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Test characteristics of the SD FK80 Plasmodium falciparum/Plasmodium vivax rapid diagnostic test in a non-endemic setting
No full textBACKGROUND: The SD FK80 P.f/P.v Malaria Antigen Rapid Test (Standard Diagnostics, Korea) (FK80) is a three-band malaria rapid diagnostic test detecting Plasmodium falciparum histidine-rich protein-2 (HRP-2) and Plasmodium vivax-specific lactate dehydrogenase (Pv-pLDH). The present study assessed its performance in a non-endemic setting. METHODS: Stored blood samples (n = 416) from international travellers suspected of malaria were used, with microscopy corrected by PCR as the reference method. Samples infected by Plasmodium falciparum (n = 178), Plasmodium vivax (n = 99), Plasmodium ovale (n = 75) and Plasmodium malariae (n = 24) were included, as well as 40 malaria negative samples. RESULTS: Overall sensitivities for the diagnosis of P. falciparum and P. vivax were 91.6% (95% confidence interval (CI): 86.2% - 95.0%) and 75.8% (65.9% - 83.6%). For P. falciparum, sensitivity at parasite densities >or= 100/microl was 94.6% (88.8% - 97.6%); for P. vivax, sensitivity at parasite densities >or= 500/microl was 86.8% (75.4% - 93.4%). Four P. falciparum samples showed a Pv-pLDH line, three of them had parasite densities exceeding 50.000/microl. Two P. vivax samples, one P. ovale and one P. malariae sample showed a HRP-2 line. For the HRP-2 and Pv-pLDH lines, respectively 81.4% (136/167) and 55.8% (43/77) of the true positive results were read as medium or strong line intensities. The FK80 showed good reproducibility and reliability for test results and line intensities (kappa values for both exceeding 0.80). CONCLUSION: The FK80 test performed satisfactorily in diagnosing P. falciparum and P. vivax infections in a non-endemic setting
Improved models of mini anion exchange centrifugation technique (mAECT) and modified single centrifugation (MSC) for sleeping sickness diagnosis and staging
No full textStrategies to optimize HIV treatment outcomes in resource-limited settings
No full textAlthough the availability of antiretroviral therapy has increased rapidly to reach over three million people in low- and middle-income countries, coverage remains low as only 31% of people in need were receiving antiretroviral therapy in sub-Saharan Africa. Antiretroviral therapy scale-up needs to continue to grow exponentially to meet the need for universal access and keep pace with or exceed the new HIV infections. This calls for strategies that will have the greatest impact on the reduction of opportunistic infections, toxicities, and early mortality after antiretroviral therapy initiation as well improve adherence, clinical, immunological, and virologic responses, patient retention in antiretroviral therapy programs, and overall quality of life of people living with HIV/AIDS. Expanding antiretroviral therapy to all those eligible requires evidence-based decisions about how, when, and where expansion should occur. In this article we highlight some of the strategies that have optimized HIV treatment outcomes within the constraints of limited resources in sub-Saharan Africa. Key strategies to optimize HIV treatment outcomes include, i) scaling up HIV testing to identify all in need of HIV treatment, ii) strengthening the links between HIV diagnosis and comprehensive HIV/AIDS care, iii) timely initiation of antiretroviral therapy, iv) optimal diagnosis and treatment of opportunistic infections and comorbidities, v) investing in laboratory tests to support clinical monitoring of patients on antiretroviral therapy, vi) maximizing adherence to antiretroviral medication and retention of patients in HIV/AIDS care, viii) improving the health infrastructure, and increasing the human resources to handle the growing numbers of people in need of HIV treatment
Fluoroquinolone resistance in Mycobacterium tuberculosis and mutations in gyrA and gyrB
No full textThis study evaluated cross-resistance of Mycobacterium tuberculosis strains to ofloxacin, moxifloxacin, and gatifloxacin and investigated the presence of mutations in gyrA and gyrB. Fluoroquinolone susceptibilities were determined for 41 M. tuberculosis strains by the proportion method on 7H11, and MICs were determined by the resazurin microtiter assay. Forty strains shared the same resistance results for the three fluoroquinolones. However, one strain, with an Asn-533 Thr mutation in gyrB, was susceptible to ofloxacin but resistant to moxifloxacin and gatifloxacin
Antropometría de importancia cardio-metabólica. Referencias bolivianas para adolescentes
No full textAnthropometry is a fundamental tool in the cardioendocrinologic diagnosis. However, Bolivia has no national anthropometric references for the analysis of teenagers. The objective of this cross-sectional study was to develop percentile values and graphics for weight, height, BMI, systolic and diastolic blood pressure, and abdominal circumference (AC) for teenagers from 12 to 18 years of age, with a particular focus on the acquisition of the necessary cut points for the clinical diagnosis of metabolic syndrome. The objective was also to show the differences between the different cut points of international references (CDC 2000, IOTF and 2007 WHO). Values come from the MESA study (metabolic syndrome in Bolivian teenagers)obtained from 32 samples, observing the sample proportionality with replacement. Trained staff assessed 3445 teenagers from 12 to 18 years of age, 45% men and 55% women, from urban and rural schools, following the standardized procedures. Weight, AC and blood pressure were measured. BMI was calculated by formula. Percentiles 3o, 5o, 10o, 25o, 50o, 75o, 85o, 90o, 95o and 97o are presented using regression and softened by the LMS method. Anthropometric references for Bolivian teenagers are presented for their use by the medical and scientific community
