When Should Children with HIV Infection Be Started on Antiretroviral Therapy?

Background to the debate: The advent of highly active antiretroviral therapy (HAART) dramatically improved the prognosis for both adults and children infected with HIV who had access to treatment. However, the optimal timing for initiating treatment remains controversial, particularly in children. This debate lays out the case for deferred treatment against the case for early initiation of HAART in children.     

Should the WHO Growth Charts Be Used in France?

Background

Growth charts are an essential clinical tool for evaluating a child''s health and development. The current French reference curves, published in 1979, have recently been challenged by the 2006 World Health Organization (WHO) growth charts.

Objective

To evaluate and compare the growth of French children who were born between 1981 and 2007, with the WHO growth charts and the French reference curves currently used.

Design

Anthropometric measurements from French children, who participated in 12 studies, were analyzed: 82,151 measurements were available for 27,257 children in different age groups, from birth to 18 years. We calculated and graphically compared mean z-scores based on the WHO and French curves, for height, weight and Body Mass Index (BMI) according to age and sex. The prevalence of overweight using the WHO, the French and International Obesity Task Force definitions were compared.

Results

Our population of children was on average 0.5 standard deviations taller than the French reference population, from the first month of life until puberty age. Mean z-scores for height, weight and BMI were closer to zero based on the WHO growth charts than on the French references from infancy until late adolescence, except during the first six months. These differences not related to breastfeeding rates. As expected, the prevalence of overweight depended on the reference used, and differences varied according to age.

Conclusion

The WHO growth charts may be appropriate for monitoring growth of French children, as the growth patterns in our large population of French children were closer to the WHO growth charts than to the French reference curves, from 6 months onwards. However, there were some limitations in the use of these WHO growth charts, and further investigation is needed.     

Should Metabolic Diseases Be Systematically Screened in Nonsyndromic Autism Spectrum Disorders?

Background

In the investigation of autism spectrum disorders (ASD), a genetic cause is found in approximately 10–20%. Among these cases, the prevalence of the rare inherited metabolic disorders (IMD) is unknown and poorly evaluated. An IMD responsible for ASD is usually identified by the associated clinical phenotype such as dysmorphic features, ataxia, microcephaly, epilepsy, and severe intellectual disability (ID). In rare cases, however, ASD may be considered as nonsyndromic at the onset of a related IMD.

Objectives

To evaluate the utility of routine metabolic investigations in nonsyndromic ASD.

Patients and Methods

We retrospectively analyzed the results of a metabolic workup (urinary mucopolysaccharides, urinary purines and pyrimidines, urinary creatine and guanidinoacetate, urinary organic acids, plasma and urinary amino acids) routinely performed in 274 nonsyndromic ASD children.

Results

The metabolic parameters were in the normal range for all but 2 patients: one with unspecific creatine urinary excretion and the other with persistent 3-methylglutaconic aciduria.

Conclusions

These data provide the largest ever reported cohort of ASD patients for whom a systematic metabolic workup has been performed; they suggest that such a routine metabolic screening does not contribute to the causative diagnosis of nonsyndromic ASD. They also emphasize that the prevalence of screened IMD in nonsyndromic ASD is probably not higher than in the general population (<0.5%). A careful clinical evaluation is probably more reasonable and of better medical practice than a costly systematic workup.     

Pneumococcal Carriage in Children under Five Years in Uganda-Will Present Pneumococcal Conjugate Vaccines Be Appropriate?

BackgroundPneumonia is the major cause of death in children globally, with more than 900,000 deaths annually in children under five years of age. Streptococcus pneumoniae causes most deaths, most often in the form of community acquired pneumonia. Pneumococcal conjugate vaccines (PCVs) are currently being implemented in many low-income countries. PCVs decrease vaccine-type pneumococcal carriage, a prerequisite for invasive pneumococcal disease, and thereby affects pneumococcal disease and transmission. In Uganda, PCV was launched in 2014, but baseline data is lacking for pneumococcal serotypes in carriage.ObjectivesTo study pneumococcal nasopharyngeal carriage and serotype distribution in children under 5 years of age prior to PCV introduction in UgandaMethodsThree cross-sectional pneumococcal carriage surveys were conducted in 2008, 2009 and 2011, comprising respectively 150, 587 and 1024 randomly selected children aged less than five years from the Iganga/Mayuge Health and Demographic Surveillance Site. The caretakers were interviewed about illness history of the child and 1723 nasopharyngeal specimens were collected. From these, 927 isolates of S. pneumoniae were serotyped.ResultsOverall, the carriage rate of S. pneumoniae was 56% (957/1723). Pneumococcal carriage was associated with illness on the day of the interview (OR = 1.50, p = 0.04). The most common pneumococcal serotypes were in descending order 19F (16%), 23F (9%), 6A (8%), 29 (7%) and 6B (7%). One percent of the strains were non-typeable. The potential serotype coverage rate for PCV10 was 42% and 54% for PCV13.ConclusionAbout half of circulating pneumococcal serotypes in carriage in the Ugandan under-five population studied was covered by available PCVs.     

