Epidemiological and clinical characteristics of human ocular helaziasis in China from 2011 to 2022 based on bibliometrics / 中国血吸虫病防治杂志

Objective To understand the clinical and epidemiological characteristics of human ocular thelaziasis patients in China. Methods Case reports regarding human ocular thelaziasis cases in China were retrieved in international and national electronic databases, including CNKI, VIP, CBM, Traditional Chinese Medical Literature Analysis and Retrieval System, Wanfang Database, PubMed and Web of Science from 2011 to 2022. Patients’ gender, age, clinical symptoms, treatment, recurrence, site of infections, time of onset, affected eye, affected sites, number of infected Thelazia callipaeda, sex of T. callipaeda and source of infections were extracted for descriptive analyses. Results A total of 85 eligible publications were included, covering 101 cases of human ocular thelaziasis, including 57 males (56.44%) and 44 females (43.56%) and aged from 3 months to 85 years. The main clinical manifestations included foreign body sensation (56 case-times, 22.49%), eye itching (38 case-times, 15.26%), abnormal or increased secretions (36 case-times, 14.46%), tears (28 case-times, 11.24%) and eye redness (28 case-times, 11.24%), and conjunctival congestion (50 case-times, 41.67%) was the most common clinical sign. The most common main treatment (99/101, 98.02%) was removal of parasites from eyes using ophthalmic forceps, followed by administration with ofloxacin and pranoprofen. In publications presenting thelaziasis recurrence, there were 90 cases without recurrence (97.83%) and 2 cases with recurrence (2.17%). Of all cases, 51.96% were reported in four provinces of Hubei, Shandong, Sichuan, Hebei and Henan, and ocular thelaziasis predominantly occurred in summer (42.19%) and autumn (42.19%). In addition, 56.45% (35/62) had a contact with dogs. Conclusions The human thelaziasis cases mainly occur in the continental monsoon and subtropical monsoon climate areas such as the Yellow River and the Yangtze River basin, and people of all ages and genders have the disease, with complex clinical symptoms and signs. Personal hygiene is required during the contact with dogs, cats and other animals, and individual protection is required during outdoor activities to prevent thelaziasis.

Screening and bioinformatic analysis of trehalase in Thelazia callipaeda / 中国血吸虫病防治杂志

Objective To characterize the trehalase gene in Thelazia callipaeda through screening the annotated data of the T. callipaeda genome, and to investigate the biological characteristics of the trehalase gene-coding protein. Methods The trehalase gene was screened from the T. callipaeda genome and subjected to validation by using a PCR assay. The structural features of the coding protein were analyzed with bioinformatics tools, including hydrophobicity, transmembrane region, signal peptides, conserved domains, as well as the secondary and tertiary structures and the antigen epitope. Homology analysis of the amino acid sequences was performed, and the phylogenetic tree was built by the MEGA X software. In addition, the protein-protein interaction network was deduced from the STRING database. Results The sequence of the trehalase gene with the complete CDS region was obtained from T. callipaeda genome, which had a length of 1 638 bp and encoded 545 amino acids. The encoded protein was predicted to have a molecular weight of 63 478.48 ku and be a secretory protein. The 5′ domain of the encoded protein contained a signal peptide without transmembrane regions, and was predicted to contain 7 antigen epitopes. Based on the protein-protein interaction network of nematodes in the STRING database, the protein-protein interaction network of the trehalase gene of T. callipaeda was deduced, and 27 interactions covering 10 genes were identified. Conclusions A trehalase gene is successfully identified in T. callipaeda genome and its coding protein receives a bioinformatics analysis, which provides insights into the research on the biological functions of the protein and the screening of vaccine candidates for thelaziasis callipaeda.

