Alimentation et transmission mère-enfant

Bien que de nombreux auteurs aient traité, dans la relation mère-enfant, l'importance de l'alimentation, (et donc du rapport à la nourriture) et l'interprétation des troubles qui peuvent en résulter, nous proposons dans cet article de constituer une vérification expérimentale d'une question spécifique: que se transmet-il entre mère et enfant dans le contexte alimentaire ? Au travers d'une recherche multidisciplinaire alliant socio-anthropologie et psychologie, nous avons constitué et étudié un recueil de données couplant représentations socioculturelles, histoires alimentaires personnelles ainsi qu'observations et analyses de la qualité des interactions alimentaires auprès d'une population de mères françaises et leur enfant (sain) âgé de 1 à 2 ans.

Rapid Diagnostic Test-Based Management of Malaria: An Effectiveness Study in Papua New Guinean Infants With Plasmodium falciparum and Plasmodium vivax Malaria.

Background. In malaria-endemic areas it is recommended that febrile children be tested for malaria by rapid diagnostic test (RDT) or blood slide (BS) and receive effective malaria treatment only if results are positive. However, RDTs are known to perform less well for Plasmodium vivax. We evaluated the safety of withholding antimalarial drugs from young Papua New Guinean children with negative RDT results in areas with high levels of both Plasmodium falciparum and P. vivax infections. Methods. longitudinal prospective study of children aged 3-27 months visiting outpatient clinics for fever. RDT was administered at first visit. RDT and microscopy were performed if children returned because of persistent symptoms. Outcomes were rates of reattendance and occurrence of severe illnesses. Results. Of 5670 febrile episodes, 3942 (70%) involved a negative RDT result. In 133 cases (3.4%), the children reattended the clinic within 7 days for fever, of whom 29 (0.7%) were parasitemic by RDT or microscopy. Of children who reattended, 24 (0.7%) presented with a severe illness: 2 had lower respiratory tract infections (LRTIs) with low-density P. vivax on BS; 2 received a diagnosis of P. vivax malaria on the basis of RDT but BSs were negative; 16 had LRTIs; 3 had alternative diagnoses. Of these 24, 22 were cured at day 28. Two children died of illnesses other than malaria and were RDT and BS negative at the initial and subsequent visits. Conclusion. Treatment for malaria based on RDT results is safe and feasible even in infants living in areas with moderate to high endemicity for both P. falciparum and P. vivax infections.

Effect of malaria and fever on energy metabolism in Gambian children.

The aim of the present study was to measure the changes in resting energy expenditure (REE) induced by malaria and to assess to what extent they are related to fever and nutritional status. The REE of 19 Gambian children (mean age +/- SEM, 9 +/- 1 y; weight, 24 +/- 2 kg; expected weight for height 86 +/- 1%) were measured with a hood system at repeated intervals at the onset of malaria crisis (test A), 3 to 4 d after therapy (test B), and 14 to 21 d later (test C). Axillary temperature averaged 39.2 +/- 0.1, 36.6 +/- 0.1, and 36.7 +/- 0.1 degrees C in the tests A, B, and C, respectively. REE in test A was significantly higher than REE in test B (223 +/- 10 versus 174 +/- 8 kJ/kg.d, p less than 0.0001), but in test C (169 +/- 8 kJ/kg.d), it did not differ from that observed in test B. The percentage of increase in REE was significantly correlated with the difference in axillary temperature (r = 0.46, p less than 0.05); the slope of the regression line indicated an increase of 6.9% in REE/degree C of fever. Furthermore, the individual increase in REE/degree C was correlated to the percentage of weight for height of the children (r = 0.54, p less than 0.05), indicating that the child's nutritional status influences the magnitude of the hypermetabolism due to fever. We concluded that Gambian children suffering from an acute episode of malaria have an increase in REE averaging 30%; however, REE promptly returns to baseline value a few days after the beginning of therapy.