"It's better not to know": perceived barriers to HIV voluntary counseling and testing among sub-Saharan African migrants in Belgium
No full textThis study explored perceptions, needs, and barriers of sub-Saharan African migrants in relation to HIV voluntary counseling and testing (VCT). Using an inductive qualitative methodological approach, data were obtained from focus group discussions. Results showed that participants were in principle in favor of VCT. However, they indicated that barriers outweighed advantages. Such barriers included fear of positive test results and its related personal and social consequences, lack of information, lack of preventive health behavior, denial of HIV risk, and missed opportunities. Limited financial resources were only a concern for some subgroups like young people, asylum seekers, and recent migrants. This study identified multiple and intertwined barriers to VCT from a community perspective. In order to promote VCT, interventions such as raising awareness through culturally sensitive education should be adopted at community level. At level of service provision, provider initiated HIV testing including target group tailored counseling should be promoted
Buruli ulcer (Mycobacterium ulcerans infection): a re-emerging disease
No full textMycobacterium ulcerans infection is an emerging disease that causes indolent, necrotizing skin lesions known as Buruli ulcer (BU). Approximately 10% of patients develop reactive osteitis or osteomyelitis beneath skin lesions or metastatic osteomyelitis from lymphohematogenous spread of M. ulcerans. The most plausible mode of transmission is by skin trauma at sites contaminated by M. ulcerans. Pathogenesis is mediated by a necrotizing, immunosuppressive toxin produced by M. ulcerans called mycolactone. The incidence of BU is highest in children up to 15 years old and is a public health problem in countries of endemicity due to disabling scarring and bone destruction. Today, most BU occurs in West Africa, but the disease has been reported in over 30 countries. Treatment options for BU are antibiotics and surgery. BCG vaccination provides short-term protection against BU and prevents osteomyelitis. HIV seropositivity may increase the risk for BU and render BU osteomyeletis highly aggressive
Visceral leishmaniasis elimination programme in India, Bangladesh, and Nepal: reshaping the case finding/case management strategy
No full textObjective
We sought to estimate visceral leishmaniasis (VL) burden in Bangladesh, India, and Nepal and document care-seeking behaviour for VL to provide baseline information for monitoring the VL elimination program and identify options for improved case finding and management.
Design
A cross-sectional study using cluster sampling (clusters being villages) of 4 VL endemic districts was used in order to document all current and existing VL cases over the preceding 12 mo. Extended (in-depth) interviews were conducted in a subsample of households to explore (a) VL-related knowledge, attitudes, and practices of the population; (b) use of VL care by patients; and (c) delay between onset of symptoms, diagnosis, and start of treatment, as well as treatment interruption. Findings were discussed with national program managers and policy makers to develop improved strategies.
Results
Screening for VL was done in 18,933 households (106,425 inhabitants). The estimated annual incidence of VL in the endemic districts was on average 22 times higher than the elimination target of less than one case per 10,000 inhabitants in 2015. This incidence varied widely between study sites, from 9.0 to 29.8 per 10,000 inhabitants. The percentage of newly detected cases through the household screening was high in the districts least covered by health-care services (particularly Rajshahi, Bangladesh, 49%; and to a lesser extent Vaishali in Bihar, India, 32.5%), and much lower in districts with greater availability of VL care (Muzaffarpur, India, 3.8%). On average 267 houses had to be visited, i.e., at least three to four working days per health worker, to identify a new VL (ranging from 1,432 houses in Muzaffarpur, India to only 166 houses in Rajshahi, Bangladesh). Knowledge of the disease and its vectors was good in India and Nepal but poor in Bangladesh (Rajshahi) where very little attention has been given to VL over the last decades. Although all socio-demographic indicators showed high levels of poverty, people in India preferred private medical practitioners for the treatment of VL, whereas in Nepal, and even more in Bangladesh, the public health-care sector was preferred. Delays between onset of symptoms and diagnosis as well as start of treatment was high. Reported non-adherence to treatment was particularly high in the more under-served districts and was mainly due to lack of resources.
