Effect of Moisture Stress on the Development of False Codling Moth Thaumatotibia leucotreta (Lepidoptera: Tortricidae) on Two Tomato Varieties.

False codling moth Thaumatotibia leucotreta (Meyrick) is a pest native to sub-Saharan Africa infesting over 100 plant species including tomato. Its survival and performance are influenced by changes in precipitation and stress-related biochemical changes in the host plant. Water availability for agricultural production continues to decline due to climate change affecting drought-sensitive crops like tomatoes. Little is known on host plant-insect interactions of T. leucotreta and tomato as influenced by moisture stress. Hence, our study tested the impact of different water holding capacities (WHC) (40%, 50%, 60%, 70%, and 90%) of plant growing media on the growth of Anna F1 and Yaye tomato varieties and the infestation rate and development of T. leucotreta on the two varieties. WHC significantly influenced the growth of Anna F1 and Yaye tomato varieties. WHC significantly affected stem girth of Anna F1 variety and leaf length, leaf width, stem girth, and plant height of the Yaye variety. For Yaye variety, T. leucotreta laid a significantly high number of eggs when grown at 70% WHC and had the highest pupation when grown at 60% WHC. The development of T. leucotreta as observed on wing growth was highest at 40% and 50% WHC for both Anna F1 variety and Yaye variety. Our study shows that the infestation of tomato by T. leucotreta is likely to be high when grown in water-scarce media. The results are useful for predicting possible future T. leucotreta trends with increasing water scarcity due to climate change and in designing pest management programmes.

Addition of host genetic variants in a prediction rule for post meningitis hearing loss in childhood: a model updating study.

BACKGROUND: Sensorineural hearing loss is the most common sequela in survivors of bacterial meningitis (BM). In the past we developed a validated prediction model to identify children at risk for post-meningitis hearing loss. It is known that host genetic variations, besides clinical factors, contribute to severity and outcome of BM. In this study it was determined whether host genetic risk factors improve the predictive abilities of an existing model regarding hearing loss after childhood BM. METHODS: Four hundred and seventy-one Dutch Caucasian childhood BM were genotyped for 11 single nucleotide polymorphisms (SNPs) in seven different genes involved in pathogen recognition. Genetic data were added to the original clinical prediction model and performance of new models was compared to the original model by likelihood ratio tests and the area under the curve (AUC) of the receiver operating characteristic curves. RESULTS: Addition of TLR9-1237 SNPs and the combination of TLR2 + 2477 and TLR4 + 896 SNPs improved the clinical prediction model, but not significantly (increase of AUC's from 0.856 to 0.861 and from 0.856 to 0.875 (p = 0.570 and 0.335, respectively). Other SNPs analysed were not linked to hearing loss. CONCLUSIONS: Although addition of genetic risk factors did not significantly improve the clinical prediction model for post-meningitis hearing loss, AUC's of the pre-existing model remain high after addition of genetic factors. Future studies should evaluate whether more combinations of SNPs in larger cohorts has an additional value to the existing prediction model for post meningitis hearing loss.

Independent validation of an existing model enables prediction of hearing loss after childhood bacterial meningitis.

OBJECTIVE: This study aimed external validation of a formerly developed prediction model identifying children at risk for hearing loss after bacterial meningitis (BM). Independent risk factors included in the model are: duration of symptoms prior to admission, petechiae, cerebral spinal fluid (CSF) glucose level, Streptococcus pneumoniae and ataxia. Validation helps to evaluate whether the model has potential in clinical practice. STUDY DESIGN: 116 Dutch school-age BM survivors were included in the validation cohort and screened for sensorineural hearing loss (>25 dB). Risk factors were obtained from medical records. The model was applied to the validation cohort and its performance was compared with the development cohort. Validation was performed by application of the model on the validation cohort and by assessment of discrimination and goodness of fit. Calibration was evaluated by testing deviations in intercept and slope. Multiple imputation techniques were used to deal with missing values. RESULTS: Risk factors were distributed equally between both cohorts. Discriminative ability (Area Under the Curve, AUC) of the model was 0.84 in the development and 0.78 in the validation cohort. Hosmer-Lemeshow test for goodness of fit was not significant in the validation cohort, implying good fit concerning the similarity of expected and observed cases. There were no significant differences in calibration slope and intercept. Sensitivity and negative predicted value were high, while specificity and positive predicted value were low which is comparable with findings in the development cohort. CONCLUSIONS: Performance of the model remained good in the validation cohort. This prediction model might be used as a screening tool and can help to identify those children that need special attention and a long follow-up period or more frequent auditory testing.

Simulated effect of pneumococcal vaccination in the Netherlands on existing rules constructed in a non-vaccinated cohort predicting sequelae after bacterial meningitis.

