Interleukin 15: its role in inflammation and immunity

Interleukin 15 (IL-15) is a 14-15 kDa polypeptide that belongs to the 4 alpha-helix-bundle family of cytokines and was originally discovered due to its T cell proliferative activity. It utilizes the signal-transducing beta/gamma polypeptides of the IL-2 receptor complex, thus sharing many biological activities with IL-2, in addition to its high-affinity private receptor subunit IL-15R alpha. Accumulating evidence indicates that the biological relevance of IL-15 may not solely be confined to T lymphocytes, but to a variety of cell populations within the immune system as well as outside the immune system of the host. The expression of both IL-15 and its high-affinity receptor component, IL-15R alpha, are readily demonstrable in a wide variety of tissues and appear to be augmented in response to environmental/stress stimuli and infectious agents. There is increasing evidence to suggest that IL-15 may play an important role in protective immune responses, allograft rejection and the pathogenesis of autoimmune diseases, where mononuclear cell infiltration is a hallmark feature. Herein, the effects of IL-15 on cells associated with host defense, immunity and inflammation are reviewed and support a central role for this cytokine in orchestrating multiple aspects of effector functions in immunity and inflammation.     

Strong association between house characteristics and malaria vectors in Sri Lanka

The objective of this study was to determine whether house characteristics could be used to further refine the residual insecticide-spraying program in Sri Lanka. Indoor-resting mosquito densities were estimated in 473 houses based on fortnightly collections over a two-and-a-half-year period. The type of house construction and the exact location of all houses were determined. In a multivariate analysis, distance of less than 750 meters between a house and the main vector-breeding site was strongly associated with the presence of Anopheles culicifacies in the house (odds ratio [OR] 4.8, 95% confidence interval [CI] 3.4-6.8) and to a lesser extent with the presence of An. subpictus (OR 1.4, 95% CI 1.1-1.7). Poor housing construction also was an independent risk factor (OR for An. culicifacies 1.3, 95% CI 1.0-1.9; OR for An. subpictus 1.3, 95% CI 1.0-1.6). It is recommended that a malaria control strategy focus on residential areas within 750 meters of streams and rivers, with special attention given to areas with the poorest type of house construction.     

A development framework for promoting evidence-based policy action: drawing on experiences in Sri Lanka

Most developing countries have embarked on one form or another of 'health sector reform' as a result of the global trend for health and health care reform that has emerged during the past decade. One consequence is that the issue of health sector performance is moving higher on the agenda of many developing countries, and particularly that of the corporate performance of health sector staff. Along with this movement has come increased attention to strengthening evidence-based management decision-making. To date, studies on measuring health sector performance, have had little impact on developing country health systems and have been limited to explorations primarily at an operational level. However, there is a growing recognition that there is a need to strengthen the policy function of ministries and their ability to monitor policy impact. Sri Lanka is one country that has identified the need to strengthen policy at national level. Many developing countries, like Sri Lanka, are familiar with input, process and output dimensions of operational performance. However, most are not ready to engage in routine performance assessment that can strengthen policy processes at national level. This paper explores (1) the implication and the use of indicators to support evidence based policy decision-making, and (2) the complexity of doing so in Ministries of Health that are undergoing some form of health sector reform. The paper emphasizes that new forms of organizational support are required for performance management at policy level. A conceptual framework for managing the collection and use of performance evidence is developed, including proposals for the introduction of outcome indicators into that process. The paper concludes with recommendations on initiatives required to develop appropriate organizational and technical capacity to engage with performance management at policy level and for further research towards creating ministries of health as 'learning organizations' that can change and adapt with informed decisions.     

Experience with the oral iron chelator deferiprone in transfusion-dependent children

OBJECTIVE: To establish efficacy and safety of deferiprone. DESIGN: Prospective study. SETTING: The Lady Ridgeway Hospital for Children, Colombo. PATIENTS: Transfusion-dependent children in the age group 1 to 15 years. INTERVENTION: Patients were given 75 mg/kg/day of deferiprone orally in divided doses. MEASUREMENTS: Efficacy of deferiprone therapy was assessed by 4 to 6 monthly serum ferritin (SF) assays. Safety of therapy was assessed by 4-weekly white cell counts and serum alanine aminotransferase (ALT) levels. The Z-score was used to assess the significance of the difference between the mean initial and final SF level. RESULTS: 82 patients received deferiprone therapy for a mean duration of 30 +/- 14 months. Initial SF levels ranged from 1115 to 12,165 micrograms/l with a mean of 5156 +/- 2631 micrograms/l. Final SF levels ranged from 312 to 15,285 micrograms/l with a mean of 2809 +/- 2380 micrograms/l (Z score 5.99; p < 0.001). Two (2.4%) children developed agranulocytosis which reverted to normal on discontinuation of treatment. 41 (50%) developed arthropathy and in 17 this was severe enough to require discontinuation of therapy. Serum ALT levels were raised in 35 (43%) patients but reverted to pretreatment values or lower despite continuation of deferiprone therapy. There was one death in a 9-year old child who developed diabetes mellitus and heart failure despite deferiprone therapy for 3 years. CONCLUSIONS: A final SF level < 2500 micrograms/l was achieved in 52% children. Severe arthropathy and agranulocytosis may necessitate permanent discontinuation of therapy.     

