Finger-prick Samples Research Articles

Field evaluation of two point-of-care tests for syphilis among men who have sex with men, Verona, Italy

ObjectivesThe incidence of HIV and syphilis among men who have sex with men (MSM) in Europe has recently increased. Rapid point-of-care tests (POCTs) for syphilis can improve access to screening....

A pilot evaluation of whole blood finger-prick sampling for point-of-care HIV viral load measurement: the UNICORN study

There is a global need for HIV viral load point-of-care (PoC) assays to monitor patients receiving antiretroviral therapy. UNICORN was the first study of an off-label protocol using whole blood finger-prick samples tested with and without a simple three minute spin using a clinic-room microcentrifuge. Two PoC assays were evaluated in 40 HIV-positive participants, 20 with detectable and 20 with undetectable plasma viral load (pVL) (<20 copies/ml). Using 100 µl finger-prick blood samples, the Cepheid Xpert HIV-1 Viral Load and HIV-1 Qual cartridges were compared with laboratory pVL assessment (TaqMan, Roche). For participants with undetectable viraemia by TaqMan, there was poor concordance without centrifugation with the TaqMan platform with only 40% ‘undetectable’ using Xpert VL and 25% ‘not detected’ using the Qual assay. After a 3 minute spin, 100% of samples were undetectable using either assay, showing full concordance with the TaqMan assay. Defining a lower limit of detection of 1000 copies/ml when including a spin, there was 100% concordance with the TaqMan platform with strong correlation (rho 0.95 and 0.94; p < 0.0001 for both assays). When including a simple microcentrifugation step, finger-prick PoC testing was a quick and accurate approach for assessing HIV viraemia, with excellent concordance with validated laboratory approaches.

Quantification of cotinine in dried blood spots as a biomarker of exposure to tobacco smoke

Objective: We present an ultra-sensitive, minimally-invasive method for quantifying cotinine in dried blood spot (DBS) samples as a biomarker of exposure to tobacco smoke that can be collected using a simple heel or finger prick to obtain blood samples.Methods: Cotinine levels were measured in matched plasma and reconstituted DBS samples from smokers and nonsmokers to evaluate assay parameters. In addition, we applied this new method to finger-prick DBS samples that were collected from infants, children and young adults ages 1–21 to estimate exposure to tobacco smoke. Partitioning of cotinine across red blood cells and haematocrit effects were investigated.Results: Cotinine levels measured in matched plasma and reconstituted DBS samples from smokers and nonsmokers were found to be highly correlated (R2=0.94), with 100% sensitivity and 94% specificity to differentiate reported smokers from nonsmokers. With this method, the LOQ is <0.25 ng/mL using a single 3.2 mm punch of a DBS, and haematocrit effects are negligible.Conclusions: This sensitive, high-throughput and minimally-invasive method for quantifying cotinine in DBS samples provides a simple and cost effective means for estimating exposure to tobacco smoke in population based studies, and has particular advantages in studies involving infants and children.

An Evaluation of the Point-of-Care Test i-CHROMA Prostate-Specific Antigen Method for Screening in the Community

Background This study evaluated and compared the performance of the i-CHROMA point-of-care testing (POCT) method for the quantification of prostate-specific antigen (PSA) against a traditional laboratory PSA method (Abbott Architect assay). Materials and Method Blood samples (venous [143] serum [143]) and finger prick (55) were collected from volunteers at a PSA screening campaign. Both venous and finger-prick samples were analyzed using the i-CHROMA PSA method and serum samples using the Abbott Architect method. Results were compared using linear regression and Red Amber Green analysis, a scoring system based on volunteer's age and PSA level. Red indicated a raised PSA, amber indicated a slightly raised PSA, and green indicated a normal PSA. Results The data showed that both the i-CHROMA PSA results using the venous samples (r2 = 0.9841) and the finger-prick samples (r2 = 0.90845) showed a good correlation when compared with the serum samples using the laboratory method. The Red Amber Green analysis showed the i-CHROMA' venous PSA method identified 15 reds, 13 ambers, and 115 greens compared with 9 reds, 8 ambers, and 126 greens identified by Abbot Architect method. The i-CHROMA finger-prick PSA method identified 3 reds, 3 ambers, and 49 greens compared with 3 reds, 1 ambers, and 51 greens identified by Abbot Architect method. Conclusions The i-CHROMA POCT PSA method showed good correlation with the Abbott Architect PSA method. Higher numbers of raised and abnormal PSA were identified by the i-CHROMA POCT PSA method due to the positive bias observed. The i-CHROMA POCT PSA method is a reliable method for total PSA within its limitations.

