Tuberculosis case finding for vaccine trials in young children in high-incidence settings: a randomised trial

SETTING

A high tuberculosis (TB) burden rural area in South Africa.

OBJECTIVE

To compare TB case yield and disease profile among bacille Calmette-Guérin (BCG) vaccinated children using two case-finding strategies from birth until 2 years of age.

DESIGN

BCG-vaccinated infants were enrolled within 2 weeks of birth and randomised to 3-monthly home visits for questionnaire-based TB screening plus record surveillance of TB registers, hospital admission and X-ray lists at health facilities for TB suspects and cases (Group 1), or record surveillance (as above) only (Group 2). Both groups received a close-out visit after 2 years. Participants were evaluated for suspected TB disease using standardised investigations.

RESULTS

A total of 4786 infants were enrolled: 2392 were randomised to Group 1 and 2394 to Group 2. The case-finding rate was significantly greater in Group 1 (2.2/100 py) than in Group 2 (0.8/100 py), with a case-finding rate ratio of 2.6 (95%CI 1.8-4.0, P < 0.001). Although the proportion of cases with bacteriological confirmation was lower in Group 1, this difference did not reach statistical significance. There was also no significant difference in the proportions with TB symptoms and signs.

CONCLUSION

Home visits combined with record surveillance detected significantly more cases than record surveillance with a single study-end visit. The TB case profile did not differ significantly between the two groups.

Tuberculin skin test and QuantiFERON® assay in young children investigated for tuberculosis in South Africa

SETTING

Although the literature on interferon-gamma release assays on tuberculosis (TB) in children has increased, data pertaining to young children remain relatively limited.

OBJECTIVE

To compare results from the tuberculin skin test (TST) and the QuantiFERON®-TB Gold In-Tube assay (QFT) in children aged <3 years investigated for TB disease.

DESIGN

TB suspects were evaluated by medical history and examination, TST, QFT, chest radiography, induced sputum and gastric washings for smear and culture for Mycobacterium tuberculosis.

RESULTS

A total of 400 children were enrolled. Among 397 children with both test results, 68 (17%) were QFT-positive and 72 (18%) were TST-positive (≥10 mm). Agreement between the tests was excellent (94%, κ = 0.79, 95%CI 0.69-0.89). TB disease was diagnosed in 52/397 (13%) participants: 3 definite, 35 probable and 14 possible TB. QFT sensitivity and specificity for TB disease were respectively 38% and 81%. TST sensitivity and specificity were respectively 35% and 84%.

CONCLUSION

While TST and QFT had excellent concordance in this population, both tests had much lower sensitivity for TB disease than has been reported for other age groups. Our results suggested equivalent performance of QFT and TST in the diagnosis of TB disease in young children in a high-burden setting.

Abnormal patterns of cerebral lateralisation as revealed by the Universal Chimeric Faces Task in individuals with autistic disorder

A previous study by Workman, Chilvers, Yeomans, and Taylor (2006), using the "Universal" Chimeric Faces Task (UCFT) for six emotional expressions, demonstrated that an overall left hemispatial/right hemisphere (RH) advantage has begun to develop by the age of 7-8. Moreover, the development of this left hemispatial advantage was observed to correlate positively with the ability to read emotions in the faces of others. Adopting the UCFT, the current study compared autistic children (11-15) with unimpaired children of two age groups (5-6 and 7-8) from this previous study. The autistic children showed a left hemispatial/RH advantage only for the two emotional expressions of "happiness" and "anger". Results for the autistic children revealed a similar overall pattern of lateralisation to the 5-6-year-olds and one that is less lateralised than the pattern for the 7-8-year-olds. Autistic children appear to show a developmental deficit for left hemispatial/RH advantage for emotional expression with the exception of "happiness" and "anger." The findings are discussed in terms of role hemisphericity and an approach-avoidance model.

Induced sputum or gastric lavage for community-based diagnosis of childhood pulmonary tuberculosis?

OBJECTIVES

To compare the diagnostic yield of Mycobacterium tuberculosis from induced sputum (IS) and gastric lavage (GL) among children in a community setting.

