PDRU – Helminthology & Filariasis

The Department of Parasitology has a well-established research programme on helminthology, begun from as early as the 1950s. Much work has been done on lymphatic filariasis and soil-transmitted helminthiasis. The research findings of these studies initiated by  world renowned parasitologists such as Professor Mahroof Ismail and Professor Stanley Dissanaike made a significant impact on national as well as international health policies in relation to control of both groups of infections.

The most significant body of work that Prof. Ismail and his collaborators produced was to demonstrate for the first time that albendazole combined with diethylcarbamazine citrate or ivermectin has a pronounced and sustained effect of reducing microfilaraemia for over two years. This combination is currently being successfully used by the WHO and the Ministries of Health in 83 endemic countries as part of the global strategy to eliminate filariasis.

In addition, the work related to soil transmitted helminthiasis enabled national policies to be operational regarding the replacement of the three day regime of mebendazole with a single dose of 500mg which was shown to ensure greater compliance.  Bi-annual treatment of children in the plantation sector successfully reduced the prevalence of soil transmitted helminths in Sri Lanka.

Currently, studies on lymphatic filariasis and soil transmitted helminthiases are continuing in the Department with research findings being published in recognized indexed journals both internationally and locally.

  1. Transmission/ risk factors/ socio-demographics, prevalence and epidemiology
  • Gunawardena S, Gunawardena N, Kahathuduwa G, Karunaweera N, de Silva N, Ranasinghe U, Samarasekara S, Nagodavithana K, Rao R, Rebollo M and Weil G. (2014). Integrated school-based surveillance for soil-transmitted helminth infections and lymphatic filariasis in Gampaha district, Sri Lanka. American Journal of Tropical Medicine and Hygiene. 90: 661 – 666. doi:10.4269/ajtmh.13-0641.
  • Gunawardena GSA, Gunatilleke MH, Ismail MM. (2013). Prevalence of Enterobius vermicularisinfection among schoolchildren attending four selected schools in the Hambantota district of Sri Lanka. Sri Lankan Journal of Infectious Diseases 3: 17 – 20.
  • Gunawardena GSA, Karunaweera ND, Ismail MM. (2005). Effect of climate, socio-economic and behavioural factors on hookworm (Necator americanus) transmission in two low country plantations of Sri Lanka. Annals of Tropical Medicine and Parasitology99: 601 – 609.
  • Gunawardena GSA, Karunaweera ND, Ismail MM. (2004). Socio-economic and behavioural factors affecting the prevalence of Ascaris infection in a low country tea plantation in Sri Lanka. Annals of Tropical Medicine and Parasitology98: 615 – 621.
  • Gunawardena GSA, Karunaweera ND and Ismail MM. (2004). Wet-days: are they better indicators of Ascarisinfection levels? Journal of Helminthology 78: 305 – 310.
  • Fernando SD, de Silva D, Wickremasinghe AR. (2001). Geo-helminth infections in a rural area of Sri Lanka. Southeast Asian Journal of Tropical Medicine and Hygiene,32 (1): 23-26.
  • Gunawardena GSA, Karunaweera ND, Ismail MM. (2001). A study on the seasonal variation in the incidence of Ascarisinfection in the plantation sector of Sri Lanka. In: Collected papers on the control of soil-transmitted helminthiases. Asian Parasite Control Organization, Eds. Hayashi, S et al., Vol. VII: 104 – 112.
  • Fernando SD, Paranavitane SR, Rajakaruna J, Weerasinghe S, De Silva D,  Wickramasinghe AR. (2000). The health and nutritional status of school children in two rural communities in Sri Lanka.  Tropical Medicine and International Health, 5 (6): 450-452.21
  • Sorenson E, Ismail M, Amarsinghe D.K.C., Hettiarachchi I and Dassenaike T.S.  de C (1996). The prevalence and control of soil-transmitted nematode infections among children and women in the plantations in Sri Lanka. Ceylon Medical Journal, 41: 37-41


