Iodine deficiency disorders (IDD) control in India.

Iodine deficiency disorders (IDD) constitute the single largest cause of preventable brain damage worldwide. Majority of consequences of IDD are invisible and irreversible but at the same time these are preventable. In India, the entire population is prone to IDD due to deficiency of iodine in the soil of the subcontinent and consequently the food derived from it. To combat the risk of IDD, salt is fortified with iodine. However, an estimated 350 million people do not consume adequately iodized salt and, therefore, are at risk for IDD. Of the 325 districts surveyed in India so far, 263 are IDD-endemic. The current household level iodized salt coverage in India is 91 per cent with 71 per cent households consuming adequately iodized salt. The IDD control goal in India was to reduce the prevalence of IDD below 10 per cent in the entire country by 2012. What is required is a "mission approach" with greater coordination amongst all stakeholders of IDD control efforts in India. Mainstreaming of IDD control in policy making, devising State specific action plans to control IDD, strict implementation of Food Safety and Standards (FSS) Act, 2006, addressing inequities in iodized salt coverage (rural-urban, socio-economic), providing iodized salt in Public Distribution System, strengthening monitoring and evaluation of IDD programme and ensuring sustainability of IDD control activities are essential to achieve sustainable elimination of IDD in India.

Recombination drives genetic diversification of Streptococcus dysgalactiae subspecies equisimilis in a region of streptococcal endemicity.

Infection of the skin or throat by Streptococcus dysgalactiae subspecies equisimilis (SDSE) may result in a number of human diseases. To understand mechanisms that give rise to new genetic variants in this species, we used multi-locus sequence typing (MLST) to characterise relationships in the SDSE population from India, a country where streptococcal disease is endemic. The study revealed Indian SDSE isolates have sequence types (STs) predominantly different to those reported from other regions of the world. Emm-ST combinations in India are also largely unique. Split decomposition analysis, the presence of emm-types in unrelated clonal complexes, and analysis of phylogenetic trees based on concatenated sequences all reveal an extensive history of recombination within the population. The ratio of recombination to mutation (r/m) events (11:1) and per site r/m ratio (41:1) in this population is twice as high as reported for SDSE from non-endemic regions. Recombination involving the emm-gene is also more frequent than recombination involving housekeeping genes, consistent with diversification of M proteins offering selective advantages to the pathogen. Our data demonstrate that genetic recombination in endemic regions is more frequent than non-endemic regions, and gives rise to novel local SDSE variants, some of which may have increased fitness or pathogenic potential.

Molecular markers for discriminating Streptococcus pyogenes and S. dysgalactiae subspecies equisimilis.

Given the increasing aetiological importance of Streptococcus dysgalactiae subspecies equisimilis in diseases which are primarily attributed to S. pyogenes, molecular markers are essential to distinguish these species and delineate their epidemiology more precisely. Many clinical microbiology laboratories rely on agglutination reactivity and biochemical tests to distinguish them. These methods have limitations which are particularly exacerbated when isolates with mixed properties are encountered. In order to provide additional distinguishing parameters that could be used to unequivocally discriminate these two common pathogens, we assess here three molecular targets: the speB gene, intergenic region upstream of the scpG gene (IRSG) and virPCR. Of these, the former two respectively gave positive and negative results for S. pyogenes, and negative and positive results for S. dysgalactiae subsp. equisimilis. Thus, a concerted use of these nucleic acid-based methods is particularly helpful in epidemiological surveillance to accurately assess the relative contribution of these species to streptococcal infections and diseases.

A review of tracking progress towards elimination of iodine deficiency disorders in Tamil Nadu, India.

BACKGROUND: Iodine deficiency disorders (IDD) are significant health problem in India. But there is dearth of regional/state level information for the same. OBJECTIVE: This study was designed to study the current status of IDD in Tamil Nadu. MATERIALS AND METHODS: A cross-sectional community-based survey was conducted in the state of Tamil Nadu. The study population was children in the age group of 6-12 years and the probability proportional to size 30 cluster methodology was used for sample selection. The parameters studied were prevalence of goiter, urinary iodine excretion, and iodine content in salt at the household level. RESULTS: A total of 1230 children aged between 6 and 12 years were studied. The total goiter rate was 13.5% (95% CI: 11.1-14.9). The median urinary iodine excretion was found to be 89.5 µg/L (range, 10.2-378 µg/L). The 56% of the urinary iodine excretion values were <100 µg/L. The proportion of households consuming adequately iodized salt (iodine content ≥ 15 parts per million) was 18.2% (95% CI: 16.1-20.5). CONCLUSION: The total goiter rate of 13.5% and median urinary iodine excretion of 89.5 µg/L is indicative of iodine deficiency in Tamil Nadu.

