International journal of epidemiology, Jan 14, 2015
Growth faltering in the first 2 years of life is high in South Asia where prevalence of stunting ... more Growth faltering in the first 2 years of life is high in South Asia where prevalence of stunting is estimated at 40-50%. Although nutrition counselling has shown modest benefits, few intervention trials of food supplementation exist showing improvements in growth and prevention of stunting. A cluster-randomized controlled trial was conducted in rural Bangladesh to test the effect of two local, ready-to-use foods (chickpea and rice-lentil based) and a fortified blended food (wheat-soy-blend++, WSB++) compared with Plumpy'doz, all with nutrition counselling vs nutrition counselling alone (control) on outcomes of linear growth (length and length-for-age z-score, LAZ), stunting (LAZ < -2), weight-for-length z-score (WLZ) and wasting (WLZ < -2) in children 6-18 months of age. Children (n = 5536) were enrolled at 6 months of age and, in the food groups, provided with one of the allocated supplements daily for a year. Growth deceleration occurred from 6 to 18 months of age but de...
Approximately 4000 preschool children in weighed and measured at 3-mo intervals from March 1977 t... more Approximately 4000 preschool children in weighed and measured at 3-mo intervals from March 1977 to December 1978. Children recovering from xerophthalmia over a 3-mo interval gained an average of 124 g (95% CI 42-206) more over 3 mo than normal children. Their height gain was similar to normal children's. Children who developed xeroph- thalmia during a 3-mo period gained 199
The purpose of this study was to estimate the bias and design effects associated with the Expande... more The purpose of this study was to estimate the bias and design effects associated with the Expanded Program on Immunization&#39;s (EPI) sampling design when estimating xerophthalmia prevalence, and to estimate the savings associated with EPI in terms of distance travelled within selected clusters. Computer simulation of the EPI sampling strategy was done using maps from a xerophthalmia survey of 40 wards in Sarlahi district, Nepal. Samples of fixed cluster sizes of 7, 10, 15, 20 and 25 were compared. The estimated prevalence using the EPI design was compared with the true prevalence in the 40 wards to estimate the bias. The design effect was estimated by taking the ratio of the variance under EPI sampling to that of stratified random sampling (SRS) with fixed cluster sizes. The EPI was also modified by increasing the distance between selected houses from nearest neighbour to skipping 1-4 houses between selected ones. The difference between the distance travelled within clusters using SRS compared with EPI was weighed against the bias and increased variance. The prevalence of xerophthalmia was 2.8%. The EPI design overestimated xerophthalmia prevalence by between 0.27% and 1.16%. The design effects of EPI cluster sampling within wards varied between 0.73 and 1.35. Neither the bias nor the design effect was related to distance between households or cluster size. Distance travelled within wards was always less for EPI designs with cluster sizes of 7 or 10. There was no saving in terms of distance travelled for designs with cluster sizes from 15 to 25 if there were two or more houses between selected ones. For fixed cluster sizes of 15 or fewer, the EPI sampling design using nearest or next nearest neighbours is a better choice than SRS in terms of minimizing the distance travelled and the mean square error. The choice of an optimum method would need to account for the density of clusters and difficulty of travel between clusters, as well as the costs of travel within clusters. Based on certain assumptions, EPI with 15 children per cluster would be favoured over examining all children in selected wards unless the travel time between wards was more than 2 days.
