DISCUSSION:
Human Dirofilariasis is an emerging zoonotic infection. Dirofilaria commonly presents with ocular and subcutaneous involvement followed by pulmonary manifestations. It was first described in 1885, after that approximately 1782 cases of human dirofilariasis have been reported [1]. However, the reported cases maybe lesser due to underreporting of unnoticed
subcutaneous nodules and asymptomatic fibrosis.
The initial cases of human ocular dirofilariasis infection in India were reported from south India (Kerala) in 1976 and 1978 [4,5]. This region of India is considered endemic for dirofilariasis due to its climatic conditions and the presence of vectors.
Subcutaneous Dirofilariasis which is caused by adult and pre adult Dirofilaria repens worm presents as subcutaneous nodules, which are either migratory or non-migratory. It grows gradually over a period of weeks to months. Histological examination reveals four types of nodules with diverse contents and characteristics [2]. Although the highest incidence of subcutaneous cases occurs in individuals of age 40 -49 years, infections can occur in patients of all ages, mostly in Sri Lanka where 33.6% of reported infections have occurred in children under the age of ten years.
The Definitive diagnosis of human subcutaneous dirofilariasis can be made after surgical excision on biopsy. Blood eosinophilia or elevated serum IgE levels are rarely observed [3]. In sub cutaneous nodules, high resolution ultra sound imaging is helpful for spotting parasite migration. Surgical Excision is both diagnostic and therapeutic. Anti-helminthic medications like ivermectin may assist to halt the parasite’s migration, while their benefits are not entirely evident. In all the four cases we reported, children responded well to surgical excision and had complete recovery with no recurrence of the disease.
Dirofilariasis should be considered in the differential diagnosis of asymptomatic migratory or non-migratory subcutaneous swelling both in pediatric and adult population, especially if the patient is coming from Endemic Areas [7].
CONCLUSION :
Human infection with dirofilariasis is at a rise in India as well as other part of the world. Most of the cases remain undiagnosed because of the asymptomatic nature of the disease. Diagnosed cases remain unreported as well. Hence there is an increased need of awareness about this infection and active surveillance that will help determine the actual prevalence of the disease.