Ocular thelaziasis: A case report from Assam, India

The C/EBPβ-SESN2 Axis Promotes M2b Macrophage Polarization Induced by T.cp-MIF to Suppress Inflammation in Thelazia Callipaeda Infection

Infection by the conjunctival sucking nematode Thelazia callipaeda results in ocular inflammation and immune impairment. T.cp-MIF, a macrophage migration inhibitor factor of T. callipaeda, can induce macrophage polarization and is involved in the host innate immune response, but little is known about the regulatory mechanisms and the actual immune effect. Understanding the immunoregulatory mechanisms carries significant clinical relevance for the development of novel preventative and therapeutic strategies. The macrophages were induced by T.cp-MIF in vitro, and the polarization direction at different times and the expression of inflammatory factors were detected by flow cytometry analysis, qPCR and western blotting. The key transcription factors and target genes were screened through transcriptome data, and the functions of transcription factors were verified by inhibition experiments in vitro. T.cp-MIF and T. callipaeda adult worms can cause inflammation of the ocular conjunctiva and macrophage infiltration. T.cp-MIF activated macrophages presenting M2b polarization after 48 h and played a role in inhibiting inflammation. Furthermore, based on the results of transcriptome data analysis and inhibition experiments, we demonstrate that this polarization is dependent on the involvement of the transcription factor C/EBPβ and its target gene SESN2. Our results demonstrated that the C/EBPβ-SESN2 axis plays an important regulatory role in T.cp-MIF-induced macrophage M2b polarization and it provides a new perspective for understanding the immune escape of ocular parasite infection.

Canine ocular thelaziosis: first report in Andhra Pradesh

Thelaziosis is a vector-borne zoonotic disease with worldwide distribution, including in India and reports on canine ocular thelaziosis are very limited. The present case documentation will provide basic information to initiate the geographical epidemiological studies which will help to prevent the spread to these zoonotic diseases in the specified location. This communication reports about the rare case of canine ocular thelaziosis in Andhra Pradesh with the morphological features of the parasite and the management of ocular manifestations with suitable antimicrobial and anti-inflammatory eye drops along with ivermectin injections.

Rare Thelazia californiensis infant ocular infestation

Purpose

A rare case of Thelazia californiensis ocular infestation was diagnosed and treated in an 11-month-old patient.

Observations

The patient presented with a visual acuity of 20/130 OU by Teller cards. Exam demonstrated a white, mobile worm in the inferomedial fornix of the right eye. The remainder of the exam was otherwise normal. The worm was removed under anesthesia and identified as Thelazia californiensis by the Division of Parasitic Diseases and Malaria, at the Centers for Disease Control and Prevention.

Conclusions and importance

This case demonstrates a rare but important cause of follicular conjunctivitis and mobile foreign bodies, especially in patients with a supportive history of exposure to the intermediate and definitive hosts of Thelazia species.

Canine ocular thelaziosis from North East India

Thelazia callipaeda is a vector borne zoonotic nematode transmitted by drosophilid flies of Phortica genus. It has been reported in humans from different parts of India including North Eastern region. Only one case of canine ocular thelaziosis has been reported from southern India while no case has yet been reported from the rest of the country. This communication reports the first case of canine ocular thelaziosis from Nagaland and the entire North East region of India along with the morphological characters and treatment.

Phthiriasis palpebrarum, thelaziasis, and ophthalmomyiasis

INTRODUCTION

Parasitic infections of the eye are a major cause of ocular-surface diseases globally. While most infections are treatable, parasites can cause varying levels of damage mostly due to late diagnosis or misdiagnosis as a result of doctors' unfamiliarity with their characteristics of latency and crypsis, as well as lack of awareness by the patients.

CASE REPORTS

In this study, we present three cases of phthiriasis palpebrarum, thelaziasis, and ophthalmomyiasis, respectively. Two of the cases were treated at the clinic and did not recur. One patient refused treatment and was lost to follow-up.

DISCUSSION

By evaluating the natural histories, morphology, symptoms, clinical findings, and treatment of these parasitic diseases, we systematically analyzed several distinct and unique parasite characteristics, especially latency and crypsis. Furthermore, we have proposed specific examination techniques and methods as well as prevention and treatment strategies from these specific perspectives, aiming to prompt timely diagnoses and early interventions for these diseases by health care workers and improve the public's awareness of parasitic infections.

CONCLUSION

Parasitosis on the ocular surface is a global infectious disease, and prevention strategies include maintaining personal and environmental hygiene and limiting contact with animals. We recommend that health care workers should enhance their ability to detect and diagnose these diseases while promoting the public's awareness of them in the context of our new perspectives.