Previously, we showed that antenatal micronutrient supplementation increases birth weight in a ma... more Previously, we showed that antenatal micronutrient supplementation increases birth weight in a malnourished rural South Asian setting, but the long-term effects are unknown. Between 1999 and 2001, pregnant women were sector-randomized to receive from early pregnancy through 3 mo postpartum daily micronutrient supplements containing either vitamin A alone as the control or with folic acid; folic acid+iron; folic acid+iron+zinc; or a multiple micronutrient supplement that included the above nutrients plus 11 others. From 2006 to 2008, 3524 children (93% of surviving children) were revisited between the ages of 6 and 8 y. Blood pressure, BMI, waist circumference, glycated hemoglobin, cholesterol, triglycerides, glucose, insulin, and the urinary microalbumin:creatinine ratio were assessed among children. Insulin resistance was estimated using the homeostasis model assessment (HOMA) and metabolic syndrome was defined using a modified National Cholesterol Education Program definition. None of the micronutrient supplement combinations affected blood pressure, cholesterol, triglycerides, glucose, insulin, or HOMA. There was a reduced risk of microalbuminuria (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =3.40 mg/mmol creatinine) in the folic acid [odds ratio (OR), 0.56; 95%CI, 0.33-0.93; P = 0.02) and folic acid+iron+zinc (OR, 0.53; CI, 0.32-0.89; P = 0.02) groups and a reduced risk of metabolic syndrome in the folic acid group (OR, 0.63; CI, 0.41-0.97; P = 0.03). Maternal supplementation with folic acid or folic acid+iron+zinc reduced the risk of kidney dysfunction and, to some extent, metabolic syndrome among children at 6-8 y of age. Supplementation with multiple micronutrients had no such affect. Future follow-up studies are needed to examine long-term supplementation effects on risk of chronic diseases in adults.
Dietary quality and diversity reflect adequacy of vitamin A. Both can deteriorate in response to ... more Dietary quality and diversity reflect adequacy of vitamin A. Both can deteriorate in response to economic crises. Although the nutritional consequences of the 2008 world food price crisis remain unclear, past studies of diet, status, and socioeconomic standing under usual (deprived) and unusually disruptive times suggest dietary quality and vitamin A status decline in mothers and young children. This is presumably the result of shifting diets to include less preformed vitamin A-rich animal source foods and, to a lesser extent, vegetables and fruits. Cross-sectional assessments of diet, deficiency, and socioeconomic status in a number of countries and surveillance data collected during the Indonesian economic crisis of 1997-8 indicate that the prevalence of vitamin A deficiency, night blindness, and other related disorders (e.g., anemia) may have increased during the 2008 crisis, and that it might not have necessarily recovered once food prices waned later in 2008. Lost employment may be a factor in slow nutritional recovery, despite some easing of food prices. Vitamin A deficiency should still be preventable amid economic instabilities through breast feeding promotion, vitamin A supplementation, fortification of foods targeted to the poor, and homestead food production that can bolster income and diversify the diet.
Birth size is an important gauge of fetal and neonatal health. Birth size measurements were colle... more Birth size is an important gauge of fetal and neonatal health. Birth size measurements were collected within 72 h of life for 16 290 live born, singleton infants in rural Bangladesh from 2004 to 2007. Gestational age was calculated based on the date of last menstrual period. Newborns were classified as small-for-gestational age (SGA) based on a birthweight below the 10th percentile for gestational age, using three sets of US reference data. Birth size distributions were explored based on raw values as well as after z-score standardisation in reference to World Health Organization (WHO) 2006 growth standards. Mean (SD) birthweight (g), length (cm) and head circumference (cm) measurements, completed within [median (25th, 75th percentile)] 15 (8, 23) h of life, were 2433 (425), 46.4 (2.4) and 32.4 (1.6), respectively. Twenty-two per cent were born preterm. Over one-half (55.3%) of infants were born low birthweight; 46.6%, 37.0% and 33.6% had a weight, length and head circumference below -2 z-scores of the WHO growth standard at birth; and 70.9%, 72.2% and 59.8% were SGA for weight based on Alexander et al., Oken et al. and Olsen et al. references, respectively. Infants in this typical rural Bangladesh setting were commonly born small, reflecting a high burden of fetal growth restriction and preterm birth. Our findings, produced by active birth surveillance, suggest that low birthweight is far more common than suggested by cross-sectional survey estimates. Interventions that improve fetal growth during pregnancy may have the largest impact on reducing SGA rates.
Page 1. Ecology of Food and Nutrition, Vol. 39, pp. 199-223 C 2000 OPA (Overseas Publishers Assoc... more Page 1. Ecology of Food and Nutrition, Vol. 39, pp. 199-223 C 2000 OPA (Overseas Publishers Association) NV Reprints available directly from the publisher Published by license under Photocopying permitted by license only the Gordon and Breach Publishers imprint. ...