METHODS

Specimen-collection methods for bacteriological confirmation of pulmonary tuberculosis (PTB) were compared during a tuberculosis vaccine trial near Cape Town, South Africa (2001-2006). Children with a tuberculosis contact or compatible symptoms were investigated for suspected PTB. Diagnostic yields from 764 paired IS and GL specimens were compared in 191 culture-confirmed cases.

MEASUREMENTS AND MAIN RESULTS

The crude yield of M tuberculosis was 10.4%, n = 108 by IS (5.8%) and n = 127 by GL (6.8%), from a total of 194 cases, of which three had incomplete IS/GL specimen pairs. Agreement between IS and GL was poor (kappa = 0.31). The comparative yield of a single IS sample (38%) was equivalent to a single GL sample (42%), with a difference in yield of -4% (95% CI -15% to +7%). The combined yield of same-day IS and GL specimens (67%) was equivalent to two consecutive GL specimens (66%), with a difference in yield of 1% (95% CI -9% to 11%), but significantly greater than two consecutive IS specimens (55%), with a difference in yield of 12% (95% CI 2% to 21%). The adjusted odds of a M tuberculosis culture were increased by a positive tuberculin skin test or chest radiograph compatible with PTB.

CONCLUSIONS

In this community setting, the diagnostic yield of a single IS sample was equivalent to that of a single GL sample. The optimal diagnostic yield may be obtained from paired IS and GL specimens taken on a single day or two GL specimens taken on consecutive days.

Prevalence of bacterial contamination of powdered infant feeds in a hospital environment

BACKGROUND

The study arose as part of a best-practice nutrition model regarding the introduction of ready-to-use (RTU) infant feeds in place of powdered infant feeds (PIFs) as a standard formula for infants under the age of 1 year who are unable to be breastfed. Internationally and locally there is grave concern regarding the safety and efficacy of mixing PIFs, especially in a hospital setting, and the resultant bacterial contamination causing enteric infections, especially in premature, immunocompromised and sick infants.

OBJECTIVE

To evaluate the prevalence of bacterial contamination of PIFs given to infants at Red Cross War Memorial Children's Hospital, Cape Town.

METHODS

Quantitative levels of bacterial contamination were determined and were expressed as colony-forming units (CFUs) per millilitre of sample. Aliquots of milk were inoculated onto agar, and the milk samples were then incubated at 25 degrees C overnight (N = 10), 30 degrees C overnight (N = 48) and 30 degrees C for 6 hours (N = 34). Post-incubation milk samples were cultured again. Contamination was defined as any positive culture before administration (i.e. pre incubation) or > 10(2) CFU/ ml after administration (i.e. post incubation).

RESULTS

Fifty samples of PIFs (N = 82) were contaminated pre incubation, with 25/82 samples (30.4%) being heavily contaminated ( >or= 10(4) CFU/ml). Post incubation, 43/92 samples (46.7%) were contaminated with > 102 CFU/ml. The acidified PIFs appeared to have some bactericidal effect against some of the organisms, but not all.

CONCLUSIONS

RTU infant feeds are sterile and are recommended for use in all hospitalised infants. The results of this study indicate that even when milk is prepared in a controlled environment there is significant bacterial contamination of PIFs post production. As RTU feeds are now readily available in South Africa every attempt should be made to use a sterile RTU system for hospitalised infants.

Visual laterality effects in readers of a deep and a shallow orthography

Using a tachistoscopic split-field paradigm, hemifield asymmetry for single word recognition was examined in monolingual English speakers and in fluent bilingual English-Welsh speakers. A robust right hemifield advantage was found for both groups and both languages. Among bilinguals, the laterality index was significantly greater for Welsh than for English, supporting previous findings. The magnitude of the laterality index was unaffected by which language was learned first (Welsh or English) and by the age of acquisition (before or after 5-6years old) of the second language. However, among bilinguals there was a significant difference in the laterality index for Welsh words compared with English words for those participants brought up in a predominantly Welsh-speaking environment, but not for those brought up in a predominantly English-speaking or dual-language environment. We attribute our results to the difference in orthographic depth between Welsh and English. and argue that the transparency of Welsh favours adoption of a left-hemisphere based phonological decoding strategy in reading. Such a strategy is not necessarily used exclusively by readers of Welsh, but is encouraged by regular exposure to the Welsh language on a day-to-day basis.