  1. Disease
  • Cooray J.H.L and Ismail M.M (1999). Re-examination of the diagnostic criteria of tropical pulmonary eosinophilia. Respiratory Medicine 93, 655-659
  • Dissanaike A.S ., Abeywickrama W.,  Wijesundara M. de S., Weerasooriya M.V Ismail M . M (1997). Human dirofilariasis  caused by Dirofilaria  (Nochtiella) repens  in Sri Lanka. Parasitologia  39: 375-382
  • Hettiarachchi, S. (1987). Human infections with Dirofilaria a filarial  parasite of animals in Sri Lanka. CCSLMA. No. 100  p 75.
  • Paul, M., Dissanaike, A.S. (1977). Solitary intraperitoneal granuloma caused by Ascaris lumbricoides.  Ceylon Med J 22 : 171 – 178.
  • Nagaratnam, N., Deen, M.F.O., Fernando, D.J.S., Kulasegaram, V., Ismail, M.M., (1975). Benign obstraction of the subclavian and axillary vein possible due to filariasis.  Proc SLAAS.  1: 11-12.  [abstracted in Trans Ceylon Col Phys 8(1): 58.]
  • Kannangara, D.W.W., Karunaratne, G.M.S. (1970). A note on intestinal helminthes of dogs in Colombo. Ceylon Vet J 18: 47 – 79.
  • Dissanaike, A.S., Niles, W.J. (1967). On two infective filarial larvae in Mansonia crassipeswith a note on other infective larvae in wild caught mosquitoes in Ceylon. J Helminthol 41: 291 – 298.


  1. Drug use and other therapy
  • Gunawardena S, Sri Ranganathan S and Fernandopulle R. (2008). Pharmacovigilance through consumer feedback (reporting) in the mass treatment of lymphatic filariasis using diethylcarbamazine and albendazole in two districts of Sri Lanka. Tropical Medicine and International Health. 13: 1153 – 1158.
  • Gunawardena GSA, Siriwardana C, Paranavitane SR, Ismail MM and Fernando SD. (2008). Anthelminthic prescribing patterns of a sample of General Practitioners from selected areas in the Colombo district of Sri Lanka. Indian Journal of Community Medicine. 33: 93 – 99.
  • Gunawardena GSA, Ismail MM, Bradley M and Karunaweera ND. (2007). Factors influencing drug compliance in the mass drug administration programme against filariasis in the Western province of Sri Lanka. Transactions of the Royal Society of Tropical Medicine and Hygiene. 101: 445 – 453.
  • Gunawardena GSA, Ismail MM, Bradley MH and Karunaweera ND. (2007). Impact of mass drug administration in 2004, at selected time points, in urban and rural areas of the Western province of Sri Lanka. Annals of Tropical Medicine and Parasitology. 101: 335 – 341.
  • Fernando SD, Gunawardena GSA, Siriwardena C, Palihawadana VP, Ismail MM. (2007). Knowledge and Practice on use of anthelminthics by mothers in selected areas in the Colombo District. Ceylon Medical Journal. 52: 70 – 71.
  • Gallella SD, Gunawardena GSA, Karunaweera ND. (2004). Bertiella studeriinfection: resistance to niclosamide. Ceylon Medical Journal 49: 65
  • de Silva NR, Pathmeswaran A, Fernando SD, Weerasinghe CR, Selvaratnam RR, Padmasiri EA, Montresor A. (2003). Impact of mass chemotherapy for the control of filariasis on geohelminth infections in Sri Lanka. Annals of Tropical Medicine and Parasitology, 97 (4): 421-425.
  • Ismail MM, Jayakody RL, Weil GJ, Fernando SD, De Silva MSG, De Silva GAC, Balasooriya WK. (2001). Long term efficacy of single dose combinations of albendazole, ivermectin and diethylcarbamazine for the treatment of bancroftian filariasis. Transactions of the Royal Society of Tropical Medicine and Hygiene, 95(3): 332-335.
  • De Silva N.R., Sirisena J.L.G.J Gunasekara D.P.S., Ismail M.M and de silva H.J. (1999) Effect of mebendazole therapy in pregnancy on birth outcome .Lancet. 353:  1148-1149
  • Ismail M.M and Jayakody R.L. (1999). Effiacacy of albendazole and its combinations with ivermectin or diethylcarbamazin (DEC) in the treatment of Trichuris trichura infections in Sri Lanka. Annals of Tropical Medicine and Parasitology, Vol. 93, No. 5, 501-504
  • Maharoof Ismail , Tissa Naotunne and Indira Hettiarachchi. (1999). Effectiveness of a Bi-annual Deworming Progarmme in The Plantations in Sri Lanka: An evaluation after 4 years . Collected Papers on the Control of Soil-transmitted Helminthiases by the Asian Parasite Control Organization. Vol VII. : 104-112 Presented at the 21st APCO Parasitologists` Meeting Tokyo, 1999
  • Ottesen E.A., Ismail M.M and Horton J. (1999) The role of Albendazole in Programmes to Eliminate Lymphatic filariasis. Parasitology Today, vol. 15, no 9
  • Ismail M.M and Laal Jayakody (1998). Efficacy of Albendazole and its combinations with ivermectin or Diethylcarbamazine (DEC) in the treatement of Trichuris trichiura infections in Sri Lanka . Collected papers on the control of Soil-transmitted Helminthiases by the Asian Parasite Control Organization. Vol VII .: 104-112 Presented at the 20thAPCO Parasitologists’ Meeting Chiba, 1998
  • Ismail M.M (1998). Efficacy of Anthelmintics in Mass treatment of Soil-transmitted Helminthiases by the Asian Parasite Control Organization . Vol VII .:  104-112 Presented at the 20thAPCO Parasitologists’ Meeting Chiba, 1998
  • Ismail M.M ., Jayakody R.L., Weil G.J., Nirmalan N., Jayasinghe K.S.A., Abeywickrama W., Rezvi Sheriff M.H. , Rajaratnam H.N., Amarasekara N ., de Silva D.C.L., Michalski M.L and Dissanaike A.S. (1998). Efficacy of single dose combination of albendazole, ivermectin and dicarbamazine for the  treatment of bancroftian filariasis. Transaction of the Royal Society of Tropical Medicine and Hygine.  (1998). 92, 94-97
  • Ismail M.M., Weil G.J., Jayasinghe K.A.S., Premaratne U.N., Abeywickrama W., Rajaratnam H.N ., Rezvi Sheriff M.H., Selvie Perera C. and Dissanaike A.S (1996). Prolonged clearance of microfilaraemia in patients with bancroftian filariasis after multiple high doses of ivermectin  or diethylcarbamazine. Transactions of the Royal Society of Tropical Medicine and Hygine. 90,684-688
  • Ismail, M.M., Jayakody, L., Nirmalan, N., Sheriff, R. (1994). Safety study in humans on the use of combinations of albendazole with ivermectin or diethylcarbamazine (DEC). Proc SLAAS 50(1): 1.
  • Ismail, M.M.,Jayasinghe, K.S.A., Premaratne,U.N., Abeywickreme, W., Rajaratnam, H.N., Sheriff, M.H.R., Perera , C.S. (1994). Ivermectin – Its efficacy as a macrofilaricide in Bancroftian filariasis. The first International Congress of Parasitology and Tropical Medicine August 25-28. Kuala Lampur, Malaysia.
  • De Silva, D.G.H., Hettiarachi, S., Fonseka, P.   (1987). Treatment of soil transmitted infections with albendazole CCSLMA., 98.


