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An outbreak of trematode-induced granulomas of the conjunctiva
S Rathinam1, T R Fritsche, M Srinivasan
1Aravind Eye Hospital, Madurai, India. Department of Laboratory Medicine, University of Washington School of Medicine, Seattle, Washington, USA.
Insights
Pediatric conjunctival granulomas in southern India are linked to trematode infections, often associated with exposure to village freshwater ponds. Further investigation into the parasite
Area of Science:
- Ophthalmology and Parasitology: Investigating the intersection of ocular diseases and parasitic infections in pediatric populations.
Background:
- Allergic conjunctival granulomas are a common presentation in pediatric ophthalmology.
- Previous studies identified hospital-based cases, prompting a field investigation into potential environmental exposures.
Observation:
- A prospective study in a southern Indian village identified 41 children with conjunctival granulomas.
- A significant cluster of cases originated from a single village with a shared freshwater pond used for recreation.
- Clinical presentations ranged from small nodules to larger lesions requiring surgical intervention.
Findings:
- Histopathologic examination of excised lesions revealed trematode fragments and Splendore-Hoeppli phenomenon in 4 out of 13 surgically treated cases.
- Nine cases showed granulomatous inflammation with eosinophils, while four exhibited non-granulomatous inflammation.
- The presence of trematode elements strongly suggests parasitic etiology in these pediatric conjunctival granulomas.
Implications:
- Trematode infection is identified as a potential cause of conjunctival granulomas in children in this region.
- The findings highlight the need for epidemiological studies to understand the parasite's life cycle and transmission routes.
- Public health interventions may be necessary to prevent further cases, especially in communities with shared water sources.
Purpose:
To describe the epidemiologic, clinical, and histopathologic features of trematode granulomas of the conjunctiva, eyelid, and anterior chamber in pediatric patients.
Design:
Prospective noncomparative case series.
Participants:
Forty-one children from a southern Indian village with conjunctival granulomas.
Methods:
The village of Sellananthal was selected for a field visit after analysis of earlier hospital-based allergic conjunctival granuloma cases. Children with ocular diseases were examined, and histories of exposure to assumed risk factors and clinical findings were evaluated. Selected patients were brought to the base hospital for excisional biopsy. Serial sections obtained from the excised nodules were examined for the presence of a parasite.
Main Outcome Measures:
Histopathologic examination of excised conjunctival lesions or response of lesions to local medical therapy.
Results:
In this year-long prospective study, 41 children (16 years or younger; 38 boys and 3 girls) with clinical features of allergic conjunctival granulomas were examined. Thirty-four patients were from a single village located in the southern Indian state of Tamil Nadu; the remaining 7 were from various parts of the same state. All children swam in their village's freshwater pond. Twenty patients with nodules less than 5 mm in diameter received medical treatment; 13 with larger nodules underwent surgical excision of the lesions. Nine of these 13 cases revealed a zonal granulomatous inflammation admixed with eosinophilic leukocytes; 4 of these 9 displayed fragments of the tegument and internal structures of a trematode and Splendore-Hoeppli phenomenon. The remaining 4 of the 13 cases revealed nongranulomatous inflammation made up of lymphocytes, histiocytes, and eosinophils. Eight patients refused surgical treatment.
Conclusions:
In southern India, one cause of allergic conjunctival granulomas in children seems to be trematode infection. The clustering of cases in a single village and exposure to a village freshwater pond indicate the need for an epidemiologic investigation and study of the parasite's life cycle. Sporadic cases from other parts of the state with similar histories of exposure to their local pond or river water suggest a widespread distribution of the etiologic agent.