestic dog feces, which was 37.70% (23/61), followed by Tuqiang Town, with a detection rate of 36.36% (20/55), and Baihua Village, which was not detected (0/13). There was a statistically significant difference in the detection rate of different sampling sites (χ² = 19.717, P < 0.05). Conclusion In Da Hinggan Ling area, domestic dogs were found infected with multiple parasites, showing considerably higher positive rate detected in some parts of the area, thus, there exists risk of infection caninee-source parasites to local residents.

The patient was an 87-year-old male farmer from Yongcheng, Henan. He reported having nausea and decreased appetite without obvious causes on June 25th, 2023, accompanied by diarrhea (4-5 times/d) and low-grade fever (body temperature of 37.5 ℃). He was treated at a local community hospital without detailed examinations and showed no improvement after receiving infusions of unknown drugs. Due to a referral, he was admitted to the Yongcheng Central Hospital on July 5th. The patient has been undertaking farming for a long time, and animals such as cats and dogs are bred in his home. He has no history of breeding pigs or close contact, no history of applying pig manure, and no history of drinking unboiled water. On admission, physical examination showed a thin body type, no apparent abnormalities in heart and lung auscultation, a soft and flat abdomen, no gastrointestinal waves or peristalsis, no varicose veins in the abdomen, no liver or spleen felt under the ribs, tenderness in the lower abdomen, no tenderness or rebound tenderness in other parts, negative mobile cloudy urine, active bowel sounds, and no audible gas-water sound. The blood routine test showed a white blood cell count of 11.9 × 10⁹/L, a red blood cell count of 4.11 × 10¹²/L, a platelet count of 358 × 10⁹/L, a hemoglobin of 119 g/L, a blood potassium of 3.13 mmol/L, and an albumin of 32.5 g/L in the liver function test. The stool routine test showed a dark green loose stool, a positive occult blood test, no red blood cells or white blood cells, no parasitic eggs detected, and no abnormalities in the fecal culture. A plain and enhancement scan of the entire abdomen was performed, which showed an increased volume of the gallbladder, slightly dilated bile ducts, common bile duct, and pancreatic duct in the hepatic portal area, slightly thickened gastric wall near the cardia, and diffuse thickening and edema of the intestinal walls in the rectum and sigmoid colon. The patient was treated for rehydration and correction of electrolyte imbalance. Simultaneously, oral berberine tablets were given (0.1 g each time, 3 times/d), smecta powder (3 g each time, 3 times/d), and bifidobacterium (1 g each time, 3 times/d, taken 2 h apart from smecta powder). The frequency of the patient’s bowel movements gradually decreased and gradually turned to soft and yellow stools. On July 11st and 12th, the stool samples were microscopically observed and both tested positive for suspected Balantidium coli. After consultation with the Yongcheng Center for Disease Control and Prevention, it was confirmed to be B. coli. The patient was adjusted to oral berberine (0.1 g each time, 3 times/d) and metronidazole tablets (0.2 g each time, 2 times/d), and continued to receive nutritional support treatment. On July 13th, the patient’s bowel movements had converted to daily, yellow and soft stools, and no parasites were found under microscopy. On July 18th, the patient was discharged from the hospital after comprehensive treatment, and follow-up observations showed a good prognosis.

A 57-year-old female patient from Lucheng District was admitted to Wenzhou Central Hospital on September 28, 2021. The examination on admission showed the chronic disease face and clear consciousness; the skin and mucous membranes had no yellowish staining nor oedema but were scared. The patient was admitted to the cardiology department with “chest tightness pending further investigation” and was later transferred to the chemotherapy department due to cancerous pleural fluid. The patient had a recurrent fever since October 8. Laboratory tests showed the haemoglobin was 86 g/L, the red blood cell count was 2.74 × 10¹²/L suggesting moderate anaemia. The leukocyte count was 12.7 × 10⁹/L, the absolute neutrophil count was 10.6 × 10⁹/L. The patient also had mildly elevated total and indirect bilirubin; urine culture detects mixed growth of more than 3 bacteria, persistent urinary occult blood 2 +. Wright’s stain of the blood smear was performed on October 25, microscopic examination showed that 1-4 ringlets with purplish-red nuclei and blue cytoplasmic could be found in some red blood cells, which was considered to be a parasitic infection. The patient was a long-term resident of urban Wenzhou with no history of domestic or international travel, and no clear history of tick bites. The patient underwent breast-conserving surgery for left breast cancer in 2005, received chemotherapy and targeted drug therapy for multiple lung metastases between 2014 and 2021 and had 12 blood transfusions from June to October 2021. The PCR product of blood DNA amplificated by primers specific to Babesia was sequenced and identified with 99.43% homology to B. microti (GenBank accession: MG674832.1). The diagnosis of Babesia microti infection was confirmed. The patient was treated with oral chloroquine phosphate tablets (0.5 g/d, double the first dose for 5 d) and intravenous clindamycin (600 mg/d + saline 500 ml intravenously for 10 d), with some relief of symptoms, and parasites were still detected on microscopic examination after 5 days. The symptoms of high fever, jaundice and haemolysis caused by Babesia infection somewhat exacerbate the progression of terminal-stage cancer. On November 8, the patient died of multi-organ failure and unsuccessful resuscitation.