Rural tourism as risk factor for the transmission of schistosomiasis in Minas Gerais, Brazil

Recently, the booming rural tourism in endemic areas of the state of Minas Gerais was identified as a contributing factor in the dissemination of the infection with Schistosoma mansoni. This article presents data from six holiday resorts in a rural district approximately 100 km distant from Belo Horizonte, MG, Brazil, where a possibly new and until now unperceived way of transmission was observed. The infection takes place in swimming pools and little ponds, which are offered to tourists and the local population for fishing and leisure activities. The health authorities of the district reported cases of schistosomiasis among the local population after visiting these sites. As individuals of the non-immune middle class parts of the society of big urban centers also frequent these resorts, infection of these persons cannot be excluded. A malacological survey revealed the presence of molluscs of the species Biomphalaria glabrata and Biomphalaria straminea at the resorts. The snails (B. glabrata) of one resort tested positive for S. mansoni. In order to resolve this complex problem a multidisciplinary approach including health education, sanitation measures, assistance to the local health services, and evolvement of the local political authorities, the local community, the tourism association, and the owners of the leisure resorts is necessary. This evidence emphasizes the urgent need for a participative strategic plan to develop the local tourism in an organized and well-administered way. Only so this important source of income for the region can be ensured on the long term without disseminating the disease and putting the health of the visitors at risk.

Lutzomyia longipalpis in Clorinda, Formosa province, an area of potential visceral leishmaniasis transmission in Argentina

Phlebotomine captures were performed during 2004 in Clorinda, Argentina. Clorinda is located across the branches of the Paraguay river in front of Asunción city, Paraguay. Reports of canine and human visceral leishmaniasis in Asunción have been increasing since 1997, however neither leishmaniasis cases nor sand flies were ever recorded from Clorinda. Light traps were located in migration paths (bridges, port), and peridomestic environments of Clorinda and surrounding localities. Lutzomyia longipalpis was found in Clorinda and Puerto Pilcomayo, first report in a potential visceral leishmaniasis transmission area for Argentina. Active surveillance is required immediately in the localities involved and the surrounding area.

The use of biodiversity as source of new chemical entities against defined molecular targets for treatment of malaria, tuberculosis, and T-cell mediated diseases: a review

The modern approach to the development of new chemical entities against complex diseases, especially the neglected endemic diseases such as tuberculosis and malaria, is based on the use of defined molecular targets. Among the advantages, this approach allows (i) the search and identification of lead compounds with defined molecular mechanisms against a defined target (e.g. enzymes from defined pathways), (ii) the analysis of a great number of compounds with a favorable cost/benefit ratio, (iii) the development even in the initial stages of compounds with selective toxicity (the fundamental principle of chemotherapy), (iv) the evaluation of plant extracts as well as of pure substances. The current use of such technology, unfortunately, is concentrated in developed countries, especially in the big pharma. This fact contributes in a significant way to hamper the development of innovative new compounds to treat neglected diseases. The large biodiversity within the territory of Brazil puts the country in a strategic position to develop the rational and sustained exploration of new metabolites of therapeutic value. The extension of the country covers a wide range of climates, soil types, and altitudes, providing a unique set of selective pressures for the adaptation of plant life in these scenarios. Chemical diversity is also driven by these forces, in an attempt to best fit the plant communities to the particular abiotic stresses, fauna, and microbes that co-exist with them. Certain areas of vegetation (Amazonian Forest, Atlantic Forest, Araucaria Forest, Cerrado-Brazilian Savanna, and Caatinga) are rich in species and types of environments to be used to search for natural compounds active against tuberculosis, malaria, and chronic-degenerative diseases. The present review describes some strategies to search for natural compounds, whose choice can be based on ethnobotanical and chemotaxonomical studies, and screen for their ability to bind to immobilized drug targets and to inhibit their activities. Molecular cloning, gene knockout, protein expression and purification, N-terminal sequencing, and mass spectrometry are the methods of choice to provide homogeneous drug targets for immobilization by optimized chemical reactions. Plant extract preparations, fractionation of promising plant extracts, propagation protocols and definition of in planta studies to maximize product yield of plant species producing active compounds have to be performed to provide a continuing supply of bioactive materials. Chemical characterization of natural compounds, determination of mode of action by kinetics and other spectroscopic methods (MS, X-ray, NMR), as well as in vitro and in vivo biological assays, chemical derivatization, and structure-activity relationships have to be carried out to provide a thorough knowledge on which to base the search for natural compounds or their derivatives with biological activity.

Isolation of a fragment homologous to the rp49 constitutive gene of Drosophila in the Neotropical malaria vector Anopheles aquasalis (Diptera: Culicidae)

The constitutive ribosomal gene rp49 is frequently used as an endogenous control in Drosophila gene expression experiments. Using the degenerate primer PCR technique we have cloned a fragment homologous to this gene in Anopheles aquasalis Curry, a Neotropical vector of malaria. In addition, based on this first sequence, a new primer was designed, which allowed the isolation of fragments of rp49 in two other species, Aedes aegypti (Linnaeus) and Culex quinquefasciatus Say, suggesting that it could be used to clone fragments of this gene in a number of other mosquito species. Primers were also designed to specifically amplify rp49 cDNA fragments in An. aquasalis and Ae. aegypti, showing that rp49 could be used as a good constitutive control in gene expression studies of these and other vectorially important mosquito species.

