Malaria is one of the oldest and most severe infectious diseases in China. After over 70 years of comprehensive control and prevention measures, great achievements have been made in malaria control in China, with a remarkable decline in morbidity and mortality. The malaria epidemic has been controlled effectively, ensuring people’s health, reducing the poverty due to illness, and promoting social and economic development. The milestone achievements in elimination of indigenous malaria cases nationwide has been maintained for 4 consecutive years since 2017, and thereafter the World Health Organization certificated malaria elimination in China on June 30, 2021, which is a significant milestone in the public health in China and the global history of malaria elimination. This paper systematically reviews the great impacts, performance characteristic and experiences gained from malaria elimination program, and the challenges in post-elimination stage in China.

Toll-like receptor 7 (TLR7) is a pattern recognition receptor mainly expressed in the endoplasmic reticulum of the resting immune cells including plasmacytoid dendritic cell, mononuclear macrophages, T lymphocytes, neutrophils and non-immune cells including epithelial cells, endothelial cells and keratinocytes. During an infection, TLR7 is translocated to the endosome membrane from endoplasmic reticulum of the host cells. TLR7 can directly recognize single-stranded RNA or nucleic acid analogs and bind to specific recruiting proteins to activate nuclear factor-κB, mitogen-activated protein kinase and interferon regulatory factors, which eventually triggers the innate or adaptive immune response against an infection. Here we have reviewed the structure and function of TLR7 and its ligand, the role of TLR7 against an infection and its signaling pathways to provide the scientific basis for further studies of TLR7 in infection and immunity.

Pneumocystis jirovecii, an opportunistic pathogenic fungus, may cause severe pneumocystis pneumonia (PCP), especially in immunodeficient patients. Pneumocystis was initially classified as a protozoan, named P. carinii. However, it was phylogenetically reclassified as an atypical fungal pathogen at late 1980s, which was confirmed with genetic sequence analyses, using molecular biology techniques. Due to lack of in vitro culture method, it has been difficult to clearly understand the patho-biological and epidemiological characteristics of Pneumocystis. With the wide application of molecular biology techniques, genotyping method for Pneumocystis has been extensively developed in recent years, however, no international standardization and global consensus on the genotyping scheme has been reached, hindering the investigation of epidemiology, population structure, source of infection, transmission characteristics of the clinical isolate of P. jirovecii, and in turn impeding the studies on the pathogenesis and control strategy of PCP. This review summarizes the progress in research on the genotyping approaches for P. jirovecii, in commemorating the 20th anniversary of its renaming.

With the acceleration of globalization, increased migration, the rapid development of international trade and tourism, and the intensified environmental changes, complex health problems and the resulting public crises frequently occur, which population health at serious risk as well as the animals and plants. People became aware of the close connections between human health, animal health, and the ecological system, from which the new concept and connotation of health have emerged. Under the guidance of this new concept, starting from a holistic view of “human-animal-environment” health, and with multi-institutional, interdisciplinary, and cross-regional collaboration, people began to use the theory of One Health to solve complicated health problems. In this paper, we systematically expound the One Health concept from three levels: the origin, connotation and prospect, and propose a framework of One Health connotation system to explore the ways to achieve One Health and predict the future direction of One Health.

