6320 research outputs found
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Severe multifocal form of Buruli Ulcer after Streptomycin and Rifampin treatment: comments on possible dissemination mechanisms
No full textBuruli ulcer (BU), a disease caused by Mycobacterium ulcerans, leads to the destruction of skin and sometimes bone. Here, we report a case of severe multifocal BU with osteomyelitis in a 6-year-old human immunodeficiency virus (HIV)-negative boy. Such disseminated forms are poorly documented and generally occur in patients with HIV co-infection. The advent of antibiotic treatment with streptomycin (S) and rifampin (R) raised hope that these multifocal BU cases could be reduced. The present case raises two relevant points about multifocal BU: the mechanism of dissemination that leads to the development of multiple foci and the difficulties of treatment of multifocal forms of BU. Biochemical (hypoproteinemia), hematological (anemia), clinical (traditional treatment), and genetic factors are discussed as possible risk factors for disseminatio
Unravelling the antigenic landscape of the HIV-1 subtype A envelope of an individual with broad cross-neutralizing antibodies using phage display peptide libraries
No full textBroad cross-neutralizing antibodies from persons infected with HIV-1 target a variety of epitopes. Identification of these HIV-1 epitopes may result in an optimal panel of antigenic peptides to be included in a prophylactic vaccine. Phage display peptide libraries were used to unravel the antigenic landscape of an individual (ITM1) infected with HIV-1 subtype A with broad cross-neutralizing antibodies. A stringent selection strategy resulted in the identification of 60 unique HIV-1 peptide phage, which were subjected to sequence analysis and mapped onto the ITM1 envelope sequences. Four groups of peptide phages were found: the first group (n=11) were similar with the tip of the V3 loop (KxxHxGPxxxF); the second group (n=11) represented the gp41 principal immunodominant domain (CxGxLxCTxNxP); the third group (n=16) could be localized in the V2 loop (KxxxHxxxY); and the fourth group (n=22) mimicked a conformational epitope (Hxx(S)/(T)NxK). All but the V2-binding antibodies were conserved over the 11 years of follow-up. A neutralization inhibition assay revealed the contribution of the V3 antibodies to the neutralizing capacity of the ITM1 plasma. Overall, the ITM1 immunogenic landscape was mapped and a part of the origin of this broad cross-neutralizing activity was demonstrate
Cultural adaptation of a U.S. evidence-based parenting intervention for rural western Kenya: from Parents Matter! to Families Matter!
No full textEvidence-based interventions (EBIs) are critical for effective HIV prevention, but time and resources required to develop and evaluate new interventions are limited. Alternatively, existing EBIs can be adapted for new settings if core elements remain intact. We describe the process of adapting the Parents Matter! Program, an EBI originally developed for African American parents to promote effective parent-child communication about sexual risk reduction and parenting skills, for use in rural Kenya. A systematic process was used to assess the community's needs, identify potential EBIs, identify and make adaptations, pilot-test the adapted intervention, and implement and monitor the adapted EBI. Evaluation results showed the adapted EBI retained its effectiveness, successfully increasing parent-child sexual communication and parenting skills. Our experience suggests an EBI can be successfully adapted for a new context if it is relevant to local needs, the process is led by a multidisciplinary team with community representation, and pilot-testing and early implementation are well monitore
Risque zoonotique, impact vétérinaire et surveillance des virus influenza A porcins dans le cadre de l'émergence du virus pandémique influenza A/H1N1 (2009)
No full textPlio-Pleistocene history of West African Sudanian savanna and the phylogeography of the Praomys daltoni complex (Rodentia): the environment/geography/genetic interplay
No full textRodents of the Praomys daltoni complex are typical inhabitants of the Sudanian savanna ecosystem in western Africa and represent a suitable model for testing the effects of Quaternary climatic oscillations on extant genetic variation patterns. Phylogeographical analyses of mitochondrial DNA sequences (cytochrome b) across the distribution range of the complex revealed several well-defined clades that do not support the division of the clade into the two species currently recognized on the basis of morphology, i.e. P. daltoni (Thomas, 1892) and Praomys derooi (Van der Straeten & Verheyen 1978). The observed genetic structure fits the refuge hypothesis, suggesting that only a small number of populations repeatedly survived in distinct forest-savanna mosaic blocks during the arid phases of the Pleistocene, and then expanded again during moister periods. West African rivers may also have contributed to genetic differentiation, especially by forming barriers after secondary contact of expanding populations. The combination of three types of genetic markers (mtDNA sequences, microsatellite loci, cytogenetic data) provides evidence for the presence of up to three lineages, which most probably represent distinct biological species. Furthermore, incongruence between nuclear and mtDNA markers in some individuals unambiguously points towards a past introgression event. Our results highlight the importance of combining different molecular markers for an accurate interpretation of genetic data
Duration of cough, TB suspects' characteristics and service factors determine the yield of smear microscopy
No full textObjective To determine the efficiency of routine tuberculosis (TB) case detection by examining sputum smear positivity for acid-fast bacilli in relation to duration of cough, characteristics of TB suspects examined and health service factors. Method We combined patient interviews with routine data from laboratory registers in 6 health care facilities in San Juan de Lurigancho district, Lima, Peru. A TB case was defined as a TB suspect with at least one positive sputum smear. We calculated adjusted odds ratios with 95% confidence intervals for the association between smear positivity and health service and patient's characteristics. Results Smear positivity was 7.3% (321/4376). Of the 4376 adults submitting sputa, 55.3% (2418) reported cough for 2 weeks, being referred by health care staff, attending a secondary-level health care facility, male sex and age between 15 and 44 years were independent determinants of smear positivity. Conclusions Routine case detection yields a low proportion of smear-positive cases because of the inclusion of a high proportion of patients without cough or coughing for <2 weeks. Adherence to the national TB control programme guidelines on the selection of TB suspects would have a positive impact on the smear positivity rate, reduce laboratory costs and workload and possibly improve the reading quality of smear microscop