Arsenic has immunomodulatory properties and may have the potential to alter susceptibility to inf... more Arsenic has immunomodulatory properties and may have the potential to alter susceptibility to infection in humans. We aimed to assess the relation of arsenic exposure during pregnancy with immune function and hepatitis E virus (HEV) infection, defined as seroconversion during pregnancy and postpartum. We assessed IgG seroconversion to HEV between 1st and 3rd trimester (TM) and 3 months postpartum (PP) among 1100 pregnancies in a multiple micronutrient supplementation trial in rural Bangladesh. Forty women seroconverted to HEV and were matched with 40 non-seroconverting women (controls) by age, parity and intervention. We assessed urinary inorganic arsenic plus methylated species (∑As) (µg/L) at 1st and 3rd TM and plasma cytokines (pg/mL) at 1st and 3rd TM and 3 months PP. HEV seroconverters' urinary ∑As was elevated throughout pregnancy. Non-seroconverters' urinary ∑As was similar to HEV seroconverters at 1st TM but declined at 3rd TM. The adjusted odds ratio (95% confidence...
Journal of the American Veterinary Medical Association
To determine the effect of maternally derived antibodies on induction of protective immune respon... more To determine the effect of maternally derived antibodies on induction of protective immune responses against bovine viral diarrhea virus (BVDV) type II in young calves vaccinated with a modified-live bovine viral diarrhea virus (BVDV) type I vaccine. Blinded controlled challenge study. 24 neonatal Holstein and Holstein-cross calves that were deprived of maternal colostrum and fed pooled colostrum that contained a high concentration of (n = 6) or no (18) antibodies to BVDV. At 10 to 14 days of age, 6 seropositive and 6 seronegative calves were given a combination vaccine containing modified-live BVDV type I. All calves were kept in isolation for 4.5 months. Six calves of the remaining 12 untreated calves were vaccinated with the same combination vaccine at approximately 4 months of age. Three weeks later, all calves were challenged intranasally with a virulent BVDV type II. Seronegative unvaccinated calves and seropositive calves that were vaccinated at 2 weeks of age developed sever...
The efficacy of modified-live (MLV) bovine respiratory syncytial virus (BRSV) vaccines and the co... more The efficacy of modified-live (MLV) bovine respiratory syncytial virus (BRSV) vaccines and the correlates of vaccine-induced immunity were investigated in calves using a virulent experimental infection. Clinical disease and pulmonary pathology were significantly reduced, relative to unvaccinated controls, in calves vaccinated according to label directions with commercial multivalent MLV BRSV vaccines. In vitro assays of cellular immunity were more consistent correlates of vaccine associated protection than presence of post vaccination serum antibody. Most vaccinated calves shed virus, but peak virus titre was suppressed compared to unvaccinated controls, with clearance coincident with the simultaneous appearance of mucosal antibody, cytotoxic cells in the lung and anamnestic or primary serum antibody responses. Virus clearance in unvaccinated calves was coincident with the appearance of BRSV specific cytotoxic cells, before mucosal antibody was detected.
To assess the impact of vitamin A supplementation at 4-month intervals on the prevalence and inci... more To assess the impact of vitamin A supplementation at 4-month intervals on the prevalence and incidence of xerophthalmia among preschool-age children. A stratified, random sample of 40 wards with 4766 children in Sarlahi district of Nepal was selected to participate in a randomized, controlled, community trial. In the vitamin A group, at 4-month intervals, neonates received 50,000 IU, 1- to 11-month-old infants received 100,000 IU, and children 1 through 4 years of age received 200,000 IU. Children underwent eye examination before the intervention and 16 months later. Before the intervention, 4318 children were examined for xerophthalmia. The prevalence was 2.3% in the vitamin A group and 3.3% in the placebo group. All children with xerophthalmia were treated with vitamin A at the time of the examination. Of those examined at baseline, 38 in the vitamin A group and 48 in the placebo group died in the 16 months after intervention. There were 1871 (84%) surviving children in the vitamin A group and 1711 (85%) in the placebo group examined at follow-up. After adjustment for the baseline prevalence of xerophthalmia, vitamin A reduced the prevalence at follow-up by 63% (95% confidence interval, 21% to 83%). The apparent incidence was 3.2/1000 per year in the vitamin A group and 9.2/1000 per year in the placebo group, an adjusted reduction of 62% (95% confidence interval, 0% to 86%). Supplementation was effective at reducing the prevalence and incidence of xerophthalmia.