Emerging infectious diseases (EIDs) are either newly emerging or previously existing infectious diseases that are experiencing a rapid increase in incidence or geographic spread. The risk of EIDs outbreaks and pandemics is escalating due to factors such as climate change, pathogen evolution. Outbreaks of EIDs, like coronavirus disease 2019 (COVID-19), have significantly impacted on global health, the economy, and social stability. Such global pandemics not only directly affect human health but also negatively impact on economic development, poverty reduction, and education. To tackle the challenges of EIDs, organizations at national and international levels have adopted a series of comprehensive prevention and control strategies, including reducing the risk of pathogen spillover, establishing comprehensive detection and early warning systems, and promoting cross-sectoral collaboration and sharing information with other departments, and implementing the One Health concept for cross-sectoral prevention and control. This article summarizes the challenges posed by EIDs pandemics, the prevention and control strategies at the national and international levels, the current progress, and specific cases to provide a reference for future responses to EIDs pandemics.

Objective To understand the epidemic situation of echinococcosis in Qinghai Province, to provide the scientific basis for optimization of prevention and control measures. Methods Echinococcosis surveillance was performed among residents, primary school students, intermediate hosts, definitive hosts, and questionnarire survey was conducted for primary school students in 39 echinococcosis endemic counties in Qinghai Province in 2020 (32 in typeⅠ and 7 in type Ⅱ). One or several nearby administrative villages (natural villages) were randomly sellected from each surveillance county as the surveiooance sites, each of which will not be repeated within 5 years. No less than 1 000 residents were surveyed at each surveillance, and examined using abdominal ultrasonography. From places near the surveillance site in the county, 1-5 primary schools were selected, in which all students in Grades 1 and 6 were examined by abdomen ultrasound scanning, with at least 500 students being examineds. A total of 300-500 cattle or sheep raised in the county were sampled from the surveillance county’s centralized slaughterhouse, and examined by inspection with naked eyes or palpation on the cystic matter or hard nodule of liver and the lung, with which autopsy was followed to determine Echinococcus infection. In each surveillance county with endemic alveolar echinococcosis, ten areas having people’s activity were selected to catch small rodents. From each selected area, no less than 50 animals were examined by dissection of livers and lungs to determine Echinococcus multilocularis infection. Ten dog owners were randomly selected from each administrative village in all epidemic townships in the surveiooance county to collect fresh domestic dog feces sample, one from each owner, while in type Ⅰ endemic county additional fecal samples of stray dogs and wild canines were collected. The Echinococcus antigen was detected using dog coproantigen detection kit. A questionnaire survey on echinococcosis prevention and control knowledge and behavior was undertaken in students of several classes selected from grade 3 to grade 6 in the schools under surveiooance scheme, with no fewer than 300 persons being surveyed in each county. Results In 2020, a total of 73 191 individuals in Qinghai Province were investigated by B-ultrasound, and 294 patients were with echinococcosis positive (including 5 new cases), with an overall prevalence of 0.40%. The prevalence in local residents and school children was 0.59% (276/46 922) and 0.07% (18/26 