Seroprevalence of varicella zoster virus infections in Colombo district, Sri Lanka.

BACKGROUND: Although Varicella Zoster virus (VZV) infections occur worldwide, the epidemiology is remarkably different in tropical and temperate climates. VZV infections result in significant morbidity and mortality among adults in Sri Lanka. AIMS: For future VZV vaccination strategies, we set to determine the age-specific seroprevalence rate of VZV infections in Colombo, Sri Lanka. MATERIALS AND METHODS: The study was carried out from 1999 to 2000. Multi-stage cluster sampling technique was used to collect 913 blood samples, which were tested for the presence of VZV-specific IgG antibodies. RESULTS: VZV seroprevalence rates were markedly lower in all age groups when compared to temperate climates. The seroprevalence rates increased with age in both the rural and urban populations. Of those aged 60 years, only 50% in the rural population and 78.9% in the urban population were immune to VZV. Seroprevalence rates of VZV infections were significantly different between the urban and rural populations (P< 0.001), with VZV-specific IgG antibodies detected in 47.5% in the urban population and 27.9% in the rural population. It was found that 56.2% (131) of females of childbearing age were nonimmune to VZV. CONCLUSIONS: These findings highlight the need for a VZV vaccination program, which is likely to have a huge impact on the incidence of chickenpox and its associated morbidity and mortality.

Dengue infections during pregnancy: a case series from Sri Lanka and review of the literature.

BACKGROUND: Dengue is a major public health problem in several countries. Few reports document presentations and outcomes of dengue during pregnancy. In many endemic countries as the average age of getting dengue infections is shifting upwards, dengue in pregnancy is likely to be encountered more frequently. Patterns of dengue in patients from different regions are needed if we are to draft evidence based management guidelines. OBJECTIVES: To document clinical and laboratory findings in a cohort of hospitalised patients with dengue during pregnancy in Sri Lanka and compare their presentation and outcomes with previously published cases. STUDY DESIGN: Clinical, laboratory, maternal and fetal outcomes and demographic information were collected from patients with confirmed dengue infections during pregnancy treated in a Maternity Hospital in Sri Lanka from 1 January 2000 to 30 June 2004. The Medline database was searched to identify reports relating to dengue infection during pregnancy since 1965. RESULTS: Twenty-six patients [mean (S.D.) age: 29 (4.2) years] were studied. One (3.8%), 2 (7.7%) and 20 (77%) presented in the first, second and third trimesters of pregnancy, and 3 (11.5%) in the immediate post-partum period. Seventeen (65.3%) had primary and nine (34.7%) secondary dengue infections. Ten (38.5%) had DF, 6 (23.1%): DHF grade I and 10 (38.5%): DHF grade II. Five (19.2%) and three (11.5%) patients who first presented with cough/breathlessness or vaginal bleeding, were initially managed as having a pulmonary embolism or a primary obstetric cause for their vaginal bleeding. Bradycardia was noted in three of the four patients who had a cardiac arrhythmia. Seven (26.9%) needed admission to an ICU. Raised AST and ALT levels were seen in 81.2% and 43.7% of 16 patients in whom liver function tests results were available. No fetal malformations were seen in any of the babies born. The single patient who developed DHF in the first trimester had an abortion while having acute symptoms of dengue. CONCLUSIONS: Awareness of clinical and laboratory manifestations of dengue in pregnancy should allow its early recognition and institution of appropriate treatment. Reports on dengue in pregnancy from different regions should allow more evidence-based guidelines to be formulated for optimum evaluation and care of such patients. Our data contributes towards this goal.

Seroprevalence of hepatitis A antibodies in relation to social factors--a preliminary study.