  1. Experimental and lab methods
  • Irvine MA, Njenga SM, Gunawardena S, Wamae CN, Cano J, Brooker SJ, Hollingsworth, TD. (2016). Understanding the relationship between prevalence of microfilariae and antigenaemia using a model of lymphatic filariasis infection. Transactions of the Royal Society of Tropical Medicine and Hygiene. 110(2): 118–124 & 110(5): 317.
  • Irvine MA, Reimer LJ, Njenga S, Gunawardena S, Kelly-Hope L, Bockarie M and Hollingsworth TD. (2015). Modelling strategies to break transmission of lymphatic filariasis – aggregation, adherence and vector physiology greatly alter elimination. Parasites & Vectors. 8: 547.
  • Adikaram ND, De Silva NR, Fernando A, Fernando D, Lamabadasuriya S, Reid CB. (2006). Filarial antigens detected in urine using immunochromatographic card test. Ceylon Medical Journal, 51 (4): 157-158
  • Siridevava, K., Karunanayake, E.H., Premaratne,U., Abeywickreme, W., Ismail, M.M. (1990). Detection of Wuchereria bancroftimicrofilaria in human blood samples using a species-specific DNA probe. Proc SLAAS 46(1): 01.
  • Sirideva, K., Karunanayake, E.H., Abeywickrama, W., Premaratne,U.N., Ismail, M.M., Jayasekara, N.(1990). Detection of L3 larvae of Wuchereria bancroftiusing a species-specific DNA probe. SLAAS 46(1):  02.
  • Jayawardena, K.H. and Premaratne, U.N. (1989). Study on bancroftian filariasis using monoclonal antibodies. Proc SLAAS 45(1): 7.
  • Amaratunga, M., Galahitiyawa, S.C., Ismail, M.M., Dissanayake, S. (1985).  Antigenic cross reactivity of trichloroacetic acid soluble antigans of Setaria digitata.  Proc SLAAS 41(1):88.
  • Fernando, P.H.P., Chandana, A.K., Sivakanesan, R., Ismail, M.M., Dissanayake, S. Premaratne, U.N., Denham, D.A., Parkhouse, R.M.E., (1985).  The use of anti-cat monoclonal antibodies in the study of Brugia pahangiinfection in cats.  Proc SLAAS 41(1): 11.
  • Dissanaike, S., Galahitiyawa, S.C., Ismail , M.M. (1983). Application of monoclonal antibodies in Wuchereria bancroftiinfections in man.  Helminthol Abs Series, A, 52 – 45.
  • Rajakulendran, S., (1983). Studies on Cardiofilaria nilesiin the chicken: A laboratory model for filariasis.  Proc SLAAS 39 (1): 7.
  • Dissanaike, S., Ismail, M.M. (1979). An enzyme linked immunosorbent assay (ELISA) for the detection of anti. Wuchereria bancroftiantibodies in human filariasis subjects.  Proc SLAAS 1:12.
  • Mendis, K., Ponnudurai, T. (1975). Specficity of indirect fluorescent antibody test for filariasis.  Proc SLAAS 1: 3.
  • Denham, A.D., Dennis, D.P., Ponnudurai, T. (1971). Comparison of a counting chamber and thick smear methods of counting microfilariae Trans R Soc Trop Med Hyg 65: 521 – 526.
  • Ponnudurai, T. (1971). The use of a membrane feeding technique for infecting mosquitoes with filarial worms transported between laboratories. J Helminthol 45: 415 – 418.
  • Dissanaike, A.S., Dissanaike, G.A., Niles, W.J., Surendranathan, R. (1966). Follow – up of 32 P labeled infection larvae of Wuchereria bancroftiin the skin of a kitten. J Helmionthol 40: 297 – 308.
  • Dissanaike, A.S., Fernando, M.A. (1965). Cardiofilaria nilesi n. sp. Recovered from a chick experimentally infected with larvae from Mansonia crassipes. J Helminthol 39: 151 – 158.
  • Dissanaike, A.S. (1965). On some gaps in our knowledge of filariases.  Ceylon Med J 10: 48 – 57.
  • Dissanaike, A.S., Niles, W.J. (1965).  Attempts to transmit Wuchereria bancroftito cats and to a toque monkey.  Ann Trop Med Parasitology 59 : 189 – 192.
  • Jayasinghe, J.B., Fernando, S.D.A., Dissanaike, A.S. (1964). Electrocardiographic evidence of cardiac hypertrophy in a hare infected with the filarial worm Brugia (Brugiella) buckleyi.  Ann Trop Med Parasitology 58 : 328 – 333.
  • Dissanaike, A.S. (1962). The use of radioisotopes in the study of helminth life cycles.  In Radioisotopes in Tropical medicine Vienna.  International Atomic Energy Agency, 322 – 340.
  • Sivalingam, V., Fernando, P.V.D. (1958). The influence of Piperazine compounds on  the development of ova of Ascaris Lumricoides.  Indian J Child Hlth. 7: 817 – 823.
  • Dissanaike, A.S., Dissanaike, G.A. Niles, W.J. (1957). Production of radioactive infective larvae of Wuchereria bancroftiin Culex fatigans. Expl Parasitol 6: 52 – 59.
  • Dissanaike, A.S., Dissanaike, G.A. Niles, W.J. Surendranathan, R. (1957). Further studies on radioactive mosquitoes and filarial larvae using autoradiographic technique. Expl Parasitol 6: 261 – 270.
  • Dissanaike, A.S., Dissanaike, G.A., Niles, W.J. (1956). Inflective filarial larvae tagged with 32Trans R Soc Trop Med Hyg 50:425