269), respectively. The residents and school children in type Ⅰ endemic counties had a prevalence rate of 0.70% (276/39 364) and 0.08% (18/22 646), respectively. There were no echinococcosis patients among type Ⅱ inhabitants or primary school students, showing a significant difference in the prevalence of echinococcosis between type Ⅰ and Ⅱ endemic counties (χ² = 53.32, P < 0.01). A total of 11 626 domestic animals were examined, and the total echinococcosis infection rate was 0.55% (64/11 626). The infection rate among sheep was 0.28% (18/6 491) and that among cattle was 0.89% (46/5 135). A total of 7 121 small rodents were investigated in the alveolar echinococcosis endemic county, and the infection rate of E. multilocularis was 0.38% (27/7 121). The positive rate of Echinococcus coproantigen was 0.54% (208/38 496) in 38 496 domestic dog feces samples. The positive rates of domestic dogs in type Ⅰ and Ⅱ endemic counties were 0.63% (177/27 882) and 0.29% (31/10 614), respectively, and the difference was not significant (χ² = 0.07, P > 0.05). A total of 7 253 fecal samples from stray dogs and wild canines were examined, and found coproantigen positive rate was 0.65% (47/7 253). Among them, the positive rates in type Ⅰ and Ⅱ endemic counties were 0.63% (43/6 853) and 1.00% (4/400) respectively, and the difference was not statistically significant (χ² = 0.82, P > 0.05). A total of 12 216 primary school students participated in the questionnaire survey. The awareness rate of knowledge on echinococcosis prevention was 97.8% (11 944/12 216), and the excellent rate was 88.6% (10 827/12 216). The awareness rates among students in type Ⅰ and Ⅱ endemic counties were 97.7% (9 865/10 096) and 98.1% (2 079/2 120) (χ² = 1.01, P > 0.05), and the excellent rates were 89.0% (8 986/10 096) and 86.8% (1 841/2 120) (χ² = 8.16, P < 0.01), respectively. The analysis of endemic situation of echinococcosis in different topographic areas of type Ⅰ endemic counties in Qinghai Province showed that the prevalence in people of Qingnan area, Qaidam Basin, arround the lake area and Hehuang Valley were 1.00% (261/25 980), 0.22% (21/9 354), 0.06% (10/17 200) and 0.02% (2/9 446). There was significant difference in the prevalence among residents in the four topographic areas (χ² = 271.31, P < 0.01). The positive rate of Echinococcus coproantigen from domestic dogs was 0.56% (34/6 043), 0.92% (21/2 283), 0.94% (62/6 613), and 0.46% (60/12 943) in the Qingnan area, Qaidam Basin, arround the lake area, and Hehuang Valley, respectively. The positive rate of coproantigen differed significantly between the area around the lake and Qingnan, Hehuang Valley, Qaidam Basin, and Hehuang Valley (χ² = 5.90, 15.86, 7.64; P < 0.05 or P < 0.01). The positive rates of coproantigen in stray dogs and wild canines were 0.75% (24/3 190), 0.38% (3/800), 0.72% (13/1 812) and 0 (0/1 051), respectively. There were significant differences in the positive rates of fecal antigen between street dogs and wild canines in Qingnan area, around the lake area and Hehuang Valley (χ² = 7.95, 7.58, P < 0.01). The infection rate of cattle in Qaidam Basin was the highest at 1.71% (12/700), which was significantly different from that in Qingnan area 0.87% (20/2 307) and around the lake area 0.57% (7/1 228) (χ² = 4.22, 6.58, P < 0.05). Alveolar echinococcosis endemic counties are mainly distributed in Qingnan area and around the lake area, where the infection rate of Echinococcus in small rodents was 0.39% (24/6 121) and 0.60% (3/500), respectively (χ² = 0.49, P > 0.05). Conclusion Both echinococcosis patients and new cases in Qinghai Province are distributed in typeⅠendemic counties in southern Qinghai Province, and the transmission cycle has not been entirely interrupted. The risk of infection in the population remains.