Tracking progress towards sustainable elimination of iodine deficiency disorders in Bihar.

OBJECTIVES: To assess the status of the iodine deficiency in the population of Bihar and track progress of the elimination efforts. METHODS: A community based field survey was conducted. Using quantitative and qualitative research methods, data was collected by following internationally recommended protocol and methodology. Thirty clusters were selected using population proportionate to size technique. School age children (6 to 12 years) were the target group studied. Urinary iodine in target children and iodine content of salt at households were the indicators used. RESULTS: Total of 1169 children were studied. The median urinary iodine concentration was found to be 85.6 microg/L. Urinary iodine concentration was less than 50 microg/L in 31.5% of the subjects. Only 40.1% of the household salt samples were found to be adequately iodised as determined by titration method (> or =15 ppm iodine). CONCLUSIONS: Study results show existence of iodine deficiency in the state. There is need to accelerate our efforts to achieve iodine sufficiency and this should be done on a war-footing.

Estimation of iodine in salt fortified with iodine & iron.

BACKGROUND & OBJECTIVE: The National Institute of Nutrition (NIN), Hyderabad has developed double fortified salt (DFS) containing both iodine and iron to control the twin problems of iodine deficiency disorders (IDD) and iron deficiency anaemia (IDA). When the iodine content of DFS was estimated by the conventional iodometric titration using sulphuric acid (H(2)SO(4)), problems such as wide variation between duplicate analysis and under/overestimations of iodine content were encountered, which led to inconsistent results. This study was undertaken to develop a modified method for the estimation of iodine in DFS so as to get reliable iodine content of DFS. METHODS: A modified method was developed using orthophosphoric acid (H(3)PO(4)) and the sensitivity of the method was confirmed by estimating the iodine content of potassium iodate (KIO(3)) standard at different concentrations of iodine (0 to 100 ppm). The iodine content of DFS and iodized salt (IS) from local market and factory was estimated by the modified method as well as the conventional iodometric titration and the results were compared. RESULTS: The pH of DFS was acidic. The time gap between the additions of acid and potassium iodide (KI) played a crucial role in getting the actual iodine content of DFS. The H(2)SO(4) and ferrous sulphate (FeSO(4)) interfered with the estimation of iodine in DFS resulting in underestimation or overestimation of iodine. Modified method (H(3)PO(4)) produced consistent and reliable iodine content of DFS. Both H(2)SO(4) and H(3)PO(4) gave same results when tested with KIO(3) standard, Reference salt and IS (both experimental and purchased from local market). Actually 0.50 ml of 1 per cent KI was sufficient to estimate the iodine content of DFS or IS. INTERPRETATION & CONCLUSION: The results of the present study showed that the conventional method using H(2)SO(4) was not suitable for the estimation of iodine in DFS. The modified method using H(2)PO(4) was ideally suited for the estimation of iodine in DFS. Also, iron from DFS did not interfere during estimation of iodine by this method. As both the conventional and the modified methods gave the same results for the iodine content of IS, it is practically prudent to use the modified method (H(2)PO(4)) for both DFS and IS instead of following one method (H(3)PO(4)) for DFS and another (H(2)SO(4)) for IS. The quantity of KI is also reduced and the order of additions of reagents is changed in the modified procedure.

Iodine nutrition status of exclusively breast-fed infants and their mothers in New Delhi, India.

OBJECTIVE: To assess the iodine nutrition status of exclusively breast-fed infants and their mothers. HYPOTHESIS: In the presence of environmental and maternal iodine deficiency, an exclusively breast-fed baby is likely to receive a suboptimal iodine supply during the period of rapid brain growth. METHODS: Spot urinary iodine (UI) and serum TSH levels were measured in 175 healthy, exclusively breast-fed infants and their mothers. Iodine content of salt used by participants for domestic consumption was also analyzed. RESULTS: The median UI levels in mothers and infants was 124 microg/l and 162 microg/l, respectively. 34% of mothers and 21% of infants had UI levels <100 microg/l indicating iodine deficiency. Serum TSH was elevated in 29% of mothers and 2% of infants. No correlation was observed between individual mother-infant UI or serum TSH levels (r = -0.036, r = -0.1 for UI excretion and serum TSH, respectively). 96% of the salt samples tested had adequate iodine concentration, i.e. >15 ppm. CONCLUSION: The present study demonstrated significant iodine deficiency in both mothers and infants despite consumption of adequately iodized salt. The iodine nutrition status of the infants was better compared to the mothers, indicating a preferential iodine supply to the infants over the mothers.

Enterococcal infections with special reference to phenotypic characterization & drug resistance.

