Parasitic infections in pirarucu fry, Arapaima gigas Schinz, 1822 (Arapaimatidae) kept in a semi-intensive fish farm in Central Amazon, Brazil.

Studies regarding parasite fauna in farmed fish are of great relevance to lhe knowledge of the parasites species. allowing interference in their proliferation in order to avoid epizooties and consequently. economical losses, This study was designed to investigate the prevalence and intensity of parasites in fry Arapaima gigas maintained in ponds of a semi-intensive fish farm in Amazonas State, Brazil. On necropsy, 96,0% of A. gigas were found parasitized by Dawestrema cycloancistrioides. Dawestrema cycloancistrioides (Monogenoidea). Trichodina sp., Ichthyobodo sp. (Protozoa). Camallamus tridentatus, Terranova serrata, Goezia spinulosa (Nematoda) and Argulidae. However, D. cycloancistrium. D, cycloancistrioides and Trichodina fariai were the parasites of' greatest intensity. This study is the first to report parasitic infections in farmed A. gigas and the results indicated a high rate of infection that might lead to important changes in the health of the hosts

Association between the plasma/whole blood lead ratio and history of spontaneous abortion: a nested cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Blood lead has been associated with an elevated risk of miscarriage. The plasmatic fraction of lead represents the toxicologically active fraction of lead. Women with a tendency to have a higher plasma/whole blood Pb ratio could tend towards an elevated risk of miscarriage due to a higher plasma Pb for a given whole blood Pb and would consequently have a history of spontaneous abortion.</p> <p>Methods</p> <p>We studied 207 pregnant Mexico City residents during the 1^sttrimester of pregnancy, originally recruited for two cohorts between 1997 and 2004. Criteria for inclusion in this study were having had at least one previous pregnancy, and having valid plasma and blood Pb measurements. Pb was measured in whole blood and plasma by inductively coupled plasma mass spectrometry using ultra-clean techniques. History of miscarriage in previous pregnancies was obtained by interview. The incidence rate of spontaneous abortion was defined as the proportion of previous pregnancies that resulted in miscarriage. Data were analyzed by means of Poisson regression models featuring the incidence rate of spontaneous abortion as the outcome and continuous or categorized plasma/blood Pb ratios as predictor variables. All models were adjusted for age and schooling. Additionally, logistic regression models featuring inclusion in the study sample as the outcome were fitted to assess potential selection bias.</p> <p>Results</p> <p>The mean number of miscarriages was 0.42 (range 0 to 4); mean Pb concentrations were 62.4 and 0.14 μg/L in whole blood and plasma respectively. Mean plasma/blood Pb ratio was 0.22%. We estimated that a 0.1% increment in the plasma/blood Pb ratio lead was associated to a 12% greater incidence of spontaneous abortion (p = 0.02). Women in the upper tertile of the plasma/blood Pb ratio had twice the incidence rate of those in the lower tertile (p = 0.02). Conditional on recruitment cohort, inclusion in the study sample was unrelated to observable characteristics such as number of abortions, number of pregnancies, blood Pb levels, age schooling, weight and height.</p> <p>Conclusion</p> <p>Women with a large plasma/whole blood Pb ratio may be at higher risk of miscarriage, which could be due to a greater availability of placental barrier-crossing Pb.</p

Rapid age-grading and species identification of natural mosquitoes for malaria surveillance

The malaria parasite, which is transmitted by several Anopheles mosquito species, requires more time to reach its human-transmissible stage than the average lifespan of mosquito vectors. Monitoring the species-specific age structure of mosquito populations is critical to evaluating the impact of vector control interventions on malaria risk. We present a rapid, cost-effective surveillance method based on deep learning of mid-infrared spectra of mosquito cuticle that simultaneously identifies the species and age class of three main malaria vectors in natural populations. Using spectra from over 40, 000 ecologically and genetically diverse An. gambiae, An. arabiensis, and An. coluzzii females, we develop a deep transfer learning model that learns and predicts the age of new wild populations in Tanzania and Burkina Faso with minimal sampling effort. Additionally, the model is able to detect the impact of simulated control interventions on mosquito populations, measured as a shift in their age structures. In the future, we anticipate our method can be applied to other arthropod vector-borne diseases

Development of an integrated framework for knowledge sharing and integration on land use and land management in West Africa