Objective To understand the epidemic situation of visceral leishmaniasis in China in 2022 and provide scientific basis for formulating prevention and control strategy. Methods Data of visceral leishmaniasis in 2022 was collected from the web-based National Infectious Diseases Reporting Information Management System. After excluding suspected cases, duplicates and cutaneous leishmaniasis cases, a visceral leishmaniasis database was established and underwent descriptive epidemiological analysis with Microsoft Excel 2016. Results A total of 239 cases of visceral leishmaniasis were reported in 104 counties of 11 provinces (autonomous regions and municipalities) in 2022, among them 191 cases were reported from mountain-type zoonotic visceral leishmaniasis endemic areas, 4 cases from desert-type zoonotic visceral leishmaniasis endemic areas, 2 cases from anthroponotic visceral leishmaniasis endemic areas and 42 cases were imported from non-endemic areas. These cases were mainly distributed in Shanxi (110 cases), Shaanxi (34 cases), Henan (23 cases) and Hebei (23 cases), the total reported accounting for 79.30% (190/239) of the overall total in China. A total of 197 local transmitted cases were reported from 42 endemic counties and other 63 counties were of non-endemic areas, reporting 39 imported cases. Pingding County, outer suburbs of Yangquan City, Jingxing County and Huazhou District were the major endemic counties with 25, 15, 16 and 10 cases reported respectively, the total accounting for 27.62% (66/239) of the overall total cases in China. Recurrence endemic counties of visceral leishmaniasis were mainly concentrated in Shanxi (Qinshui County, Gaoping City, Fushan County, Houma City, Yicheng County, Jiangxian County, Yuanqu County, Wenshui County), Hebei (Mining district of Jingxing County, Zanhuang County, Lincheng County, Xindou District), Henan (Yanshi District, Shangjie District, Qibin District), Beijing (Changping District) and Xinjiang (2th regiment farm) in 2022, with a total of 23 local cases reported. The peak incidence occurred in July. The ratio of male to female cases was 1 ∶ 0.38. Farmers, infants and young children are the high-risk population of visceral leishmaniasis, accounted for 53.97% (129/239) and 16.74% (40/239) of the total cases respectively. The reported cases at age of ≥ 15 accounted for 81.17% (194/239). Conclusion Visceral leishmaniasis is at a low prevalence status in China, whereas the endemic area is gradually expanding, and the number of cases is gradually increasing in mountain-type zoonotic visceral leishmaniasis endemic area.

Objective To investigate the regulatory effect of galectin-receptor interaction on the small intestine immunopathology of Toxoplasma gondii-infected mice. Methods Eighteen female BALB/c mice were randomly divided into 4 groups: 4 mice in uninfected group (naive group), 4 mice in lactose group (lactose group), 5 mice in T. gondii infection group (Tg group) and 5 mice in T. gondii infection + lactose group (Tg+lactose group). Each mouse in the Tg group and the Tg+lactose group was intraperitoneally (i.p.) injected with 1 000 tachyzoites of T. gondii RH strain, while the naive group and lactose group were i.p. injected with 0.2 ml PBS. Starting from day 0 post infection, each mouse in the Tg+lactose group and the lactose group was i.p. injected with 0.2 ml 0.2 mol/L of lactose, while each mouse in the naive group and the Tg group was i.p. injected with an equal volume of PBS, once in the morning and once in the evening for 7 consecutive days. After infection with T. gondii, the mice survival time in each group was recorded. The mice were euthanized on the 7th day after infection to collect middle segment of jejunum from each mouse for prepareing paraffin sections, which were stained with hematoxylin and eosin (HE) to observe the pathological changes; from the lower segment of jejunum of each mouse, total RNA was extracted and reverse-transcribed, and used in quantitative real-time reverse transcription PCR (qRT-PCR) with β-actin as an internal reference gene to detect the relative mRNA expression level of surface antigen 1 (SAG1), galectin-3, galectin-9, T cell immunoglobulin mucin 3 (Tim-3), leukocyte differentiation antigen 137 (CD137), interleukin 12 (IL-12), interferon-γ (IFN-γ), IL-10, IL-4, transforming growth factor β (TGF-β), chemokine receptor 2 (CCR2) and chitinase 3 like molecule 3 (Ym1). Results After infection with T. gondii, there was no mice died in the naive group and the lactose group. The survival time of the mice in the Tg group was 182-188 h, and the survival time