Padam Singh

Aflatoxin B1 contamination of parboiled rice samples collected from different states of India: A multi-centre study

Under a multi-centre study conducted by the Indian Council of Medical Research, 1511 samples of parboiled rice were collected from rural and urban areas of 11 states representing different geographical regions of India. These samples were analysed for contamination with aflatoxin B1. The presence of aflatoxin B1 at levels ≥ 5 μg kg−1 was found in 38.5% of the total number of samples of the parboiled rice. About 17% of the total samples showed the presence of aflatoxin B1 above the Indian regulatory limit of 30 μg kg−1. No statistically significant difference in percentage of samples contaminated with >30 μg kg−1 was observed between pooled rural (19.4%) and urban (14.5%) data. A median value of 15 μg kg−1 of aflatoxin B1 was observed in samples from Assam, Bihar and Tripura. In all other states surveyed the median value was <5 μg kg−1.

Potential of Mw as a prophylactic vaccine against pulmonary tuberculosis

Mycobacterium w (Mw), is a cultivable, non-pathogenic mycobacterium and has been tried extensively as an immunomodulator in leprosy. This has been found to be safe and has shown beneficial immunoprophylactic effect in population based, double blind placebo controlled trials in North India. These effects were also observed in the vaccine trials in South India. Keeping in view these beneficial effects and its earlier reported protective effect against tuberculosis in animals, its protective efficacy was evaluated in a rural population of about 28,948 people belonging to 272 villages in Ghatampur, Kanpur (India). The population was vaccinated with two doses (1st dose of 1x10(9) heat killed organisms followed 6 months later with a 2nd dose of 5x10(8) organisms) of Mw 10-13 years ago originally to investigate its effect against leprosy. The vaccine/placebo was given to healthy contacts of leprosy patients who had no evidence of suffering from tuberculosis. Incidence and prevalence of pulmonary tuberculosis in the present study was assessed in a blind manner by an active field survey and also retrospectively by history of anti tuberculosis treatment received by the patient in the intervening period (since vaccination), which was also corroborated by scrutinizing the medical records. Diagnosis was confirmed by standard clinical and bacteriological criteria. A total of 69 patients were diagnosed to be suffering from pulmonary tuberculosis during the survey which included 17 new sputum smear positive cases and 52 previously partially treated but still active pulmonary tuberculosis cases. The difference in the new sputum positive cases between the vaccinated (5/17) and placebo groups (12/17) was significant at 5% level of significance for 1 tailed test (Z>1.64). As 75% (52/69) of the cases had been diagnosed as suffering from pulmonary tuberculosis but had not taken adequate therapy all the cases diagnosed during the intervening period were recorded and re-analysis done. The differences are more significant at 1% level of significance for 1 tail test (Z>2.59) when all cases were analysed as a group. A small proportion 12.85% (total number=3036) of the contacts in the study population had BCG scars. On analysis of results on protection against tuberculosis in this group, BCG did provide protection against tuberculosis (p<0.01). In the placebo group the prevalence of tuberculosis was 1.11% which reduced to 0.70% for those who received Mw vaccine (p<0.01) which further decreased to 0.53% in those who had BCG scars and received Mw. These results thus provide evidence suggesting protective efficacy of Mw against pulmonary tuberculosis and that Mw merits investigation in future prospective immunoprophylactic trials along with other candidates for protection against pulmonary tuberculosis.

Iodine deficiency disorders in 15 districts of India

Methods : A multicentre study to assess iodine deficiency disorders (goitre and deaf-mutism/cretinism) in 1,45, 264 children (6-<12 years old) from 15 districts of ten states was carried out during 1997-2000. Urinary iodine excretion was also determined in 27481 children, while iodine content was estimated in 5881 samples of edible salt. The sampling methodology followed was a “30 cluster survey”.Results : The overall prevalence of goitre was 4.78% (4.66% of grade I and 0.12% of grade II) amongst the children examined. The highest prevalence of 31.02% goitre was observed in Dehradun district, while the lowest prevalence of 0.02% goitre was recorded in Bishnupur and Badaun districts. The overall prevalence of cretinism among children examined from seven districts was 0.072% whereas that of deaf-mutism was 0.27% among children examined from 8 districts. Median urinary iodine values was marginally less than the WHO cut-off values only in children of the 3 out of the 15 districts surveyed. Iodine content was found to be adequate in 55.45% of the salt samples.Conclusion : The results suggested a significant decline in the prevalence of goitre in most parts of the country.

