Illustrated key to the adult female <Emphasis Type="Italic">Anopheles</Emphasis> (Diptera: Culicidae) mosquitoes of Sri Lanka

The identification of adult female anopheline mosquitoes is an important aspect in malaria surveillance and control strategy throughout the world, and taxonomic keys are being regularly revised and updated as new information becomes available. However, the currently available key to the anophelines of Sri Lanka is of limited use, because they were published more than 25 years ago. This paper presents an illustrated key for the identification of 23 adult female Anopheles mosquitoes which are currently recognized as local anopheline species in Sri Lanka.     

10,000 year history of plant use at Bosumpra Cave,Ghana

Investigations of hunter-gatherer subsistence, early food production, and the development of agroforestry systems during the Later Stone Age (LSA) of West Africa have proven challenging because of limited recovery and analysis of archaeological evidence relating directly to subsistence. This paper examines changes in the use of plant resources over a 10,000 year period at Bosumpra Cave, southern Ghana. Large quantities of recovered Canarium schweinfurthii (incense tree) and Elaeis guineensis (oil palm) endocarp preserved at the site allow for the assessment of previous observations about changes in the relative importance of tree fruit resources over time. Results point to the possibility that C. schweinfurthii was a managed resource and may be useful as a marker of forager subsistence in tropical forest regions. The exploitation of C. schweinfurthii persisted in the early and middle Holocene, but was eventually overshadowed in the late Holocene by Kintampo food-producing economies based on Pennisetum glaucum (pearl millet), Vigna unguiculata (cowpea) and E. guineensis. The Bosumpra deposits also yielded domesticated pearl millet and cowpea, allowing for the comparison of LSA hunter-gatherer and early food producer subsistence practices and cultural interactions in southern Ghana.     

A study of long-term complications associated with enteral ostomy and their contributory factors

Background

Complications of ostomy significantly affect the quality of life of ostomates. There is little evidence on the rate of long-term complications in ostomates, especially from the developing countries which include Sri Lanka. This study was aimed to describe the long-term complications of enteral ostomies and their contributory factors.

Methods

A retrospective analysis was carried out on 192 patients who underwent ostomy creation over a period of 5 years. Data on type of complications, age, sex, type of ostomy, type of surgery and perioperative care by enteric stoma therapist were gathered. Associations were established using Chi square test and multiple logistic regression.

Results

Out of 192 patients, only 146 patients presented regularly for follow up. The mean follow up duration was 28 months (range: 3–183). Around 34.2% developed surgical long-term complications related to the ostomy. Common complications were prolapse (n = 24, 16.4%), skin excoriation (n = 22, 15.1%) and parastomal hernia (n = 14, 9.6%). Overall complication rate was significantly less in loop ostomies (p < 0.05) and defunctioning ostomies (p < 0.05). Skin excoriation was significantly high in males (p < 0.05) and in ileostomies (p < 0.001). Parastomal hernia was commoner in end ostomies (p < 0.05). Perioperative care by enteric stoma therapist reduced the overall and specific complications (p < 0.001).

Conclusion

The overall complication rate in our cohort of patients was 34.2%. The perioperative care of a stoma therapist may be very effective in preventing complications particularly in a setting with limited resources.

     

Change in Dengue and Japanese Encephalitis Seroprevalence Rates in Sri Lanka

Background

Sri Lanka has been affected by epidemics of dengue infections for many decades and the incidence and severity of dengue infections have been rising each year. Therefore, we investigated the age stratified seroprevalence of dengue infections in order to facilitate future dengue vaccine strategies. In addition, since the symptomatic dengue infections have increased during the past few decades, we also investigated the possible association with Japanese Encephalitis Virus (JEV) antibody seropositivity with symptomatic dengue in a community cohort in Sri Lanka.

Methods

1689 healthy individuals who were attending a primary health care facility were recruited. Dengue and JEV antibody status was determined in all individuals and JEV vaccination status was recorded.