Objective To understand the endemic status and characteristics of soil-transmitted nematode infection in China in 2019 to provide data support for developing control strategies. Methods Survey was carried out in nationwide surveillance sites (counties) in 31 provinces/municipalities/autonomous regions in China in 2019. A unified sampling method was used in all surveillance sites: each site was divided into five areas geographically (east, west, south, north, and mid part), followed by selecting one administrative village from each area; 200 permanent residents older than 3 years were cluster sampled, resulting in 1 000 residents being surveyed in each surveillance site. Stool samples were collected from survey participants and examined microscopically using the modified Kato-Katz thick smear method (two slide-reading/sample) for parasite eggs, which were counted for estimating infection rate and infection intensity. Infection rates were analyzed using Chi-square test. In addition, soil surveys Ascaris eggs were conducted in 23 provinces/municipalities/autonomous regions, including Beijing, Fujian, and Gansu; one soil sample was collected from farmer’s field or vegetable garden from each of five households randomly selected from each village. From the soill samples, hook worm larvae were identified using 5% salt solution at 45 ℃, while Ascaris eggs were examined by floating method with sodium nitrate solution. A comparative analysis of the infection rates of overlapping surveillance sites in 2019 and 2018 was conducted. Results In total, 424 766 people from 414 nationwide surveillance sites were investigated in 2019, the overall infection rate of soil-transmitted nematodes was 1.40% (5 959/424 766), with the highest found in Sichuan (8.05%, 2 518/31 292), followed by Yunnan (5.30%, 885/16 693) and Chongqing (3.87%, 238/6 149). There was no significant difference between infection rate in males (1.37%, 2 842/207 188) and females(1.43%, 3 117/217 578) (χ ² = 2.84, P > 0.05). The participant group aged ≥ 60 years had the highest infection rate, of 2.51% (2 722/108 260), followed by the 45-59 age group (1.19%, 1 237/104 218) and the 7-14 age group (1.12%, 657/58 556), with statistically significant differences among the age groups (χ² = 1 351.00, P < 0.01). The infection rates of hookworm, Ascaris lumbricoides, and Trichuris trichiura were 0.84% (3 580/424 766), 0.36% (1 528/424 766) and 0.27% (1 126/424 766), respectively, with the majority were of light infection. In 2019, 2 056 soil samples were examined, and found the detection rate of Ascaris eggs and hookworm larvae was 5.79% (119/2 056) and 3.45% (71/2 056), respectively. In 2019, 77 surveillance sites in 25 provinces/municipalities/autonomous regions overlapped with the sites in 2018, where the infection rate was 1.43% in 2019, being compared with 1.42% in 2018, showing no statistically significant difference (χ² = 0.01, P > 0.05). Conclusion The overall infection rate of soil-transmitted nematodes in China in 2019 was at a low level, but provinces with higher infection rate and transmission risk remained, thus continuing surveillance and control are urged.

With the acceleration of globalization, the sustained increase of mobility, the intensification of global warming and environmental changes, the transmission of diseases has become more diverse. In recent years, the corona virus disease 2019(COVID-19) has caused huge economic losses and social unrest around the world. A single-discipline has been unable to solve such complex public health problems effectively. The proposal and development of the One Health approach is closely related to the issues on veterinary medicine and zoonoses. One Health focuses on intradisciplinary, multi-sectoral, and cross-fields collaboration at three levels, including local, regional and global levels, to explore the humans-animals-environment interface complexity. In this review, the development process of One Health approach was introduced. The relationship between the One Health and zoonoses, the role of the One Health in the prevention and control of zoonoses, and how to effectively implement the One Health approach in the real world were explored, providing references for research on zoonoses prevention and control, anti-microbial resistance, food safety, and the impact of climate change on health.

Malaria epidemic data in 31 provinces/municipalities/autonomous regions (excluding Taiwan region, Hong Kong SAR and Macao SAR) of China in 2021 were collected from the Information System for Parasitic Disease Prevention and Control. The epidemiological characteristic of malaria cases was analyzed. In 2021, 799 malaria cases were reported in China, which was declined by 26.4% compared to that in 2020 (1 086). Of these cases, 798 imported cases and one long incubation case infected with Plasmodium malariae were identified, and no indigenous cases were reported. In addition, 783 cases were of Chinese nationality (98.0%, 783/799) and 16 cases were of foreign nationality (2.0%, 16/799). Most of the cases were within the age range of 30-49 years (55.7%, 445/799), with a male-to-female ratio of 14.4 ∶ 1. The reported cases included 390 cases of P. falciparum infection (48.8%, 390/799), 182 cases of P. vivax infection (22.8%, 182/799), 187 cases of P. ovale infection (23.4%, 187/799), 31 cases of P. malariae infection (3.9%, 31/799) and 9 cases with mixed-infection (1.1%, 9/799). The cases were reported from 31 provinces/municipalities/autonomous regions, with the top 5 provinces of Guangdong, Yunnan, Shanghai, Sichuan and Zhejiang, from which 480 cases (60.1%, 480/799) were reported. Totally 3 deaths were reported from Liaoning (1 case), Zhejiang (1 case) and Guangdong (1 case) provinces, which was decreased by 3 cases compared to 6 deaths in 2020. Noticeably, there have been no reported cases of of indigenous mosquito-borne malaria in China for consecutive five years. Nevertheless, it is imperative to continuously strengthen the surveillance on imported malaria and border malaria to prevent malaria re-introduction and consolidate the achievements of malaria elimination in China.