Performance evaluation of BD FACSPresto™ point of care CD4 analyzer to enumerate CD4 counts for monitoring HIV infected individuals in Nigeria.

BackgroundDespite the upsurge in support and intervention of donor agencies in HIV care and treatment programing in Sub-Sahara African, antiretroviral (ART) programs are still confronted with access and coverage challenges which influence enrolment of new patients. This study investigated the validity of point of care BD FACSPresto™ CD4 analyzer for CD4+ cell count, overall agreement, correlation, sensitivity, and specificity in comparison to a reference standard flow cytometry method. We also assessed the feasibility of use among non-laboratorians.MethodsBlood samples from 300 HIV infected individuals were analyzed for CD4+ T cell and CD4%, using finger prick capillary sample from 150 PMTCT clients and 150 ART clients at Murtala Mohammed Specialist Hospital, Kano, Nigeria. Their venous samples were compared on a flow cytometry reference method using BD FACSCount CD4+ count system. The accuracy of the BD FACSPresto machine in comparison to BD FACSCount was evaluated. Statistical analysis was carried out using STATA (version 12). Bland-Altman method and correlation analysis were used to analyze agreement between both measurements. In addition, sensitivity and specificity of both measurements were determined. Statistical significance was set at p-value <0.05.ResultsThe mean bias and limit of agreement for CD4+ count between BD FACSPresto and BD FACS count machine were 7.49 (95% CI: 2.44 to 12.54) and -8.14 to 96.39 respectively. Further analysis revealed close agreement between BD FACSPresto and BD FACSCount with no significant difference between the two methods (p = .0.95). Using a threshold of 500 cells/μL, sensitivity and specificity of BD FACSPresto were 95.1% and 97.1% respectively, compared to BD FACSCount. There was no statistically significant difference in the misclassification between BD FACSPresto and BD FACSCount results (p = 0.23). Furthermore, sensitivity and specificity were similar when BD FACSPresto machine was operated by a nurse or laboratory scientist, there was no substantial difference in testing variability observed between laboratory and non-laboratory operators using the BD FACSPresto analyzer.ConclusionsOverall, BD FACSPresto Point of Care CD4+ count finger stick capillary blood results is a reliable method in comparison to venous sample cytometry method and no significant difference variability observed between laboratory personnel and non-laboratory operators. The BD FACSPresto is simple, more robust and easy to use equipment without significant variability in reliability by non-laboratory health care workers hence will be a valuable instrument in increasing access and coverage of CD4 estimations in developing countries. The introduction of the BD FACSPresto POC analyzer has a high potential in reducing patients waiting time and improving the overall quality of ART service and clients’ satisfaction especially in rural settings.