Background: Previously we showed that women in rural Nepal experience multiple micronutrient defi... more Background: Previously we showed that women in rural Nepal experience multiple micronutrient deficiencies in early pregnancy. Objective: This study examined the effects of daily antenatal mi- cronutrientsupplementationonchangesinthebiochemicalstatusof several micronutrients during pregnancy. Design: In Nepal, we conducted a randomized controlled trial in which4combinationsofmicronutrients(folicacid,folicacidiron, folic acid iron zinc, and a multiple micronutrient supplement containingfolicacid,iron,zinc,and11othernutrients)plusvitamin A, or vitamin A alone as a control,
Direct observation techniques are increasingly being used to measure human behavior as part of he... more Direct observation techniques are increasingly being used to measure human behavior as part of health research and intervention studies. One problem with this approach that has not been well-explored is the effect of the observer's presence on the behaviors being observed, ...
Pregnancy exacerbates vitamin A (VA) deficiency and anaemia among women in developing countries. ... more Pregnancy exacerbates vitamin A (VA) deficiency and anaemia among women in developing countries. Improving circulating haemoglobin (Hb) requires erythrocyte production and availability of iron. Insulin-like growth factor- 1 (IGF-1) functions in erythropoiesis, but its association with VA status and pregnancy-associated anaemia has not been studied. The aim of this study was to examine the relationship between serum retinol, IGF-1, and Hb among pregnant women in extant samples collected during a placebo-controlled trial of VA and beta-carotene (BC) supplementation in rural Nepal conducted from 1994 to 1997. Mid-pregnancy serum IGF-1 was measured in serum from n=589 randomly selected women of n=1186 in whom anthropometric, VA (retinol) and iron (Hb, erythrocyte zinc protoporphyrin (ZP), and ferritin) status data were available. Associations of IGF-1 with retinol, Hb or anaemia, and iron status were determined using multiple linear and logistic regression. Path analysis was used to exp...
International journal of epidemiology, Jan 14, 2015
Growth faltering in the first 2 years of life is high in South Asia where prevalence of stunting ... more Growth faltering in the first 2 years of life is high in South Asia where prevalence of stunting is estimated at 40-50%. Although nutrition counselling has shown modest benefits, few intervention trials of food supplementation exist showing improvements in growth and prevention of stunting. A cluster-randomized controlled trial was conducted in rural Bangladesh to test the effect of two local, ready-to-use foods (chickpea and rice-lentil based) and a fortified blended food (wheat-soy-blend++, WSB++) compared with Plumpy'doz, all with nutrition counselling vs nutrition counselling alone (control) on outcomes of linear growth (length and length-for-age z-score, LAZ), stunting (LAZ < -2), weight-for-length z-score (WLZ) and wasting (WLZ < -2) in children 6-18 months of age. Children (n = 5536) were enrolled at 6 months of age and, in the food groups, provided with one of the allocated supplements daily for a year. Growth deceleration occurred from 6 to 18 months of age but de...
