Genetic diversity of merozoite surface antigens in Babesia bovis detected from Sri Lankan cattle

Babesia bovis, the causative agent of severe bovine babesiosis, is endemic in Sri Lanka. The live attenuated vaccine (K-strain), which was introduced in the early 1990s, has been used to immunize cattle populations in endemic areas of the country. The present study was undertaken to determine the genetic diversity of merozoite surface antigens (MSAs) in B. bovis isolates from Sri Lankan cattle, and to compare the gene sequences obtained from such isolates against those of the K-strain. Forty-four bovine blood samples isolated from different geographical regions of Sri Lanka and judged to be B. bovis-positive by PCR screening were used to amplify MSAs (MSA-1, MSA-2c, MSA-2a1, MSA-2a2, and MSA-2b), AMA-1, and 12D3 genes from parasite DNA. Although the AMA-1 and 12D3 gene sequences were highly conserved among the Sri Lankan isolates, the MSA gene sequences from the same isolates were highly diverse. Sri Lankan MSA-1, MSA-2c, MSA-2a1, MSA-2a2, and MSA-2b sequences clustered within 5, 2, 4, 1, and 9 different clades in the gene phylograms, respectively, while the minimum similarity values among the deduced amino acid sequences of these genes were 36.8%, 68.7%, 80.3%, 100%, and 68.3%, respectively. In the phylograms, none of the Sri Lankan sequences fell within clades containing the respective K-strain sequences. Additionally, the similarity values for MSA-1 and MSA-2c were 40–61.8% and 90.9–93.2% between the Sri Lankan isolates and the K-strain, respectively, while the K-strain MSA-2a/b sequence shared 64.5–69.8%, 69.3%, and 70.5–80.3% similarities with the Sri Lankan MSA-2a1, MSA-2a2, and MSA-2b sequences, respectively. The present study has shown that genetic diversity among MSAs of Sri Lankan B. bovis isolates is very high, and that the sequences of field isolates diverged genetically from the K-strain.     

Multilocus microsatellite typing (MLMT) reveals genetic homogeneity of Leishmania donovani strains in the Indian subcontinent

In this population genetic study of Leishmania donovani parasites in the Indian subcontinent, 132 isolates obtained from patients in Bangladesh, India, Nepal and Sri Lanka suffering from Kala-azar (100), post-Kala-azar dermal leishmaniasis (PKDL) (25) and cutaneous leishmaniasis (CL) (2), and from 5 patients whose clinical patterns were not defined, were analysed by using 15 hyper-variable microsatellite loci. Multilocus microsatellite typing (MLMT) data were analysed by using a Bayesian model-based clustering algorithm and constructing phylogenic tree based on genetic distances. In total, 125 strains from Bangladesh, Bihar (India) and Nepal formed a very homogeneous population regardless of geographical origin, clinical manifestation, and whether they presented in vitro or in vivo susceptibility to antimonial drugs. Identical multilocus microsatellite profiles were found for 108 strains, other strains differed in only one marker. Considerably different microsatellite profiles were identified for three Indian strains most closely related to L. donovani from Kenya, and for four strains from Indian and Sri Lankan CL cases. The circulation of a single homogeneous population of L. donovani in Bihar (India), Bangladesh and Nepal is, most probably, related to the epidemic spread of visceral leishmaniasis in this area.     

Type-specific PCR assays for Babesia bovis msa-1 genotypes in Asia: Revisiting the genetic diversity in Sri Lanka,Mongolia, and Vietnam

Babesia bovis is the most virulent Babesia organism, resulting in a high mortality rate in cattle. The genetic diversity of B. bovis merozoite surface antigens (MSAs), such as MSA-1, MSA-2b, and MSA-2c, might be linked to altered immune profiles in the host animals. The present study aimed to develop type-specific PCR assays for Asian msa-1 genotypes, thereby re-analyzing the genetic diversity of msa-1 in Sri Lanka, Mongolia, and Vietnam. Specific primers were designed for nine Asian msa-1 genotypes, which had been detected based on the phylogeny constructed using msa-1 gene sequences retrieved from the GenBank database. Specificity of the type-specific PCR assays was confirmed using plasmids containing the inserts of msa-1 gene fragments that represent Asian genotypes. Furthermore, no amplicons were observed by these PCR assays when DNA samples of Babesia bigemina, Babesia ovata, Theileria annulata, Theileria orientalis, Trypanosoma evansi, Trypanosoma theileri, Anaplasma marginale, and Anaplasma bovis, and non-infected bovine blood were analyzed. In total, 109 B. bovis-positive blood DNA samples sourced from Sri Lanka (44 cattle), Mongolia (26 cattle), and Vietnam (23 cattle and 16 water buffaloes) were then screened by the type-specific PCR assays. The sequences derived from all of the PCR amplicons were phylogenetically analyzed. Out of 109 DNA samples, 23 (20 from cattle and 3 from water buffaloes) were positive for at least one genotype. In agreement with previous studies, five and four different genotypes were detected among the DNA samples from Sri Lanka and Vietnam, respectively. In contrast, four genotypes, including three novel genotypes, were detected from Mongolia. Five DNA samples were found to be co-infected with multiple genotypes. The sequences of the PCR amplicons clustered phylogenetically within the corresponding clades. These findings indicated that the type-specific PCR assays described herein are useful for the determination of genotypic diversity of the B. bovis msa-1 gene in Asia.     