Enzyme-Linked Immunoassay-Based Quantitative Measurement of Apolipoprotein B (ApoB) in Dried Blood Spots, a Biomarker of Cardiovascular Disease Risk

ABSTRACTApolipoprotein B (ApoB) is a strong predictor of cardiovascular disease, which remains the leading cause of mortality in both higher and lower income countries. Here, we adapted an enzyme-linked immunosorbent assay (ELISA) development kit for quantitative determination of ApoB levels in serum and plasma for use with dried blood spots (DBS). After confirming the dilution linearity of the assay for DBS, we measured ApoB in 208 venous DBS samples. Then, using Passing-Bablok regression analysis and Spearman rank correlation analysis, we evaluated the correspondence in ApoB values between matched plasma and finger-prick DBS samples from 40 individuals who had ApoB values spanning the range of ApoB values observed in the 208 vDBS samples. We also evaluated assay precision and recovery, the effects of hematocrit, number of freeze-thaw cycles, and different storage temperatures on ApoB levels in DBS. There was a strong, significant correlation between plasma and DBS ApoB levels with little bias. Assay precision and recovery were within the range recommended by the U.S. government’s industry guidelines for bioanalytical assay validation. The assay was not affected by the DBS matrix or physiological hematocrit levels. This DBS-based ELISA assay will facilitate population-scale assessment of cardiovascular risk in previously unexplored populations.

EFFECT OF COMMUNITY-BASED SCHEDULED SCREENING AND TREATMENT (CSST) OF MALARIA IN PREGNANCY ON INFANT MALARIA INFECTION IN A SEASONAL MALARIA TRANSMISSION SETTING

BackgroundChildren born to mothers who had malaria in pregnancy have an increased risk of malaria infection in the first 24 months of life and they also experience earlier episodes of...

ASSESSMENT OF THE ENDEMICITY STATUS OF SCHISTOSOMIASIS AND SOIL-TRANSMITTED HELMINTHIASIS IN THE GAMBIA

BackgroundThe Ministry of Health and Social Welfare, The Gambia with support from WHO and Task Force for Global Health (TFGH), conducted a national endemicity mapping survey for schistosomiasis (SCH) and...

Poor Validity of Noninvasive Hemoglobin Measurements by Pulse Oximetry Compared with Conventional Absorptiometry in Children in Côte d'Ivoire.

Anemia remains a major public health issue in many African communities. We compared a novel, commercially available noninvasive hemoglobin (Hb)-measuring device to direct Hb measurements by finger-prick samples in a pediatric cohort in rural Côte d'Ivoire. Noninvasive Hb measurements were attempted in 191 children 2-15 years of age and obtained in 102 (53.5%) children. The median Hb for the 102 children was 12.0 g/dL (interquartile range [IQR] = 11.3-12.7 g/dL) for conventional absorptiometry and 13.3 g/dL (IQR = 12.1-14.2 g/dL) for noninvasive measurements. A Bland-Altman analysis demonstrated a median bias of +1.1 g/dL (IQR = 0.4-2.0 g/dL), with greater overestimation of Hb by noninvasive testing occurring at low Hb values. This overestimation of the noninvasive Hb-measuring device to direct Hb measurements persisted across preschool- and school-aged children, and both sexes. The Pearson correlation coefficient was 0.50 for children 4-9 years of age, and 0.33 for children 10-15 years of age. Further study and development of noninvasive Hb devices is necessary prior to implementation in African pediatric populations.

0506 Effect of milk protein intake and casein: Whey ratio in breakfast meals on postprandial glucose, satiety ratings and subsequent meal intake

