Wan-Zhong Jia

Cystic echinococcosis (CE), a neglected zoonotic disease caused by Echinococcus granulosus sensu lato , remains a significant public health and veterinary concern worldwide. Despite efforts to develop recombinant protein-based vaccines against EG95, a key protective antigen, existing platforms suffer from limited immunogenicity, short-lived immunity, and complex production processes. Here, we designed and evaluated three novel mRNA-LNP vaccines, including EG95 mRNA-LNP vaccine, IL-4-EG95 mRNA-LNP vaccine encoding EG95 fused with IL-4 via a flexible linker to enhance immune stimulation, and EG95-EC95 mRNA-LNP vaccine that multivalent formulation incorporating EC95 antigens from Echinococcus canadensis . The vaccine candidates were efficiently encapsulated in lipid nanoparticles and demonstrated robust target expression in vitro and in vivo. Immunization induced significantly stronger, more durable humoral and cellular immune responses compared to a commercial EG95 subunit vaccine both in mice and lambs. Notably, high levels of specific antibodies persisted for over 12 months post-vaccination. Parasites infection challenge experiments confirmed that these three mRNA-LNP vaccines, especially the IL-4-EG95 vaccine conferred superior protection, inhibited protoscolex survival and cyst growth. These results highlight the advantages of mRNA-based vaccines in safety, scalability, and flexibility over conventional approaches, offering a promising strategy for controlling E. granulosus sensu lato transmission and reducing the zoonotic burden of CE.

Background: Cystic echinococcosis (CE) is a zoonotic disease caused by the larval stage of Echinococcus granulosus and associated with productivity and economic losses in the livestock population across the world. Objectives: This cross‐sectional study spanned over a period of 1 year (2024) to determine the seroprevalence and associated risk factors of CE in large ruminants (cattle and buffaloes) hosted in different districts of Punjab, Pakistan, using an in‐house developed ELISA. Methods: Overall, 430 serum samples from 197 buffaloes and 233 cattle were collected for detection of anti‐ E. granulosus antibodies using an in‐house ELISA. Results: The highest seropositivity rate (68.24%) was in cattle, whereas buffaloes had 19.28%. The geographical variation revealed that the lowest seropositivity rate (9.52%) was in Haroonabad, whereas Bahawalpur had the highest seropositivity rate (96.29%). Sex‐wise, females showed a seroprevalence of 46.13%, whereas males had a seroprevalence of 37.50%. Age‐wise trends showed that seropositivity increased up to 10–12 years of age, while decreasing in older animals. Breed‐wise, the highest seropositivity rate of 96.29% was observed in the Cholistani cattle, and the lowest rate of 25.25% was shown by Nili‐Ravi buffaloes. The LASSO model revealed a high prediction accuracy of 76.98% and an area under the curve (0.73), suggesting geographical and host‐related impacts on the epidemiology of CE. However, our findings indicate widespread seropositivity, the study does not evaluate production losses or economic impact, and our conclusion refers to epidemiological patterns. Conclusions: There is a prompt need for targeted strategies under the One Health concept for region‐specific surveillance, improving animal husbandry practices and controlling definitive hosts, particularly in high‐risk areas of Pakistan.

Peste des petits ruminants (PPR) is a highly contagious viral disease prevalent in sheep and goats, and causes significant economic losses. The study was conducted in 2024 in Punjab Province, Pakistan, to estimate the seroprevalence of the PPR virus (PPRV) and to analyze animal‐level risk factors in unvaccinated small ruminants. Over a 12‐month period, multistage random sampling provided 722 serum samples of sheep and goats aged 6 months or older, collected across six districts. The anti‐PPRV antibodies were detected using competitive enzyme‐linked immunosorbent assay (cELISA), and species, age, sex, breed, parity, lactation status, pregnancy status, body condition score (BCS), and reproductive history were analyzed using univariable and multivariable logistic regression analyses. The overall seroprevalence rate was 79.77%, but significantly higher in goats (90.27%) than in sheep (68.75% and p < 0.0001). The results demonstrated district wise disparity, with variation in seroprevalence between districts: 52.05% (Okara) and 100% (Nankana). An increased likelihood of seropositivity was found to be associated with male sex, some breeds (Makhi Cheeni and Beetal), certain species‐district interactions, and age‐sex interactions. These data confirm the high endemicity of PPRV in Punjab and justify the targeted vaccination and surveillance in high‐risk areas and among susceptible animal populations.