Expression, purification and biochemical characterization of recombinant Ca-dependent protein kinase 2 of the malaria parasite Plasmodium falciparum.

Calcium-dependent protein kinases (CDPKs) are serine/threonine kinases that react in response to calcium which functions as a trigger for several mechanisms in plants and invertebrates, but not in mammals. Recent structural studies have defined the role of calcium in the activation of CDPKs and have elucidated the important structural changes caused by calcium in order to allow the kinase domain of CDPK to bind and phosphorylate the substrate. However, the role of autophosphorylation in CDPKs is still not fully understood. In Plasmodium falciparum, seven CDPKs have been identified by sequence comparison, and four of them have been characterized and assigned to play a role in parasite motility, gametogenesis and egress from red blood cells. Although PfCDPK2 was already discovered in 1997, little is known about this enzyme and its metabolic role. In this work, we have expressed and purified PfCDPK2 at high purity in its unphosphorylated form and characterized its biochemical properties. Moreover, propositions about putative substrates in P. falciparum are made based on the analysis of the phosphorylation sites on the artificial substrate myelin basic protein (MBP).

Entre l'exemple et l'expérience: de la transmission par la famille d'une tradition à celle d'un ethos religieux

(Résumé de l'ouvrage) Les textes rassemblés dans cet ouvrage proposent diverses approches du phénomène religieux contemporain. Ils en montrent le caractère "flottant", les frontières incertaines. Ils font découvrir de nouveaux lieux vers lesquels s'oriente aujourd'hui une certaine quête de sens et de sacré. Ils pistent les dérives des grandes religions traditionnelles occidentales et les tentatives qu'entreprennent celles-ci pour freiner l'abandon qu'elles enregistrent ou - pire- l'indifférence qu'elle suscitent. Récusant tout autant "la mort de Dieu" que " le retour du religieux", les auteurs soulignent tous la complexité croissante de ce qu'on appelle couramment le religieux.

A new challenge for malaria control in Brazil: asymptomatic Plasmodium infection - a review

The evolution of malaria in Brazil, its morbidity, the malaria control programs, and the new challenges for these programs in the light of the emergence of asymptomatic infection in the Amazon region of Brazil were reviewed. At least six Brazilian research groups have demonstrated that asymptomatic infection by Plasmodium is an important impediment to malaria control, among mineral prospectors in Mato Grosso and riverside communities in Rondônia and, in our group, in the middle and upper reaches of the Negro river, in the state of Amazonas. Likewise, other researchers have studied the problem among indigenous communities in the Colombian, Peruvian, and Venezuelan parts of the Amazon basin, adjacent to Brazil. The frequency of positive results from the polymerase chain reaction (PCR) among asymptomatic individuals has ranged from 20.4 to 49.5%, and the presence of Plasmodium in the thick blood smears, from 4.2 to 38.5%. Infection with Anopheles darlingi has also been demonstrated by xenodiagnosis among asymptomatic patients with positive PCR results. If a mean of 25% is taken for the asymptomatic infection caused by Plasmodium sp. in the Amazon region of Brazil, malaria control will be difficult to achieve in that region with the measures currently utilized for such control.

Dynamics of feeding and defecation in Triatoma vitticeps (Stal, 1859) (Hemiptera, Reduviidae, Triatominae) and its potential in the transmission of Trypanosoma cruzi

Adults of Triatoma vitticeps infected by flagellates similar to Trypanosoma cruzi are frequently captured by the inhabitants of rural areas in the Brazilian state of Espírito Santo. The dynamics of feeding and defecation were observed in three groups of adult triatomines, consisting of sylvatic T. vitticeps and laboratory-reared specimens of this species and T. infestans. Triatomines were observed from the moment they were presented with an immobilized chicken as a bloodmeal source until 240 min after feeding had ended. Mean times between the end of feeding and defecation for T. infestans, wild T. vitticeps and laboratory-reared specimens of the latter species were 1.2, 21.1, and 64 min respectively. All T. infestans defecated within 10 min of feeding, while only 29.9 of wild and 52.8% laboratory-reared specimens of T. vitticeps did so within this period. These results may explain the low efficiency of T. vitticeps in T. cruzi transmission to man. The shorter time between feeding and defecation in laboratory-reared T. vitticeps may indicate a change in behaviour of this species as a result of adaptation to an artificial environment.

