Analysis of the new WHO guideline to accelerate the progress towards elimination of schistosomiasis in China / 中国血吸虫病防治杂志

On February 2022, WHO released the evidence-based guideline on control and elimination of human schistosomiasis, with aims to guide the elimination of schistosomiasis as a public health problem in disease-endemic countries by 2030 and promote the interruption of schistosomiasis transmission across the world. Based on the One Health concept, six evidence-based recommendations were proposed in this guideline. This article aims to analyze the feasibility of key aspects of this guideline in Chinese national schistosomiasis control program and illustrate the significance to guide the future actions for Chinese national schistosomiasis control program. Currently, the One Health concept has been embodied in the Chinese national schistosomiasis control program. Based on this new WHO guideline, the following recommendations are proposed for the national schistosomiasis control program of China: (1) improving the systematic framework building, facilitating the agreement of the cross-sectoral consensus, and building a high-level leadership group; (2) optimizing the current human and livestock treatments in the national schistosomiasis control program of China; (3) developing highly sensitive and specific diagnostics and the framework for verifying elimination of schistosomiasis; (4) accelerating the progress towards elimination of schistosomiasis and other parasitic diseases through integrating the national control programs for other parasitic diseases.

Contribution to global implementation of WHO guideline on control and elimination of human schistosomiasis by learning successful experiences from the national schistosomiasis control program in China / 中国血吸虫病防治杂志

Schistosomiasis is a parasitic disease that seriously hinders socioeconomic developments and threatens public health security. To achieve the global elimination of schistosomiasis as a public health problem by 2030, WHO released the guideline on control and elimination of human schistosomiasis on February, 2022, with aims to provide evidence-based recommendations for schistosomiasis morbidity control, elimination of schistosomiasis as a public health problem, and ultimate interruption of schistosomiasis transmission in disease-endemic countries. Following concerted efforts for decades, great achievements have been obtained for schistosomiasis control in China where the disease was historically highly prevalent, and the country is moving towards schistosomiasis elimination. This article reviews the successful experiences from the national schistosmiasis control program in China, and summarizes their contributions to the formulation and implementation of the WHO guideline on control and elimination of human schistosomiasis. With the progress of the "Belt and Road" initiative, the world is looking forward to more China's solutions on schistosomiasis control.

Progress of researches on the diagnostic techniques for schistosomiasis / 中国血吸虫病防治杂志

Schistosomiasis is an important zoonotic parasitic disease, and is categorized as a neglected tropical disease by the World Health Organization. Following the concerted efforts for more than 70 years, great achievements have been made in the national schistosomiasis control program in China, and the prevalence, disability and mortality due to schistosomiasis has remarkably dropped. Nevertheless, the frequent identification of imported schistosomiasis and the resulting potential transmission risk in mainland China have been recently paid much attention following the implementation of the “Belt and Road Initiative” and the China-Africa Cooperation Forum. This review describes the advances in the diagnostic tools for schistosomiasis, including pathogenic techniques, immunodiagnostic techniques and nucleic acid assays, in order to consolidate schistosomiasis control achievements and promote the capability for detection of external biological safety risks.

Advances in pathogenic mechanisms of Angiostrongylus cantonensis infection / 中国血吸虫病防治杂志

Angiostrongylosis, a food-borne parasitic disease, is caused by the migration of larvae of Angiostrongylus cantonensis to the host’s central nervous system after it is infected. It is a serious disease with eosinophilic encephalitis and meningoencephalitis as the main clinical manifestations. Understanding of its pathogenic mechanism is important for the prevention and treatment of angiostrongylosis. This paper reviews the mechanism of eosinophilic meningitis and meningoencephalitis caused by A. cantonensis infection.