of the mice in the Tg+lactose group was 180-182 h; the difference of the survival time between the two groups was statistically significant (χ² = 19.52, P < 0.05). HE staining showed no inflammation in the mice jejunal tissue in the naive group and lactose group. Shortened intestinal villus, shallower intestinal crypts, necrosis of epithelial cells at the top of villi and inflammatory cell infiltration in the intestinal mucosa were observed in the mice small intestine from the Tg group and Tg+lactose group. Compared with the Tg group, the pathological change of the mice small intestine in the Tg+lactose group was more severe. The qRT-PCR results showed that the relative mRNA expression of SAG1 in the mice small intestine of the Tg+lactose group was 9.17 ± 1.65, which was higher than that in the Tg group (1.00 ± 0.84, t = 4.40, P < 0.05). The relative mRNA expression levels of galectin-3 in the mce small intestine of the naive group, lactose group, Tg group, and Tg+lactose group were 1.00 ± 0.28, 1.71 ± 0.31, 2.46 ± 1.11, and 7.10 ± 1.57, respectively (F = 10.15, P < 0.01). The mRNA expression levels of galectin-9 in the 4 groups were 1.00 ± 0.31, 1.44 ± 0.26, 3.21 ± 1.01, and 7.00 ± 1.08, respectively (F = 14.53, P < 0.01). The mRNA expression levels of Tim-3 in the 4 groups were 1.00 ± 0.12, 0.88 ± 0.28, 1.64 ± 0.31, and 4.89 ± 0.69, respectively (F = 19.15, P < 0.01). The mRNA expression levels of CD137 in the 4 groups were 1.00 ± 0.42, 1.03 ± 0.30, 0.89 ± 0.11, and 3.84 ± 0.77, respectively (F = 8.46, P < 0.01). The mRNA expression levels of IL-12 in the 4 groups were 1.00 ± 0.35, 1.14 ± 0.56, 12.37 ± 4.43, and 18.42 ± 3.89, respectively (F = 10.18, P < 0.01). The mRNA expression levels of IFN-γ in the 4 groups were 1.00 ± 0.56, 1.65 ± 0.53, 5.57 ± 1.84, and 21.26 ± 6.48, respectively (F = 10.38, P < 0.01). The mRNA expression levels of IL-10 in the 4 groups were 1.00 ± 0.20, 1.10 ± 0.25, 8.65 ± 2.52, and 21.98 ± 3.96, respectively (F = 20.84, P < 0.01). The mRNA expression levels of IL-4, TGF-β, and CCR2 in the mice small intestine among the naive group, lactose group, Tg group, and Tg+lactose group had no statistically significant differences (F = 1.09, 4.74, and 2.03, P > 0.05). Ym1 mRNA expression was not detected in the naive group and lactose group, and Ym1 mRNA expression levels between the Tg group and the Tg+lactose group had no statistically significant difference (t = 0.24, P > 0.05). Conclusion Blockage of galectins-receptor interaction in mice infected with T. gondii leads to increased parasite burden in small intesting tissues, and aggravated pathological impairment, as well as upregulated expression of galectin-3, galectin-9, Tim-3, CD137, IL-10 and IFN-γ.

Objective This study investigates the effect of thioredoxin peroxidase (TPx) in the excretory-secretory antigen (ESA) of Cysticercus cellulosae on activation of dendritic cell (DC) in piglets. Methods Healthy piglet medulla-derived DC were cultured in vitroo, in which lipopolysaccharide (LPS) was added at a final concentration of 100 ng/ml on 7 d for stimulation for 2 days, and then continuously cultured for 2 more days to collect immature DC (imDC) and mature DC (mDC) separately. The morphological changes of DCs were observed by light microscopy and scanning electron microscopy on 1 to 9 d of culture. The expression of surface markers CD1 and major histocompatibility complex (MHC-Ⅱ) was detected by flow cytometry. The 7 d imDC was used in the assay with the assigned groups of negative control, TPx, ESA and LPS positive control, to which RPMI 1640 medium, TPx (50 μg/ml), ESA (50 μg/ml) and LPS (100 ng/ml) was added, respectively, to stimulate for 48 h for examining the expression of DC surface markers MHC-Ⅱ, CD80 and CD86 using flow cytometry and for detecting secretion levels of tumor necrosis factor-α (TNF-α), interleukin (IL-6), IL-10, IL-12 in DC culture supernatant by ELISA. One-way ANOVA was used for comparison between multiple groups, and LSD-t test was used for two-way comparison between groups. Results Under ligth microscope, imDC were ovoid in shape with single form at the first day of culture; with the extension of culture time, DC increased in size, appeared pseudopods and spines and other features, and changed from ovoid to irregular shape. Scanning electron microscopy showed that compared with imDC, mDC had irregular morphology, roughly long shuttle shape, and numerous protrusions of different lengths radiating from the cytosol, which were distributed in a dendritic pattern, a typical dendritic structure. Flow cytometry showed that the expression of CD1 