Historically, the ultimate control and elimination of infectious diseases were all attributed to the inoculation of vaccines. For more than 60 years, scientists have never stopped their efforts on developing effective malaria vaccines. Recently, clinical trials on subunit vaccine RTS,S and attenuated sporozoite vaccine have shedded light on production of a safe and effective malaria vaccines. However, there are still many technical and theoretical bottlenecks that hinder the final development of effective malaria vaccine. In this paper, we analyze the problems currently encountered in the malaria vaccine development process from the view point of biological and immunological characteristics ofPlasmodium spp., in the hope to provide clues and directions for the ultimate development of effective malaria vaccines.

Schistosomiasis is distributed worldwide and listed as one of the neglected tropical diseases by the World Health Organization. Although many countries have made certain achievements in the prevention and control of schistosomiasis, there are still many challenges for global elimination of the disease due to the complex life cycle of schistosomes, limited health resources, and unitary prevention and control measure. This review systematically summarizes the current status of global schistosomiasis epidemic, the goals, main strategies and measures for prevention and control, analyzes the current challenges and proposes pertinent recommendations, in order to provide reference for the professionals in schistosomiasis control and management.

Objective To compare the effects of the 36-item short form health survey (SF-36) and the five-level EuroQol five-dimensional questionnaire(EQ-5D-5L) on the quality of life of patients with advanced schistosomiasis. Methods A total of 125 patients with advanced schistosomiasis were selected from two hospitals in Jiaxing City in 2020, and the general information of the patients was collected, including name, sex, age, and clinical classification of advanced schistosomiasis. The SF-36 and EQ-5D-5L scales were used in questionnaire; investigate the quality of life of patients with advanced schistosomiasis, the reliability and validity of the two scales in evaluating the quality of life of patients with advanced schistosomiasis, and the degree of differentiation in patients with different health levels were compared. The correlation between the scores of the two scales and the factors influencing patient scores were also analyzed. Results The 125 patients with advanced schistosomiasis ranged in age from 47 to 93 years, with an average age of (75.04 ± 7.53) years. There were 46 males (36.80%) and 79 females (63.20%). There were 54 cases (43.20%) of splenomegaly type and 71 cases (56.80%) of ascitic type. The Cronbach’s α coefficient of internal coherence in SF-36 was 0.780 and two factors were extracted by principal component analysis, with a cumulative contribution rate of 70.427%. The Cronbach’s α coefficient of EQ-5D-5L was 0.850 and two factors were extracted by principal component analysis, with a cumulative contribution rate of 85.884%. Among the dimensions of SF-36, the highest average score was on mental health (66.82 ± 7.90), and the lowest scores were on role physical (0) and role emotional (0); the average score of physical component summary (PCS) was(33.85 ± 8.92) and mental health measurement (MCS) was(39.76 ± 4.93), and number of patients with higher MCS score were higher than those with PCS. The average EQ-5D-5L utility index (UI) score was (0.801 ± 0.214). The patients with the dimension of "pain or discomfort" presenting “moderate difficulty, severe difficulty and extreme difficulty” accounted for highest proportion of 24.80%, and the dimension “anxiety or depression” lowest proportion of 5.60%. The average score on visual analogue scale (EQ-VAS) was 66.64 ± 7.85. The age of the patients showed significant influence on the scores of PCS, MCS and EQ-VAS (P < 0.01), but there was no significant difference in the scores of different gender and clinical classification of the patients (P > 0.05). The UI score and EQ-VAS score of those with higher PCS and MCS scores were higher than those with lower PCS and MCS scores (P < 0.01). With the increase of the severity of each dimension of EQ-5D-5L, PCS and MCS scores of patients decreased. PCS was correlated with UI and EQ-VAS scores (r = 0.716, 0.689, P < 0.01), and MCS was correlated with UI and EQ-VAS scores( r = 0.622, 0.544, P < 0.01). Conclusion Both SF-36 and EQ-5D-5L can be used to evaluate quality of life of patients with advanced schistosomiasis, and the assessment outcomes are comparable and complemental. However, as EQ-5D-5L advantages with higher reliability, validity and simpler system structure, thus is more suitable for evaluation of quality of life of patients with advanced schistosomiasis.