Should Forest Restoration with Natural Hybrids Be Allowed?

One of the greatest challenges of forest restoration is the choice of appropriate plant material that is adapted to local environments, provides the desired ecological services, and does not compromise the local biodiversity. Plant restoration programs use native seeds, a mixture of local and introduced seeds of the same species or allopatric species. However, restoration programs rarely use local hybrid individuals if a local species exhibits natural hybridization. Hybridization is an important evolutionary process that can result in new genotypic combinations that might be suited better to the target habitat than the parental species and allow adaptation to rapid environmental change. European forests are generally under strict legal regulations so that only certified seeds can be used for their restoration. The European certification procedure for seeds from forest trees has been devised to commercialize clearly identified species with known adaptation to a given area. Natural hybrids, for which taxonomic status is uncertain and fitness is generally unknown, are excluded, which is not the case of artificial hybrids because they have been previously tested in the field. Here we discuss the pressing need to include natural hybrid populations as a source of certified seeds for restoration purposes. Using the example of two ash species and their well‐adapted hybrids along the Loire River in France, we show why European forest guidelines must be made more flexible to allow the provision of stable ecosystem services.     

Should Bacteriophages Be Classified As Parasites Or Predators?

Bacteriophages are viruses infecting bacteria and propagating in bacterial cells. They were discovered over 100 years ago, and for decades they played crucial roles as models in genetics and molecular biology and as tools in genetic engineering and biotechnology. Now we also recognize their huge role in natural environment and their importance in human health and disease. Despite our understanding of bacteriophage mechanisms of development, these viruses are described as parasites or predators in the literature. From the biological point of view, there are fundamental differences between parasites and predators. Therefore, in this article, I asked whether bacteriophages should be classified as former or latter biological entities. Analysis of the literature and biological definitions led me to conclude that bacteriophages are parasites rather than predators and should be classified and described as such. If even more precise ecological classification is needed, bacteriophages can perhaps be included in the group of parasitoids. It might be the most appropriate formal classification of these viruses, especially if strictly virulent phages are considered, contrary to phages which lysogenize host cells and those which develop according to the permanent infection mode (or chronic cycle, like filamentous phages) revealing features of classical parasites.     

ROC Volumes – Should They Be Used?

Invited comment on Alonzo, T.A. and Nakas, C.T. (2007). Comparison of ROC umbrella volumes with an application to the assessment of lung cancer diagnostic markers. Biometrical Journal 49, 654-664. Issues remain as to the appropriateness of volumes as summary measures of accuracy when distinguishing between multiple disease classes and when comparing accuracy of tests.     

Which Effect Measure Should Be Used for Impact Assessment in a New Population Context?

One characteristic feature in impact assessment based on epidemiologic studies is the transfer of an exposure-response association into a new population context. The consequences of basing this estimation procedure either on relative effect measures (e.g., relative risks) or on measures on the difference scale (e.g., excess rate) were exemplary illustrated with two air pollution studies which quantified the association between lung cancer and PM₁₀ in cohorts with varying lung cancer incidence due to different smoking habits. This example showed that the type of measure chosen may markedly influence the result of an impact assessment, if the frequency of the disease of interest varies across different populations due to other risk factors than the one considered. Thus, it was concluded that whenever studies from different population contexts are pooled, careful considerations about the appropriate type of measure are required. In environmental health risk assessment with usually small risks and unspecific (i.e., multicausal) health endpoints, an excess rate-based approach may provide a more reliable and stable estimate than a relative risk based approach in many circumstances. Methodological details of an excess rate-based approach are presented in the paper.