Giemsa-stained thick blood films as a source of DNA for Plasmodium species-specific real-time PCR
No full textBACKGROUND: This study describes the use of thick blood films (TBF) as specimens for DNA amplification with the Plasmodium species-specific real-time PCR that was recently validated on whole blood samples. METHODS: The panel of 135 Giemsa-stained clinical TBFs represented single infections of the four Plasmodium species with varying parasite densities or only gametocytes, mixed infections, and negative samples and was stored for up to 12 years. Half of the Giemsa-stained TBF was scraped off by a sterile scalpel and collected into phosphate buffered saline. DNA was extracted with the Qiagen DNA mini kit with minor modifications. DNA was amplified with the 18S rRNA real-time PCR targeting the four Plasmodium species with four species-specific primers and probes in combination with one genus-specific reverse primer. Results of the PCR on TBF were compared to those of the PCR on whole blood and to microscopy. RESULTS: Correct identification for single species infections was obtained for all TBF samples with Plasmodium falciparum (n=50), Plasmodium vivax (n=25), Plasmodium ovale (n=25) and in all but one samples with Plasmodium malariae (n=10). Compared to whole blood samples, higher Ct-values were observed by PCR on TBF with a mean difference of 5.93. Four out of five mixed infections were correctly identified with PCR on TBF. None of the negative samples (n=20) gave a PCR signal. PCR on TBF showed a detection limit of 0.2 asexual parasites/ul compared to 0.02/ul for whole blood. Intra-run variation was higher for PCR on TBF (%CV 1.90) compared to PCR on whole blood (%CV 0.54). Compared to microscopy, PCR on TBF generated three more species identifications in samples containing a single species and detected the same four mixed-infections. CONCLUSIONS: Giemsa-stained TBFs are a reliable source of DNA for Plasmodium real-time PCR analysis, allowing applications in reference and research settings in case whole blood samples are not available
Estratos de incidencia de tuberculosis en los municipios de Cuba: 1999-2002 y 2003-2006
No full textOBJECTIVE: Identify Cuban municipalities with high, medium, and low incidence of tuberculosis (TB), compare incidence rates for the periods 1999-2002 and 2003-2006, and analyze distribution of the disease by population density and economic activity. METHODS: TB incidence was calculated by municipality, confidence interval (95%), and the percentage of variation for the defined strata according to population density and the predominant economic activity. The municipalities were divided into three categories based on incidence (> 10 per 100 000; > 5 per 100 000 to 10 per 100 000 fell from 22.5% to 5.9%. National incidence fell by 28.7%-from 8.7 per 100 000 in 1999-2002 to 6.2 in 2003-2006. Municipalities that were not very densely populated and where agricultural activities predominated showed significant reductions in incidence. The rates in densely populated municipalities devoted primarily to industrial and service activities are still high. CONCLUSIONS: TB incidence is gradually and sustainably declining in the majority of municipalities. Differentiated strategies are needed to reduce TB incidence rates in municipalities where they continue to be relatively high
Malaria transmission and vector behaviour in a forested malaria focus in central Vietnam and the implications for vector control
No full textBACKGROUND: In Vietnam, malaria is becoming progressively restricted to specific foci where human and vector characteristics alter the known malaria epidemiology, urging for alternative or adapted control strategies. Long-lasting insecticidal hammocks (LLIH) were designed and introduced in Ninh Thuan province, south-central Vietnam, to control malaria in the specific context of forest malaria. An entomological study in this specific forested environment was conducted to assess the behavioural patterns of forest and village vectors and to assess the spatio-temporal risk factors of malaria transmission in the province. METHODS: Five entomological surveys were conducted in three villages in Ma Noi commune and in five villages in Phuoc Binh commune in Ninh Thuan Province, south-central Vietnam. Collections were made inside the village, at the plot near the slash-and-burn fields in the forest and on the way to the forest. All collected mosquito species were subjected to enzyme-linked immunosorbent assay (ELISA) to detect Plasmodium in the head-thoracic portion of individual mosquitoes after morphological identification. Collection data were analysed by use of correspondence and multivariate analyses. RESULTS: The mosquito density in the study area was low with on average 3.7 anopheline bites per man-night and 17.4 culicine bites per man-night. Plasmodium-infected mosquitoes were only found in the forest and on the way to the forest. Malaria transmission in the forested malaria foci was spread over the entire night, from dusk to dawn, but was most intense in the early evening as nine of the 13 Plasmodium positive bites occurred before 21H. The annual entomological inoculation rate of Plasmodium falciparum was 2.2 infective bites per person-year to which Anopheles dirus s.s. and Anopheles minimus s.s. contributed. The Plasmodium vivax annual entomological inoculation rate was 2.5 infective bites per person-year with Anopheles sawadwongporni, Anopheles dirus s.s. and Anopheles pampanai as vectors. CONCLUSION: The vector behaviour and spatio-temporal patterns of malaria transmission in Southeast Asia impose new challenges when changing objectives from control to elimination of malaria and make it necessary to focus not only on the known main vector species. Moreover, effective tools to prevent malaria transmission in the early evening and in the early morning, when the treated bed net cannot be used, need to be developed