BACKGROUND & OBJECTIVES: Enterococci, classified as group D streptococci, are the second leading cause of nosocomial infections. The incidence of enterococcal infections and species prevalent in India is not thoroughly investigated. The present study was undertaken to isolate and characterize enterococci from clinical specimens and determine the antimicrobial susceptibility pattern of these isolates. METHODS: Clinical specimens (blood, urine and swabs) were cultured on bile esculin azide agar (BEAA) for isolation of enterococci. The phenotype based scheme included Gram staining of growth on BEAA and subculturing of cocci on sheep blood agar plates for vancomycin disk diffusion and hydrolysis of L-pyrrolidonyl-beta-napthylamide (PYR) testing. The phenotypic method was used to surveillance cultures that yielded growth on BEAA. Enterococcal strains were further identified to the species level by conventional biochemical tests. PYR positive isolates were further characterized into vancomycin resistant enterococci (VRE) and nonVRE depending upon vancomycin inhibition zone size. The isolates were characterized into vanA, vanB and vanC depending upon minimum inhibitory concentration (MIC) values. Conventional method was used to study the antibiogram of isolates. RESULTS: A total of 52 isolates of enterococci (10 Enterococcus faecalis, 42 E. faecium) were isolated from 534 clinical specimens. Of the 52 isolates, 12 isolates were resistant to vancomycin with an MIC > 4 microg/ml but sensitive to teicoplanin (vanB isolates). INTERPRETATION & CONCLUSION: Our study reveals the problem of multiple drug resistant enterococci and emergence of VRE. Better susceptibility tests need to be used to measure the vancomycin resistance accurately.

Evaluation & revaluation of upper limits of normal values of anti-streptolysin O & anti-deoxyribonuclease B in Mumbai.

BACKGROUND & OBJECTIVES: For the serodiagnosis of group A streptococcal (GAS) infections and their late sequelae, a battery of tests have been suggested. However, anti-streptolysin O (ASO) and antideoxyribonuclease B (ADNase B) are the most widely accepted tests for the same. It is essential to evaluate the upper limits of ASO and ADNase B levels in age and sex matched normal population before using them for the detection of patients. For this study, these values were determined in the past and were revaluated again in 2001-2002, in normal subjects. METHODS: A total of 200 healthy individuals were included in the study in 1991-1992 and same number of age and sex matched healthy individuals were included in 2001-2002. The methodology used for determination of ASO and ADNase B levels were as per the techniques recommended by the WHO. RESULTS: The findings show that the upper limits of normal ASO titers are 195 IU and 305 IU for adults and children respectively while the said levels for ADNase B for both adults and children were found to be 200 IU. INTERPRETATION & CONCLUSION: The findings of the present study will be helpful in the follow-up, better diagnosis and prognosis of group A streptococcal infections.

Radioiodine kinetics and thyroid function following the universal salt iodization policy.

BACKGROUND: Universal salt iodization was introduced in Delhi in 1989. The present study quantifies the change in iodine kinetics as a result of this. The previous values were reported 10-30 years earlier, when Delhi was iodine deficient. METHODS: Thirty subjects (18 men and 12 women, 17-48 years of age) who were residents of Delhi and had no thyroid disorder, were recruited from our outpatient clinic in 1999. The 24-hour urinary excretion of iodine and the iodine content of salt consumed at home by these subjects were estimated. Kinetic studies of iodine using radiotracer 131I were done to determine thyroid iodine clearance, renal iodine clearance, percentage uptake and absolute iodine uptake by the thyroid gland, and plasma inorganic iodine. RESULTS: The median 24-hour urinary iodine excretion was 341.3 micrograms. The mean (SD) thyroid uptake of radioactive iodine was 4.9 (2.3)% at 2 hours and 19.1 (8.0)% at 24 hours. The median calculated plasma inorganic iodine was 1.36 micrograms/dl, absolute iodine intake 6.5 micrograms/hour and thyroid iodine clearance was 4.8 ml/minute (geometric means 1.68 micrograms/dl, 8.5 micrograms/hour and 8.1 ml/minute, respectively). The serum thyroid hormones and thyroid stimulating hormone were within normal limits. CONCLUSION: Compared to the values reported 10-30 years ago when the population was iodine deficient, the present urinary iodine excretion, plasma inorganic iodine and absolute iodine intake have increased, while the percentage thyroid uptake of iodine ingested and thyroid clearance have decreased. The lack of change in the serum thyroid hormone levels after 10 years of universal salt iodization indicates that iodine consumption has had no adverse effect on thyroid function in these normal individuals. These changes are consistent with the increase in iodine consumption. Since the iodine ingestion in a community may change with time, assessment of iodine kinetics should be done periodically in different regions of the country.