Trichomonas vaginalis is a type of flagellated protozoan and the most common sexually transmitted pathogens in the world. T. vaginalis mainly parasitizes in the female vagina, leading to trichomonal vaginitis. In addition, T. vaginalis can also infect males, and the parasites may retrograde to the bladder, prostate, seminal vesicle, testis, epididymis and other tissues, through the urogenital tract, thus causing serious damage to sperm cells or other tissues; causing urethritis, prostatitis, prostate cancer, asthenospermia or azoospermia, eventually affecting the male fertility. However, T. vaginalis infection in males often presents mild or no clinical symptoms, resulting in ignorance of the infection. In this paper, we review the related mechanisms underlying the T. vaginalis infection-induced abnormal sperm, testicular and prostate functions, and thereby male infertility.

Objective To study the induction of neutrophil extracellular traps (NETs) by Giardia lamblia using qualitative and quantitative methods. Methods Neutrophils were collected from blood samples of a healthy participant by using isolation reagent kit, and cultured with G. lamblia (4 × 10⁵/ml) in M199 medium for 30, 60, 120, 180 or 240 min. The concentration of double-stranded DNA (dsDNA) in the supernatant at the defined time points was determined by PicoGreen staining method. The concentration of myeloperoxidase (MPO) in the supernatant was assayed by ELISA. In the test group designed, 200 μl of neutrophils was added with 200 μl of G. lamblia (both 4 × 10⁵/ml) into 24-well plates and cultured at 37 ℃ for 4 h. Neutrophils producing extracellular trap nets were double-stained with anti-H3Cit and anti-MPO fluorescence. For visualization, DNA was labeled with blue fluorescence, citrullinated histone H3 protein was labeled with green fluorescence, and MPO was labeled with red fluorescence. Laser confocal microscopy was used to observe the formation of NETs. The positive group was set by using the neutrophils treated with 100 nmol/L phorbol ester, while the negative control group was the untreated neutrophils. SPSS software was used for statistical analysis, and the experimental data were analyzed with independent sample t-test. Results The purity of neutrophils isolated from the blood was over 75%. The neutrophils with rod-shaped or lobulated nuclei could be observed under a microscope. The fluorescence intensities after mixing the neutrophils with Giardia (4 × 10⁵/ml) for 30, 60, 120, 180, and 240 min were 7.30 ± 1.12, 11.15 ± 1.10, 21.69 ± 2.71, 26.35 ± 2.26, and 29.29 ± 3.27, respectively, while those in the negative control group and the positive control group were 3.79 ± 0.48 and 35.78 ± 2.83, respectively. The level of dsDNA in the supernatant of the test group was higher than that of the negative control group, and the content of dsDNA increased with prolonged culture time(P < 0.05). ELISA results showed that the absorbance related to the MPO content in the supernatant of the negative control group, test group and positive control group were 0.209 4 ± 0.018 2, 0.611 5 ± 0.060 7, and 0.721 7 ± 0.087 9, respectively. The MPO content of the test group was higher than that of the negative control group (P < 0.05). Laser confocal microscopy revealed presence of a reticular substance between neutrophils and Giardia, which was enriched with histone and MPO. Conclusion Giardia trophozoites have the potential to activate neutrophils releasing extracellular traps in vitro.

The spread of COVID-19 has increased the risk of contact transmission between people, and imposes challenges and opportunities for the prevention and control of important parasitic diseases. There may be risks of COVID-19 infection during the implementation of the virus control, including in field investigation and intervention, contacting with fecal samples, or with asymptomatic infected people. Therefore, corresponding prevention and control measures should be taken before and during field investigation, and in sample transportation and detection to prevent the risks effectively. In this paper, the risks and corresponding countermeasures in the above processes are discussed in detail, and the opportunities that COVID-19 brought to the disease control system are also analyzed.

