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.