Discussion
The findings suggest that (a) house-to-house screening may be useful in highly endemic districts with a poor passive case detection system, but further evidence on case finding adapted to local conditions has to be collected; (b) strengthening the quality of the public health sector is imperative in the three countries, especially in India, with its largely unregulated private-sector provision of VL care
Vitamin D deficiency and hyperparathyroidism in relation to ethnicity: a cross-sectional survey in healthy adults
No full textBACKGROUND: The study of vitamin D status at population level gained relevance since vitamin D deficiency was recently suggested to trigger chronic disease. AIM OF THE STUDY: We aimed to describe vitamin D status, its association with bone and mineral metabolism and risk factors for deficiency in adults over 40 years in Belgium. METHODS: We conducted a cross-sectional survey in a stratified random sample of 401 subjects aged between 40 and 60 years living in Brussels, and drawn from 4 different ethnic backgrounds: autochthonous Belgian, Moroccan, Turkish and Congolese. 25-Hydroxyvitamin D (25OHD), parathyroid hormone (PTH), osteocalcin, C-telopeptide and bone mineral density was measured. RESULTS: Three-hundred and six subjects (77%) showed 25OHD concentrations below 50 nmol/l,135 (34%) below 25 nmol/l and 18 (5%) below 12.5 nmol/l. The proportion of subjects with vitamin D deficiency was four times greater amongst those of Moroccan or Turkish descent compared with those of Congolese or Belgian descent. Moroccan subjects showed a significant higher PTH and bone marker concentrations compared to Belgian. Ethnicity, season and sex were independently associated with vitamin D deficiency in multivariate analysis. CONCLUSION: The prevalence of vitamin D deficiency is very high amongst the adult population of Brussels but immigrants are at greater risk. Given the established link between population health and adequate vitamin D status, a policy of vitamin D supplementation should be considered in these risk groups
International network for comparison of HIV neutralization assays: the NeutNet report
No full textBACKGROUND: Neutralizing antibody assessments play a central role in human immunodeficiency virus type-1 (HIV-1) vaccine development but it is unclear which assay, or combination of assays, will provide reliable measures of correlates of protection. To address this, an international collaboration (NeutNet) involving 18 independent participants was organized to compare different assays. METHODS: Each laboratory evaluated four neutralizing reagents (TriMab, 447-52D, 4E10, sCD4) at a given range of concentrations against a panel of 11 viruses representing a wide range of genetic subtypes and phenotypes. A total of 16 different assays were compared. The assays utilized either uncloned virus produced in peripheral blood mononuclear cells (PBMCs) (virus infectivity assays, VI assays), or their Env-pseudotyped (gp160) derivatives produced in 293T cells (PSV assays) from molecular clones or uncloned virus. Target cells included PBMC and genetically-engineered cell lines in either a single- or multiple-cycle infection format. Infection was quantified by using a range of assay read-outs that included extracellular or intracellular p24 antigen detection, RNA quantification and luciferase and beta-galactosidase reporter gene expression. FINDINGS: PSV assays were generally more sensitive than VI assays, but there were important differences according to the virus and inhibitor used. For example, for TriMab, the mean IC50 was always lower in PSV than in VI assays. However, with 4E10 or sCD4 some viruses were neutralized with a lower IC50 in VI assays than in the PSV assays. Inter-laboratory concordance was slightly better for PSV than for VI assays with some viruses, but for other viruses agreement between laboratories was limited and depended on both the virus and the neutralizing reagent. CONCLUSIONS: The NeutNet project demonstrated clear differences in assay sensitivity that were dependent on both the neutralizing reagent and the virus. No single assay was capable of detecting the entire spectrum of neutralizing activities. Since it is not known which in vitro assay correlates with in vivo protection, a range of neutralization assays is recommended for vaccine evaluation