Prevalence of mental disorders in children living in Alberta, Canada, as determined from physician billing data.

BACKGROUND: The prevalence of mental disorders is often assessed using survey techniques. Although providing good estimates of prevalence, these techniques are time-consuming and expensive. OBJECTIVE: To estimate the prevalence of mental disorders among children aged 0 to 17 years living in Alberta, Canada, using health care administrative data. DESIGN: This was a cross-sectional study. International Classification of Diseases, Ninth Revision, Clinical Modification chapter 5 diagnostic codes from physician billing data were used. Codes were grouped into 10 categories. Prevalence rates for each category were calculated, stratified by age, sex, and premium subsidy status (a proxy for socioeconomic status). The age pattern, times of greatest risk, and the effect of sex on type and prevalence of mental disorder were estimated. SETTING: All fee-for-service health care venues in Alberta between April 1, 1995, and March 31, 1996, providing services to children registered with the Alberta Health Care Insurance Commission on March 31, 1996. RESULTS: Prevalence of mental disorders varied by disorder category, age, sex, and premium subsidy status. For boys, maximum prevalence of 9.5% occurred at age 10 years; for girls, maximum prevalence of 12.0% occurred at age 17 years. Mental disorders were most common in young boys and adolescent girls and among children receiving welfare. Distinct patterns of disorder were evident and comorbidity was common. CONCLUSIONS: Administrative data can be used to estimate the prevalence of mental disorders in a pediatric population. The estimates made are lower than those obtained by using surveys of similar populations, perhaps indicating the difference between treated and untreated prevalence. Strengths of this study are that the estimates reflect the entire population, are more easily and obtained at less cost, and are useful for the planning of mental health services.

Cell-mediated and antibody immune responses to AIK-C and Connaught monovalent measles vaccine given to 6 month old infants.

Measles vaccination of infants younger than 1 year of age should be successful in populations with a high proportion of measles vaccinated mothers. Infants whose mothers were vaccinated are born with less maternal antibody which can interfere with vaccination compared with infants whose mothers had measles. AIK-C or Connaught (CLL) measles vaccine was given to 300 6 month infants born to mothers who had measles (group 1) or who were vaccinated against measles (group 2). Pre- and post-vaccination measles antibody was measured by EIA and PRN and cell mediated immunity (CMI) by blast transformation and production of interferon-gamma and interleukin-10. After vaccination, mean antibody level, seroconversion and blastogenesis were significantly lower for group 1 than group 2 (p < 0.05). Post-vaccination measles IgG was significantly higher for group 2 CLL vaccinees compared with group 2 AIK-C (p < 0.05); seroconversion rates were 73 and 63%, respectively. More than 93% of group 2 infants had elevated measles IgG after vaccination. About 89% of all children had some evidence of a blastogenic response. Lymphoproliferation correlated strongly with cytokine production and weakly with IgG. Not all seroresponders had a CMI response and vice versa. AIK-C and CLL vaccines induce strong measles specific T and B immunity in most 6 month infants of vaccinated mothers.

Comparison of esophageal, rectal, axillary, bladder, tympanic, and pulmonary artery temperatures in children.

Our objective was to determine the most reliable site for temperature measurement in children. In anesthetized children esophageal temperature readings were closest to those in the pulmonary artery (mean difference 0.1 degree C +/- 0.5 degree C compared with Genius tympanic thermometer (mean difference 0.6 degree C +/- 1.0 degree C), IVAC tympanic thermometer (mean difference 0.8 degree C +/- 1.0 degree C), rectal probe (mean difference 0.7 degree C +/- 1.7 degrees C), bladder probe (mean difference 0.9 degree C +/- 1.4 degrees C), and axillary probe (mean difference 1.3 degrees C +/- 1.3 degrees C).

Who gets missed: coverage in a provincial newborn screening program for metabolic disease.