Nutrient composition of 19 fish species from Sri Lanka and potential contribution to food and nutrition security

Fish is an important part of the Sri Lankan diet. However, existing data on the nutrient composition of fish in Sri Lanka is highly outdated and limited. The aim of this study was to report the nutrient composition of commonly consumed marine fish species in Sri Lanka and assess the potential contribution of selected key nutrients in fish to recommended nutrient intakes (RNI). Fish were sampled during a survey with research vessel Dr. Fridtjof Nansen around Sri Lanka. Species were categorised as either small (<25 cm, n = 12) or large (>25 cm, n = 7), and three composite samples from each species were analysed using accredited methods. Small species commonly consumed whole contained significantly higher concentrations of micronutrients such as calcium (960 mg/100 g), iron (3.3 mg/100 g), zinc (2.1 mg/100 g), vitamin A (295 μg/100 g), and EPA and DHA (0.14 and 0.32 g/100 g, respectively) than larger species where only the fillet is consumed. Several species were identified to contribute ≥25 % of the RNI of women of reproductive age for multiple essential nutrients. These data may represent an important contribution to the future development of the Sri Lankan food composition database.     

Leishmania donovani and cutaneous leishmaniasis, Sri Lanka

To investigate the relationship of cutaneous leishmaniasis isolates from Sri Lanka to known species, we performed DNA sequencing and microsatellite analyses. We identified Leishmania donovani as the agent of Sri Lanka cutaneous leishmaniasis and showed that these parasites are closely related to those causing visceral leishmaniasis in the Indian subcontinent.     

Influence of evolutionary events on the Indian subcontinent on the phylogeography of dengue type 3 and 4 viruses

During 1960–80 dengue disease profile in India was mild despite circulation of all four serotypes of dengue virus (DENV). Increase in disease severity with a concomitant change in the population of DENV-1 and 2 have been reported since then. To determine population dynamics of DENV-3 and 4, the envelope (E) gene sequence was determined for 16 Indian isolates of DENV-3 and 11 of DENV-4 and analyzed together with 97 DENV-3 and 43 DENV-4 global sequences.All Indian DENV-3 isolates belonged to genotype III, lineages C, D, E and F. Lineage F was newly identified and represented non-circulating viruses. Three non-conservative amino acid changes in domain I, II & III were identified during the transition from lineages F/E, associated with mild disease, to A–D, associated with severe disease. For DENV-4, the current viruses clustered in genotype I, lineage C, whilst the isolates from 1960s formed the new genotype V. A 1979 Indian isolate of DENV-4 was found to be an inter-genotypic recombinant of Sri Lankan isolate (1978) of genotype I and Indian isolate (1961) of genotype V. The rates of nucleotide substitution and time to the most recent common ancestor (tMRCA) estimated for DENV-3 (1782–1934) and DENV-4 (1719–1931) were similar to earlier reports. However, the divergence time for genotype III of DENV-3, 1938–1963, was a more accurate estimate with the inclusion of Indian isolates from the 1960s. By phylogeographical analysis it was revealed that DENV-3 GIII viruses emerged from India and evolved through Sri Lanka whilst DENV-4 emerged and dispersed from India.The present study demonstrates the crucial role that India/Sri Lanka have played in the evolution and dispersion of the major genotypes, GIII of DENV-3 and GI of DENV-4 which are more virulent and show higher dissemination potential.     