Effect of chronic morphine administration on glucose tolerance and insulin binding to isolated rat adipocytes.

Morphine addiction was induced in six male Wistar rats. Improved glucose tolerance (peak value less by 28%, p<0.01) was observed in chronically morphinized rats as compared to the control rats, injected with saline. An increase in the maximal specific binding of 125I-labeled insulin to unit membrane area of adipocytes was observed in the experimental group (p < 0.01). The changes in insulin receptor number could be responsible for the improved glucose tolerance observed during morphine addiction.

Antibodies detected against Plasmodium falciparum haemozoin with inhibitory properties to cytokine production.

Haemozoin, the malaria pigment, regulates the synthesis of several host cytokines and has been found to be associated with the disease severity. Here we describe that malarial patients produce a significant amount of anti-haemozoin IgM antibodies. Levels of these antibodies were higher among the complicated Plasmodium falciparum cases compared to the non-complicated P. falciparum group and Plasmodium vivax patients. The P. falciparum haemozoin also induced the synthesis of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) by the monocytes of the healthy individuals, but the production of these cytokines by the monocytes was inhibited in the presence of the anti-haemozoin IgM antibodies. Therefore, it seems that the host produces these antibodies (mainly IgM types) during malarial infection that can influence the progression of the disease by inhibiting the production of cytokines.

Validation of spot-testing kits to determine iodine content in salt.

Iodine deficiency disorders are a major public health problem, and salt iodization is the most widely practised intervention for their elimination. For the intervention to be successful and sustainable, it is vital to monitor the iodine content of salt regularly. Iodometric titration, the traditional method for measuring iodine content, has problems related to accessibility and cost. The newer spot-testing kits are inexpensive, require minimal training, and provide immediate results. Using data from surveys to assess the availability of iodized salt in two states in India, Madhya Pradesh and the National Capital Territory of Delhi, we tested the suitability of such a kit in field situations. Salt samples from Delhi were collected from 30 schools, chosen using the Expanded Programme on Immunization (EPI) cluster sampling technique. A single observer made the measurement for iodine content using the kit. Salt samples from Madhya Pradesh were from 30 rural and 30 urban clusters, identified by using census data and the EPI cluster sampling technique. In each cluster, salt samples were collected from 10 randomly selected households and all retailers. The 15 investigators performing the survey estimated the iodine content of salt samples in the field using the kit. All the samples were brought to the central laboratory in Delhi, where iodine content was estimated using iodometric titration as a reference method. The agreement between the kit and titration values decreased as the number of observers increased. Although sensitivity was not much affected by the increase in the number of observers (93.3% for a single observer and 93.9% for multiple observers), specificity decreased sharply (90.4% for a single observer and 40.4% for multiple observers). Due to the low specificity and resulting high numbers of false-positives for the kit when used by multiple observers ("real-life situations"), kits were likely to consistently overestimate the availability of iodized salt. This overestimation could result in complacency. Therefore, we conclude that until a valid alternative is available, the titration method should be used for monitoring the iodine content of salt at all levels, from producer to consumer, to ensure effectiveness of the programme.

Simple microplate method for determination of urinary iodine.

BACKGROUND: Urinary iodine is a good biochemical marker for control of iodine deficiency disorders. Our aim was to develop and validate a simple, rapid, and quantitative method based on the Sandell-Kolthoff reaction, incorporating both the reaction and the digestion process into a microplate format. METHODS: Using a specially designed sealing cassette to prevent loss of vapor and cross-contamination among wells, ammonium persulfate digestion was performed in a microplate in an oven at 110 degrees C for 60 min. After the digestion mixture was transferred to a transparent microplate and the Sandell-Kolthoff reaction was performed at 25 degrees C for 30 min, urinary iodine was measured by a microplate reader at 405 nm. RESULTS: The mean recovery of iodine added to urine was 98% (range, 89-109%). The theoretical detection limit, defined as 2 SD from the zero calibrator, was 0.11 micromol/L (14 microg/L iodine). The mean intra- and interassay CVs for samples with iodine concentrations of 0.30-3.15 micromol/L were < or = 10%. The new method agreed well with the conventional chloric acid digestion method (n = 70; r = 0.991; y = 0.944x + 0.04; S(y|x) = 0.10) and with the inductively coupled plasma mass spectrometry method (n = 61; r = 0.979; y = 0.962x + 0.03; S(y|x) = 0.20). The agreement was confirmed by difference plots. The distributions of iodine concentrations for samples from endemic areas of iodine deficiency diseases showed similar patterns among the above three methods. CONCLUSIONS: Our new method, incorporating the whole process into a microplate format, is readily applicable and allows rapid monitoring of urinary iodine.