OBJECTIVE: To determine coverage of the newborn screening program (NSP) for metabolic disease in Alberta, Canada, and to determine reasons for not being screened. STUDY DESIGN: Coverage was estimated by deterministic matching of live birth registration data with newborn screening data for the year 1992. Demographic characteristics of not-matched infants were compared with good-match infants using logistic regression. RESULTS: For 42 392 live births, there were 41 553 screening records, of which 40 593 infants were very good matches to NSP records. Another 960 were possible matches. A total of 839 infants were not matched at all, and coverage was estimated at 98.0%. Determinants of infant not-matched status were death in week 1 (adjusted odds ratio [OR]: 383); birth weight of <1500 g (adjusted OR: 18.9) or between 1500 and 2500 g (adjusted OR: 3.2); having a mother who was single (adjusted OR: 2.7) or formerly married (adjusted OR: 12.9); or being born out of hospital (OR: 19. 2). The calculated 98% coverage is close to an estimate of 98.3% made by the NSP comparing total births with initial screenings. CONCLUSION: The matched data give insight as to who was missed and point to the need for closer attention for infants at greater risk of not being screened for metabolic disease.

Kinetics of immunologic responses after primary MMR vaccination.

To study the kinetics of humoral as well as cellular immunity to measles and to test for associated immunosuppression 124 12 month old children were studied twice, before routine MMR and either 14, 22, 30, or 38 days after vaccination. Plaque reduction neutralization (PRN) titres were determined at these time points and lymphocytes were evaluated to identify changes in proportions of phenotype, their capacity to generate cytokines and to respond to blast transformation (BT) to measles hemagglutinin (HA), tetanus toxoid and Candida antigen. The PRN titre and BT to HA plateaued at 30 days and CD8+ and NK cells increased after immunization. Interleukin 2, 4, and 10 showed no significant changes. There was mild suppression of BT at 14 and 22 days post-immunization Interferon-gamma was the principal cytokine produced after primary measles immunization, suggesting primary measles immunization induces predominantly a TH1 type response.

Differential modulation of the immune response by breast- or formula-feeding of infants.

Spontaneous integrin expression on CD4+, CD8+ and CD19+ lymphocytes at 6 months was significantly lower in breastfed than formula-fed infants (p < 0.05). In another study of 59 formula-fed and 64 breastfed 12-month-old children blast transformation and cytokine production by lymphocytes, and T cell changes were measured before and after measles-mumps-rubella vaccination (MMR). Before vaccination, lymphocytes of breastfed children had lower levels of blast transformation without antigen (p < 0.001), with tetanus toxoid (p < 0.02) or Candida (p < 0.04), and lower interferon-gamma production (p < 0.03). Fourteen days after the live viral vaccination, only the breastfed children had increased production of interferon-gamma (p < 0.02) and increased percentages of CD56+ (p < 0.022) and CD8+ cells (p < 0.004). These findings are consistent with a Th1 type response by breastfed children, not evident in formula-fed children. Feeding mode has an important long-term immunomodulating effect on infants beyond weaning.

Measles vaccination of infants in a well-vaccinated population.

During outbreaks of measles, measles vaccine is recommended for infants considered to be at risk who are 6 months of age and older. In a prospective trial the serologic response to early measles immunization has been evaluated in 125 infants given monovalent measles vaccine at 6 to 8.5 months of age and measles-mumps-rubella at 15 months. The response to vaccination was measured by plaque reduction neutralization (PRN) assay and enzyme immunoassay. Infants were grouped by the mother's immunization history: natural immunity (n = 60, Group 1); killed followed by live, further attenuated vaccine (n = 22, Group 2); and live, further attenuated vaccine only (n = 43, Group 3). The prevaccination geometric mean titer (GMT) by PRN for Group 1 (GMT = 69) was significantly higher than that of Group 2 (GMT = 18) or 3 (GMT = 13). Seroconversion (4-fold increase in PRN titer) rates after monovalent vaccine were 31, 71 and 76% for Groups 1, 2 and 3, respectively. Seroconversion percentages were higher when measured 6 to 8 weeks after vaccination compared with 4 to 5 weeks. After measles-mumps-rubella > or = 97% of all infants had PRN titers > 120 and were measles IgG-positive by enzyme immunoassay. These data show that as demographics shift to a well-vaccinated maternal population and susceptibility in younger infants, measles vaccination before the currently recommended age will be effective.

Infant feeding practices in a poor district of Santo Domingo.

