HOMERESEARCH

RESEARCH

Distribution of Leishmania vector and associated risk factors for disease transmission

Summary

Leishmaniasis is emerging as a major health threat in Sri Lanka. Recently, the number of cases has been increased dramatically.Sri Lanka is the newest reported focus of leishmaniasis in the Indian subcontinent where the disease is caused by the most virulent visceralizing species, Leishmania donovani. However, the potential for visceralization in the cutaneous variant of L. donovani in Sri Lanka is not known.

There has been very little published research on the taxonomy, geographical distribution, prevalence and biology of sandflies in Sri Lanka, which is grossly inadequate to implement a control programme. Even though an action plan has been drawn by the Ministry of Health in 2008 from control, it has not become a practical effort since many of the health staff involves in control activities rather do not have a proper knowledge on the disease. Given the importance of leishmaniasis vectors, investigations on the biology and behaviour of these insects should be integrated into routine of public health services, especially in areas where the disease is endemic. The studies on sandflies are essential to determine the fauna, their distribution, population dynamics, involvement in transmission and ultimately for building up cost effective methods for disease control.Colonies of insect vectors are suitable for a wide range of investigations, from basic biological aspects to applied research. Laboratory colonies are essential to understand sandfly physiology, epidemiology of Leishmaniasis, and parasite vector-host relationships. There is no proper insectary in Sri Lanka which maintains the medically important sandflies for experimental research purposes as described above.

Therefore, this project focuses to establish facilities and techniques for the maintenance medically important leishmaniasis vectors. Thereby, key research areas such as physiology of sandflies, epidemiology leishmaniases, parasite vector-host relationships, systematic of leishmaniasis vectors, vector biology and vector bionomics will be studied in detail. Hence, the establishment of a sandfly colony at a laboratory setting would be an useful effort to study about the above aspects which, no adequate studies performed in Sri Lanka up till now. This study may add new information to the existing knowledge of leishmaniasis disease in Sri Lanka, which would also facilitate to adopt appropriate control measures upon evidence based approaches. Further, the proposed laboratory will be expanded as a training and research centre with sufficient material and facilities for experimental research on leishmaniasis in the country. A reference collection of sandflies will be established at the Faculty of Medicine, University of Kelaniya. The collection will be opened for entomologists and scientists who are willing to do future studies relevant to medical entomology.

Funding Source: National Research Council (NRC), Sri Lanka- Grant No. NRC 16-142.

Amount: LKR 4,977,500.00

Message from the Principal Investigator

dr.nayana Sri Lanka is the newest reported focus of Leishmaniasis in the Indian subcontinent, where the disease is caused by the most virulent visceralizing species, Leishmania donovani MON-37.However, the potential for visceralization in the cutaneous variant of L. donovani in Sri Lanka is not known. Detection of the disease in Sri Lanka is passive and only the patients seeking medical attention for their symptoms are screened for the presence of parasites. No organized programmes are conducted to detect patients at early stages of infection.

The studies on sandflies are essential to determine the fauna, their distribution, population dynamics, involvement in transmission which ultimately are useful for building up cost effective methods for disease control. The vector(s) of the disease is yet to be confirmed apart from some recent studies showing the vectorial capacity of Phlebotomus (Euphlebotomus) argentipes indicating it as a vector. Therefore, proper identification of vector species is of paramount importance. Unfortunately, the number of sand fly species present in the country is still suspicious. There has been very little published research on the taxonomy, geographical distribution, prevalence, resting, breeding, host preferences and biology of sandflies in Sri Lanka, which are grossly inadequate to implement a control programme. Some studies have shown that the level of awareness of the disease among the local population is very low and some people have never heard of the disease even though they are living in an endemic area.

Given the importance of Leishmania vectors, investigations of the biology, behavior, distribution and population dynamics of these insects should be integrated into routine of public health services, especially in areas where the disease is endemic. Further, immediate actions are essential in order to increase the scientific knowledge about the disease and a higher effectiveness in the patient management. Therefore, the present research funded by the National Research Council (NRC 16-142) of Sri Lanka will enable to reduce the knowledge gaps related to the above aspects. 

Principal Investigator

Dr. Nayana Gunathilaka
Department of Parasitology
Faculty of Medicine
University of Kelaniya
Sri Lanka.
E mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Tel- 071- 8733816

Co-Investigator

Prof. N. K. Gunewardena
Department of Parasitology,
Faculty of Medicine,
University of Kelaniya,
Sri Lanka.      

Research Assistant

Mr. Tharaka Wijerathne
Department of Parasitology
Faculty of Medicine
University of Kelaniya
Sri Lanka.

Metodology

Study areas: Polpothigama, Galgamuwa and Maho MOH areas in Kurunegala District.
Duration: 3 years (2016-2019)

Entomological survey

re-4 re-1 re-3 re-2

Hand catch  

Light trap Cattle Baited Net Trap (CBNT)        Sticky trap 

 

Field Work

Laboratory Work

 

National survey of intestinal nematode infections in Sri Lanka-2017

Summary

This survey covers all nine administrative provinces of Sri Lanka, as well as populations known to be at high risk of intestinal nematode infections, living in low income settlements in the coastal cities and in the plantations in the central part of the country. The study population consists of children attending Grade 1 and Grade 2 in state schools, i.e. children aged 5 – 7 years of age.  Survey is carried out in randomly selected 130 Schools covering all nine provinces.