Transmission electron microscopic observation on gonad of Oncomelania hupensis offspring bred in Weishan Lake areas / 中国血吸虫病防治杂志

Objective To observe the morphological changes in the testes and ovaries of adult 12th-generation Oncomelania hupensis bred for 12 winters in Weishan Lake areas. Methods The offspring of the adult O. hupensis snails bred in the Weishan Lake that were originated from the Yangzhou section of the Yangtze River was defined as the experiment group, while uninfected, adult O. hupensis snails captured from the marshland of the Yangzhou section of the Yangtze River served as the control group. Snails were dissected and intact testicular and ovarian specimens were sampled, routinely fixed, dehydrated, embedded, polymerized in an oven and sliced on an ultramicrotome. The sections were visualized under a transmission electron microscope, and the ultrastructure of the snail gonad was compared between the experiment and control groups. Results Transmission electron microscopy showed “9 + 2” microtubules on the transverse sections of the tails of sperm cells in the testes of male snails in the control group, with triangular acrosomes and spiral, dense nuclei seen in the tip, while in the experiment group, the “9 + 2” microtubules disappeared on the transverse sections of the tails of sperm cells in the testes of male snails, with low chromatin density found in the tip. Transmission electron microscopy revealed clear nucleolus and nuclear membranes in the ova of female snail ovaries, and displayed yolk body, liposomes and endoplasmic reticulum in the cytoplasm, bilayer twists of nuclear membrane and a uniform nucleolus in the control group, while in the experiment group, smooth nuclear membrane and unclear nucleolus were observed in the ova of female snail ovaries, with few contents seen within cells. Conclusions Following breeding for 12 winters in the Weishan Lake, the 12th-generation O. hupensis snails fail to fully adapt to the natural environment in northern China, and the remarkable changes in the ultrastructure of the snail gonad may be a cause of gradual decline and even extinction of O. hupensis in the Weishan Lake areas.

Comprehensive Review of Ocular Angiostrongyliasis with Special Reference to Optic Neuritis

Angiostrongyliasis, caused by Angiostrongylus cantonensis infection, is a food-borne parasitic disease. Its larvae evoke eosinophilic inflammation in the central nervous system, but can also cause pathological changes in the eyes. Among ocular angiostrongyliasis cases, the incidence of optic neuritis is low and only few sporadic reports exist. Some patients with optic neuritis developed obvious hypopsia or even vision loss, which would seriously influence the quality of life of patients. Prompt treatment of optic neuritis caused by A. cantonensis is the key factor for minimizing the incidence of serious complications of this disease. In this review, we first provide a comprehensive overview of ocular angiostrongyliasis, and then focus on the clinical features of optic neuritis caused by A. cantonensis.

Cloning and expression in Escherichia coli of a new gene of Schistosoma japonicum encoding casein kinase II beta subunit / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Nowadays it is now a focus topic in schistosomiasis research to find ideal vaccine candidates and new drug targets for developing anti-schistosomiasis vaccine. We cloned a new gene, casein kinase II beta subunit, of Schistosoma japonicum (S. japonicum) and express it in Escherichia coli (E. coli).</p><p><b>METHODS</b>The ESTs obtained in our laboratory were analyzed by homologous searching, and a new gene was recognized. The full-length cDNA of the new gene was obtained by joining the 3'RACE PCR fragment and the EST clone. To express the new gene, the cDNA was cloned into pGEX-4T-1 vector and then transformed into E. coli JM109. The recombinant protein was analyzed by SDS-PAGE and Western-blot.</p><p><b>RESULTS</b>A 908 bp cDNA was isolated from S. japonicum and identified to be casein kinase II beta subunit gene by sequence analysis. The open reading frame of the gene encodes a protein of 217 amino acids exhibiting 75.8%, 75.8%, 73.9%, 68.2%, 51.6% identity to the amino acids sequence of the corresponding genes of Homo sapiens (H. sapiens), Xenopus laevi (X. laevi), Drosophila melanogaster (D. melanogaster), Caenorhabditis elegan (C. elegan), and Schizosaccharomyces pombe (S. promber) respectively. The predicted molecular weight of the protein was 24.921 kDa. The new cDNA sequence had been submitted to GenBank, and its accession number is AY241391. This cDNA was subcloned into the pGEX-4T-1 vector and expressed in E. coli JM109. The recombinant protein could be recognized by the S. japonicum infected rabbit serum.</p><p><b>CONCLUSION</b>The full-length cDNA sequences encoding S. japonicum casein kinase II beta subunit were firstly sequenced, cloned, and expressed in E. coli.</p>