Results

1152/1689 (68.2%) individuals were seropositive for dengue and only 133/1152 (11.5%) of them had been hospitalized to due to dengue. A significant and positive correlation was observed for dengue antibody seropositivity and age in children (Spearmans R = 0.84, p = 0.002) and in adults (Spearmans R = 0.96, p = 0.004). We observed a significant rise in the age stratified seroprevalence rates in children over a period of 12 years. For instance, in year 2003 the annual seroconversion rate was 1.5% per annum, which had risen to 3.79% per annum by 2014. We also found that both adults (p<0.001) and in children (p = 0.03) who were hospitalized due to dengue were more likely to be seropositive for JEV antibodies. However, 244 (91.4%) of adults who were seropositive for JEV had not had the JEV vaccine.

Conclusions

Dengue seroprevalence rates have risen significantly over the last 12 years in Sri Lanka, possibly due to increased transmission. As individuals who were hospitalized due to dengue were more likely to be seropositive for JEV, the possibility of cross-reactive assays and/or of JEV infection on immunity to the DENV and clinical disease severity should be further investigated.     

A vegetation map of tropical continental Asia at scale 1:5 million

Abstract. A vegetation map at scale 1:5 million is presented. * * Attached on the inside of this issue's back cover.
It covers Bangladesh, Burma (Myanmar), India, Cambodia, Laos, Thailand, Vietnam and Sri Lanka and fills a conspicuous gap in the cartography of tropical vegetation, following the publication of vegetation maps of South America, Africa and Malaysia. For conformity, it is presented as one sheet at a scale of 1:5 million. It uses the basic map of the American Geographical Society (1942; bipolar oblique conformal projection) which forms the base for FAO's Soil map of the world. Basic information was obtained from many published maps, unpublished observations and satellite data. The limits of the main vegetation types have been updated with a complete set of Landsat MSS images (369 scenes) with a mosaic of Landsat TM data for 1991 and with recent forest maps from Asia. Nine main vegetation units, which are groups of forest formations, have been identified and mapped, including woodlands, thickets and wooded savannas. Agricultural land has been shown in a uniform pale green colour in order to clearly express the extent of human impacts on woody vegetation. In spite of the necessary oversimplification of the ground data, this map is probably the most explicit expression of the remaining forest stands and of the regression of natural vegetation in the region. It can be considered as a benchmark for future monitoring of tropical vegetation.     

Twelve Years of Rabies Surveillance in Sri Lanka, 1999–2010

Background

Rabies is endemic in Sri Lanka, but little is known about the temporal and spatial trends of rabies in this country. Knowing these trends may provide insight into past control efforts and serve as the basis for future control measures. In this study, we analyzed distribution of rabies in humans and animals over a period of 12 years in Sri Lanka.

Methods

Accumulated data from 1999 through 2010 compiled by the Department of Rabies Diagnosis and Research, Medical Research Institute (MRI), Colombo, were used in this study.

Results

The yearly mean percentage of rabies-positive sample was 62.4% (47.6–75.9%). Three-fourths of the rabies-positive samples were from the Colombo, Gampaha, and Kalutara districts in Western province, followed by Galle in Southern province. A high percentage of the rabies samples were from dogs (85.2%), followed by cats (7.9%), humans (3.8%), wild animals (2.0%), and livestock (1.1%). Among wild animals, mongooses were the main victims followed by civets. The number of suspect human rabies cases decreased gradually in Sri Lanka, although the number of human samples submitted for laboratory confirmation increased.

Conclusions

The number of rabid dogs has remained relatively unchanged, but the number of suspect human rabies is decreasing gradually in Sri Lanka. These findings indicate successful use of postexposure prophylaxis (PEP) by animal bite victims and increased rabies awareness. PEP is free of charge and is supplied through government hospitals by the Ministry of Health, Sri Lanka. Our survey shows that most positive samples were received from Western and Southern provinces, possibly because of the ease of transporting samples to the laboratory. Submissions of wild animal and livestock samples should be increased by creating more awareness among the public. Better rabies surveillance will require introduction of molecular methods for detection and the establishment of more regional rabies diagnostic laboratories.     