and MHC-Ⅱ in imDC was (0.113 ± 0.005)% and (0.430 ± 0.016)%, respectively, which was lower than that of mDC (21.400 ± 0.327)% and (21.333 ± 0.450)% (t = 130.341, 92.906, both P < 0.05). The expression levels of MHC-Ⅱ, CD80, and CD86 in the TPx group were (15.300 ± 0.245)%, (22.900 ± 0.374)% and (13.033 ± 0.249)%, respectively, which were lower than those in the LPS positive control group (19.000 ± 0.374)%, (31.600 ± 0.082)%, and (21.300 ± 0.245)% (t = 11.53, 46.32, 43.84, all P < 0.05) and the ESA group (18.365 ± 0.618)%, (40.400 ± 0.356)% and (30.300 ± 0.283)%] (t = 9.55, 93.17, 91.57, all P < 0.05). The MHC-Ⅱ expression level in the TPx group was higher than that of the negative control group (12.133 ± 0.492)% (t = 9.87, P < 0.05). ELISA results showed that IL-6 level in DC of the TPx group was 15.682 ± 0.660, which was ower than that of 21.041 ± 0.901 in the control group (t = 6.51, P < 0.05); TNF-α (35.711 ± 4.196), IL-6, IL-10 (22.216 ± 1.357) and IL-12 (16.799 ± 0.523) were all lower than those of the LPS positive control group 169.037 ± 7.823, 42.118 ± 1.932, 34.730 ± 1.772, 52.504 ± 2.431 (t = 36.79, 32.09, 13.09, 35.05, all P < 0.05); IL-12 level were lower than that of the ESA group at 23.854 ± 1.020 (t = 6.93, P < 0.05). Conclusion TPx mediates immune tolerance by inducing high expression of DC surface molecules MHC-Ⅱ, low expression of CD80 and CD86, and reducing the secretion levels of IL-6.

Objective To develop a method for rapid detection of Clonorchis sinensis metacercaria based on the polymerase chain reaction (PCR) technology combined with clustered regularly interspaced short palindromic repeats-associated 12a protein (CRISPR/Cas12a). Methods PCR amplification was performed using internal transcribed spacer (ITS) primers with the C. sinensis genomic DNA as template. The CRISPR reaction system was prepared by mixing PCR amplification product, Cas12a protein, CRISPR-derived RNA (crRNA), and single stranded DNA (ssDNA) reporter molecule, subsequently, the mixture was observed under ultraviolet light to verify the feasibility of the detection system, in which the ssDNA reporting molecule concentration was optimized by designing 5 gradients (100, 200, 300, 400, 500 nmol/L), and the Cas12a/crRNA ratio was optimized by formulating 5 proportional gradients (1.0 : 1, 1.5 : 1, 2.0 : 1, 2.5 : 1, 3.0 : 1) while maintaining crRNA concentration at 50 nmol/L, while the fluorescence signals were detected by using a fluorescence quantitative PCR instrument. The sensitivity of the detection system was evaluated through PCR and CRISPR reaction using the recombinant plasmid diluted to 10 different concentrations (10^-2-10⁷ copies/μl) to examine the reacted fluorescence signal. In addition, the genomic DNA extracted from C. sinensis metacercaria, Metorchis orientalis metacercaria, Spirometra erinaceieuropaei plerocercoid, Anisakis pegreffii and Taenia asiatica used as the template to assess the specificity of the detection system through PCR and CRISPR reaction, judged by checking the fluorescence signal. Samples of small-sized freshwater fish flesh from the clonorchiasis endemic area was examined by microscopy on crushed smears, from them 8 types of mixed infection were separately selected: the samples infected with mixed metacercaria of C. sinensis, M. orientalis and unknown species, metacercaria of C. sinensis and M. orientalis, C. sinensis and unknown species, M. orientalis and unknown species, C. sinensis alone, M. orientalis alone, metacercaria of unknown species alone, and none cercaria infection. These selected sample were used to extract DNA respectively for performing PCR-CRISPR/Cas12a detection, of which the reaction results were observed under ultraviolet light. The data was analyzed by using software GraphPad Prism 9.0 to perform one-way ANOVA. The comparison between groups was analyzed using graph based multiple test. Results The complete PCR-CRISPR/Cas12a detection system was able to generate fluorescence signal under ultraviolet light. When the reported molecular concentration of ssDNA is 400 nmol/L, the average fluorescence value of the reaction system is (40 786 ± 1 758) AU, which is higher than (32 029 ± 2 651) AU at the level of 300 nmol/L (P < 0.05), but no statistically significant difference (P > 0.05) was found when compared with the vlaue of (42 698 ± 4 260) AU at the level of 500 nmol/L. Therefore, the reported molecular concentration of ssDNA was 400 nmol/L. When the Cas12a/crRNA ratio was 2.0 : 1, the average fluorescence value of the reaction system was (48 950 ± 3 723) AU which was higher than (37 700 ± 3 