Sublineages of Beijing Strain of Mycobacterium tuberculosis in Sri Lanka.

Strains of the Beijing/W genotype of Mycobacterium tuberculosis have been responsible for large outbreaks of tuberculosis around the world, sometimes involving multi-drug resistance. It has been shown that more recently evolved Beijing sublineages are prone to cause outbreaks. Furthermore Beijing is the single predominant cluster in Sri Lanka. The present study identifies that recently evolved sublineages of Beijing strains are present in the study population. The majority of Beijing isolates (92.85%) were pan-susceptible. However, these findings may have important implications for the control and prevention of tuberculosis in Sri Lanka.

A simple, cost effective method for isolation and transportation of Leishmania parasites.

Isolation and propagation of Leishmania parasites using conventional culture methods are difficult, especially under field conditions. Transportation of live parasites requires the maintenance of low temperatures, which increases the cost considerably. The present study demonstrates that monophasic micro capillary culture is a simpler, more economical and better alternative to using conventional Evan's modified Tobie's medium to isolate and transport the Leishmania parasite over long distances without the use of temperature control methods.

Is leishmaniasis in Sri Lanka benign and be ignored?

Cutaneous leishmaniasis is now an endemic disease in Sri Lanka. Many studies have focussed on various aspects of this disease but the knowledge, particularly on epidemiological and vector aspects is still poor and the awareness among the general public and even medical/paramedical personnel regarding this disease remains grossly inadequate. The steady increase in the numbers and spread of cutaneous leishmaniasis cases in Sri Lanka and the very close similarity (genotypic and phenotypic) between the local parasite Leishmania donovani MON-37 and the parasite causing visceral leishmaniasis in India (L. donovani MON-2), considered together with the more recent case reports of autochthonous cases of visceral disease in this country, calls for urgent action for setting up of a surveillance programme to estimate the true disease burden and to implement an organized control strategy, combined with operational and epidemiological research to aid control efforts to avert a potentially major catastrophe of more virulent form of leishmaniasis, particularly the visceral type becoming endemic in Sri Lanka.

Molecular diversity of Mycobacterium tuberculosis isolates from patients with pulmonary tuberculosis in Sri Lanka.

The strain diversity of 100 Mycobacterium tuberculosis isolates collected over a period of 18 months from tuberculosis (TB) cases in Sri Lanka was studied by spoligotyping. When compared to the international spoligotyping database, 43 spoligotype patterns were identified, of which 20 were previously described. The majority of isolates (72.45%) were clustered into major genetic group 1, and the most common spoligotype pattern belonged to the Beijing (ST1) strain family. All the Beijing strain isolates belonged to more recently evolved sublineages of M. tuberculosis. The characterization of Sri Lankan M. tuberculosis isolates by spoligotyping shows a heterogeneous pattern. The physical separation from the main Indian peninsula may be responsible for the different patterns observed between the two countries. An in-depth field study is needed to understand the spread and the true epidemiology of this infection.

Cutaneous leishmaniasis in southern Sri Lanka.

Cutaneous leishmaniasis is an established disease in Sri Lanka. The majority of cases have been reported from the North-Central Province, with the southern parts of the country considered less affected. However, during 2004, when the services of a dermatologist were available, a considerable number of patients were referred from the Southern Province, which formed the basis for this study. The clinical pattern, detailed geographical distribution within the Southern Province and periodicity of the cases were studied over a period of 12 months. Of the 113 patients diagnosed, the highest number was within the 10-19 years age group. Most patients were from densely populated rural areas around Matara, a large town within this province. There was a notable increase in the number of cases presenting during February-March and August-September, which are periods following monsoonal rains. Exposed areas of the skin were commonly affected, with the majority of patients having single lesions. Females and males were equally affected. This is in contrast to our previous findings in the North-Central Province where the majority of patients were male soldiers with multiple lesions.

Microculture for the isolation of Leishmania parasites from cutaneous lesions -- Sri Lankan experience.

Novy, McNeal and Nicolle (NNN) medium and Evans' modified Tobie's medium are two conventional media for the isolation of Leishmania parasites in in-vitro cultures. Both are biphasic, with a solid layer of blood agar, and are normally prepared in glass test-tubes. In Sri Lanka at least, a monophasic microcapillary culture, based solely on RPMI 1640 medium supplemented with foetal calf serum, has been found simpler, more economical and more sensitive, for the isolation of L. donovani from skin lesions, than the use of Evans' modified Tobie's medium.