Thelazia Callipaeda Infestation with Tarsal Ectropion

PURPOSE: To report a case of Thelazia callipaeda infestation with tarsal ectropion.CASE SUMMARY: A 79-year-old man presented with epiphora and a sensation of a foreign body in his right eye that had persisted for several months. On the initial examination, he had conjunctival injection, conjunctival follicles, telangiectasia of the lid margins, meibomian gland dysfunction, and tarsal ectropion. We performed a lateral tarsal strip operation to treat the tarsal ectropion. During surgery, we identified and removed four parasites (about 1–2 cm in length and 0.5 mm in width) that had not been apparent on slit lamp examination. The parasites were identified as Thelazia callipaeda. The patient's symptoms subsequently improved considerably; he has followed up to the present time without recurrence.CONCLUSIONS: In the presence of continuous extraocular inflammation, as with infestation by Thelazia callipaeda, ectropion can be induced by several possible causes. Involutional ectropion can be accelerated mechanically through rubbing. Other causes include inferior force from inflammation of the connective tissue and temporary blepharospasm.

Advances in etiology, epidemiology and genetic diversity of Thelazia callipaeda / 中国血吸虫病防治杂志

Thelazia callipaeda, T. californiensis and T. gulosa are three causative agents of human thelaziasis. Most of the reported cases were caused by T. callipaeda, occurring in the old world, particularly in Asian and European countries. T. californiensis and T. gulosa have rarely been reported infecting humans in North America. T. callipaeda has long been called the oriental eye worm, referring to its traditional distribution across eastern and southeastern Asia (i.e., China, Korea, Japan, Indonesia, Thailand, and India) where infection is endemic in animals and humans, usually in poorer rural areas and mainly among children and the elderly. The identification of the parasite was mainly based on the characteristics of oral and genital organs. In Asia and Europe, vectors for this nematode are male Phortica okadai and P. variegata drosophilids respectively, which feed on ocular secretions of hosts and transmit infective stage larvae to domestic and wild carnivores, lagomorphs, and humans. China probably has the largest number of cases with thelaziasis in the world, and lots of cases have been existed in other Asian countries such as Japan and Korea. Although a few of human cases have been reported, there were high infection rates of wild animals and domesticated dogs and cats in most of European countries. Based on the cox1 gene, a total of 21 haplotypes were identified in the samples from worldwide, in which, one circulated only in European countries (h1), while the other 20 haplotypes were distributed in Korea, Japan and China. In general, the Chinese clinical isolates of T. callipaeda expressed high genetic diversity. The population differences between Europe and Asian countries were greater than those among China, Korea and Japan. The T. callipaeda populations from Europe and Asia should be divided into two separate sub-populations. These two groups started to diverge during the middle Pleistocene.

Live encysted Thelazia callipaeda presenting as a lump adjacent to the right lacrimal sac in a 42-year-old female: A rare case report

Thelazia callipaeda or the oriental eye worm infects a wide variety of hosts including dogs, cats, foxes, rabbits, and humans through the Drosophila flies. We report here a case of a 42-year-old female who presented with pain, redness, and cystic swelling in the right lacrimal sac area for 8 months. Ocular examination was within normal limits. Excision biopsy of the cyst revealed a live worm. In humans, the worm is usually found in the conjunctival sac, lacrimal canaliculi, or the lacrimal sac leading to a disease which can be subclinical or symptomatic. Thus, we report a rare presentation of thelaziasis, that is, periocular involvement. This case presentation is first of its kind in the Indian literature.

A Case of Twice Recurring Ocular Thelaziasis from Thelazia callipaeda

PURPOSE: We report a case of recurrent ocular thelaziasis by Thelazia callipaeda. CASE SUMMARY: A 71-year-old male visited the ophthalmic clinic, complaining of itching, a foreign body sensation, and irritation in the right eye. He was previously diagnosed with Thelazia callipaeda infection, 3 months prior, at another hospital. A parasite, shaped like a thin small thread, was found in the conjunctival sac of his right eye, with active movement. The parasite was identified as Thelazia callipaeda by pathology. Four months after removal of the parasite, symptoms relapsed in the same eye. Two parasites were rediscovered and removed. Since then, no additional specific sign related to the parasite has been noted in follow- up examinations. CONCLUSIONS: Due to frequent recurrence of infections caused by the short life cycle of the parasite, monthly follow-up examinations are required for at least 1 year after discovery of the parasite.