887) AU with the ratio of 1.5 : 1 (P < 0.05) and no statistically significant difference (P > 0.05) compared to (55 630 ± 3 110) AU with the ratio of 2.5 : 1. Thus, the Cas12a/crRNA ratio was selected as 2.0 : 1. When the concentration of the recombinant plasmid was 10^-1 copies/μl, the fluorescence value of the reaction system was (39 336 ± 7 231) AU, which showed a statistically significant difference compared to the negative control (2 216 ± 743) AU (P < 0.05); when the concentration decreased to 10^-2 copies/μl, the average fluorescence value was (5 451 ± 1 957) AU, which had no statistically significant difference with that of the negative control (P > 0.05). The results of PCR showed that ITS primers could simultaneously amplify 5 kinds of genomic DNA of C. sinensis, M. orientalis, S. erinaceieuropaei, A. pegreffii, and T. asiatica. The CRISPR detection results of the same amplification products showed that only the reaction system using the genomic DNA of C. sinensis as a template generated fluorescence signals under ultraviolet light. The results of PCR-CRISPR/Cas12a detection showed that fluorescence signals were observed in four tubes containing C. sinensis metacercariae in the reaction system of 8 types of fish sample infected with the different metacercaria. Conclusion This study established a PCR-CRISPR/Cas12a method for detection of C. sinensis metacercaria, and the method is highly sensitive, specific and modularized, with significant potential for field application.

Objective To establish a rolling circle amplification (RCA) method for detection of Cysticercus pisiformis infection in rabbits. Methods The novel-miR1 derived from C. pisiformis in rabbit serum served as the diagnostic target to establish an RCA diagnostic method for cysticercosis pisiformis fection in rabbit. To establish the RCA method, ligation sequence and the locking probe sequence were designed, and five important reaction conditions were optimized, including the ratio of ligation sequence and padlock probe, ligation reaction time, ligase dosage, amplification reaction time, and dNTP dosage. The sensitivity of the RCA method was assessed, the novel-miR1 standard was serially diluted into 9 samples of different concentrations ranging from 1 fmol/L to 100 nmol/L. The sensitivity and specificity of the optimized RCA methods were assayed using the serum miRNA from 20 healthy rabbits and 20 C. pisiformis infected rabbits (Laboratory preserved samples), and analyzed by the receiver operating characteristic curve (ROC curve) method. To evaluate the application effectiveness of the RCA, 20 female rabbits were infected by gavage with 1 000 eggs of T. pisiformis for collection of serum every month post-infection, which were used to prepare miRNA for application in RCA method under optimized condition. Results The agarose gel electrophoresis results showed that the RCA amplification products remained in the sampling wells of agarose gel, forming a bright band. The tests to optimize RCA condition indicated that the concentration of ligation sequence was 2 μmol/L, padlock probe was 1 μmol/L (ratio of ligation sequence and padlock probe was 2∶1), T4 DNA ligase was 350 U, and the efficacy of ligation reaction was found the highest when ligating for 180 min. The optimal amplification reaction system was 0.5 μmol/L dNTP and amplification reacted 240 min in 100 μl amplification reaction system. Lastly, the RCA method limit of detection was proved to be 10 pmol/L. The RCA method detected showed that the average serum miRNA fluorescence intensity of the samples from healthy rabbits and C. pisiformis infected rabbits were 53.298 ± 1.707 and 97.498 ± 5.892, respectively, which was statistically significant (t = 7.206, P < 0.01). ROC curve showed that the RCA method cut-off value was 61.69 and both sensitivity and specificity were 95%, the area under the curve (AUC) is 0.955 0, likelihood ratio was 19.00. Using the RCA method to detect 20 healthy rabbits’ serum miRNA found 19 samples were negative and 1 positive. The results of RCA detection of the C. pisiformis infected rabbits serum miRNA at different times found that 17 were positive, 2 were suspected, 1 were negative 1 month post-infection. One was negative, and 19 were positive 2 mouths post-infection. Three were negative, and 17 were positive 3 months post-infection. Conclusion An RCA method was established for detecting C. pisiformis infection in rabbits. It was demonstrated that novel-miR1 could be detected by RCA in the serum of rabbits within 3 months post-infection of C. pisiformis, showing good application potential.