  1. Case studies
  • Gunawardena SA and Gunawardena GSA. (2008). Acute large bowel obstruction due to Ascaris lumbricoides in a child from Sri Lanka. Tropical Medicine and Health. 36: 41-43.
  • Chandrasoma, P.T., Mendis, K.N. (1978). Filarial infection of the breast.  Am J Trop Med Hyg 27: 770- 773.
  • Chandrasoma, P.T., Mendis, K.N. (1977), Enterobius vermicularisin ectopic sites.  Am J Trop Med Hyg 26: 644 – 649.
  • Chandrasoma, P.T., Mendis, K.N., Kumararatne, D.S. (1977). Microfilarial  granuloma of the breast in a patient with tropical pulmonary eosinphilia.  Am J Trop Med Hyg 26: 570 – 571.
  • Ariyatilleke, W.A. (1973). Chilomastix mesniliin a Ceylonese.  J clin Soc Gen Hosp Col Cey 4: 37.
  • Dissanaike, A.S. (1973). Dirofilaria infection in man in Ceylon.  Southeast Asian J Trop Med Pub Hlth.  4: 274 – 275.
  • Dissanaike, A.S., Lykov, V.P., Sri Skandarajah Sivayoham, I., Perera, M.C.S. (1972). Four more cases of human infection with Dirofilaria(Nochtiella) Ceylon Med J 17: 105 – 112.  (and addendum 116.)
  • Disssanike, A.S. (1972). Dirofilaria (Nochtiella) linstowi A filariotd of monkeys in Ceylon. J Helminthol 46: 117-124.
  • Dissanaike, A.S. (1971). Human infections with dirofilaria, a filarial parasite of animals in Ceylon with a brief review of recent cases. Ceylon Med J  16: 91 – 99.
  • Attygale, D., Dissanaike, A.S. (1970). The third case of human infection with Dirofilaria sp. From Ceylon. H.D. Srivastava Commemoration Volume, 453 – 454.
  • Ratnavale, W.D., Dissanaike, A.S. (1964). On the second case of human infection with Dirofilaria (Nochtiella) repensfrom Ceylon.  J Helminthol 38: 287-290.
  • Dissanaike, A.S., Aparamananthan. D.C. (1962). Some observations on Brugia (Brugiella) buckleyi. Dissanaike & Paramananthan 1961, A filarial worm from the heart and blood vessels of the Ceylon hare.  Ceylon J Med Sci 11: 15-21.
  • Fernando, C.H., Dissanaike, A.S. (1962). A hairworm (Gordiacea) “ Parasitic” in a child in Ceylon.  Ceylon J Med Sci 11 : 47 – 49,
  • Wijetilake, S.E., Attygalle, D., Dissanaike, A.S. (1962). A case of human infectition with Dirofilaria (Nochtiella)Probable repens from Ceylon.  Ceylon J Med Sci 11: 51 – 53.
  • Dissanaike, A.S., Paramananthan, D.C. (1961). Brugiatype adults and microfilariae in a Ceylon hare.  Trans R Soc Trop Med Hyg 55: 299.
  • Dissanaike, A.S., Paramananthan, D.C. (1961). On Brugia (Brugiella subgen. nov) buckleyi  from heart and blood vessels of the Ceylon hare.  J Helminthol 35: 209 – 220.
  • DissanaikeHeterophyopsis yehi, A.S., (1961). On some helminths of dogs in Colombo and their bearing on human infections, with a description of a new trematode sp.  (Heterophydae). Ceylon J Med Sci 10: 1 -12.
  • Dissanaike, A.S. (1961). Hepatozoon canisinfection in dogs in Ceylon. Ceylon Vet J 8: 144 – 145.