Approximately 4000 preschool children in weighed and measured at 3-mo intervals from March 1977 t... more Approximately 4000 preschool children in weighed and measured at 3-mo intervals from March 1977 to December 1978. Children recovering from xerophthalmia over a 3-mo interval gained an average of 124 g (95% CI 42-206) more over 3 mo than normal children. Their height gain was similar to normal children's. Children who developed xeroph- thalmia during a 3-mo period gained 199
The purpose of this study was to estimate the bias and design effects associated with the Expande... more The purpose of this study was to estimate the bias and design effects associated with the Expanded Program on Immunization&#39;s (EPI) sampling design when estimating xerophthalmia prevalence, and to estimate the savings associated with EPI in terms of distance travelled within selected clusters. Computer simulation of the EPI sampling strategy was done using maps from a xerophthalmia survey of 40 wards in Sarlahi district, Nepal. Samples of fixed cluster sizes of 7, 10, 15, 20 and 25 were compared. The estimated prevalence using the EPI design was compared with the true prevalence in the 40 wards to estimate the bias. The design effect was estimated by taking the ratio of the variance under EPI sampling to that of stratified random sampling (SRS) with fixed cluster sizes. The EPI was also modified by increasing the distance between selected houses from nearest neighbour to skipping 1-4 houses between selected ones. The difference between the distance travelled within clusters using SRS compared with EPI was weighed against the bias and increased variance. The prevalence of xerophthalmia was 2.8%. The EPI design overestimated xerophthalmia prevalence by between 0.27% and 1.16%. The design effects of EPI cluster sampling within wards varied between 0.73 and 1.35. Neither the bias nor the design effect was related to distance between households or cluster size. Distance travelled within wards was always less for EPI designs with cluster sizes of 7 or 10. There was no saving in terms of distance travelled for designs with cluster sizes from 15 to 25 if there were two or more houses between selected ones. For fixed cluster sizes of 15 or fewer, the EPI sampling design using nearest or next nearest neighbours is a better choice than SRS in terms of minimizing the distance travelled and the mean square error. The choice of an optimum method would need to account for the density of clusters and difficulty of travel between clusters, as well as the costs of travel within clusters. Based on certain assumptions, EPI with 15 children per cluster would be favoured over examining all children in selected wards unless the travel time between wards was more than 2 days.
Previously, we showed that antenatal micronutrient supplementation increases birth weight in a ma... more Previously, we showed that antenatal micronutrient supplementation increases birth weight in a malnourished rural South Asian setting, but the long-term effects are unknown. Between 1999 and 2001, pregnant women were sector-randomized to receive from early pregnancy through 3 mo postpartum daily micronutrient supplements containing either vitamin A alone as the control or with folic acid; folic acid+iron; folic acid+iron+zinc; or a multiple micronutrient supplement that included the above nutrients plus 11 others. From 2006 to 2008, 3524 children (93% of surviving children) were revisited between the ages of 6 and 8 y. Blood pressure, BMI, waist circumference, glycated hemoglobin, cholesterol, triglycerides, glucose, insulin, and the urinary microalbumin:creatinine ratio were assessed among children. Insulin resistance was estimated using the homeostasis model assessment (HOMA) and metabolic syndrome was defined using a modified National Cholesterol Education Program definition. None of the micronutrient supplement combinations affected blood pressure, cholesterol, triglycerides, glucose, insulin, or HOMA. There was a reduced risk of microalbuminuria (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =3.40 mg/mmol creatinine) in the folic acid [odds ratio (OR), 0.56; 95%CI, 0.33-0.93; P = 0.02) and folic acid+iron+zinc (OR, 0.53; CI, 0.32-0.89; P = 0.02) groups and a reduced risk of metabolic syndrome in the folic acid group (OR, 0.63; CI, 0.41-0.97; P = 0.03). Maternal supplementation with folic acid or folic acid+iron+zinc reduced the risk of kidney dysfunction and, to some extent, metabolic syndrome among children at 6-8 y of age. Supplementation with multiple micronutrients had no such affect. Future follow-up studies are needed to examine long-term supplementation effects on risk of chronic diseases in adults.
Dietary quality and diversity reflect adequacy of vitamin A. Both can deteriorate in response to ... more Dietary quality and diversity reflect adequacy of vitamin A. Both can deteriorate in response to economic crises. Although the nutritional consequences of the 2008 world food price crisis remain unclear, past studies of diet, status, and socioeconomic standing under usual (deprived) and unusually disruptive times suggest dietary quality and vitamin A status decline in mothers and young children. This is presumably the result of shifting diets to include less preformed vitamin A-rich animal source foods and, to a lesser extent, vegetables and fruits. Cross-sectional assessments of diet, deficiency, and socioeconomic status in a number of countries and surveillance data collected during the Indonesian economic crisis of 1997-8 indicate that the prevalence of vitamin A deficiency, night blindness, and other related disorders (e.g., anemia) may have increased during the 2008 crisis, and that it might not have necessarily recovered once food prices waned later in 2008. Lost employment may be a factor in slow nutritional recovery, despite some easing of food prices. Vitamin A deficiency should still be preventable amid economic instabilities through breast feeding promotion, vitamin A supplementation, fortification of foods targeted to the poor, and homestead food production that can bolster income and diversify the diet.