Visceral leishmaniasis once was one of the five parasitic diseases that were a serious public health problem in China. After decades of unremitting efforts, visceral leishmaniasis was eliminated in most endemic areas in the early 1980s. Since the 21st century, the disease has rebounded sharply, and the areas with endemic have been expanding steadily in western China. This review summarized the endemicity of visceral leishmaniasis and the tasks, strategies and measures for visceral leishmaniasis control in China. The challenges and potential approaches for future prevention and control of visceral leishmaniasis are also discussed.

To establish a real-time fluorescence quantitative PCR (qPCR) method for rapid and accurate detection of Leishmania. A pair of specific primers and a Taq-Man probe were designed, based on the conserved sequence of the small circle in kinetoplast of Leishmania, and the DNA of bone marrow samples from positive cases of Leishmania was used as a template for PCR amplification. The amplified product was 83 bp long, and ligated to the pESI-T vector for cloning and sequencing. The sequences were BLAST aligned on GenBank, and found 100% homologous to L. infantum and L. donovani. The plasmids with correct sequences were diluted to 10²-10⁷ copies/μl as the standard sample for qPCR. The obtained standard curve equation was y = 39.23-2.956 x, the amplification efficiency was 117.93%, R² was 0.994, and when the threshold cycle number was 35, the minimum detection limit was 26.98 copies/μl, theoretically less than 1 Leishmania parasite could be detected. The qPCR was used to detect 14 bone marrow and 26 blood samples from leishmaniasis patients, and respective, 1 sample of bone marrow, blood, spleen, lung, lymph node, liver, and kidney from dogs with leishmaniasis, 2 samples of sandfly positive for Leishmania, and 2 samples of Leishmania culture from bone marrow of patient and dog with leishmaniasis, and all had positive results; 56 blood samples from persons with negative Leishmania seroantibodies, 1 DNA sample of each of Salmonella, Shigella, and Bacillus cereus, 4 blood samples from patients with malaria, 1 blood sample from each of patients with toxoplasmosis gondii or paragonimiasis wesleyi, and all had negative results. The method has high sensitivity and specificity, and can be applied to the rapid detection of infection and carrier status of leishmaniasis patients, host animals, and vectors, and can also be used to determine the therapeutic efficacy in patients.

Toxoplasma gondii is an important obligate intracellular pathogenic protozoan with worldwide distribution that may cause zoonotic toxoplasmosis, severely impacting the human health and the economy of animal husbandry. Studies have shown that the type I strain of T. gondii can escape from the killing effect of autophagy in host cells by changing the expression of autophagy-related proteins in the host, while the type Ⅱ and Ⅲ strains of T. gondii can be effectively cleared up or suppressed by the autophagy system of host cells. This review provides an update on the interplay between T. gondii infection and host cell autophagy system and the related molecular mechanisms.