PIP: During August-December 1989, in the Dominican Republic, local health promoters interviewed 103 primary caretakers and took anthropometric measurements from 103 children aged 3 years and under during home visits in three poor neighborhoods of Los Alcarrizos (Alto de Chavon, Barrio Landia, and Pueblo Nuevo) to examine infant feeding practices. 95% of the mothers had started breast feeding. The median duration of breast feeding was 7.5 months. Almost 33% had quit breast feeding by 3 months. Perception of insufficient milk was the leading reason for early discontinuation of exclusive breast feeding. The local pharmacies in all three communities offered powdered milk. About 25% of mothers began using breast milk substitutes within the first week. A non-infant formula milk powder was the most commonly used breast milk substitute. 30% of mothers stored prepared milk for later feeds, as long as half a day. Only 13% of households had a refrigerator. The most frequently used first weaning foods were orange juice, lime juice, and beans. 76% of mothers had used or were currently using baby bottles. 95% of them reported washing the bottle in boiling water. The median age of introducing the baby bottle was 3 days. Only 44% of mother covered prepared food during storage. The most commonly eaten foods among children aged at least 1 year were milk, beans, rice, and citrus fruits. Yet the children did not eat all these foods daily. 18% of 1-2 year olds and 13% of 2-3 year olds did not eat meats and alternatives regularly. 7% of 1-2 year olds and 10% of 2-3 year olds did not eat fruits and vegetables regularly. 4% of 1-2 year olds and 3% of 2-3 year olds did not eat breads and cereals regularly. About 14% of all children were not consuming any milk at the time of the survey. These findings will be used to refine nutrition education programs in the district to make them more effective.^ieng

Reduced measles immunity in infants in a well-vaccinated population.

The recommended age for measles vaccination is based in part on information gathered when most mothers had natural measles. Nowadays many mothers have received measles vaccine. To assess this change measles antibody neutralization titers (NT) were determined for 278 mother-infant pairs. One hundred sixty-four mothers, born before 1958, likely had had natural measles (Group 1). Sixty mothers received one to three killed plus one attenuated measles vaccination (Group 2) and 54 received 1 attenuated measles vaccination only (Group 3). NT were determined for the mother and for the infant at birth and in the infant during the fourth and sixth months. Group 1 mothers and infants at every age had higher geometric mean NT than those in Groups 2 or 3 (P less than 0.05). By 7 months 65% of Group 1 infants and greater than 90% of Group 2 and 3 infants had an NT less than 1:10. The rate of antibody decay was significantly faster for Group 1 infants (P less than 0.05). Earlier vaccination in the infant should be considered.

Human colostrum contains an activity that inhibits the production of IL-2.

The effect of human colostrum on T cell immune function was investigated. Colostrum inhibited the proliferation of human T cells activated by allogeneic, concanavalin A (Con A) or phytohaemagglutinin (PHA) stimulation. Colostrum also inhibited the production of IL-2 by Con A-activated human peripheral blood T cells and by Con A-activated Jurkat cells, a human T lymphoma line. Similarly, human colostrum inhibited the production of IL-2 by EL4 cells, a murine thymoma line, when stimulated with phorbol myristate acetate. The inhibitory activity was not cytotoxic and could not be neutralized by antibody to transforming human growth factor beta.

Validity of convenient indicators of obesity.

A validation study of convenient indicators of obesity was undertaken in 540 male and female subjects, aged 7-14 yr. Four adiposity measures that have commonly accepted obesity classification points [relative weight, relative body mass index (BMI), sum of five skinfolds, and triceps skinfold] were derived from measures of height, weight, and five skinfold thickness measurements. Body density measures were converted to percentage of body fat using Lohman's (1986) age- and gender-specific regression equations. Using greater than or equal to 20% body fat for males and greater than or equal to 25% for females as the standard for obesity, the diagnostic utilities (sensitivity, specificity, overall accuracy, and positive and negative predictive values) of the four obesity indicators at their commonly used obesity cutoff points were determined. Preliminary analyses demonstrate that use of these indicators should not be considered independent of the gender of the subject or without reference to the purpose for classifying subjects as obese. Secondary analyses, in which the obesity cutoff point in each indicator was altered to obtain a minimum specificity level of 95%, demonstrated that a sum of skinfolds was better at identifying true obesity than all other indicators in both males and females. There is potential for inappropriate labeling with all convenient indicators of obesity, and thus they should be used with caution.