First report of Nosomma monstrosum ticks infesting Asian water buffaloes (Bubalus bubalis) in Pakistan

Nosomma monstrosum Nuttall & Warburton, 1908 is a hard tick infesting mainly Asian water buffaloes, but it has also been recorded from cattle, horses, bears, dogs, wild boar and humans in the Oriental region. This tick species has previously not been recorded from Pakistan. A total of 15 adult N. monstrosum ticks (five females and ten males) were collected from an Asian water buffalo herd grazing in Haripur district, Khyber Pakhtunkhwa (KP), Pakistan. Molecular characterization using partial 12S, 16S rRNA, and cytochrome c oxidase 1 (cox1) gene sequences confirmed the identity as N. monstrosum. A phylogenetic analysis showed that N. monstrosum from Pakistan is closely related to specimens reported from Sri Lanka and Vietnam.     

Population genetics of the malaria vector Anopheles aconitus in China and Southeast Asia

Anopheles aconitus is a well-known vector of malaria and is broadly distributed in the Oriental Region, yet there is no information on its population genetic characteristics. In this study, the genetic differentiation among populations was examined using 140 mtDNA COII sequences from 21 sites throughout Southern China, Myanmar, Vietnam, Thailand, Laos and Sri Lanka. The population in Sri Lanka has characteristic rDNA D3 and ITS2, mtDNA COII and ND5 haplotypes, and may be considered a distinct subspecies. Clear genetic structure was observed with highly significant genetic variation present among population groups in Southeast Asia. The greatest genetic diversity exists in Yunnan and Myanmar population groups. All population groups are significantly different from one another in pairwise Fst values, except Northern Thailand with Central Thailand. Mismatch distributions and extremely significant F_s values suggest that the populations passed through a recent demographic expansion. These patterns are discussed in relation to the likely biogeographic history of the region and compared to other Anopheles species.     

Incidence and predictors of onboard injuries among Sri Lankan flight attendants

Background  

Occupational injuries among flight attendants have not been given appropriate attention in Sri Lanka. The purpose of this study was to estimate the incidence of onboard injury among Sri Lankan flight attendants and to describe the determinants of onboard injury.     

Sri Lankan tsunami refugees: a cross sectional study of the relationships between housing conditions and self-reported health

Background  

On the 26^th December 2004 the Asian tsunami devastated the Sri Lankan coastline. More than two years later, over 14,500 families were still living in transitional shelters. This study compares the health of the internally displaced people (IDP), living in transitional camps with those in permanent housing projects provided by government and non-government organisations in Sri Lanka.     

Molecular epidemiology of human rabies viruses in Sri Lanka

Rabies is a lethal zoonotic disease caused by the rabies virus, which is transmitted by rabid animals to humans. Rabies is prevalent in all continents, with over 60% of human deaths occurring in Asia. Sri Lanka is a rabies-endemic country. This study shows that rabies afflicted more older individuals than children in Sri Lanka between 2008 and 2010. This novel finding indicates that older people in Sri Lanka should be more aware of the risk of rabies. Phylogenetic analyses of the rabies N and G genes showed that the Sri Lankan rabies viruses are distinct and probably originated from a single clone. The G–L noncoding region is highly diverse, and is suitable for the analysis of virus evolution within a country. A phylogenetic analysis of this region showed high diversity in the currently circulating Sri Lankan rabies viruses, which can be divided into seven clades. Some clades are unique to a specific geographic region, whereas others occur at multiple locations. This indicates that the movement of dogs, the main rabies-transmitting animal in Sri Lanka, is restricted in some areas but less limited in others. These data may help to formulate a more efficient rabies control program in Sri Lanka.     

Consumption and use of the winged bean by Sri Lankan villagers†

The objectives of this study were to investigate the production, preparation, consumption and use of the winged bean by Sri Lankan villagers, to identify their perceptions of its value as a food, and to assess the potential for its increased production and consumption in Sri Lanka. The investigators found that the winged bean plant is well known and integrated into the foodways of the Sinhalese, Buddhist Sri Lankan, but that only the tender, immature pods and leaves are normally eaten. Intervention efforts to increase the consumption of any of the winged bean parts will require modifications in the foodways of the Sri Lankans.

The winged bean (Psophocarpus tetragonolobus) is a creeper in the Leguminoseae family that grows wild and under cultivation in the humid, tropical areas of South and Southeast Asia and the Western Pacific. The plant has recently received international attention because of its ability to fix large amounts of nitrogen, and as a result the pods, leaves, seeds, and tuberous roots are uniquely rich in protein.     