International audienc

Caractérisation paysanne de Hippopotamus amphibius Linné 1758, dans la Réserve de Biosphère de la Mare aux Hippopotames, en zone sud soudanienne du Burkina Faso

peer reviewedL’étude de la caractérisation de l’hippopotame par les populations villageoises a visé à inventorier les savoirs endogènes sur l’espèce dans la Réserve de Biosphère de la Mare aux Hippopotames du Burkina Faso. L’inventaire de ces savoirs a porté sur l’effectif des populations d’hippopotames, la différenciation sexuelle, le régime alimentaire, les valeurs socioéconomiques et culturelles ainsi que les dégâts dus à cette espèce. L’enquête a été conduite dans six villages de l’ethnie Bobo et a concerné un échantillon de 77 personnes. Les personnes enquêtées savent que les hippopotames sont présents dans la réserve et estiment leur effectif à environ 33 individus. A l’aide de critères morphologiques et éthologiques, les villageois opèrent une différenciation sexuelle chez ces animaux. Le régime alimentaire est connu et comprendrait selon eux une quarantaine d’espèces végétales. Outre les valeurs socioéconomiques, culturelles et touristiques que la présence des hippopotames procure, les populations savent aussi que ces animaux participent au maintien de la biodiversité et à la fertilisation de la mare pour la production de poissons. Toutefois, l’espèce serait également à l’origine de la destruction des filets de pêche, de dégâts sur les cultures céréalières et de quelques accidents mortels

Preparatory entomological surveys for full-scale tsetse-fly control, assisted with a geographic information system: PATTEC case in Burkina Faso

A geographic information system is a helpful tool for the defi­nition of a control plan against tsetse. Its practical application in entomological data collection for the planning and future evaluation of tsetse control was carried out in Western Burkina Faso from December 2007 to November 2008. The sampling area was selected according to the main rivers basins and the limits of Glossina palpalis gambiensis and G. tachinoides dis­tributions. The study area was gridded in 100-kilometer-square cells. In each cell a maximum of 13 potential trapping sites were selected, then spotted in the field by using a global posi­tioning system. The entomological survey was carried out with biconical Challier-Laveissière traps collected 72 hours after their installation. The data analysis was performed with binomial mixed random and Poisson distribution models. Mapping was carried out with Arc GIS 9.3 to help to deter­mine the Northern limit (12° 45’ N) of tsetse distribution in the target area. The proportions of infested sites were 89.6 and 76.4% on the ascending and descending sections of Mou­houn River, respectively (the first flows northeastward from the spring, and the second southeastward, then southward from the confluence with Sourou River), and 16.7 and 10.3% on their tributaries, respectively. Between isohyets 700–800 and 800–900 m no significant differences were observed in tsetse apparent density per trap or in the infested sites. Both trapped species were however distributed unevenly depending on the sections of Mouhoun River. On the ascending branch G. p. gambiensis represented 79.5% of tsetse catches, and on the descending branch G. tachinoides represented 96.0% of them. Catches of mechanical vectors were relatively few. Their distri­butions were similar to that of tsetse but with higher densities on some tributaries

Population genetic structure of Guinea <i>Trypanosoma brucei gambiense</i> isolates according to host factors

Human African trypanosomiasis (HAT) or sleeping sickness is a major public health problem in sub-Saharan Africa and is due to the kinetoplastid parasite Trypanosoma brucei gambiense in West and Central Africa. The exact role of multiple infections, the basis of clinical diversity observed in patients and the determinism that leads trypanosomes into different body fluids of the host remain opened questions to date. In this paper we investigate, in three Guinean foci, whether strains found in blood, lymph or cerebrospinal fluid (CSF) or in patients at different phase of HAT (phase 1, early phase 2 and late phase 2) are representative of the focus they belong to. Amplifications of parasites directly from body fluids led to substantial amounts of allelic drop outs, especially so for blood and CSF samples, which required data recoding of all homozygous sites into missing data. While controlling for geography, date of sampling and patient's phase of the disease, we found no effect of body fluids in the genetic structure of T. b. gambiense despite the presence of mixed infections. On the contrary, we found that the strains found in patients in different phase of the disease differed genetically, with early phase patients being more likely to be infected with more recent strains than patients at a more advanced phase of the disease. Thus, the combination of date of sampling and patient's status represents a parameter to be controlled for in population genetic structure analyses. Additional studies will also be required to explore further the phenomenon of mixed infections and its consequences