Effect of breast-feeding on antibody response to conjugate vaccine.

Infants were immunised at the ages of 2, 4, and 6 months with conjugate Haemophilus influenzae type b vaccine, and their responses to the vaccine were evaluated by feeding method (breast or formula). There were no significant differences between the groups in antibody levels at early ages. However the antibody levels were significantly higher in the breast-fed (57 infants) than the formula-fed group (24 infants) at 7 months (mean [SD] 29.8 [32.0] vs 17.5 [14.8] micrograms/ml) and at 12 months (55 vs 26 infants; 4.8 [4.4] vs 3.0 [2.3] micrograms/ml). These findings are strong evidence that breast-feeding enhances the active immune response in the first year of life, and therefore the feeding method must be taken into account in the evaluation of vaccine studies in infants.

Comparison of convenient indicators of obesity.

A comparative study of obesity measurements was undertaken with 533 male and female subjects, aged 11.8-15.9. Six adiposity measures (three skinfold indices, three height-weight indices) were derived from measures of height, weight, and eight skinfold thickness measurements. A principal components analysis of these adiposity measures resulted in a unifactorial solution accounting for 85.6% of the total variance. A cross-tabulation analysis with the derived factor scores and a criterion visual inspection rating supported the interpretation that the underlying construct of the factor was adiposity, and that a factor score of greater than 1.5 SD above the mean was a suitable standard for labeling obesity. Utilizing this dichotomy of factor scores as a standard, the differential diagnostic capabilities of four adiposity scales commonly used in identifying obesity was undertaken. Pursuit of this methodology, with the use of additional measures and larger sample sizes, is recommended to ensure the validation of an obesity measure.

Prospective trial of timing of bacillus Calmette-Guérin vaccination in Canadian Cree infants.

We studied 184 Cree Indian infants in randomized, prospective fashion to assess the effect of age on lymphocyte sensitization to purified protein derivative (PPD) before and after and without bacillus Calmette-Guérin (BCG) vaccination. Lymphocyte responses to PPD, Candida, and streptokinase were measured at birth and at intervals later. The mean response of paired values from 26 infants without BCG vaccination rose for the PPD stimulation index (SI) from 2.7 at birth to 3.9 before 2 yr of age. The SI for both Candida and streptokinase for this group of infants rose significantly in the first 2 yr (p less than 0.05). In 66 infants who received BCG in the first 7 days of life, the PPD-SI rose from 3.1 to 35.3 (p less than 0.001). In 17 infants who received the vaccine later but before 9 months, it rose from 3.1 at birth to 24.9, and in 14 who received it between 9 months and 2 yr, it rose from 2.2 to 52.9. The lymphocyte responses to PPD after BCG in these two groups were significantly different (p less than 0.05). There was no evidence in the older infants that a raised PPD-SI before BCG vaccination affected lymphocyte sensitization by the vaccine. We conclude that increasing the age at vaccination with BCG from birth to more than 9 months enhances immunologic sensitization to PPD significantly in this population.

Effect of breast-feeding on immune response to BCG vaccination.

The effect on BCG immunisation of feeding either formula or breast milk was assessed in Canadian Cree infants who were vaccinated either at birth or after 1 month of age. The response to BCG was measured in terms of lymphocyte blastogenesis stimulated by purified protein derivative of Mycobacterium tuberculosis. Breast-feeding significantly enhanced cell-mediated immune response to BCG vaccine given at birth, but had no significant effect if vaccine was given after 1 month. These findings were not related to maternal history of tuberculosis or BCG vaccination, and the feeding method did not influence lymphocyte stimulation by candida or streptococcal antigens.

A description of the changing body composition of the growing premature infant.