A Case of Thelazia callipaeda Infestation with Preseptal Cellulitis

PURPOSE: To report a case of Thelazia callipaeda infection with preseptal cellulitis. CASE SUMMARY: A 24-year-old female presented with symptoms of conjunctival injection and ocular pain in her left eye and a parasite was found in her conjunctival sac. Using light microscopy, we identified Thelazia callipaeda and many larvae were observed in the vulva of an adult female worm. Three days later, erythematous swelling occurred in the left upper eyelid and four adult worms were found and removed with forceps. Third-generation cephalosporin and nonsteroidal anti-inflammatory drugs were administered orally; the eyelid swelling improved but the conjunctival injection remained. Later five and seven adult worms were removed every 4 weeks and the conjunctival injection improved with no parasites detected after the final extraction. CONCLUSIONS: In the case of Thelazia callipaeda infection, it is necessary to identify eggs and larvae and to observe the patient for more than 1 month because of postextraction growth of the larvae. In addition, the possibility of preseptal cellulitis by Thelazia callipaeda should be considered.

Sequential analysis of genome of Thelazia callipaeda / 中国血吸虫病防治杂志

Objective To investigate the molecular characteristics of genome sequence of Thelazia callipaeda(T.cp).Meth-ods The obtained T.cp genome assembling data were annotated by using a combination of ab initio gene by softwares,Gene-Mark and GeneID,and the homology of the experimentally confirmed genes was predicted by software GeMoMa.The results were integrated by software EVM to predict all genes of genome.The obtained genes were annotated in the common public data-base and three dedicated databases(CAZyme,TCDB and PHI),respectively.Results The Scaffolds and Contigs gene struc-ture of T.cp genome(79.34 Mb)was analyzed,and a total of 6 333 genes were obtained.The sequence search was conducted in the public databases using BLASTx,of which 97.85％of the genes could be annotated.The genes annotated in the NR database were the most(98.69％),and those enriched in the KEGG pathway were the least(50.50％).The functional genes were blasted by KOG database and totally 4 517 genes were found.The three special databases(CAZyme,TCDB and PHI)were used to an-notate all the genes,and 136,139 and 1 498 genes were assigned respectively,and the number of genes in the PHI database was the largest.In the cytochrome proprietary database,238 cytochrome P450 genes were predicted.Conclusion We have pre-liminarily revealed the T.cp genome structure characteristics and annotation information,and totally 6 333 genes are obtained.

Prediction and analysis for secretory proteins from Thelazia callipaeda at Genome Scale / 中国人兽共患病学报

We conducted prediction and analysis for secretory proteins from Thelazia callipaeda at Genome Scale based on the previous full genome annotation.The software SignalP,TMHMM,big-PI Predictor,MEME,Protcomp and SecretomeP were combined to process the prediction of the secretome of Thelazia callipaeda.The analyses of secretory proteins by GO function enrichment,KEGG pathway,and statistics of domains were performed.Results showed that totally 259 secretory proteins were found in Thelazia callipaeda genome and the amino acid lengths of secretory proteins were mainly concentrated between 100 to 700 aa exclusively.GO function analysis of secretory proteins indicated that they were enriched in the secreting pathways and in the interactions with host.The results of KEGG metabolism secretory proteins suggested that some of them contributed to drug metabolism and glutathione metabolism.And domain analysis suggested that most of them were glycoside hydrolase,contributing to sugar metabolism.Around 126 secretory proteins had antigenicity of B-cell epitope.In summary,we found that secretory proteins in Thelazia callipaeda were most small proteins,which were involved in sugar metabolism and antioxidative activity,facilitating Thelazia callipaeda to invade the hosts and play a key role in the parasitic course.

