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El trabajo en equipo en consultorios médicos compartidos: opción a desarollar en la atención primaria
No full textCan malaria be controlled where basic health services are not used?
No full textThe definitive version is available at www3.interscience.wiley.comOBJECTIVE: To assess the potential of integrating malaria control interventions in underused health services. METHODS: Using the Piot predictive model, we estimated malaria cure rates by deriving parameters influencing treatment at home and in health facilities from the best-performing African malaria programmes and applying them to Yanfolila district, Mali. RESULTS: Without any malaria control intervention, the population cure rate is 8.4% with home treatment, but would be 13% if access to timely treatment were improved (as in Kenya). A further 3.2% of malaria patients could be cured in institutional settings with more sensitive diagnosis, timely start of treatment, better compliance (as in Uganda, Tanzania, Ghana) and 80% chloroquine efficacy. Applied in a setting where 7.6% of malaria patients seek institutional care, these assumptions would result in a total population cure rate of 14.5%. Increasing the health service user rate from 0.17 in Yanfolila to 0.95 new cases/inhabitant/year (as in Namibia) would result in half of all malaria patients attending professional services, raising the cure rate to 26.1%. CONCLUSION: If malaria patients are to be treated and followed-up early and appropriately, basic health services need to deliver integrated care and be attended by an adequate pool of users. Improved service user rates and case management can increase malaria cure rates far more than isolated control interventions can. This has implications for international policies endorsing a narrow disease-based approach
Replicative fitness of CCR5-using and CXCR4-using human immunodeficiency virus type 1 biological clones
No full textCCR5-tropic viruses cause the vast majority of new HIV-1 infections while about half of the individuals infected with HIV-1 manifest a co-receptor switch (CCR5 (R5) to CXCR4 (X4)) prior to accelerated disease progression. The underlying biological mechanisms of X4 outgrowth in AIDS patients are still poorly understood. Although X4 viruses have been associated with increased "virulence" in vivo, in vitro replication and cytopathicity studies of X4 and R5 viruses have led to conflicting conclusions. We studied the replicative fitness of HIV-1 biological clones with different co-receptor tropism, isolated from four AIDS patients. On average, R5 and X4 clones replicated equally well in mitogen-activated T cells. In contrast, X4 variants were transferred more efficiently from dendritic cells to autologous CD4+ T cells. These observations suggest that interaction between X4 viruses, DC and T cells might contribute to the preferential outgrowth of X4 viruses in AIDS patients
Cutting edge: resistance to HIV-1 infection among African female sex workers is associated with inhibitory KIR in the absence of their HLA ligands
No full textNK cells are regulated in part by killer Ig-like receptors (KIR) that interact with HLA molecules on potential target cells. KIR and HLA loci are highly polymorphic and certain KIR/HLA combinations were found to protect against HIV disease progression. We show in this study that KIR/HLA interactions also influence resistance to HIV transmission. HIV-exposed but seronegative female sex workers in Abidjan, Côte d'Ivoire, frequently possessed inhibitory KIR genes in the absence of their cognate HLA genes: KIR2DL2/KIR2DL3 heterozygosity in the absence of HLA-C1 and KIR3DL1 homozygosity in the absence of HLA-Bw4. HIV-seropositive female sex workers were characterized by corresponding inhibitory KIR/HLA pairings: KIR2DL3 homozygosity together with HLA-C1 and a trend toward KIR3DL1/HLA-Bw4 homozygosity. Absence of ligands for inhibitory KIR could lower the threshold for NK cell activation. In addition, exposed seronegatives more frequently possessed AB KIR genotypes, which contain more activating KIR. The data support an important role for NK cells and KIR/HLA interactions in antiviral immunity
Nitrate reductase assay for detection of drug resistance in Mycobacterium tuberculosis: simple and inexpensive method for low-resource laboratories
No full textThe nitrate reductase assay (NRA) was used as an alternative method for detection of resistance to the first-line antituberculous drugs isoniazid, rifampicin, ethambutol and streptomycin. A total of 320 strains of Mycobacterium tuberculosis were studied and the results compared with the proportion method (PM) on Löwenstein-Jensen medium. The mean time to obtain results was 10 days and the overall agreement between the NRA and PM was 98.8 %. The NRA was easy to perform and represents a useful tool for rapid and accurate determination of drug-resistant M. tuberculosis strains in low-resource countries
Direct detection of Mycobacterium tuberculosis complex DNA and rifampin resistance in clinical specimens from tuberculosis patients by line probe assay