Enrichment planting to improve habitat quality and conservation value of tropical rainforest fragments

Many areas of tropical rainforest have been fragmented and the habitat quality of fragments is often poor. For example, on Borneo, many forest fragments are highly degraded by repeated logging of Dipterocarpaceae trees prior to fragmentation, and we examined the viability of enrichment planting as a potential management tool to enhance the conservation value of these forest fragments. We planted seedlings of three dipterocarp species with contrasting light demands and tolerances (Parashorea malaanonan (light demander), Dryobalanops lanceolata (intermediate), Hopea nervosa (shade tolerant)) in eight forest fragment sites (3–3529 ha), and compared seedling performance with four sites in continuous forest. Eighteen months after planting, survival rates of seedlings were equally high in fragment sites (mean survival = 63 %), and in continuous forest sites (mean survival = 68 %). By contrast, seedling growth and herbivory rates were considerably higher in fragments (by 60 % for growth and 45 % for herbivory) associated with higher light environments in degraded forest fragments compared with continuous forest sites. Among the three study species, H. nervosa seedlings had the highest survival rates overall, and P. malaanonan seedlings generally grew fastest and suffered highest herbivory rates. There were no interactions between species performance and the effects of fragment site area, forest structure or soil characteristics of sites suggesting that the three species responded similarly to fragmentation effects. High survival of planted seedlings implies that enrichment planting would be a successful forest management strategy to improve forest quality, and hence conservation value, of fragments.     

Canopy processes: implications for transpiration,interception and splash induced erosion,ultimately for forest management and water resources

Some recent experimental and theoretical developments in research related to tropical forest canopies are reviewed. Deuterium tracing studies in India, which rely on the collection of samples of transpired water from leaves in the canopy, have established the importance of tree size as an index of whole tree transpiration and the use of leaf area, basal area and sapwood area for scaling transpiration from the tree to plot scale is discussed.Experimental studies of the interception loss from tropical trees in Indonesia, India and Sri Lanka have established that conventional interception models of the Rutter type, although adequate for use in temperate climates, are entirely inappropriate for use in the tropics. It is now recognised that the failure of this approach is due to neglect of the process of drop size dependent canopy wetting. The use of rainfall simulators and optical disdrometers in the tropics has demonstrated that to achieve the same degree of canopy wetting upwards of ten times the depth of rainfall may be required for high intensity tropical storms (with large drop sizes) as compared with low intensity, frontal rainfall systems, common in temperate climates. Rainfall simulator studies have also demonstrated that the final degree of wetting is also reduced when vegetation is wetted with drops of large size. These studies have also demonstrated that the drop size of secondary drops falling from vegetation is dependent on the vegetation type and is very much greater for large leafed species such as Tectona grandis as compared with species such as Pinus caribaea with smaller needle formed leaves.The combination, in the tropics, of large drop sizes in the primary rainfall and large drop sizes in secondary drops falling from vegetation helps to explain why in absolute and relative terms interception loss from tropical trees is less than that in temperate climates. The recognition that drop size generation is related to vegetation type has important implications for splash induced erosion and the choice of tree species on soils subject to erosion.Knowledge of forest canopy processes is now leading to a better appreciation of the hydrological, meteorological and water resource impacts of forests. The impact of trees in Amazonia and the Sahel on climate and trees in the Zambezi basin on water resources is discussed. New spatially distributed modelling methods which are being incorporated within Decision Support Systems for forest and water resource management, which also take account of ecological and socio-economic objectives, are also outlined.     

Random Amplified Polymorphic DNA (RAPD) for differentiation between Thai and Myanmar strains of Wuchereria bancrofti

Background

Information on the physical and psychosocial disability of lymphatic filariasis in Sri Lanka is scarce. Therefore this study was carried out to describe the physical disability and psychosocial impact associated with chronic lymphoedema in patients attending filariasis clinics in the Colombo district, Sri Lanka.

Methods

Four hundred and thirteen patients with lymphoedema of limbs attending filariasis clinics in Werahera and Dehiwala in the Colombo district were enrolled in the study after obtaining informed written consent. Data were collected using a pre-tested, interviewer-administered questionnaire and analyzed using SPSS.