Birth size is an important gauge of fetal and neonatal health. Birth size measurements were colle... more Birth size is an important gauge of fetal and neonatal health. Birth size measurements were collected within 72 h of life for 16 290 live born, singleton infants in rural Bangladesh from 2004 to 2007. Gestational age was calculated based on the date of last menstrual period. Newborns were classified as small-for-gestational age (SGA) based on a birthweight below the 10th percentile for gestational age, using three sets of US reference data. Birth size distributions were explored based on raw values as well as after z-score standardisation in reference to World Health Organization (WHO) 2006 growth standards. Mean (SD) birthweight (g), length (cm) and head circumference (cm) measurements, completed within [median (25th, 75th percentile)] 15 (8, 23) h of life, were 2433 (425), 46.4 (2.4) and 32.4 (1.6), respectively. Twenty-two per cent were born preterm. Over one-half (55.3%) of infants were born low birthweight; 46.6%, 37.0% and 33.6% had a weight, length and head circumference below -2 z-scores of the WHO growth standard at birth; and 70.9%, 72.2% and 59.8% were SGA for weight based on Alexander et al., Oken et al. and Olsen et al. references, respectively. Infants in this typical rural Bangladesh setting were commonly born small, reflecting a high burden of fetal growth restriction and preterm birth. Our findings, produced by active birth surveillance, suggest that low birthweight is far more common than suggested by cross-sectional survey estimates. Interventions that improve fetal growth during pregnancy may have the largest impact on reducing SGA rates.
Page 1. Ecology of Food and Nutrition, Vol. 39, pp. 199-223 C 2000 OPA (Overseas Publishers Assoc... more Page 1. Ecology of Food and Nutrition, Vol. 39, pp. 199-223 C 2000 OPA (Overseas Publishers Association) NV Reprints available directly from the publisher Published by license under Photocopying permitted by license only the Gordon and Breach Publishers imprint. ...
Arsenic has immunomodulatory properties and may have the potential to alter susceptibility to inf... more Arsenic has immunomodulatory properties and may have the potential to alter susceptibility to infection in humans. We aimed to assess the relation of arsenic exposure during pregnancy with immune function and hepatitis E virus (HEV) infection, defined as seroconversion during pregnancy and postpartum. We assessed IgG seroconversion to HEV between 1st and 3rd trimester (TM) and 3 months postpartum (PP) among 1100 pregnancies in a multiple micronutrient supplementation trial in rural Bangladesh. Forty women seroconverted to HEV and were matched with 40 non-seroconverting women (controls) by age, parity and intervention. We assessed urinary inorganic arsenic plus methylated species (∑As) (µg/L) at 1st and 3rd TM and plasma cytokines (pg/mL) at 1st and 3rd TM and 3 months PP. HEV seroconverters' urinary ∑As was elevated throughout pregnancy. Non-seroconverters' urinary ∑As was similar to HEV seroconverters at 1st TM but declined at 3rd TM. The adjusted odds ratio (95% confidence...
Journal of the American Veterinary Medical Association
To determine the effect of maternally derived antibodies on induction of protective immune respon... more To determine the effect of maternally derived antibodies on induction of protective immune responses against bovine viral diarrhea virus (BVDV) type II in young calves vaccinated with a modified-live bovine viral diarrhea virus (BVDV) type I vaccine. Blinded controlled challenge study. 24 neonatal Holstein and Holstein-cross calves that were deprived of maternal colostrum and fed pooled colostrum that contained a high concentration of (n = 6) or no (18) antibodies to BVDV. At 10 to 14 days of age, 6 seropositive and 6 seronegative calves were given a combination vaccine containing modified-live BVDV type I. All calves were kept in isolation for 4.5 months. Six calves of the remaining 12 untreated calves were vaccinated with the same combination vaccine at approximately 4 months of age. Three weeks later, all calves were challenged intranasally with a virulent BVDV type II. Seronegative unvaccinated calves and seropositive calves that were vaccinated at 2 weeks of age developed sever...