Development of cerebral lateralisation for recognition of emotions in chimeric faces in children aged 5 to 11

In contrast to research into the development of language laterality, there has been relatively little research into the development of lateralisation of emotional processing. If language lateralisation begins in childhood and is complete by puberty (Lenneberg, 1967) it seems reasonable that the lateralisation of the perception of emotions might also occur during this period. In this study a split field chimeric faces test using the six universal facial expressions proposed by Ekman and Friesen (1971), an emotion in the eyes test, and a situational cartoon test were administered to three groups of children aged 5/6, 7/8, and 10/11. No overall hemispace advantage was seen for the 5/6-year-old group, but by the age of 10/11 a clear left hemispace advantage (right hemisphere) was found for all six emotions. Such a pattern is comparable to a previous study that made use of adults on this task (Workman, Peters, & Taylor, 2000b). Moreover, a significant positive correlation between a child's ability to recognise emotions in cartoon situations and their left hemispatial advantage score was uncovered. Finally, a significant positive correlation between a child's ability to recognise emotions in the eyes of others and their left hemispatial advantage score was also uncovered. These findings are taken as evidence that there may be a relationship between the development of emotional processing in the right hemisphere and a child's emerging ability to perceive or attend to the emotional states of others. Results are discussed in relation to the child's development of a theory of mind.

Determining the prevalence of malnutrition in hospitalized paediatric patients

AIM

To determine the prevalence of malnutrition in hospitalised paediatric patients at Red Cross War Memorial Children's Hospital.

METHOD

A 1-day cross-sectional survey was completed in all medical and surgical wards and some specialist outpatient clinics.

RESULTS

A total of 227 children participated in the study. Thirty-five per cent of patients were moderately malnourished (< or = -2 z-score), of whom 70% had no road to health card with them. Thirty-four per cent of children under 60 months of age received supplements in addition to a normal ward diet, 7.8% were enterally fed and less than 1% were parenterally fed. Almost 14% of children were found to be overweight/obese, which is higher than the national average of 6%. The prevalence of HIV infection on the day of the audit was 18% across all age groups compared with the Western Cape antenatal prevalence of 15.7% (2005).

CONCLUSION

The overall prevalence of undernutrition was 34%, which is comparable with similar studies. However, the proportion of overweight children (14%) was greater than the national average. In view of the level of malnutrition seen, a nutrition risk-screening tool, identifying risk factors for malnutrition such as food access and vulnerability, should be developed. The tool should be used to assess nutrition status and risk during the course of hospitalisation, in addition to planning appropriate nutrition care plan interventions for discharge.

Lateralisation of perceptual processing of pro- and anti-social emotions displayed in chimeric faces

Previous studies using a restricted range of split field chimeric faces suggest that the processing of facial emotional expressions is a highly lateralised phenomenon. Two theories have emerged with regard to the role the two cerebral hemispheres play in this processing. The "right hemisphere" hypothesis (e.g. Borod, Koff, Lorch, & Nicholas, 1988) suggests that the right hemisphere plays a prominent role in the processing of both positive and negative facial expressions. In contrast, the "valence hypothesis" (e.g. Reuter-Lorenz & Davidson, 1981) proposes that, while the right hemisphere plays the major role in processing negative emotions, the left hemisphere has a special role for positive emotions. Using all six of the human "universal facial expressions" (Ekman &Friesen, 1971) we present evidence that, superimposed onto a left visual field advantage (right hemisphere specialisation) for emotional processing, there is a "left shift" (right visual field advantage) for pro- as opposed to anti-social expression. We propose that facial expressions that are likely to be related to approach for communicative purposes initiate a greater degree of left hemisphere involvement. As a consequence, we suggest that for future laterality studies, the six universal emotional expressions should be reconsidered using a pro- to anti-social dimension rather than positive and negative groupings.

Differential bilingual laterality: mythical monster found in Wales

Paradis (1992) likens studies of bilingual laterality to reported sightings of the Loch Ness Monster, in that although some studies claim differential laterality much conflicting research evidence does not-and like the mythical Scottish monster, what reason have we to suspect that any such phenomenon might exist? This study reexamines differential bilingual laterality using four groups of English-Welsh bilinguals which differ in their age of acquisition and in their environment of acquisition. Using a split visual field paradigm we present evidence which, supports the notion of greater right hemisphere processing in a later learned language. Our findings also suggest the pattern of lateralization in bilinguals is strongly affected by the specific language environment during development such that the shift toward greater right hemisphere involvement for the later learned language will be more pronounced in individuals which are brought up in areas where that language is not regularly heard.