Results

Majority (95%) of patients had lower limbs affected and there was a significant association with difficulty in walking (p = 0.023). The swollen limb affected the work of 87 (52 %) of employed patients and 26 persons reported loss of job. Approximately 25 % and 6 % reported having problems interacting with the community and family, respectively and 8.7 % felt that they were rejected by society. The swollen limb was perceived as a major problem by 36.8 % of patients. Of the married persons, 5.7 % and 6.2 % reported sexual and marital problems respectively, due to their swollen limb/s. Of those who had marital problems, 77.3% reported sexual problems as well (p < 0.001).

Conclusion

Lymphoedema significantly affects physical, psychological and social functioning in affected individuals. Morbidity control, in addition to control of physical disability, should target the psychosocial consequences.     

Costs of Dengue Control Activities and Hospitalizations in the Public Health Sector during an Epidemic Year in Urban Sri Lanka

Background

Reported as a public health problem since the 1960s in Sri Lanka, dengue has become a high priority disease for public health authorities. The Ministry of Health is responsible for controlling dengue and other disease outbreaks and associated health care. The involvement of large numbers of public health staff in dengue control activities year-round and the provision of free medical care to dengue patients at secondary care hospitals place a formidable financial burden on the public health sector.

Methods

We estimated the public sector costs of dengue control activities and the direct costs of hospitalizations in Colombo, the most heavily urbanized district in Sri Lanka, during the epidemic year of 2012 from the Ministry of Health’s perspective. The financial costs borne by public health agencies and hospitals are collected using cost extraction tools designed specifically for the study and analysed retrospectively using a combination of activity-based and gross costing approaches.

Results

The total cost of dengue control and reported hospitalizations was estimated at US$3.45 million (US$1.50 per capita) in Colombo district in 2012. Personnel costs accounted for the largest shares of the total costs of dengue control activities (79%) and hospitalizations (46%). The results indicated a per capita cost of US$0.42 for dengue control activities. The average costs per hospitalization ranged between US$216–609 for pediatric cases and between US$196–866 for adult cases according to disease severity and treatment setting.

Conclusions

This analysis is a first attempt to assess the economic burden of dengue response in the public health sector in Sri Lanka. Country-specific evidence is needed for setting public health priorities and deciding about the deployment of existing or new technologies. Our results suggest that dengue poses a major economic burden on the public health sector in Sri Lanka.     

The relationship between population size,amount of brood,and individual foraging behaviour in the honey bee,Apis mellifera L.

This study experimentally examines the relationship between colony state and the behaviour of individual pollen and nectar foragers in the honey bee, Apis mellifera L. In the first experiment we test the prediction that individual pollen foragers from colonies with higher brood quantities should exhibit a greater work effort for pollen resources than individual pollen foragers from colonies with low brood quantities. Eight colonies were assigned into two treatment groups; HIGH brood colonies were manipulated to contain 9600±480 cm² brood area; LOW brood colonies were manipulated to contain 1600±80 cm² brood area. We measured colony brood levels over the course of the experiment and collected individual pollen loads from returning pollen foragers. We found that, while colonies remained significantly different in brood levels, individual pollen foragers from HIGH brood colonies collected larger loads than individuals from LOW brood colonies. In the second experiment we investigated the influence of colony size on the behaviour of individual nectar foragers. We assigned eight colonies to two treatment groups; LARGE colonies were manipulated to contain 35000±1700 adult workers with 3500±175 cm² brood area, and SMALL colonies were manipulated to contain 10000±500 adult workers with 1000±50 cm² brood area. We observed foraging trips of individually marked workers and found that individuals from LARGE colonies made longer foraging trips than those from SMALL colonies (LARGE: 1666.7±126.4 seconds, SMALL: 1210.8±157.6 seconds), and collected larter nectar loads (LARGE: 19.2±1.0 l, SMALL: 14.6±0.8 l). These results indicate that individual nectar foragers from LARGE colonies tend to work harder than individuals from SMALL colonies. Both experiments indicate that the values of nectar and pollen resources to a colony change depend on colony state, and that individual foragers modify their behaviour accordingly.     

Antenatal Depression in Anuradhapura,Sri Lanka and the Factor Structure of the Sinhalese Version of Edinburgh Post Partum Depression Scale among Pregnant Women

Background

Mental health problems among women of reproductive age group contribute to 7% of Global Burden of Diseases of women of all ages. Purpose of this study was to determine the prevalence and correlates of antenatal depression among pregnant women in Anuradhapura, Sri Lanka, and to explore the factor structure of EPDS.