Aflatoxin B1 contamination in wheat grain samples collected from different geographical regions of India: A multicenter study.

In a multicenter study conducted by the Indian Council of Medical Research, 1,646 samples of wheat grain collected from rural and urban areas of 10 states representing different geographical regions of India were analyzed for aflatoxin B1 (AFB1). AFB1 concentrations of > or = 5 microg kg(-1) were recorded in 40.3% of the samples, and concentrations above the Indian permissible regulatory limit of 30 microg kg(-1) were found in 16% of the samples. The proportion of samples with AFB1 concentrations above the Indian regulatory limit ranged from 1.7 to 55.8% in different states, with the minimum in Haryana and the maximum in Orissa. The variation in wheat contamination among states seems to be mainly the result of unsatisfactory storage conditions. Median AFB1 concentrations of 11, 18, and 32 microg kg(-1) were observed in samples from Uttar Pradesh, Assam, and Orissa, respectively; concentrations in other states were <5 microg kg(-1). The maximum AFB1 concentration of 606 microg kg(-1) was observed in a sample from the state of Uttar Pradesh. The calculated probable daily intakes of AFB1 through consumption of contaminated wheat for the population in some states were much higher than the suggested provisional maximum tolerable daily intake. Human health hazards associated with such AFB1 exposure over time cannot be ruled out.

Vitamin A deficiency disorders in 16 districts of India

A multicentre study to assess vitamin A deficiency disorders (Bitot’s spot and corneal scars) in 1,64,512 children (< 6 years) and night blindness among 1,13,202 children (24–71 months) from 16 districts of 11 states was carried out during 1997–2000. The prevalence of night blindness among 6,633 pregnant women from 15 districts was also assessed. The sampling methodology followed was a “30 cluster survey”. The highest prevalence of Bitot’s spot (4.71%), corneal scar (0.5%) and night blindness (5.17%) in children was found in Gaya district whereas the highest prevalence of night blindness (19.62%) among pregnant women was observed in Dibrugarh. No case of Bitot’s spot was found in children screened from Mandi, Dehradun and Badaun districts. Similarly prevalance of night blindness was ‘nil’ among pregnant women of Badaun, Baramulla, Dehradun, Mainpuri, Srinagar, Bikaner and Raigarh

Immunisation status of children in BIMARU states

To assess the immunisation status of children in the states of Bihar, Madhaya Pradesh, Rajasthan and UP the evaluation covered BCG, DPT, OPV, Measles, Pulse Polio and Vitamin A. WHO 30 cluster survey methodology with certain modifications incorporating information on sex of the child, literacy of parents and distance of the village was used. Study covered 30 districts, 900 villages and 6300 children. About 48 per cent of children received all the vaccines (BCG, DPT, OPV, Measles) in these states as compared to 63 per cent at All India level. These states accounted for about 70 per cent of non-immunised children. The coverage levels were lower for children of illiterate mothers and in small, inaccessible and triple villages. The literacy of mother is the key to the success of the Universal Immunisation Programme (UIP). Information, Education and Communication (IEC) activities should specially be targeted to educate the moters in rural areas. The underserved areas of these four states should have special focus in the programme and hence the tribal, small and inaccessible villages in the coverage should be focused and targeted, immediate improvement in the coverage could also be achieved by better follow-up and reducing drop-out rate.

Validity of causes of infant death by verbal autopsy

The aim of this study was to investigate the suitability of the verbal autopsy technique in identification of cause of death during infancy. The study was carried out in 23 randomly selected clusters with 70 live births each, in districts Cuttack and Koraput of Orissa State. Each death occurrence during the reference period (1992–93) was investigated by the field investigator and cross checked by a medical professional using the same proforma. The probable cause of death in each case was analysed separately by the field investigator and then by the professionally qualified medical person. These were then compared using suitable statistical tests.A total of 179 infant deaths and 16 still births were reported by the field investigator in the area as compared to 183 deaths and 12 still births by professionally trained personnel. There was an agreement for 85.79 percent deaths and 75 percent still births. Disagreement was observed for fever, pneumonia, septicemia and meningitis as causes of deaths. It was more in rural area as compared to urban areas. The sensitivity and specificity of the tool were found to be 85.6 percent and 90.4 percent respectively.The technique is found to be cost effective, time saving and reasonably reliable. After intensive training the lay reporters can be used for recording easily recognizable signs and symptoms of infant deaths and thus help in monitoring infant mortality rate and causes of infant death in a vast country like India so as to achieve “health for all” by 2000 AD.