The isolation of Burkholderia cepacia in a hospital setting in Sri Lanka

INTRODUCTION: Burkholderia cepacia is widely prevalent in nature. The natural habitat of this organism is soil, water and vegetation, but the hospital environment remains the main source of infection. It causes a wide variety of infections in hospitalised patients. Since there are no reports of its prevalence in Sri Lanka, a data retrieval and analysis was undertaken to determine its incidence among patients at Sri Jayawardenepura General Hospital (SJGH). OBJECTIVE: To determine the prevalence, morphological characteristics, biochemical profile and antibiotic susceptibility pattern of B cepacia in a Sri Lankan tertiary care hospital. METHODS: Relevant clinical data were retrieved from all isolates of B cepacia from SJGH for 12 months from October 1996. Standard procedures were used to isolate the organism from clinical specimens. API 20E was employed for biochemical identification. Antibiotic susceptibility tests was carried out using the modified Kirby Bauer method. RESULTS: B cepacia was isolated from 17 patients. 16 of them were hospitalised and were from the medical, surgical, and intensive care units. All were in a compromised state of health. The organism was isolated from a variety of specimens which included swabs of surgical wounds, chronic ulcers, sputum, bronchial lavage, endotracheal aspirate, urine, peritoneal fluid and blood. Blood agar, MacConkey agar and cystine lactose electrolyte deficient medium supported the growth of all strains. They were motile Gram negative rods. All strains were oxidase positive. Strains gave variable results with other biochemical tests. Antibiograms too were variable. All strains were sensitive to ceftazidime, and the majority of the strains were sensitive to the other third generation cephalosporines. All strains were resistant to four or more antimicrobial agents included in the study. Of the 17 patients from whom B cepacia was isolated, only 9 seem to have had actual infection; others were probably instances of colonisation or contamination. CONCLUSIONS: The present report confirms the prevalence and importance of B cepacia as a hospital pathogen in Sri Lanka. Hospital laboratories should be equipped to isolate, identify and perform antibiotic sensitivity test on these strains. Antibiotic susceptibility testing is necessary as the patterns seem to differ among strains. The multiple drug resistant nature of the organism warrants strict infection control measures to prevent spread in a hospital setting.     

A village treatment center for malaria: community response in Sri Lanka

Early diagnosis and treatment of malaria cases is one of the basic elements of the current global malaria control strategy. In order to provide this service to people in rural areas there is a need for new cost-effective approaches. To ensure that such new approaches are acceptable to the target communities, it is important to know the rationale for people's malaria treatment-seeking behavior. The present study provides insights into the reasons for people's preferences for different types of healthcare facilities and describes variation of these preferences within a rural community in Sri Lanka. The study reports on the experiences with the establishment of a village health facility and its effect on the treatment-seeking behavior of the population. After the introduction of the village treatment center it quickly took over the role of main provider for diagnosis and treatment of malaria from the government facilities. The treatment center did not improve the response time in seeking treatment for young children, but the delay for adults was reduced by 1-2 days. Mothers with small children often preferred the government facilities since they wanted a more qualified opinion than available from the locally recruited staff of the village treatment center. The treatment center significantly reduced the stress and discomfort experienced by the elderly and handicapped segment of the community. The study indicated that the effective catchment area of a village treatment center will be influenced by the degree of initial support from key individuals in the communities, the selection procedure and training of assistants, and the history of the relationships between different villages to be served by the center. The government health services and communities across the dry zone of Sri Lanka could benefit substantially from the establishment of more village treatment centers. To ensure the long-term sustainability of these type of facilities it is necessary to assess the feasibility of charging a user fee and establishing multi-purpose clinics. Government policies and administrative procedures will need to be adjusted to make the successful operation of village treatment centers possible.