Methods

Pregnant women with gestational age of 24–36 weeks and residing in Anuradhapura district, Sri Lanka were recruited to the study using a two stage cluster sampling procedure. Sinhalese version of Edinburgh Post Partum Depression Scale (EPDS) and an interviewer administered questionnaire was use to collect data. A cut off value of 9 was used for the Sinhalese version of EPDS.

Results

A total of 376 pregnant women were studied. Median EPDS score among pregnant women was 5 (IQR 2–8). Prevalence of antenatal depression in this study sample was 16.2% (n = 61). Thought of self harming (item number 10) was reported by 26 pregnant women (6.9%). None of the socio-demographic factors were associated with depression in this study sample. Having heart burn was significantly associated with depressive symptoms (p = 0.041). Sri Lankan version of EPDS showed a two factor solution. Anxiety was not emerged as a separate factor in this analysis.

Conclusions

Prevalence of antenatal depression in Anuradhapura, Sri Lanka was relatively low. Anxiety was not emerged as a separate factor in the Sinhalese version of the EPDS.     

Genetic diversity of native and introduced populations of the invasive house crow (<Emphasis Type="Italic">Corvus splendens</Emphasis>) in Asia and Africa

The common house crow (Corvus splendens) is one of the best known and most wide spread species of the family Corvidae. It is a successful invasive species able to exploit urban environments, well removed from its natural distribution. It is considered a pest as it attains high population densities, can cause serious economic losses and has many adverse effects on native fauna and flora, including predation, competitive displacement and disease transmission. Little genetic research on the house crow has been undertaken so we have only a limited understanding of its natural genetic population structure and invasion history. In this study, we employ microsatellite and mitochondrial DNA markers to assess genetic diversity, phylogeography and population structure of C. splendens within its native range represented by Sri Lanka and Bangladesh and introduced range represented by Malaysia, Singapore, Kenya and South Africa. We found high levels of genetic diversity in some of the invasive populations for which multiple invasions are proposed. The lowest genetic diversity was found for the intentionally introduced population in Selangor, Malaysia. Sri Lanka is a possible source population for Malaysia Selangor consistent with a documented introduction over 100 years ago, with port cities within the introduced range revealing possible presence of migrants from other unsampled locations. We demonstrate the power of the approach of using multiple molecular markers to untangle patterns of invasion, provide insights into population structure and phylogeographic relationships and illustrate how historical processes may have contributed to making this species such a successful invader.     

Effects of phosphorus addition with and without nitrogen addition on biological nitrogen fixation in tropical legume and non-legume tree plantations

It is well documented that phosphorus (P) input stimulates biological nitrogen (N) fixation (BNF) in tropical forests with non-legume trees. However, in tropical legume forests with soil N enrichment and P deficiency, the effects of P availability and its combination with N on BNF remain poorly understood. In this study, we measured BNF rate in different compartments, i.e., bulk soil, forest floor, rhizosphere, and nodules, in two tropical plantations with legume trees Acacia auriculiformis (AA) versus non-legume trees Eucalyptus urophylla, (EU) in southern China after 4 years of P addition and combined N and P additions. The objective was to investigate how P addition and its combination with N addition regulate BNF in a tropical legume plantation, and to compare the effects with those in a non-legume plantation. Our results showed that total BNF rates were significantly higher in the P-addition plots than in the control plots by 27.4 ± 4.3 and 23.3 ± 1.7 % in the EU and AA plantations, respectively. Total BNF rates were significantly higher in the NP-addition plots than in the control plots by 27.7  ± 5.0 and 8.5 ± 1.4 % in the EU and AA plantations, respectively, which contrasted to our previous result that total BNF rates were significantly lower in N-addition plots than in the control plots in the AA plantation. These findings suggest that P input can stimulate BNF in tropical forest biome dominated by legume trees, even in consideration of elevated atmospheric N deposition. Thus, our study revealed the important role of P in regulating biological N input, which should be taken into account in the modeling of biogeochemical cycles in the future.     