Genetic variation of Thelazia callipaeda among isolates collected from pa-tients in Zunyi City,Guizhou Province / 中国血吸虫病防治杂志

Objective To identify the genetic variation and possible sources of Thelazia callipaeda isolates collected from pa-tients in Zunyi City,Guizhou Province. Methods Seven cases of T. callipaeda infection in Zunyi City,2016 were verified, and DNA(s)were extracted from the T. callipaeda's body collected from the thelaziasis patients. A mitochondrial COX1 frag-ment was amplified and sequenced. The sequence alignment and phylogenetical analysis were performed to compare the genetic variation of the gene sequence with the homologous sequences downloaded from Genebank. Results COX1 genes of T. callipae-da were differed among the samples from the seven cases,which had low variation. Conclusion Zunyi City is a new area with endemic of thelaziasis. The isolates from Zunyi City include either Asian origin or European origin of T. callipaeda. Moreover,at least four haplotypes are identified among the seven isolates.

Epidemic characteristics of thelaziasis and specie identification of Thelazia callipaeda by 18S rRNA gene / 中华地方病学杂志

Objective To study epidemiological characteristics of thelazjasis, in Zunyi and surrounding areas, morphology and 18S rRNA gene sequence of Thelazia callipaeda. Methods The Thelazia callipaeda was collected from several hospitals, including affiliated Hospital of Zunyi Medical College and Zunyi Aerospace Hospital, in Zunyi region since 2011 to 2015. Clinical data of infected human thelaziasis, including the patients' gender, age, residence and pets such as cats or dogs, were analyzed to find out the factors influencing the incidence. Morphology characteristics of female and male Thelazia callipaeda were observed under microscope. 18S rRNA gene of Zunyi Thelazia callipaeda was amplified by PCR, and the evolutional relationship was analyzed through the software MEGA 7.01 based on neighbour-joining (NJ) method. Homology was campared with 18S rRNA gene from GenBank in National Center of Biotechnology. Results Totally 25 cases had been reported during the study, of which 22 cases had more details. Based on the cases, we found the thelaziasis was increasing year by year. For instance, 2 cases (9.1%) were reported in 2011, 1 case (4.5%) in 2012, 3 cases in 2013 (13.6%), 10 cases (45.5%) in 2014 and 6 cases (27.3%) in 2015 . During the five years , totally 15 cases were treated between August and November, when the human thelaziasis was in typical epidemic peaks. We analyzed characteristics of the total cases reported to date. Most of the cases occurred in rural areas (20 cases). Majority of patients lived in rural region. And most cases were between 30 to 60 years old, indicating no age limit, especially, there were two cases who were at the ages of 8.5 months and 77 years old, respectively. Moreover, more women suffered from the disease than that in men, of which, the case number was 16 in women and 6 in men, and there were 7 cases who had cats or dogs at home. Under light microscope, the edge of Thelazia callipaeda had serrated cuticle with transverse striations. And male worm had a sharp peak at the tail end of Thelazia callipaeda, which cured to the ventrite and had two copulatory spicules, long one and short one, respectively. While female worm had a blunt tail, containing numerous eggs and rounded first-stage larvaes in a single line in the distal area of the uterus, near the vulva. Sequences of Thelazia callipaeda 18S rRNA gene from Zunyi and Oita Japan (AB538282.1) were showed homology of 100%, and they were clustered in a same branch of Phylogenetic tree. Conclusions Human thelaziasis cases in Zunyi region are increasing each year, and most of the cases have occurred in rural areas. 18S rRNA gene has a high homology with sequence AB538282.1 in Thelazia callipaeda. Combining clinical data, analysis of epidemiological characteristics and the characteristics of 18S rRNA should be good for specie identification and epidemiological analysis.