Novel satiating dairy-based breakfast products have potential to reduce the risk of developing and improve management of type 2 diabetes and obesity. Whey and casein proteins may induce different physiological effects on blood glucose, induction of satiation and satiety. Whey proteins have been associated with acute satiation, compared with the prolonged feelings of satiety from casein. The purpose of this work is to investigate the impact of breakfast meal milk casein:whey ratio and protein concentration on postprandial blood glucose, appetite ratings, and subsequent food intake. In a randomized, controlled, double-blinded study, healthy young adults (n = 32, 16 m/f, 23.4 ± 3.1 y, BMI 22.2 ± 2.5 kg/m2) consumed milk (250ml) with normal (80:20) or modified (40:60) casein:whey protein ratio at normal (3.1%) or high (9.3%) protein concentration, or water (control), along with 2 servings of breakfast cereal. Following an overnight fast and up to 120 min following the breakfast meal, participants had their plasma glucose concentrations determined from finger-prick samples, completed a series of scale ratings to assess satiety and consumed a weighed ad libitumpizza lunch. Repeated measures ANOVA followed by Tukey-Kramer's post hoc testing was performed. Incremental area under the curve (AUC) glucose values showed significant attenuations in postprandial plasma glucose concentration for all milk treatments, relative to control (P < 0.05). Also, the high protein treatments (9.3%) had significantly attenuated glucose concentrations compared with those with lower protein (3.1%). However, there was no effect of casein:whey protein ratio on blood glucose. Treatments were not associated with differences in total area under the curve for individual scale ratings of Hunger, Desire to Eat, Fullness, and Prospective Consumption. Nor were differences observed in mean appetite score (P = 0.86) or subsequent lunch intake (P = 0.06). Therefore, since consumption of high protein milk treatments with breakfast cereal was associated with the lowest plasma postprandial glucose concentration, new high-protein dairy breakfast products should be considered for product development.

A DBS method for quantitation of the new oral trypanocidal drug fexinidazole and its active metabolites.

Fexinidazole (FEX) is a nitroimidazole being developed as a new trypanocide treatment for human African trypanosomiasis/sleeping sickness. Its main metabolites, fexinidazole sulfoxide (M1) and fexinidazole sulfone (M2), show the same in vitro pharmacological activity as FEX. An LC-MS/MS assay was developed for quantitation of FEX in DBS, collected via finger-prick from healthy subjects. The DBS assay was specific, accurate and reproducible for FEX, M1 and M2 when validated against the current plasma assay. DBS samples were stable for 24 h at 37°C with 95% relative humidity, and 58 weeks desiccated at room temperature. DBS finger-prick sampling offers a simple, practical method for determining FEX, M1 and M2 concentrations in clinical studies in Africa.

Acceptability and feasibility of point-of-care CD4 testing on HIV continuum of care in low and middle income countries: a systematic review.

BackgroundCD4 testing is, and will remain an important part of HIV treatment and care in low and middle income countries (LMICs). We report the findings of a systematic review assessing acceptability and feasibility of POC CD4 testing in field settings.MethodsElectronic databases were searched for studies published in English between 2005 and 2015 that describe POC CD4 platforms. Studies conducted in LMICs and under field conditions outside a laboratory environment were eligible. Qualitative and descriptive data analysis was used to present the findings.ResultsTwelve studies were included, 11 of which were conducted in sub-Saharan countries and used one POC CD4 test (The Alere Pima CD4). Patients reported positively regarding the implementation of POC CD4 testing at primary health care and community level with ≥90 % of patients accepting the test across various study settings. Health service providers expressed preference toward POC CD4 testing as it is easy-to-use, efficient and satisfied patients’ needs to a greater extent as compared to conventional methods. However, operational challenges including preference toward venous blood rather than finger-prick sampling, frequent device failures and operator errors, quality of training for test operators and supervisors, and increased staff workload were also identified.ConclusionsPOC CD4 testing seems acceptable and feasible in LIMCs under field conditions. Further studies using different POC CD4 tests available on the market are required to provide critical data to support countries in selection and implementation of appropriate POC CD4 technologies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12913-016-1588-y) contains supplementary material, which is available to authorized users.

Predictors of vitamin D status in New Zealand preschool children.