INTRODUCTION: Hepatitis A is a benign illness in children with the rare possibility of fatal complications. Although an endemic disease, very few studies have been done in children regarding the seroprevalence of hepatitis A antibodies in Sri Lanka. OBJECTIVES: (i) To document the seropositivity for hepatitis A in a group of children admitted to a paediatric ward. (ii) To determine the relationship of hepatitis A viral infection to social factors in these children. METHOD: A prospective, descriptive, cross-sectional study was carried out in a ward at the Lady Ridgeway Hospital for 7 months from September 2001. Children admitted on predetermined days, needing venepuncture for their presenting illness, were studied while those who were seriously ill were excluded. Written consent was obtained and a questionnaire with details of socio-economic conditions, personal hygiene practices of the mother, access to water and sanitation and health related behaviour was administered. Total antibodies to hepatitis A were detected by ELISA on a sample of blood taken from each patient. RESULTS: Two hundred and eighty eight samples of blood were analysed. None of the children were immunised against hepatitis A. There were 158 boys (54.9%). Thirty one (10.8%) of the 288 patients had antibodies against hepatitis A. The seroprevalence was 11.6% in children under 10 years of age. Majority (78%) were from families with a monthly income of less than Rs 10,000/-. Fifteen (48.4%) of the 31 seropositive children were from families earning less than Rs 5000/- per month. Belonging to social classes IV and V and having mothers with only primary education were factors significantly associated with seropositivity. No significant difference in the presence of antibodies was observed regarding the personal hygiene practices analysed and access to basic amenities. Health related behaviour practices analysed were significantly associated with the presence of hepatitis A antibodies. CONCLUSIONS: Seroprevalence of 10.8% was observed in a selected group of children. Factors such as poor socio-economic background and having mothers with only primary education were associated with hepatitis A virus (HAV) antibodies as were certain health related behaviour practices of children.

Application of Lactobacillus acidophilus (LA 5) strain in fruit-based ice cream.

A study was performed to apply a probiotic strain into fermented ice cream mix with suitable fruit bases to develop a value-added product with a substantial level of viable organisms for a sufficient shelf life. Pure direct vat strain culture of Lactobacillus acidophilus (LA 5) in freeze-dried form was inoculated into a mixture of ice cream, frozen, and the number of viable organisms during frozen storage for a period of time was enumerated, using turbidity measurements with a spectrophotometer. An ice cream sample prepared without the probiotic culture was compared with the test sample for quality, by testing the basic quality parameters for ice cream. Results show a reduction in the over run of the probiotic ice cream compared to the nonprobiotic ice cream. Significantly high level (P < 0.05) of total solids (42%), proteins (16.5%), and titratable acidity (2.2%) was observed in the test sample compared to the nonprobiotic ice cream. Significantly low pH level in the probiotic sample may be due to the lactic acid produced by the probiotic culture. No significant difference (P > 0.05) in the fat content in the two types of ice cream was observed. A significantly low level (P < 0.05) of melting in the probiotic one may have resulted from less over run, than the nonprobiotic sample. Rapid reduction in the viable cells during frozen storage occurred at -18°C and gradual adaptation occurred over the first 4 weeks. At the 10th week, 1.0 × 10(7) numbers of viable organisms were present in 1 g of the probiotic ice cream. Results show the presence of a sufficient number of viable organisms in the product for the 10-week period, which would be beneficial to consumers.

Recombinant multiepitope protein for early detection of dengue infections.