Malaria control and elimination in sri lanka: documenting progress and success factors in a conflict setting

Background

Sri Lanka has a long history of malaria control, and over the past decade has had dramatic declines in cases amid a national conflict. A case study of Sri Lanka''s malaria programme was conducted to characterize the programme and explain recent progress.

Methods

The case study employed qualitative and quantitative methods. Data were collected from published and grey literature, district-level and national records, and thirty-three key informant interviews. Expenditures in two districts for two years – 2004 and 2009 – were compiled.

Findings

Malaria incidence in Sri Lanka has declined by 99.9% since 1999. During this time, there were increases in the proportion of malaria infections due to Plasmodium vivax, and the proportion of infections occurring in adult males. Indoor residual spraying and distribution of long-lasting insecticide-treated nets have likely contributed to the low transmission. Entomological surveillance was maintained. A strong passive case detection system captures infections and active case detection was introduced. When comparing conflict and non-conflict districts, vector control and surveillance measures were maintained in conflict areas, often with higher coverage reported in conflict districts. One of two districts in the study reported a 48% decline in malaria programme expenditure per person at risk from 2004 to 2009. The other district had stable malaria spending.

Conclusions/Significance

Malaria is now at low levels in Sri Lanka – 124 indigenous cases were found in 2011. The majority of infections occur in adult males and are due to P. vivax. Evidence-driven policy and an ability to adapt to new circumstances contributed to this decline. Malaria interventions were maintained in the conflict districts despite an ongoing war. Sri Lanka has set a goal of eliminating malaria by the end of 2014. Early identification and treatment of infections, especially imported ones, together with effective surveillance and response, will be critical to achieving this goal.     

Boreal peat properties link to plant functional traits of ecosystem engineers

Aims

Warming has the potential to alter plant litter mass loss and nutrient release during decomposition. However, a great deal of uncertainty remains concerning how other factors such as litter species or substrate quality might modify the effects of increased temperature on decomposition. Meanwhile, the temperature sensitivity of plant litter decay in tropical and subtropical forest ecosystems remains poorly resolved.

Methods

This study was designed to assess the effects of experimental warming on litter decomposition and nutrient release of two contrasting tree species (Schima superba and Machilus breviflora) by translocating model forest ecosystems from the high-elevation sites to the lower-elevation sites in subtropical China. Translocating model mountain evergreen broad-leaved forest (MEBF) to the altitude of 300 m and 30 m increased the average monthly soil temperature at 5 cm depth by 0.88 and 1.84 °C, respectively during the experimental period. Translocating model coniferous and broad-leaved mixed forest (CBMF) to the altitude of 30 m increased the average monthly soil temperature at 5 cm depth by 0.85 °C.

Results

We found that experimental warming accelerated litter decomposition in both model forest types, and the promoting efficiency was greater when the temperature increased. The litter with high quality (Schima superba) had stronger response to warming than low quality litter (Machilus breviflora). Warming accelerated Na, K, Mg, P, N and Ca release from Schima superba litter, but only simulated Ca release from Machilus breviflora litter. Overall, litter decomposition was controlled by the order: soil temperature > litter quality > soil moisture > litter incubation forest type under experimental warming in the subtropical China.

Conclusion

We conclude that leaf litter decomposition was facilitated by experimental warming in subtropical China. Litter species might modify the effects of increased temperature on litter decomposition; however, forest type has no effect on litter decomposition.

     

Neglected Patients with a Neglected Disease? A Qualitative Study of Lymphatic Filariasis

Background

Lymphatic filariasis (LF) is a so-called neglected tropical disease, currently overshadowed by higher-profile efforts to address malaria, tuberculosis, and HIV/AIDS. Despite recent successes in arresting transmission, some 40 million people who already have the disease have been largely neglected. This study aims to increase understanding of how this vulnerable, neglected group can be helped.

Methods

We used purposive sampling to select 60 men and women with filarial lymphoedema (45 with filarial elephantiasis and 15 men with filarial hydrocoele) from the south of Sri Lanka in 2004–2005. Participants were selected to give a balance of men and women and poor and nonpoor, and a range of stages of the disease. Participants'' experiences and the consequences of their disease for the household were explored with in-depth qualitative, semistructured interviews.