Developmental screening in context: adaptation and standardization of the Denver Developmental Screening Test-II (DDST-II) for Sri Lankan children

Background Developmental problems in children can be alleviated to a great extent with early detection and intervention through periodic screening for developmental delays during pre-school ages. Currently, there is no established system for developmental screening of children in Sri Lanka. Although some developmental norms, which are similar to those of Denver Developmental Screening Test-II (DDST-II), have been introduced into the Sri Lankan Child Health Developmental Record (CHDR), those norms have not been standardized to the Sri Lankan child population. The aim of this research was to establish Sri Lankan norms for DDST-II and to test the universal and regional applicability of developmental screening tests by comparing the Sri Lankan norms with the norms of DDST-II and DDST-Singapore norms, the geographically nearest standardization of DDST-II. The norms were also compared with the milestones already available in the CHDR. Methods DDST-II was adapted and standardized on a sample of 4251 Sri Lankan children aged 0-80 months. Thirteen public health nursing sisters were trained to collect the data as part of their routine work. The 25th, 50th, 75th and 90th percentile ages of acquiring each developmental milestone were then calculated using logistic regression. Results The Denver Developmental Screening Test for Sri Lankan Children (DDST-SL) was created. Most of the established DDST-SL norms were different to the comparable norms in DDST-II, DDST-Singapore and the CHDR. Conclusions In view of the results of the study, it is imperative that developmental screening tests are used in context and are adapted and standardized to the populations in question before utilization.     

Sri Lanka and the possibilities of achieving universal health coverage in a poor country

Sri Lanka has been lauded for providing good health coverage at a low cost despite having a modest per capita income. This article identifies the unique historical factors that enabled Sri Lanka to achieve near universal coverage, but it also discusses how this achievement is now being undermined by inadequate government investment in health services, the burdens of non-communicable diseases, and the growing privatisation of health services. In doing so, the article highlights the challenges of achieving and maintaining universal health coverage in a relatively low income country with a health system designed to treat infectious diseases and provide child and maternal health services as the country undergoes an epidemiological transition from infectious to non-communicable diseases. Using updated information on developments in the Sri Lankan health system, this article argues, in contrast with earlier publications, that Sri Lanka is no longer providing good health at a low cost. It shows that Sri Lanka’s low investment in health is detrimental and not an asset to achieving good health. The article also questions the possibilities of providing coverage for noncommunicable diseases at a low cost. The article has four main sections. The first details Sri Lanka’s accomplishments in moving toward universal health coverage. The second identifies the factors enabling Sri Lanka to do so. The third describes the equity and access challenges the health system now confronts. The fourth assesses what the Sri Lankan experience suggests about the requirements for universal health coverage when providing health services for treating non-communicable diseases becomes an important consideration.     

Congenital malaria due to Plasmodium vivax: a case report from Sri Lanka

A case of Plasmodium vivax malaria in an eight-week-old infant in Colombo is documented, with epidemiological and circumstantial evidence which strongly supports a transplacental route of infection. The malarial antibody levels detected by the indirect fluorescent antibody technique in both mother and child are discussed in terms of the present epidemiological pattern of malaria in the country. We also comment on the species incidence of congenital malaria, this case being the first caused by P. vivax in Sri Lanka, despite this species being more prevalent than P. falciparum which has been reported in six previous cases of congenital malaria in Sri Lanka.     

Prevalence of occupational injury and its contributing factors among rubber tappers in Galle,Sri Lanka

Background: Rubber tapping involves carrying heavy loads, navigating rough terrain, and using sharp tools. However, little is known about occupational injury among this vulnerable working population.

Objective: To assesses the prevalence, severity, and contributing factors associated with occupational injury among Sri Lankan rubber tappers and to identify possible interventions to improve occupational safety.

Methods: A questionnaire was administered to 300 Sri Lankan rubber tappers. The associations between tapper characteristics and injury within the last year were examined using log-binomial regression models. Short response answers were analyzed using qualitative content analysis.

Results: 300 tappers reported 594 injuries in the previous 12 months, and missed 1,080 days of work. The prevalence of one or more injuries was 49%. Factors associated with injury were being female, working an additional job, tapping with a two-handed approach, and depressive symptomology. Qualitative findings suggest three interventions to address injuries: (1) landscaping, (2) personal protective equipment, and (3) provision of eyeglasses.

Conclusions: Work-related injuries are common among Sri Lankan rubber tappers. These results highlight the importance of working with and including informal workers in the creation of Sri Lankan occupational health and safety regulations. We believe that the three interventions identified by respondents could help to reduce the risk of occupational injury among rubber tappers.     

Why is health relatively poor on Sri Lanka's tea estates?