BACKGROUND: Previously two prediction rules identifying children at risk of hearing loss and academic or behavioral limitations after bacterial meningitis were developed. Streptococcus pneumoniae as causative pathogen was an important risk factor in both. Since 2006 Dutch children receive seven-valent conjugate vaccination against S. pneumoniae. The presumed effect of vaccination was simulated by excluding all children infected by S. pneumoniae with the serotypes included in the vaccine, from both previous collected cohorts (between 1990-1995). METHODS: Children infected by one of the vaccine serotypes were excluded from both original cohorts (hearing loss: 70 of 628 children; academic or behavioral limitations: 26 of 182 children). All identified risk factors were included in multivariate logistic regression models. The discriminative ability of both new models was calculated. RESULTS: The same risk factors as in the original models were significant. The discriminative ability of the original hearing loss model was 0.84 and of the new model 0.87. In the academic or behavioral limitations model it was 0.83 and 0.84 respectively. CONCLUSION: It can be assumed that the prediction rules will also be applicable on a vaccinated population. However, vaccination does not provide 100% coverage and evidence is available that serotype replacement will occur. The impact of vaccination on serotype replacement needs to be investigated, and the prediction rules must be validated externally.

No structural cerebral differences between children with a history of bacterial meningitis and healthy siblings.

AIM: After bacterial meningitis, about one-third of children develops academic and/or behavioural limitations. The aim of our study was to search for structural differences in the brain, with a special focus on the hippocampus, between childhood survivors of bacterial meningitis with and without academic and/or behavioural limitations and healthy siblings. PATIENTS AND METHODS: A selection of a cohort, compiled in an earlier performed retrospective study, was used in this case-control study. Magnetic Resonance Imaging scans of the brain were performed in 43 post-meningitis children, of whom 18 had learning and/or behavioural limitations and 25 had no problems, and 18 controls. Voxel-based morphometry investigated the brain for structural changes. Hippocampal volume and lateral ventricle width were measured. RESULTS: No structural differences between the groups, in any area of the brain, were found. There were no significant differences in hippocampal volume or lateral ventricle width. The group with limitations had three children with a right hippocampal volume smaller than two standard deviations below the mean of the control group. CONCLUSION: Despite hippocampus lesions found in experimental studies, we found no anatomical differences of the brain or hippocampus related to bacterial meningitis in children, nor to the academic and/or behavioural limitations seen after bacterial meningitis.

Mannose-binding lectin in term newborns and their mothers: genotypic and phenotypic relationship.

Functional mannose-binding lectin (f-MBL) plays an important role in the innate neonatal immune system. We studied the origin of f-MBL in umbilical cord blood (UCB) by measuring maternal MBL (n=47), collected before elective cesarean section, and neonatal MBL (n=43) in arterial umbilical cord blood. In a subgroup, arterial and venous UCB MBL levels were measured. In addition, MBL expression was correlated with genetic mutations. The f-MBL levels in term infants were lower than in their mothers (0.70 microg/ml vs 1.11 microg/ml, p<0.01) and maternal and neonatal MBL levels were only weakly correlated (R=0.32, p<0.001), which suggests a fetal origin of f-MBL. Arterial and venous UCB median MBL levels did not differ (0.98 microg/ml vs. 1.40 microg/ml, p=0.20). No homozygous mutations were found. MBL was lower in mothers and infants with a (compound) heterozygous mutation than in those with a wild type. One new (HYPB) and two rare haplotypes (HXPA, LYPD) were reported in our population. Levels of MBL differed depending on the genotype of the mother or the infant. Because the role of MBL in host defense is still unclear, both f-MBL and haplotype should be measured to determine the clinical implications of MBL deficiency in infants.

Behaviour is not really at risk after surviving meningitis in childhood.

AIM: To examine behaviour problems, personality, self-perceived competence and academic deficits in children who had recovered from non-Haemophilus influenzae type b (Hib) bacterial meningitis (BM) without obvious medical sequelae. METHODS: Assessments in 182 children, mean age 10 (range 5-14) years, 4-10 years after surviving meningitis, were compared to scores of norm reference groups. RESULTS: More children were estimated to have academic deficits (27%) than behaviour problems as perceived by the parents (9%). The mean deviation from normal was absent to moderate on behaviour problems, personality variables and self-perceived competence. CONCLUSION: Children who survived non-Hib BM without severe medical sequelae hardly differ from normal children with respect to personality and self-perceived competence. A small proportion deviates from normal in behaviour problems.

Increased occurrence of left-handedness after severe childhood bacterial meningitis: support for the pathological left-handedness hypothesis.

The hypothesis that brain damage during infancy causes pathological left-handedness was tested by assessing handedness in 182 survivors of childhood non-Hemophilus influenza type b bacterial meningitis in the Netherlands (mean age of 9.7 years). These children were selected randomly after clustering them into those with or without parental report on academic and behavioural problems. Medical records were obtained from the hospitals, while handedness and neurodevelopmental outcome were assessed at school age. Logistic regression analysis was used to study the relationship between a severity score of bacterial meningitis and handedness. Fifteen percent were left-handed. Severity of childhood bacterial meningitis was related to left-handedness (Odds ratio (OR) 6.2, 95% confidence interval (CI) 2.0-18.6 for those with a total severity score above the median as compared to those below). Compared to non-left-handed children, left-handed children had lower IQ (mean difference -6.6, 95% CI -12 to -1.2), tended to have lower vocabulary scores on WISC-r (-1.0, -2.1 to 0), and lower Beery scores on visual-motor integration (-4.9, -10.1 to 0.4). Left-handed children also tended to have more combined academic and behavioural limitations (OR 2.7, 95% CI 0.9-8.6), lower manual speed of the dominant hand (mean difference -9 taps, p < 0.05) and better manual steadiness in the non-dominant hand (mean difference of contact's time -2.7 s, p < 0.05). Left-handed post-meningitic children generally have worse neurodevelopmental outcome than non-left-handed survivors. Our results support the role of early life brain damage in left-handedness.