SEROLOGICAL DIAGNOSIS OF TUBERCULOSIS.

ObjectiveTo evaluate the efficacy of ELISA for the detection of IgG antibodies against antigen 85 complex (Ag 85 complex) of Mycobacterium tuberculosis.MethodsChildren of either sex, 0-18 years of age, attending the outpatient department and admitted in the casualty and wards of the Department of Pediatrics, S.N. Medical College, Agra, were included in present study. The study was carried out on children with pulmonary and CNS tuberculosis along with matching controls (83 cases and 32 controls). Informed consents of their parents or guardians were taken. They were subjected to clinical examination, relevant laboratory investigations, tuberculin test and chest radiograph. Relevant body fluids were subjected to bacteriological tests; ELISA was applied to serum samples for detection of IgG antibodies against antigen 85 complex (Ag85). The result of ELISA was compared with bacteriological tests [Ziehl Neelson (ZN) staining for acid-fast bacilli, culture on Lowenstein Jensen (LJ) medium and culture on BacT/Alert 3D system].ResultsELISA tests showed a significantly higher sensitivity (59.1%) as compared with LJ medium culture method (19.3%), BacT/Alert 3D system (24.1%) and ZN staining (16.9%) in all patients (p<0.001). Specificity of ELISA test was 71.9%.ConclusionIn view of the convenience, low cost and good sensitivity, ELISA tests have a promising future in the diagnosis of childhood tuberculosis.

Residues of DDT and HCH in wheat samples collected from different states of India and their dietary exposure: A multicentre study

Abstract Under a multicentre study conducted by the Indian Council of Medical Research, 1712 samples of wheat grain/flour were collected from urban and rural areas in 11 states representing different geographical regions of India. These samples were analysed for residues of DDT (2,2-bis (p-chlorophenyl)-1,1,1-trichloro ethane) and different isomers of HCH (1,2,3,4,5,6-hexachloro cyclohexane, a mixture of isomers) by gas–liquid chromatography. Residues of DDT were detected in 59.4% of 1080 samples of wheat grain and in 78.2% of 632 samples of wheat flour. Different isomers of HCH were present in about 45–80% of the samples of wheat grain/flour. Medians of DDT and total HCH, respectively, for pooled samples of wheat grain were 0.013 and 0.035 mg kg−1, while those for wheat flour were 0.01 and 0.02 mg kg−1. Estimated daily intakes of DDT and different isomers of HCH through the consumption of wheat contaminated at their median and 90th percentiles constituted a small proportion of their acceptable daily intakes. Amongst the pesticide residues analysed, statutory maximum residue limits have been fixed only for γ-HCH in wheat in India, as 0.1 mg kg−1 in wheat grain and zero in wheat flour. Residue levels of γ-HCH exceeded these maximum residue limits in five of 1080 samples of wheat grain and in 340 of 632 samples of wheat flour. The failure to meet the requirement of the γ-HCH maximum residue limit in large number of wheat flour samples was attributed to the fixation of practically unachievable zero limit. Comparing the previous studies and the present one, the levels of residues of DDT and HCH in wheat were significantly decreased.

Residues of DDT and HCH pesticides in rice samples from different geographical regions of India: a multicentre study

As part of a multicentre study conducted by the Indian Council of Medical Research, 2000 samples of rice were collected from rural and urban areas of 13 states representing different geographical regions of India. The samples were analysed for residues of DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane] and different isomers of HCH [1,2,3,4,5,6-hexachlorocyclohexane, a mixture of isomers] by gas-chromatography. Residues of DDT and HCH, respectively, were detected in about 58 and 73% of the samples analysed. Medians of both DDT and HCH in rice samples were around 0.01 mg kg−1. Concentrations of α-, β-, γ- and δ-HCH exceeded the maximum residue limit of 0.05 mg kg−1 for each isomer in rice fixed by the Ministry of Health and Family Welfare of the Indian Government in 4.3, 2.6, 1.7 and 1.2% of the samples, respectively. There is no statutory limit fixed in India for DDT residues in cereals. Its maximum residue limit of 0.1 mg kg−1 in cereals recommended by Codex was exceeded by about 2% of the samples examined. Estimated intake of DDT and isomers of HCH through consumption of rice contaminated at their median and 90th percentiles constituted a small proportion of their acceptable daily intakes.