Echinococcosis is a severe parasitic zoonosis worldwide distribution, caused by the genus Echinococcus. One of its recently identified species, Echinococcus shiquicus, is believed to be endemic to the Qinghai-Tibet plateau in China. Research has confirmed that Tibetan foxes are the definitive hosts for E. shiquicus, while plateau pikas (Ochotona curzoniae) serve as intermediate hosts. In this study, cyst containing protoscolices was first observed in the lung of plateau zokor (Eospalax baileyi) in the Tibetan Autonomous Prefecture of Gannan, Gansu Province, China. This observation was confirmed using complete sequences of the cox1 and nad1 genes. We also characterized the cysts and examined the genetic diversity of Echinococcus shiquicus collected from the Qinghai-Tibet Plateau region, which includes Gansu Province, Qinghai Province, and the Tibet Autonomous Region. Phylogenetic trees and haplotype analyses for the isolates were constructed using the maximum likelihood method in MEGA 7.0.26 and DnaSP v6 software, based on the complete cox1 (1608 bp) and nad1 (897 bp) gene sequences, as well as a concatenated dataset of cox1-nad1 (2505 bp). The cyst containing protoscolices in the lung of plateau zokor was identified as Echinococcus shiquicus. The prevalence of E. shiquicus infection in plateau pikas in Luqu and Maqu counties in Gansu province was found to be 2.38% (3/126) and 3.36% (10/298), respectively, while in plateau zokors, it was 1.61% (1/62). Haplotype analysis, incorporating sequences from previous studies, revealed the presence of 17 haplotypes, indicating significant haplotype diversity in the study areas. The neutrality indices were Tajima’s D = − 1.438 (P > 0.05) and Fu’s Fs = − 3.169 (P > 0.05). This study provides important insights into Echinococcus shiquicus and its associations with plateau zokors and plateau pikas in the Qinghai-Tibet Plateau. We identified plateau zokors as a new natural intermediate host for E. shiquicus, emphasizing the complexity of its transmission dynamics and host interactions within this unique ecosystem. The observed morphological and developmental state differences in cysts between the liver and lung suggest that presence of tissue specificity in different organ. Additionally, the analysis of genetic diversity revealed high intraspecific variability, indicating a complex population structure influenced by various ecological factors.

Cystic echinococcosis (CE), caused by Echinococcus granulosus sensu stricto ( s.s. ), poses a substantial risk to both humans and domestic animals globally. Here, we compared the whole genomes of 111 E. granulosus s.s. samples from China. Genomic variation data revealed frequent cross-fertilization in the hermaphroditic E. granulosus . The G1 and G3 genotypes represent distinct mitochondrial lineages, while showing no differentiation in the nuclear genome, suggesting mito-nuclear discordance caused by historical geographic separation and subsequent fusion. Population structure, demographic history, and gene flow among populations reflected the transmission route of E. granulosus s.s. from the Middle East to Qinghai-Xizang Plateau through the migration of nomadic people, followed by introgression during secondary contact. Genomic variations highlighted selection signatures within the genome prone to balancing selection, particularly impacting genes encoding membrane-related proteins, representing a potential evolutionary strategy for adaptation to parasitic life. Balancing selection pressure on the gene-coding sodium/bile acid cotransporter led to its high level of genetic stability, which may play a crucial role in the survival and development of E. granulosus during the parasitic stage, making it a potential drug target for the treatment of CE. Meanwhile, other genomic regions under strong balancing selection may provide potential targets for protective immunity. These findings offer valuable insights into the complex dynamics and adaptive evolution of E. granulosus s.s. in China. IMPORTANCE: Echinococcus granulosus sensu stricto ( s.s. ) is the primary cause of cystic echinococcosis (CE), a parasitic disease affecting humans and livestock with significant health and economic impacts. Previous studies on this parasite relied on mitochondrial DNA to classify its genotypes and understand its genetic diversity. However, these studies cannot capture the full complexity of its evolutionary dynamics and adaptation strategies. Our research employs comprehensive genome-wide sequencing, offering a more nuanced view of its genetic landscape. We discovered that cross-fertilization appears to be a prevalent reproductive strategy in the hermaphroditic E. granulosus , underpinning the observed deep mitochondrial divergence between genotypes G1 and G3, as well as gene flow among populations. The transmission history of E. granulosus s.s. in China and its widespread genetic mixing were likely facilitated by the migrations of nomadic peoples. Furthermore, we identified genes under balancing selection, including the gene involved in the uptake of host bile acids, which play a crucial role in the parasite’s survival and development, potentially offering new targets for intervention. Our research advances the understanding of the genetic diversity and evolutionary strategies of E. granulosus , laying the foundation for improved control measures of CE.

Alveolar echinococcosis (AE) is caused by the chronic infection of E. multilocularis, whose tumor‐like growth can lead to high fatality if improperly treated. The early diagnosis of infection and the treatment of advanced AE remain challenging. Herein, bulk RNA‐seq, scRNA‐seq, and spatial transcriptomics technologies are integrated, to reveal the host immune response mechanism against E. multilocularis both spatially and chronologically, collecting mouse liver samples at multiple timepoints up to 15 months post infection. These results unveil an unprecedented high‐resolution spatial atlas of the E. multilocularis infection foci and the functional roles of neutrophils, Spp1⁺ macrophages, and fibroblasts during disease progression. The heterogeneity of neutrophil and macrophage subpopulations are critical in both parasite‐killing and the occurrence of immunosuppression during AE progression. These findings indicate the transition of parasite control strategy from “active killing” to “negative segregation” by the host, providing instructive insights into the treatment strategy for echinococcosis.