Malaria prevention in travelers.

A common approach to malaria prevention is to follow the "A, B, C, D" rule: Awareness of risk, Bite avoidance, Compliance with chemoprophylaxis, and prompt Diagnosis in case of fever. The risk of acquiring malaria depends on the length and intensity of exposure; the risk of developing severe disease is primarily determined by the health status of the traveler. These parameters need to be assessed before recommending chemoprophylaxis and/or stand-by emergency treatment. This review discusses the different strategies and drug options available for the prevention of malaria during and post travel.

Abundance of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) and urban transmission of visceral leishmaniasis in Campo Grande, state of Mato Grosso do Sul, Brazil

The outspread and urbanization of visceral leishmaniasis (VL) in Campo Grande, state of Mato Grosso do Sul, lead us to undertake the present study over diversity and abundance of sand flies in the urban area to compare with previous search carried out during 1999/2000, before the identification of the disease in the human population.The captures were carried out with automatic light traps, weekly, from February 2004 to February 2005 on three sites including a forested area (Zé Pereira), two peridomicilies (shelters of domestic animals and cultivation areas), and intradomicilie. In the present study 110 collections were obtained during 13 months for 1320 h of collections, resulting in 5004 specimens, 3649 males and 1355 females belonging to the 20 following species: Brumptomyia avellari, Brumptomyia sp., Bichromomyia flaviscutellata, Evandromyia lenti, E. termitophila, E. cortelezzii, E. borrouli, Lutzomyia sp., L. longipalpis, Micropygomyia quinquefer, N. antunesi, N. whitmani, Pintomyia christenseni, Pi. damascenoi, Psathyromyia aragaoi, Ps. campograndensis, Ps. hermanlenti, Ps. shannoni, Pychodopygus claustrei, and Sciopemyia sordellii. L. longipalpis was the most abundant species in the anthropic environment with 92.22% of the captures. This shows an increase of sixty times in the density of L. longipalpis compared to the last sand fly evaluation in 1999/2000. The high density of L. longipalpis in Campo Grande is the main factor of risk in transmission of the disease to human in the urban area. The capture of N. antunesi, typical specie from Amazonian region, in Mato Grosso do Sul is reported for the first time.

Effects of pyrimethamine-sulphadoxine, chloroquine plus chlorpheniramine, and amodiaquine plus pyrimethamine-sulphadoxine on gametocytes during and after treatment of acute, uncomplicated malaria in children

The effects of pyrimethamine-sulphadoxine (PS), chloroquine plus chlorpheniramine, a H1 receptor antagonist that reverses chloroquine resistance in Plasmodium falciparum in vitro and in vivo (CQCP), and amodiaquine plus pyrimethamine-sulphadoxine (AQPS) on gametocyte production were evaluated in 157 children with acute, symptomatic, uncomplicated falciparum malaria who were treated with these drugs. PS was significantly less effective than CQCP or AQPS at clearing asexual parasitaemia or other symptoms of malaria. Gametocyte carriage on days 3, 7, and 14 were significantly higher in those treated with PS. The ratio of the density (per µl blood) of peripheral young gametocyte (PYG), that is, < stage III to peripheral mature gametocyte (PMG), that is, stage IV and V, an index of continuing generation of gametocytes, rose to 1 by day 7 of treatment in those treated with PS, but remained consistently below 1 in the other treatment groups. PYG-PMG density ratio increased significantly from day 0-14 in those treated with PS and CQCP (chi2 = 76, P = 0.000001 and chi2 = 42.2, P = 0.00001, respectively) but decreased significantly in those treated with AQPS (chi2 = 53.2, P = 0.000001). Both PS-sensitive and -resistant infections generated PYG (18 of 29 vs 13 of 20, chi2 = 0.04, P = 0.93) but PYG was present only in those with resistant response to CQCP. Combination of PS with amodiaquine (AQ), that is, (AQPS) resulted in less production of PYG, but in this setting, PYG was not indicative of response to AQPS. These data indicate that PS enhanced production or release of young gametocytes when used alone, but generated less young gametocytes when used in combination with AQ. PYG may be used as an indicator of response to CQCP but not PS or PS-based combination drugs.