  1. Parasite and its features
  • Chandane, A.K., Ismail, M.M., Dissanayake, S. (1986). Surface antigens of Setaria digiata (filariae) microfilariae. Proc SLAAS 42(1): 25.
  • Chandane,A.K., Ismail, M.M., Dissanayake, S.(1986). Surface antigens of Setaria digita (filariae)  microfilariae. Proc SLAAS 42(1): 26.
  • Athauda, S.B.P., Amaratunge, M., Ismail, M.M., Dissanayake, S., Sivakanesan, R. (1985).  Lactate dehydrogenase of Setaria digitata.  Further characterization and cpmparison with the host (ox liver) LDH.  Proc SLAAS 41 (1): 91.


  1. Immunity
  • Amaratunga, M., Athanada, S.B.P., Sivakanesnan, R., Ismail, M.M., Dissanayake, S. (1984).  Carbohydrate antigens of Sertaria digitata:  Characterization and reaction with antibodies in Wuchereria bancrofti.  Infections.  Proc SLAAS 41(1):87.
  • S., Galahitiyawa. S.C., Ismail. M.M.  (1982). Immune complexes in Wuchereria bancrofti.
  • Dissanaike, S., De Silva, L.V.K., Ismail, M.M., (1979). Antigens of Setaria digitata.  Proc SLAAS 1: 12.