A case report of human thelaziasis and its epidemiology in China / 中国人兽共患病学报

A case of Thelazia callipaeda infection in a 7 months old infant in Dalian was reported.The epidemiology of human thelaziasis in China was investigated in this report.China is the nation with the most reported human Thelazia callipaeda cases in the world,up to 626 case reports of human Thelazia callipaeda infection that were distributed in 28 provinces from 1917 to 2016.We analyzed more than 400 Chinese thelaziosis cases with clinical data from 1917 to 2016.Ages of the patients are from 2 months to 88 years old.Male and female cases are 60.22％ and 39.78％ relatively.The occupation of patients was analyzed,that the preschool children occupied 55.38 ％,farmers occupied 32.27 ％;workers occupied 4.78 ％,and the others occupied the rest 7.57％.This study showed that it is of great significance to strengthen the research on the biology and epidemiology of the sucking nematode,to prevent the spread and epidemic of the disease.

A Case of Subconjunctival Thelasia Callipaeda Infestation

PURPOSE: To report one case involving Thelazia callipaeda subconjunctival infestation. CASE SUMMARY: A 52-year-old man came in with left eye discomfort that started about a month prior to hospital visit. Slit lamp examination identified a live white translucent parasite about 10 mm in length and about 0.3 mm in width moving under the lower left eye subconjunctiva. No other abnormal findings were found in the front or fundus. An incision of about 5 mm in the conjunctiva where the parasite was located was carried out, and after opening the area, the parasite was slowly pulled out using a clamp. Then, the bottom of the conjunctiva was washed with normal saline. Further, five additional parasites were found in the conjunctival sac and were removed. The parasite was identified as Thelazia callipaeda, and through outpatient follow-up for 1 month after removal, additional parasites were not found. CONCLUSION: The authors report this case of intraocular Thelazia callipaeda infestation because it is not known to be common; however, the authors witnessed a number of parasites in the conjunctival fornix, as well as Thelazia callipaeda in the subconjuctiva.

Human ocular Thelaziasis in Karnataka.

Thelaziasis is an Arthropod‑born disease of the eye and adnexa caused by Thelazia callipaeda, a nematode parasite transmitted by drosophilid flies to carnivores and humans. Because of its distribution mainly confined to South Asian countries and Russia, it is commonly known as Oriental Eye worm. It is often under‑reported and not been given its due clinical importance. We report first case of human Thelaziasis from Hassan District, Karnataka. Five creamy‑white, translucent worms were removed from the conjunctival sac of a 74‑year‑old male patient. Based on morphological characters, the worms were identified as nematodes belonging to the genus Thelazia and speciation was confirmed by CDC, Atlanta as callipaeda. Rarity of the disease and its ability to cause both extra and intraocular manifestations leading to ocular morbidity is the reason for presenting this case. From the available data, this is the first case report from Karnataka, India.

Ocular thelaziasis in a 7-month-old infant.

Human thelaziasis is a zoonotic eye disease caused by a nematode parasite called Thelazia. In India, seven human cases of Thelazia have been reported earlier. This is the fi rst case report of an infant infected with Thelazia. During the month of July, 2012, the infant was presented with an eye problem to the eye clinic from a village of Dibrugarh. Five worms (three female and two male) were recovered from the left eye of the infant. Thelazia infection is rare in infant, and report of this case is suggestive of prevalence of infection in the area and warrants further investigation.

The First Human Case of Thelazia callipaeda Infection in Vietnam

A 26-year-old man residing in a village of Thai Nguyen Province, North Vietnam, visited the Thai Nguyen Provincial Hospital in July 2008. He felt a bulge-sticking pain in his left eye and extracted 5 small nematode worms by himself half a day before visiting the hospital. Two more worms were extracted from his left eye by a medical doctor, and they were morphologically observed and genetically analyzed on the mitochondrial cytochrome c oxidase 1 gene. The worms were 1 male and 1 female, and genetically identical with those of Thelazia callipaeda. By the present study, the presence of human T. callipaeda infection is first reported in Vietnam.