Validating and updating a prediction rule for neurological sequelae after childhood bacterial meningitis.

Recently, a prediction rule for developing neurological sequelae after childhood bacterial meningitis was developed on a small derivation set. Before implementing in practice a prediction rule must first be tested in new patients (external validation). Our aim was to study the external validity of this rule and, if necessary, to update the rule. The prediction rule was tested on newly available data (validation set) by assessing the rule's calibration and discrimination. We updated the prediction rule by adding extra predictors and re-estimating the regression coefficients of the original predictors in the combined datasets. The rule showed poor agreement between predicted risks and observed frequencies. The ROC area was 0.65 (95% CI 0.57-0.72), which was statistically significantly lower than in the derivation set (0.87 (0.78-0.96)), p-value<0.01. The updated prediction rule showed adequate performance in the combined data sets; the ROC area was 0.77 (95% CI 0.72-0.82). Further study of the generalizability of this updated rule may stimulate application in clinical practice.

Academic and behavioral limitations and health-related quality of life in school-age survivors of bacterial meningitis.

The objectives of this study were to describe health-related quality of life of postmeningitic children and to examine the association between academic and/or behavioral limitations and health-related quality of life. One hundred and eighty-two children (mean age 9.7 years; range 5.3-14.2) were selected randomly from a cohort of 674 school-age children who recovered from non-Haemophilus influenzae type B bacterial meningitis. These children had neither meningitis with 'complex onset', nor prior cognitive or behavioral problems, nor severe disease sequelae. On average 7.4 years after meningitis, they were evaluated using an 'Academic Achievement Test' and their parents filled in the Child Behavior Checklist, the Child Health Questionnaire, and the Health Utilities Index. The long-term incidence of academic and/or behavioral limitations was 32%. Overall health-related quality of life of the postmeningitic children was decreased in comparison with that of a reference population of schoolchildren. The group of postmeningitic children with academic and/or behavioral limitations showed the most marked decrease in quality of life, especially concerning psychosocial health, cognition and family life. The negative effects on quality of life were not significantly influenced by age, gender, causative pathogen, presence of minor neurological impairment, or presence of hearing impairment. In conclusion, health-related quality of life of postmeningitic children is decreased, particularly of those with academic and/or behavioral limitations.

Neuropsychology of academic and behavioural limitations in school-age survivors of bacterial meningitis.

Neuropsychological impairments possibly underlying academic and/or behavioural limitations were studied in 149 school-age survivors of bacterial meningitis, 68 with and 81 without academic and/or behavioural limitations. Academic limitations affected mathematics, reading, and writing. Behavioural limitations were inferred from scores in the clinical range on the Child Behaviour Checklist. These children had been selected from a cohort of 674 children (57% males) who had recovered from non-Haemophilus influenzae type B bacterial meningitis and who had a mean age at infection of 2 years 4 months (range 1mo to 9y 5mo). They had neither 'complex onset' meningitis, prior cognitive or behavioural problems, nor severe disease sequelae. They were assessed with standardized assessment methods a mean of 7.8 years (range 4 to 10.4) after meningitis. Children with limitations (32% of the cohort) performed generically poorly on measures of cognitive functioning, speed, and motor steadiness, rather than having impairments in specific neuropsychological domains. The presence of two or more minor neurological signs was more frequent in the group with than in the group without limitations (30% versus 9%); this may explain the relatively poor speed and motor steadiness of the group with limitations.

Hearing loss at school age in survivors of bacterial meningitis: assessment, incidence, and prediction.

OBJECTIVES: To establish the incidence of sensorineural hearing loss in children who survived non-Haemophilus influenzae type B (Hib) bacterial meningitis, to highlight the actual percentage whose hearing was evaluated, and to develop a prediction rule to identify those who are at risk of hearing loss. METHODS: In 1999, we compiled a cohort of 628 school-aged children who were born between January 1986 and December 1994 and had survived non-Hib bacterial meningitis between January 1990 and December 1995. Presence of sensorineural hearing loss (>25 dB) was determined, based on information from questionnaires and medical records. Potential risk factors for hearing loss were obtained from medical records; independent predictors were identified using multivariate logistic regression analysis, leading to the formulation of a prediction rule. RESULTS: The incidence of hearing loss was 7%. The hearing of 68% of the children was evaluated as part of their routine follow-up after bacterial meningitis, resulting in the detection of 75% of the cases of hearing loss. The remaining 25% were detected after this follow-up had ended. Using a prediction rule based on 5 factors-duration of symptoms before admission >2 days, absence of petechiae, cerebrospinal fluid glucose level