Dengue fever is a mosquito-borne viral disease prevalent mainly in tropical countries. As the clinical manifestations of dengue are not very unique, laboratory diagnosis is crucial in identifying cases of dengue infection. Detection of dengue infection based on the identification of antidengue antibodies has emerged as a practical and reliable means of diagnosing dengue fever. We recently developed a customized recombinant dengue multiepitope protein (r-DME-G) that can specifically detect the immunoglobulin G (IgG) class of antidengue antibodies in patient sera. Using this strategy, we have now created another dengue multiepitope protein, r-DME-M, with specificity for the IgM class of antidengue antibodies. A synthetic gene encoding the r-DME-M protein was expressed as a maltose-binding protein fusion in Escherichia coli. The recombinant protein was purified in a single affinity chromatographic step to obtain yields of approximately 15 mg purified protein/liter of culture. The purified protein was used to develop an in-house IgM enzyme-linked immunosorbent assay (ELISA) and tested using a panel of 172 patient sera characterized using the commercially available Dengue Duo rapid strip test from PanBio, Australia. The IgM ELISA results showed that the r-DME-M protein not only recognized all IgM(+) samples identified by the PanBio test but also identified samples missed by the latter test. We also successfully adapted the r-DME-M protein to a rapid strip test format. This approach of creating customized antigens coupled to overexpression in E. coli and simple purification offers a promising alternative option to dengue diagnosis with the potential to circumvent the drawbacks of the whole virus antigen-based commercial kits.

A custom-designed recombinant multiepitope protein as a dengue diagnostic reagent.

Currently, dengue fever is the most important re-emerging mosquito-borne viral disease, with the major proportion of the target population residing in the developing countries of the world. In endemic areas, potentially fatal secondary dengue infections, characterized by high anti-dengue IgG antibody titers, are most common. Most currently available commercial dengue diagnostic kits rely on the use of whole virus antigens and are consequently associated with false positives due to serologic cross-reactivity, high cost of antigen production, and biohazard risk. This has prompted the need to develop an alternate antigen to replace the whole virus antigen in diagnostic tests. We have designed and expressed a novel recombinant protein antigen by assembling key immunodominant linear IgG-specific dengue virus epitopes, chosen on the basis of pepscan analysis, phage display, and computer predictions. The recombinant dengue multiepitope protein was expressed to high levels in Escherichia coli, purified in a single step, yielding >25 mg pure protein per liter culture. We developed an in-house enzyme-linked immunosorbent assay (ELISA) to detect anti-dengue antibodies in a panel of 20 patient sera using the purified recombinant dengue multiepitope protein as the capture antigen. The ELISA results were in excellent agreement with those obtained using a commercially available diagnostic test, Dengue Duo rapid strip test from PanBio, Australia. The high epitope density, careful choice of epitopes, and the use of E. coli system for expression, coupled to simple purification, jointly have the potential to lead to the development of an inexpensive diagnostic test with a high degree of sensitivity and specificity.

Using the DREEM questionnaire to gather baseline information on an evolving medical school in Sri Lanka.

The recent introduction of the Dundee Ready Education Environment Measure (DREEM) has fulfilled a long-felt need for a test instrument specifically meant to evaluate health professions education institutions. It was intended in this study to ascertain the overall DREEM score for the newly established Faculty of Medical Sciences of University of Sri Jayewardenepura (FMS/USJ), Sri Lanka and to compare the DREEM score of the students in the pre-, para- and clinical phases of the traditional curriculum practiced in this school. A total of 339 students belonging to the pre- (n = 147), para- (n = 116) and clinical (n = 76) phases of the medical course participated in this study. The DREEM questionnaire was administered face-to-face after one of their routine lectures to each group of students. The age of the students ranged from 20 to 28 years and the gender distribution was almost equal. The overall DREEM score was 108 (54%) for the pooled data for all three phases. There was no significant difference on the overall DREEM score obtained by each phase of students. The overall DREEM scores of pooled data and also for each domain indicated that the position of the FMS/USJ qualifies to be placed just on the third grade (one below the best) within the overall DREEM scale. However, on analysis of the responses for each domain, Students' Perception of Teachers (SPT), Students' Academic Self-Perceptions (SAP) and Students' Social Self-Perceptions (SSP) showed significant difference between the pre-, para- and clinical phases. Similarly, 22 out of the 50 items showed significant differences between the pre- and clinical phases. Overall, the DREEM demonstrated compatibility of its scores along with the gradual development that took place at this medical school over the last 10 years. Thus, the DREEM could be utilized in a variety of situations.