Two Cases of Human Thelaziasis and Brief Review of Korean cases

The present study was performed to describe 2 cases of human thelaziasis (HT) which occurred in Gyeongsangnam- do and to briefly review the previously reported Korean cases. A 58-year old woman, residing in Hadong-gun, Gyeongsangnam-do, came to Gyeongsang National University Hospital (GNUH) complaining of foreign body sensation and itching of the right eye in March 2000. Total 6 adult nematodes of Thelazia callipaeda (2 males and 4 females) were detected in her right eye. A 80-year old man, residing in Jinju-si, Gyeongsangnam-do, came to GNUH complaining of foreign body sensation, itching, and pain of the right eye in December 2007. A total of 5 worms (4 females and 1 degenerated) were removed from his right eye. We analyzed characteristics of the total 39 Korean HT cases reported to date, including the present 2 cases. Most of the cases (71.8%) occurred in Seoul and Gyeonggi-do before 2000, and 21 cases (53.8%) were males and 18 (46.2%) were females. The prevalence was higher in younger ages below 30 years (48.7%) than 31-60 years (41.0%) and over 61 years (10.3%). The seasonal prevalence showed a higher incidence in autumn (43.6%) than in other seasons. Most of the cases (94.9%) were conjunctival sac infections and only 2 (5.1%) were intraocular cases. The present 2 HT cases are the first reported cases in Gyeongsangnam-do. Some characteristics of Korean HT cases were analyzed.

A Case of Thelazia Callipaeda Recurred At a One-month Interval

PURPOSE: To report a relapsed case of an intra-conjunctival Thelazia callipaeda infestation within one month. CASE SUMMARY: A 59-year-old female patient presented with symptoms of itching and a sense of foreign substance in her left eye, which she had been experiencing for several days. Conjunctival hyperemia and follicle multiplication along with ten actively moving worms were identified and were extracted with forceps. The symptoms disappeared until 25 days later, when they recurred and five additional worms were extracted. All of the extracted worms were confirmed to be Thelazia Callipaeda and the patient's symptoms disappeared after the final extraction. CONCLUSIONS: More than one month of follow-up observation is required for human infection by Thelazia Callipaeda due to the post-extraction growth of the larva.

A Case Report of Human Thelaziasis

The authors report a case of infection with Thelazia callipaeda in a Korean man. The patient was a 47 year-old man. He experienced epiphora and foreign body sensation of the right eye since 3 weeks ago. Total of 2 worms were removed from the conjunctival sac; one by himself 1 day prior to examination and the other by an ophthalmologist. The worm was slender creamy white in color which was fixed in a 10% formaline solution. The worm was 17.38 mm in length, 0.45 mm in body width, 0.026 mm in length of buccal cavity, 0.63 mm in length of anterior end to vaginal opening, 0.76 mm in length of anterior end to the esophagointestinal junction and 0.06 mm in length of posterior end to the anus. There were numerous striations on surface of worms and vaginal opening was located anterior to the esophagointestinal junction. Based on aforementioned findings, it was confirmed as a female worm of Thelazia callipaeda, and the authors report it with literature.

A Case Report of Human Thelaziasis

The authors report a case of infection with Thelazia callipaeda in a Korean man. The patient was a 47 year-old man. He experienced epiphora and foreign body sensation of the right eye since 3 weeks ago. Total of 2 worms were removed from the conjunctival sac; one by himself 1 day prior to examination and the other by an ophthalmologist. The worm was slender creamy white in color which was fixed in a 10% formaline solution. The worm was 17.38 mm in length, 0.45 mm in body width, 0.026 mm in length of buccal cavity, 0.63 mm in length of anterior end to vaginal opening, 0.76 mm in length of anterior end to the esophagointestinal junction and 0.06 mm in length of posterior end to the anus. There were numerous striations on surface of worms and vaginal opening was located anterior to the esophagointestinal junction. Based on aforementioned findings, it was confirmed as a female worm of Thelazia callipaeda, and the authors report it with literature.