A retrospective study on dirofilariasis in five districts in Sri Lanka
Date
2013-07-04
Authors
Iddawela, W. M. D. R.
Adicarum, D. R. S.
Ranaweera, R. L. A. R.
Journal Title
Journal ISSN
Volume Title
Publisher
The University of Peradeniya
Abstract
Dirofilaria repens is the most important cause of human dirofilariasis in Sri Lanka. It occurs commonly in adults except in Sri Lanka, where children younger than nine years are likely to be infected. The present study was carried out to describe the patient and parasitic factors associated with human dirofilariais in Sri Lanka. A retrospective descriptive study was conducted in 80 samples of worms, referred by surgeons in Badulla, Kandy, Kegalle, Monaragala and Polonnaruwa during the past five years. Data on age, sex and site of lesion were obtained from the details given in the referral letters. Morphological identification of the worm was based on the maximum width, length and the characteristic cuticle with sharp longitudinal cuticular ridges. Sex of the worm was determined by the width, length and distance between anterior end and genital opening.
The age of the patients ranged from 8 months to 60 years. Of the study group, 69% were less than 40 years of age and 50.7% were males. Out of 80 patients, 34.5 %( 27) of the patients were less than 10 years of age. The youngest patient was 8 months. The majority (46%) of the patients were from the Kandy district. Nodules were reported in the abdominal wall (2), eye (35), face (4), foot (4), hand (3), leg (3) and scrotum (24). The largest proportion (65/80) were subcutaneous nodules. The adult worm was found in the upper part of the body in 85.6%, eye being the commonest site (41%). The scrotum was the commonest site in the lower part of the body (23.9%). Out of all adult worms, 80.8% were females while 11.5% were male worms. Only one nodule in the eye had both male and the female worms. The average lengths of the female and male worms were 12.1cm and 7.47cm, and average widths of female and male were 478.3 cm and 405.6 cm respectively. In conformity with these morphological characteristics, the filarial worms identified in these patients were Dirofilaria repens.
The active age group (< 40 years) was the most affected. There was no difference in incidence between the two sexes. This pattern was seen in the studies done in the last decade of the 20ᵗʰ century. Sri Lanka is an endemic focus of human dirofilariasis due to D. repens. Therefore, dirofilariasis should be included in the differential diagnosis of patients presenting with subcutaneous nodules at any site of the body.
Description
Keywords
Dirofilaria repens , Dirofilariasis , parasites
Citation
Peradeniya University Research Sessions PURSE - 2012, Book of Abstracts, University of Peradeniya, Sri Lanka, Vol. 17, July. 4. 2012 pp. 288