The mountainous interior of Sri Lanka is one of the world's great tea-producing areas. The labour force on the tea estates consists of a population which has migrated from Tamil Nadu, in southern India, over the last one hundred years. This migrant population is known as 'Indian Tamils' and is largely drawn from the two largest Harijan castes of agricultural labourers in Tamil Nadu. On the now government owned estates, they have formed a kind of industrial proletariat, living in long estate line housing where each family has one or two rooms. The women, who are the tea pickers, work longer hours than do the men. The Indian Tamils have been characterized by markedly higher mortality than the indigenous population (Sinhalese, Sri Lankan Tamils and Moors). This paper reports a research program which was carried out in 1987 and which employed both anthropological and demographic survey techniques in an attempt to explain these higher mortality levels. The research identified the origins of higher mortality, both in limited access to health provision and in the social characteristics and economic circumstances of the community.     

Quantifying Urbanization as a Risk Factor for Noncommunicable Disease

The aim of this study was to investigate the poorly understood relationship between the process of urbanization and noncommunicable diseases (NCDs) in Sri Lanka using a multicomponent, quantitative measure of urbanicity. NCD prevalence data were taken from the Sri Lankan Diabetes and Cardiovascular Study, comprising a representative sample of people from seven of the nine provinces in Sri Lanka (n = 4,485/5,000; response rate = 89.7%). We constructed a measure of the urban environment for seven areas using a 7-item scale based on data from study clusters to develop an “urbanicity” scale. The items were population size, population density, and access to markets, transportation, communications/media, economic factors, environment/sanitation, health, education, and housing quality. Linear and logistic regression models were constructed to examine the relationship between urbanicity and chronic disease risk factors. Among men, urbanicity was positively associated with physical inactivity (odds ratio [OR] = 3.22; 2.27–4.57), high body mass index (OR = 2.45; 95% CI, 1.88–3.20) and diabetes mellitus (OR = 2.44; 95% CI, 1.66–3.57). Among women, too, urbanicity was positively associated with physical inactivity (OR = 2.29; 95% CI, 1.64–3.21), high body mass index (OR = 2.92; 95% CI, 2.41–3.55), and diabetes mellitus (OR = 2.10; 95% CI, 1.58 – 2.80). There is a clear relationship between urbanicity and common modifiable risk factors for chronic disease in a representative sample of Sri Lankan adults.     

A feasibility study for the establishment of a national wildlife health centre in Sri Lanka

Sri Lanka is a tropical nation within a zoogeographic zone that is at high risk for infectious disease emergence. In 2010, a study was conducted on the feasibility of enhancing capacity in Sri Lanka to manage wildlife diseases through the establishment of a national wildlife health centre. The Canadian Cooperative Wildlife Health Centre was assessed as a potential model for adaptation in Sri Lanka. Interviews and group meetings were conducted with potential key participants from the Sri Lankan Departments of Wildlife Conservation and Animal Production and Health, and the Faculty of Veterinary Medicine and Animal Science of the University of Peradeniya. In addition, site visits were made to potentially participating facilities and the literature on best practices in building scientific capacity was consulted. With strategic enhancements in education and training, additional personnel, improvements in transportation and diagnostic facilities, and central coordination, Sri Lanka appears very well positioned to establish a sustainable wildlife health centre and programme.     

A profile of biomass stove use in Sri Lanka

A large body of evidence has confirmed that the indoor air pollution (IAP) from biomass fuel use is a major cause of premature deaths, and acute and chronic diseases. Over 78% of Sri Lankans use biomass fuel for cooking, the major source of IAP in developing countries. We conducted a review of the available literature and data sources to profile biomass fuel use in Sri Lanka. We also produced two maps (population density and biomass use; and cooking fuel sources by district) to illustrate the problem in a geographical context. The biomass use in Sri Lanka is limited to wood while coal, charcoal, and cow dung are not used. Government data sources indicate poor residents in rural areas are more likely to use biomass fuel. Respiratory diseases, which may have been caused by cooking emissions, are one of the leading causes of hospitalizations and death. The World Health Organization estimated that the number of deaths attributable to IAP in Sri Lanka in 2004 was 4300. Small scale studies have been conducted in-country in an attempt to associate biomass fuel use with cataracts, low birth weight, respiratory diseases and lung cancer. However, the IAP issue has not been broadly researched and is not prominent in Sri Lankan public health policies and programs to date. Our profile of Sri Lanka calls for further analytical studies and new innovative initiatives to inform public health policy, advocacy and program interventions to address the IAP problem of Sri Lanka.