Entire survey coordinates by the Department of Parasitology, Faculty of Medicine, University of Kelaniya. Four other medical faculties involve in data collection process in different provinces.

  • Department of Parasitology, University of Kelaniya–Sabaragamuwa and North Western Provinces
  • Department of Parasitology, University of Colombo– Western and North Central provinces
  • Department of Parasitology, University of Peradeniya –Central province
  • Department of Parasitology, University of Jaffna – Northern and Eastern provinces
  • Department of Parasitology, University of Ruhuna – Southern and Uva provinces
  • The island-wide survey collaborates with Family Health Bureau, Ministry of Health, Sri Lanka for the follow up of positive cases.

General Objective

To determine the prevalence of STH infections and enterobiasis among school children in Sri Lanka, in order to guide the national deworming strategy for the period 2017 – 2020. 

Specific Objectives

  • To determine the prevalence of Soil Transmitting Helminth (STH) infections among school children in each province of Sri Lanka, and in high risk populations in the plantation sector and low income settlements in urban areas.
  • To determine the prevalence of enterobiasis among school children in each province of Sri Lanka, and in high risk populations in the plantation sector and low income settlements in urban areas.

Funding Source: Children Without Worms, Task Force Global Health, Atlanta, GA, USA

Amount: US$ 31,168.00

Principal investigator

Prof. Nilanthi de Silva
Senior Professor of Parasitology, Dean of the Faculty of Medicine
University of Kelaniya


Co- Investigators

Prof. N.K. Gunawardena
Department of Parasitology
Faculty of Medicine
University of Kelaniya

Prof. A. Pathmeswaran
Department of Public Health
Faculty of Medicine
University of Kelaniya.

Prevalence of ectoparasitic infections among school children in the Gampaha District, Sri Lanka

 

Summary

Ectoparasites are responsible for a heterogenous group of infections affecting the external layers of the skin. Scabies and pediculosis (capitis, corporis and pubis) are among the most common in the group. These parasites have a worldwide prevalence and induce skin lesions either directly such as with urticarial papules and indirectly as result of itching and hypersensitivity to parasite antigens and in some instances skin superinfections. Transfer of these ectoparasites from person to person occur via intimate personal contact and is facilitated by overcrowding, uncleanliness and sexual promiscuity. Outbreaks commonly occur in nursing homes mental institutions and hospitals.               

More importantly, the itchiness causes scratching of the skin leading to secondary bacterial infection of the lesions. School life is the foundation for the future and have a major effect on host of issues including health. Providing easy access to hygiene, nutrition and health education and services to school children is a simple and cost effective tool that can go a long way in the prevention and control of communicable and non-communicable diseases. A health survey done in 1999 among children under 12 years of age living with their imprisoned mothers at the Welikada Prison in Sri Lanka reports a scabies and pediculosis prevalence of 25% and 10% respectively. Also the risk factors for spread of scabies such as overcrowding, and socio-economic factors have not been studied in Sri Lanka

Objectives

General objective

  • Investigate the prevalence of ectoparasitic infections among school children in the Gampaha district/ Sri Lanka

Specific objectives

  • Determine the prevalence of scabies infection among school children in the district of Gampaha.
  • Determine the prevalence of pediculosis among school children in the district of Gampaha/ Sri Lanka.

Principal Investigator

Dr. Nayana Gunathilaka
Department of Parasitology
Faculty of Medicine
University of Kelaniya
Sri Lanka.

E mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Tel- 071- 8733816

Co-Investigator

Prof. Nilmini Chandrasesna
Department of Parasitology,
Faculty of Medicine,
University of Kelaniya,
Sri Lanka.

 

Presence of zoonotic Brugia malayi in humans, cats, and dogs in selected areas of Gampaha district of Sri Lanka

Summary

This is a studyto evaluate epidemiology, periodicity and the possibility of the existence of zoonotic reservoir/s of remerging Brugian filariasis in Sri Lanka.  Screening of human population for Brugia filarial parasites was done in selected areas (SA) of Gampaha District. The present study includes a survey of cats and dogs within 350m radius buffer zones of human Brugian microfilariae positive cases of whole Sri Lanka. All the cats and dogs (both stray and domestic) within the SAs at the screening time period of given SA, will be taken as the study population.

Objectives

  • To determine the most vulnerable age group for human Brugia malayi infection
  • To determine the presence of Brugia malayi in cats and dogs in human Brugia malayi positive areas
  • To identify the possible animal reservoirs for human Brugia malayi infections
  • To determine the periodicity of  human Brugia infections in Sri Lanka

The study was conducted atthe Department of Parasitology, Faculty of Medicine, University of Kelaniya.  

Funding Source: University of Kelaniya [Strengthening Research 2016, grant No. RP/03/SR/04/06/01/2016] and Medical Research Institute [Project No: 40/2016] 

Investigators

  • Prof.T.G.A.N. Chandrasena
  • Dr. C.H. Mallawarachchi
  • Dr.S.D. Samarasekara
  • Prof.N.R. de Silva

 

 

 

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