Oculosporidiosis.

Dear Editor,

We read with interest the article entitled ′Oculosporidiosis in a tertiary care hospital of western Orissa, India: a case series′.1 We would like to make a few comments on the report as well as share some of our own experiences.

The etiological agent, of rhinosporidiosis, Rhinosporidium seeberi described as a phycomycete by Ashworth in 1923, has for long been a subject of taxonomic uncertainty, because the organism can neither be isolated nor cultured. Some authors postulated that the agent is not a fungus but a prokaryotic cyanobacterium called Microcystis aeruginosa.2 However, through molecular biological analysis of the organism′s ribosomal DNA, the responsible agent is now considered by most as an aquatic protistan parasite belonging to a novel group of fish parasites that infect fish and amphibians, located phylogenetically between the fungal animal divergence.3

Apart from the regions mentioned by the authors, Chhattisgarh is another area where the disease is endemic, probably because of the hot and humid climate. Here, it is mostly seen in agricultural laborers belonging to low socioeconomic status. Most of the affected persons give a history of taking bath in stagnant ponds which is shared by cattle who harbor this disease.4

The term subcutaneous involvement separately mentioned in the text and also mentioned as a separate column in Table 1 is probably involvement of the lacrimal sac showing spread to adjacent areas.

In our ongoing series started in 2001, we found recurrence in both conjunctival and lacrimal sac rhinosporidiosis. Conjunctival growths recurred less often than growths in the sac. Whether it was a true recurrence or re-infection is difficult to prove, especially in cases of conjunctival growth, because they are relatively easily removed in toto unlike those involving the sac. Cauterizing the base of the lesion after surgery may further help in reducing recurrences.

In the series presented, the authors have mentioned a low recurrence rate, at the same time reporting a recurrence in two out of five cases of lacrimal sac rhinosporidiosis (with subcutaneous involvement) within one year (40% recurrence, if lacrimal sac rhinosporidiosis is considered separately), which cannot be considered a low recurrence rate.

We routinely use povidone iodine 5% in all our cases after excision of the growth. Arseculeratne et al. have reported a metabolic inactivation of endospores on exposure to certain biocides including povidone iodine. This might prevent recurrence of the disease due to autoinoculation of the endospores contaminating the adjacent mucosal surfaces during surgery.5

The organism has also been reported to affect skin and bones apart from sites mentioned by the authors. It has also been our experience that in long-standing extensive involvement of the lacrimal sac, the surrounding bones get eroded.

Lacrimal gland involvement, as mentioned in the report (page 300 column 2 line15) has not yet been reported to the best of our knowledge, if so, it must be a unique case worth investigation.