Findings

LF was extremely debilitating to participants over long periods of time. The stigma attached to the condition caused social isolation and emotional distress, and delayed diagnosis and treatment, resulting in undue advancement of the disease. Free treatment services at government clinics were avoided because the participants'' condition would be identifiable in public. Loss of income due to the condition was reported by all households in the sample, not just the poorest. Households that were already on low incomes were pushed into near destitution, from which it was almost impossible to escape. Affected members of low-income households also had less opportunity to obtain appropriate treatment from distant clinics, and had living and working conditions that made hygiene and compliance difficult.

Significance

This highly vulnerable category of patients has low visibility, thus becoming marginalized and forgotten. With an estimated 300,000 total cases of elephantiasis and/or oedema in Sri Lanka, and around 300,000 men with filarial hydrocoele, the affected households will need help and support for many years to come. These individuals should be specially targeted for identification, outreach, and care. The global strategy for elimination is aimed at the cessation of transmission, but there will remain some 40 million individuals with clinical manifestations whose needs and problems are illustrated in this study.     

Variation in the aboveground stand structure and fine-root biomass of Bornean heath (kerangas) forests in relation to altitude and soil nitrogen availability

Key message

Borneo’s tropical heath (kerangas) forest has limited soil nutrient availability, and high variation in aboveground structure and fine-root biomass. This variation depends on altitude and soil nitrogen availability.

Abstract

To elucidate the biotic and abiotic factors affecting the variation in fine-root biomass (FRB, <2 mm diameter) of trees growing under nutrient-poor environments in Sabah, North Borneo, we investigated FRB in different forests with varying soil nitrogen (N) availability. We selected two study sites at different altitudes: the Maliau Basin (ca. 1000 m asl) and Nabawan (ca. 500 m asl). Both sites included tropical heath (kerangas) forest, on infertile soils (podzols) with a surface organic horizon overlying a bleached (eluviated) mineral horizon, and taller forests on more fertile non-podzolic soils. FRB was obtained from each plot by soil coring (to a depth of 15 cm). FRB increased with decreasing soil inorganic N content (NH₄–N and NO₃–N), tree height, and aboveground biomass. Thus, higher proportions of carbon resources were allocated to fine-roots in stands with lower N availability. FRB was significantly greater at the Maliau Basin than at Nabawan, reflecting lower soil N availability at higher altitude. Our results demonstrate high variation in FRB among the heath forests, and suggest that fine-root development is more prominent under a cooler climate where N availability limits tree growth owing to slower decomposition. The variation in N availability under the same climate (i.e., at the same altitude) appears to be related to the extent of soil podzolization.

     

Non-alcoholic fatty liver disease in a rural,physically active,low income population in Sri Lanka

Background

Non-alcoholic fatty liver disease (NAFLD) is recognized as a metabolic disorder largely seen in urbanized populations. The purpose of this study was to assess prevalence and risk factors for NAFLD in a rural, physically active, economically deprived population in Sri Lanka.

Methods

By visiting individual households in the community, 35-64 year old adults resident in two selected estates in the Nuwara Eliya District of Sri Lanka, were invited to participate in the study. Blood pressure and anthropometric measurements were made on all participants. Blood samples were obtained for the assay of fasting glucose, serum lipids, serum insulin and alanine aminotransferase. NAFLD was diagnosed on established ultrasound criteria for fatty liver in the absence of hepatitis B and C markers and high alcohol consumption.

Results

Of those invited, 403 (65%) participated in the study. Almost all participants were either Indian or Sri Lankan Tamils and 53% were females. Prevalence of NAFLD was 18% in this population. Twice as many males were diagnosed as having NAFLD compared to females. Male sex, high BMI, high waist circumference, high diastolic blood pressure and high plasma glucose levels were significant predictors of NAFLD.

Conclusion

Nearly one in five people in this predominantly Indian Tamil, rural, physically active, economically deprived population had NAFLD. The condition was associated with constituent features of the metabolic syndrome. These results support studies reporting ethnic variations in disease susceptibility and suggest that genetic factors may also play a role in determining disease risk.