No full textThe INNO-LiPA.Rif TB test (LiPA) has only been applied to a limited number of clinical specimens. To assess the utility of this test for detecting Mycobacterium tuberculosis complex DNA and rifampin (RMP) resistance, 420 sputum samples comprising specimens from untreated (n=160) and previously treated (n=260) patients from 11 countries in Asia, Africa, Europe, and Latin America were tested. DNA was extracted from sputum samples by using a modification of the Boom's method, while the rpoB core region was amplified by nested PCR. The results were analyzed in conjunction with those obtained by Ziehl-Neelsen (ZN) microscopy and by culture on solid media. The LiPA test was positive for M. tuberculosis complex DNA in 389 (92.9%) specimens, including 92.0% (286 of 311) ZN-positive and 94.5% (103 of 109) ZN-negative specimens. Of these, 30.6% were RMP resistant. In contrast, 74.3% of the specimens were positive for M. tuberculosis by culture, and 30.8% of them were RMP resistant. LiPA detected M. tuberculosis complex DNA in 92.4% (110 of 119) of the culture-positive and 100.0% (41 of 41) of the culture-negative specimens from untreated patients. There was a 99.6% concordance between the RMP resistance as determined by culture and by the LiPA test. With an optimal DNA extraction method, LiPA allows rapid detection of M. tuberculosis complex DNA and RMP resistance directly from sputum specimens. LiPA can still provide useful information when culture fails for various reasons. The rapid availability of this information is necessary to adjust patient treatment and avoid the risk of amplification of drug resistance
Tolerability of amodiaquine and sulphadoxine-pyrimethamine, alone or in combination for the treatment of uncomplicated Plasmodium falciparum malaria in Rwandan adults
No full textThe definitive version is available at www3.interscience.wiley.comOBJECTIVE: To assess the tolerability and efficacy of amodiaquine (AQ)+sulphadoxine-pyrimethamine (SP), the first-line malaria treatment in Rwanda. METHOD: Randomized, double-blind trial in 2003 in Kigali town. A total of 351 adult patients with uncomplicated Plasmodium falciparum malaria were randomly allocated to one of the following treatments: AQ+SP, AQ or SP. We followed patients until day 14 after treatment and recorded adverse events (AEs) and clinical and parasitological outcomes. RESULTS: One hundred and eighteen patients reported at least one AE: 40% in the AQ, 39% in the AQ+SP and 21% in the SP groups. The AE was classified as possibly related to the antimalarial treatment for 86 patients. The Risk Ratio for at least one AE after treatment was significantly and about fourfold higher in patients receiving AQ or AQ+SP than in patients receiving SP. Pruritus and fatigue were significantly more frequent in patients treated with AQ or AQ+SP than in those receiving SP. Severe AEs, such as fatigue, nausea, dizziness and vomiting, were observed in four patients treated with AQ, in 10 treated with AQ+SP and in one patient treated with SP. CONCLUSION: Amodiaquine+SP is not well tolerated and a substantial proportion of patients experienced pruritus and fatigue, thus decreasing their compliance and compromising the first line treatment implementation at national level. This renders AQ-containing regimens sub-optimal; better-tolerated treatments should be identified
Sensibilité in vivo de Plasmodium falciparum à la chloroquine et à la sulfadoxine-pyriméthamine dans la région de Bobo Dioulasso (1998-2001): étude des facteurs de risque associés aux échecs thérapeutiques de ces deux médicaments
No full textThe therapeutic efficacy of chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) was determined over a 4 year period (1998-2001) in Bobo Dioulasso, Burkina Faso, with an analysis of the risk factors associated to treatment failures to the 2 drugs. In total, 2008 children (6 months-15 years old) attending in 4 health centres (1 urban and 3 rural) were included in the study. Children were alternatively allocated to either CQ or SP The WHO 14-days in vivo field test was carried out. PCV was measured at day 0 and 14. CQ treatment failure was 24.4% (229/940), most of them being late failures. Between 1998 and 2001 a significant increase in CQ treatment failure (p 0.1). Univariate analysis showed that the site, the age of children, the time of recruitment and the parasitaemia were significantly associated with CQ treatment failure. In the multivariate analysis these 4 variables remain significantly and independently associated with the risk of CQ treatment failure. After adjusting for the effect of the 3 other factors, the risk of treatment failure was reduced by half in rural area compared to urban area as well as in children of 5-15 years of age compared to those under 5. The risk of treatment failure was significantly increased in 2000-2001 (OR = 1.66, p or = 16,000/microl than in those having a lower parasitaemia. For SP we have not observed such connexions with the univariate and multivariate analysis
Trypanosoma cruzi: variability of stocks from Colombia determined by molecular karyotype and minicircle Southern blot analysis
No full textNineteen Trypanosoma cruzi stocks, most of them of wild origin, and four Trypanosoma rangeli stocks from Colombia were analysed by molecular karyotype analysis with cloned DNA cruzipain as the probe. Another 27 cloned stocks of T. cruzi from different geographic areas of South America were used as reference for T. cruzi lineages. Phenetic analysis of chromosome size polymorphism demonstrated a great variability of Colombian T. cruzi stocks, suggesting that most belong to lineage I, although two of them belong to lineage II. The 2 lineage II T. cruzi, 17 T. cruzi lineage I, and 3 T. rangeli stocks from Colombia were studied further by Southern blot analysis with a panel of kinetoplast DNA minicircle probes. Hybridisation results indicate that the two T. cruzi II stocks are genetically distant from each other and from T. cruzi lineages IIb, IId, and IIe from Chile. Finally, T. cruzi minicircle probes do not cross-hybridise in any stringency condition tested with T. rangeli minicircles, a clear indication that these parasites can be easily distinguished by this method