Language laterality in English/Welsh bilinguals: Language-acquisitional and language-specific factors in the development of lateralisation

In order to test the hypothesis that monolinguals differ from bilinguals in their pattern of language lateralisation and to examine the relative merits of language-acquisitional versus language-specific factors, two experiments involving divided screen presentation of two languages were conducted using Welsh/English speaking participants. In the first experiment 80 monolingual teenagers were compared to 80 bilingual teenagers on a tachistoscopic "visual half-field" test of Welsh and English nouns and verbs. ANOVA revealed a greater left hemisphere advantage for Welsh-English bilinguals as compared to English monolinguals. Thus, in contrast to previous studies, in our bilinguals there was evidence of greater left hemisphere involvement in the processing of language. In the second experiment, four separate groups of 40 teenagers, varying in the age and manner of acquisition of their languages, were compared on the same test of Welsh and English words. These groups can be viewed as graded from the early to late bilinguals. ANOVA revealed a greater left hemisphere advantage when processing Welsh as compared to English words for all four groups. However no significant difference was observed between the four groups in respect of laterality for Welsh and English, indicating an equally greater left hemisphere bias for all four groups when processing Welsh words. We discuss these results in terms of a language-specific effect and suggest the specific orthography of the Welsh language (for individually presented nouns and verbs) promotes a left hemisphere advantage over and above language-acquisitional factors.

Qualitative analysis of value judgments in interpreting cervicovaginal smears using the Bethesda system

CONTEXT

We hypothesize that there are unrecognized value judgments that influence cytopathologists in interpreting borderline cervicovaginal smears and that these judgments contribute to the well-documented variation among cytopathologists regarding such diagnoses.

OBJECTIVE

To identify and map these values.

DESIGN

Survey consisting of Kodachromes and histories for 5 borderline smears. Respondents were asked to give their diagnoses, recommendations for treatment, and reasoning.

RESULTS

We demonstrated a wide variation in interpretation of borderline smears similar to previous studies. We then used inductive qualitative analysis to identify the clinical reasoning and value judgments that influenced the responses.

CONCLUSIONS

We mapped those diagnostic value judgments that should be used in evaluation borderline cases. We believe this map can be used to rigorously manage and standardize the use of such judgments.

Use of amniotic fluid amino acids in prenatal testing for argininosuccinic aciduria and citrullinaemia

Prenatal testing of 12 pregnancies at risk for argininosuccinic aciduria due to argininosuccinate lyase (ASAL) deficiency and three pregnancies at risk for citrullinaemia due to argininosuccinate synthatase (ASAS) deficiency was performed by metabolite detection in amniotic fluid and measurement of enzyme activity in uncultured and cultured chorionic tissue and in cultured amniocytes. From our data and those of previous studies, amniotic fluid argininosuccinate measurement alone is clearly a reliable and rapid diagnostic test for both severe and mild ASAL deficiency if maternal ASAL deficiency can be excluded. For prenatal diagnosis of ASAS deficiency, however, both measurement of the amniotic fluid citrulline level and enzyme assay should be employed.

Crystallization and preliminary X-ray analysis of an anti-staphylococcal nuclease-staphylococcal nuclease complex and of a second anti-staphylococcal nuclease antibody

The Fab fragments of several monoclonal antibodies that bind Staphylococcal nuclease have been screened for crystallization conditions. Two of these, N10 and N25, have been crystallized in forms suitable for X-ray structural analysis. The anti-Staphylococcal nuclease antibody complex N10 Fab-nuclease crystallizes with symmetry consistent with space group C2 and cell parameters of a = 234.7 A; b = 43.5 A; c = 74.4 A; beta = 106.4 degrees. A second anti-Staphylococcal nuclease antibody, N25, although crystallized starting with the Fab-nuclease complex, apparently crystallizes as uncomplexed N25 Fab with symmetry consistent with space group P3(1)21 (or its enantiomorph P3(2)21) and cell parameters of a = b = 80.9 A; c = 138.4 A.