Data from studies of two similar groups of premature infants were used to describe the changing body composition (BC) of a "typical" premature infant, 3 to 4 weeks old, gaining weight from 1,200 to 2,000 g and being fed its mother's expressed breast milk at a metabolizable energy intake of 93.6 kcal/kg/day. Serial measurements had been made of total body water (TBW), the extracellular fluid space (ECF), nitrogen balance, and gross energy balance in one group of premature (n = 17) infants and of total body potassium (TBK) in another group (n = 23); all infants studied weighed between 900 and 2,300 g. Equations relating TBW, ECF, and TBK to body weight were derived for estimating the content of these substances at body weights between 1,200 and 2,000 g. Protein content at 1,200 g body weight was estimated from measured TBK and N:K ratio (determined from the reference fetus) at this weight. Subsequent protein content was determined from average N accretion, determined from data of N balance, and carbohydrate and ash content were estimated from reference data. The remainder of the body weight was assumed to be fat. At 1,200 g, the proposed BC of the premature infant is 72.1% water, 10.7% protein, 14.9% fat, 1.9% ash, and 0.4% carbohydrate. At 2,000 g comparable figures are 67.8% water, 11.6% protein, 18.2% fat, 1.9% ash, and 0.5% carbohydrate. The description also provides estimates of the body cell mass (BCM) and intracellular fluid (ICF), the relationship of K to the BCM and ICF, and the energy balance of the growing premature infant.

Transfer of maternal specific cell-mediated immunity to the fetus.

The extent of specific cell-mediated immunity was measured in 67 consecutive newborns and their mothers. The stimulation index of blast transformation of the infants' lymphocytes in the presence of purified protein derivative, Candida extract and streptokinase was greater than 2.0 in 54%, 18% and 23% respectively. This was seen only in infants whose mothers' index was also greater than 2.0 to the same antigen. Leucocyte inhibition factor generated from lymphocytes of four babies in the presence of purified protein derivative inhibited migration of indicator cells over 50%; their stimulation index with purified protein derivative was greater than 2.0. Newborns have cell mediated immunity to the same antigens as their mothers, and this wanes during the first few months of life.

Measurement of total body potassium in premature infants by means of a whole-body counter.

This paper describes a whole-body counter (WBC) specially designed to measured total body potassium (TBK) infants under 4,500 g. The counter is a "shadow shield" design and consists of a single 10 cm X 10 cm X 45 cm NaI(Tl) crystal, positioned lengthwise and shielded from environmental background radiation by a minimum of 10 cm of lead. The standard error of counting for a 2,000-s counting period is 19.9% for a 1,000-g infant and 11.9% for a 2,000-g infant. TBK of stillborn pigs, measured by the WBC, agreed to an average of 3% of TBK determined by carcass analysis in the same animals. A total of 118 measurements of TBK have been made in 50 premature infants ranging in weight between 1,100 and 3,600 g and in age between 2 and 75 days. The observed relationship of TBK with weight is described by the equation: TBK (mEq) = 0.0433Wt (g + 1.57 r = 0.92. Potassium retention per gram weight gain is estimated to be 0.043 mEq. The obtained TBK values agree well with values published by other workers but extend the range of measurement to 1,100 g.

Effects of mother's smoking on their infants' body composition as determined by total body potassium.

It has been suggested that the lower birth weight of newborn infants of mothers who smoke is due mainly to a deficit of lean body mass (LBM). We tested this hypothesis by measuring total body potassium, thus deriving the LBM and fat mass, of newborn infants of mothers who smoked (I-SM; n = 32) or did not smoke (I-NSM; n = 46). Mothers who smoked were significantly younger than nonsmoking ones (25.4 and 28.9 yr, respectively) and with less years of education, but were similar in other parameters examined. The 78 infants, all singleton, were studied within 1 to 3 days of birth. The I-SM had significantly reduced birth weight, length, and head circumference but there was no difference in skinfold thickness. We measured total body potassium with a whole-body counter specially made for use with infants. Mean absolute total body potassium was significantly greater in the I-NSM, but the concentration in relation to weight was not different. Assuming 1 kg LBM to contain 52.1 mmol potassium, the mean LBM was 3028 g in the I-NSM and 2739 in the I-SM; mean fat mass was similar in both groups. Multiple regression analysis revealed an independent negative effect of mother's smoking on birth weight and LBM. This unequal reduction in LBM indicates a complex effect of smoking, probably mediated by alterations in protein synthesis and adipocyte metabolism. It may relate to the higher morbidity rates in infants of mothers who smoke.