Objective To establish an infection model for Toxoplasma gondii RH strain tachyzoites infection to mouse macrophage cell line RAW264.7, and to define a rapid and efficient method to culture tachyzoites in vitro. Methods The tachyzoites of T. gondii RH strain were purified with a 5 μm filtration membrane after 3 passages in Kunming mice, and then co-cultured with mouse macrophage cell RAW264.7 (ratios to tachyzoites set at 20 : 1, 10 : 1, 1 : 1 and 1 : 5) and human foreskin fibroblasts (HFF) cells (ratio to tachyzoites 1 : 1). The cells without tachyzoites were set as the control group. The co-cultures were observed at 10 min, 0.5 h, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h, 32 h and 48 h under a high-power microscope, and underwent Wright-Giemsa staining to observe the adhesion invasion of tachyzoites. The tachyzoites were inoculated at 1.5 × 10⁶/vial in a RAW264.7 T25 cell culture flask for co-culture. After 80% of pseudomonts were destroyed, the tachyzoites were collected and counted, and the productivity of tachyzoites was calculated. After staining with 0.4% trypan blue dye, the tachyzoite’s survival rate was calculated in the culture system. The harvested T. gondii tachyzoites were further used to infect new RAW264.7 cells, and the tachyzoites at each passage were inoculated at 1 × 10⁶/mouse in five healthy female Kunming mice. Meanwhile, the same amount of tachyzoites at passage 3 were inoculated in five healthy female mice as the control. The survival time of mice inoculated with tachyzoites at each passage was recorded. The statistical software SPSS 21.0 was used for statistical analysis. One-way analysis of variance was used for comparison between groups. Results When the ratio of RAW264.7 cells and tachyzoites was over 10 : 1, the boundary of infected cells turned obscure after infection for 24 h, and the cytoplasm was increased, with increased number of vesicles. After infection for 30 h, a large number of cells died, with no appearance of free tachyzoites. When the ratio was less than or equal to 1 : 1, fine particles could be seen in the cytoplasm within 24 h with no vacuoles. After infection for 30 h, more than 90% of pseudocysts were ruptured, and a plenty of tachyzoites were released into the medium. The completion in vitro development process of tachyzoites could be observed under this conditions. Therefore, tachyzoites were co-cultured with RAW264.7 cells at a ratio of 1 : 1. After infection for 0.5-1 h, about 80% of tachyzoites could invade into RAW264.7 cells, and enter both cytoplasm and nucleus. After 2-4 h, pseudocysts began to form. At 8 h, a part of pseudocysts proliferated into visible chrysanthemum shape. After 24 h, partial pseudocysts began to rupture. After 32 h, the cells were suspended and unable to adhere to the wall, most of pseudocysts ruptured and free tachyzoites were released. The morphology of the newborn tachyzoites was fine. We harvested 6 × 10⁸ tachyzoites, among which, the average live rate was higher than 92%. Tachyzoites were co-cultured with HFF cells, and the tachyzoites basically invaded the cells after 2-4 h; after 8 h, tachyzoites began to divide and proliferate; after 24 h of co-culture, the tachyzoites could divide into chrysanthemum shape; After 36 h, the cells began to burst and the tachyzoites released began a new round of HFF cell attack and infection. All passages of in vitro cultured tachyzoites showed an average lethal time to mice around 3.94-4.10 days, and the virulence of the tachyzoites was not weakened compared with those harvested under in vivo conditions in mice. Conclusion Mouse macrophage RAW264.7 cells could be used to produce large amounts of T. gondii RH tachyzoites quickly in vitro, and the yields are about 400 times of that by the in vivo culture method. Further, the in vitro produced tachyzoites have a comparable virulenc to those obtained by in vivo method, and are superior to those obtained in the HFF cells in the yield time and rate.

Historically, vivax malaria has been dominantly prevalent in Hubei Province, transmitted by the vectors Anopheles sinensis and An. anthropophagus. Two major outbreaks of malaria had occurred in Hubei Province in 1954—1955 and 1967—1973, with the incidence in 1970 reached to high as 602.4/10 000. Over the past 70 years, following the principle of "adapting measures to local conditions, classified guidance and highlighting key points", different comprehensive measures have been applied in Hubei Province, and the incidence of malaria dropped to 0.07/10 000 by 2010. In 2010, Hubei Province launched an action plan to eliminate malaria. Since 2013, no indigenous case has been reported. In 2019, the province passed appraisal of malaria elimination, achieving the goal of malaria eliminated in the whole province. This review summarizes the endemic status of and control efforts for malaria, the course of elimination work, and the challenges encountered, as well as prospects in this regard in Hubei Province.

The apical complex is the typical structure of phylum Apicomplexa which consists secretory organelles and cytoskeletal elements, of which a marked feature is the conoid formed by tubulin fibers. Toxoplasma gondii has a relatively intact conoid, thus, it provides a successful model for analyzing the structure, composition and function of conoid. The stability and relevant activities of conoid are closely related to gliding motility and microneme secretion in of Toxoplasma, and are critical for host cell invasion. In this paper, the structure stability, protein function and regulatory mechanism of conoid are reviewed.

At present, the endemic situation of schistosomiasis is at the lowest level in history in China, and the infection rate has decreased significantly, but there are still a large number of patients with advanced schistosomiasis. Advanced schistosomiasis is the most serious type of schistosomiasis, which seriously endangers the health and quality of life of patients. Liver granuloma and fibrosis caused by Schistosoma eggs are the leading cause for the death of advanced schistosomiasis patients. This article summarizes the pathological mechanism, determine approaches, treatment and prognosis of liver fibrosis in basic and clinical research of advanced schistosomiasis, hoping to provide reference information for future schistosomiasis prevention and treatment.