An epidemiological investigation of onion growers with Fungal Keratitis

Abstract

Objective To probe into the causes for the onion farmers of Minqin County who vulnerable to fungal keratitis with the main pathogenic fungi and sources. Method Through the 52cases with clinical observation of fungal keratitis and microorganism cultivation,the clinical features and main pathogenic Fungi were analyzed on site investigation of onion excavation at the scene,and found out it's etiology.Examination on the spot of the onion excavating places to search for the etiological agent,sample the scene soil,rotten onion and workers' fingers,to discover the pathogenic bacteria origins. Results Retrospectively analyzed fungal culture in the 52 cases of the patients.The most strains were Fusarium oxysporum (48％).Sixty percent excavators suffered from erosion of corneal epithelium caused by stimulating taste of onions.With Scene sampling fungal culture,a variety of fungal species were raised from three kinds of samples,what the content were most of Fusarium oxysporums in rotten onions,Aspergillus flavus and Fusarium solan in soil,and Fusarium oxysporums from operators. Conclusions Digging farmers have their corneal epithelium eroded caused by pungent smell of onions,this creates favourable conditions for fungal infections,while they are working with rotten onions and surrounding earth.When farmers get fungi on their hands,they can infect their conjunctival sac by touching their eyes.The results get from the assay of pathogenicity show that Fusarium oxysporum is major pathogen,come mainly from rotten onions. Key words: Fungal Keratitis ; Onion ; Pungent smell ; Fusarium oxysporum ;