The efficacy of modified-live (MLV) bovine respiratory syncytial virus (BRSV) vaccines and the co... more The efficacy of modified-live (MLV) bovine respiratory syncytial virus (BRSV) vaccines and the correlates of vaccine-induced immunity were investigated in calves using a virulent experimental infection. Clinical disease and pulmonary pathology were significantly reduced, relative to unvaccinated controls, in calves vaccinated according to label directions with commercial multivalent MLV BRSV vaccines. In vitro assays of cellular immunity were more consistent correlates of vaccine associated protection than presence of post vaccination serum antibody. Most vaccinated calves shed virus, but peak virus titre was suppressed compared to unvaccinated controls, with clearance coincident with the simultaneous appearance of mucosal antibody, cytotoxic cells in the lung and anamnestic or primary serum antibody responses. Virus clearance in unvaccinated calves was coincident with the appearance of BRSV specific cytotoxic cells, before mucosal antibody was detected.
To assess the impact of vitamin A supplementation at 4-month intervals on the prevalence and inci... more To assess the impact of vitamin A supplementation at 4-month intervals on the prevalence and incidence of xerophthalmia among preschool-age children. A stratified, random sample of 40 wards with 4766 children in Sarlahi district of Nepal was selected to participate in a randomized, controlled, community trial. In the vitamin A group, at 4-month intervals, neonates received 50,000 IU, 1- to 11-month-old infants received 100,000 IU, and children 1 through 4 years of age received 200,000 IU. Children underwent eye examination before the intervention and 16 months later. Before the intervention, 4318 children were examined for xerophthalmia. The prevalence was 2.3% in the vitamin A group and 3.3% in the placebo group. All children with xerophthalmia were treated with vitamin A at the time of the examination. Of those examined at baseline, 38 in the vitamin A group and 48 in the placebo group died in the 16 months after intervention. There were 1871 (84%) surviving children in the vitamin A group and 1711 (85%) in the placebo group examined at follow-up. After adjustment for the baseline prevalence of xerophthalmia, vitamin A reduced the prevalence at follow-up by 63% (95% confidence interval, 21% to 83%). The apparent incidence was 3.2/1000 per year in the vitamin A group and 9.2/1000 per year in the placebo group, an adjusted reduction of 62% (95% confidence interval, 0% to 86%). Supplementation was effective at reducing the prevalence and incidence of xerophthalmia.
Background: Previously we showed that women in rural Nepal experience multiple micronutrient defi... more Background: Previously we showed that women in rural Nepal experience multiple micronutrient deficiencies in early pregnancy. Objective: This study examined the effects of daily antenatal mi- cronutrientsupplementationonchangesinthebiochemicalstatusof several micronutrients during pregnancy. Design: In Nepal, we conducted a randomized controlled trial in which4combinationsofmicronutrients(folicacid,folicacidiron, folic acid iron zinc, and a multiple micronutrient supplement containingfolicacid,iron,zinc,and11othernutrients)plusvitamin A, or vitamin A alone as a control,
Direct observation techniques are increasingly being used to measure human behavior as part of he... more Direct observation techniques are increasingly being used to measure human behavior as part of health research and intervention studies. One problem with this approach that has not been well-explored is the effect of the observer's presence on the behaviors being observed, ...
Pregnancy exacerbates vitamin A (VA) deficiency and anaemia among women in developing countries. ... more Pregnancy exacerbates vitamin A (VA) deficiency and anaemia among women in developing countries. Improving circulating haemoglobin (Hb) requires erythrocyte production and availability of iron. Insulin-like growth factor- 1 (IGF-1) functions in erythropoiesis, but its association with VA status and pregnancy-associated anaemia has not been studied. The aim of this study was to examine the relationship between serum retinol, IGF-1, and Hb among pregnant women in extant samples collected during a placebo-controlled trial of VA and beta-carotene (BC) supplementation in rural Nepal conducted from 1994 to 1997. Mid-pregnancy serum IGF-1 was measured in serum from n=589 randomly selected women of n=1186 in whom anthropometric, VA (retinol) and iron (Hb, erythrocyte zinc protoporphyrin (ZP), and ferritin) status data were available. Associations of IGF-1 with retinol, Hb or anaemia, and iron status were determined using multiple linear and logistic regression. Path analysis was used to exp...
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Papers by Keith West