Vitamin D deficiency has adverse health effects in young children. Our aims were to determine predictors of vitamin D status and then to use these factors to develop a practical tool to predict low 25(OH)D concentrations in preschool New Zealand children. A cross-sectional sample of 1329 children aged 2 to <5 years were enrolled from throughout New Zealand in late-winter to spring 2012. 25-Hydroxyvitamin D (25(OH)D) was measured on dried blood spot (DBS) samples collected using finger-prick sampling. Caregivers completed a questionnaire. Mean (SD) DBS 25(OH)D concentration was 52(19)nmol/L. 25(OH)D < 25 nmol/L was present in 86(7%), 25(OH)D < 50 nmol/L in 642(48%), 25(OH)D 50- < 75 nmol/L in 541(41%) and 25(OH)D > 75 nmol/L in 146(11%) of children. Factors independently associated with the risk of 25(OH)D < 25 nmol/L were female gender (OR 1.92,95%CI 1.17-3.14), other non-European ethnicities (not including Māori or Pacific) (3.51,1.89-6.50), had olive-dark skin colour (4.52,2.22-9.16), did not take vitamin D supplements (2.56,1.06-6.18), had mothers with less than secondary-school qualifications (5.00,2.44-10.21) and lived in more deprived households (1.27,1.06-1.53). Children who drank toddler milk (vitamin D fortified cow's milk formula marketed to young children) had a zero risk of 25(OH)D < 25 nmol/L. The predictive tool identified children at risk of 25(OH)D < 25 nmol/L with sensitivity 42%, specificity 97% and ROC area-under-curve 0.76(95%CI 0.67-0.86, p < 0.001). Predictors of low vitamin D status were consistent with those identified in previous studies of New Zealand children. The tool had insufficient predictive ability for use in clinical situations, and suggests a need to promote safe, inexpensive testing to determine vitamin D status in preschool children.

Dried Blood Spot Methodology in Combination With Liquid Chromatography/Tandem Mass Spectrometry Facilitates the Monitoring of Teriflunomide.

Background:Teriflunomide, a once-daily oral immunomodulator approved for treatment of relapsing-remitting multiple sclerosis, is eliminated slowly from plasma. If necessary to rapidly lower plasma concentrations of teriflunomide, an accelerated elimination procedure using cholestyramine or activated charcoal may be used. The current bioanalytical assay for determination of plasma teriflunomide concentration requires laboratory facilities for blood centrifugation and plasma storage. An alternative method, with potential for greater convenience, is dried blood spot (DBS) methodology. Analytical and clinical validations are required to switch from plasma to DBS (finger-prick sampling) methodology.Methods:Using blood samples from healthy subjects, an LC-MS/MS assay method for quantification of teriflunomide in DBS over a range of 0.01–10 mcg/mL was developed and validated for specificity, selectivity, accuracy, precision, reproducibility, and stability. Results were compared with those from the current plasma assay for determination of plasma teriflunomide concentration.Results:Method was specific and selective relative to endogenous compounds, with process efficiency ∼88%, and no matrix effect. Inaccuracy and imprecision for intraday and interday analyses were <15% at all concentrations tested. Quantification of teriflunomide in DBS assay was not affected by blood deposit volume and punch position within spot, and hematocrit level had a limited but acceptable effect on measurement accuracy. Teriflunomide was stable for at least 4 months at room temperature, and for at least 24 hours at 37°C with and without 95% relative humidity, to cover sampling, drying, and shipment conditions in the field. The correlation between DBS and plasma concentrations (R2 = 0.97), with an average blood to plasma ratio of 0.59, was concentration independent and constant over time.Conclusions:DBS sampling is a simple and practical method for monitoring teriflunomide concentrations.

Tropheryma whipplei as a Cause of Epidemic Fever, Senegal, 2010-2012.

The bacterium Tropheryma whipplei, which causes Whipple disease in humans, is commonly detected in the feces of persons in Africa. It is also associated with acute infections. We investigated the role of T. whipplei in febrile patients from 2 rural villages in Senegal. During June 2010-March 2012, we collected whole-blood finger-prick samples from 786 febrile and 385 healthy villagers. T. whipplei was detected in blood specimens from 36 (4.6%) of the 786 febrile patients and in 1 (0.25%) of the 385 apparently healthy persons. Of the 37 T. whipplei cases, 26 (70.2%) were detected in August 2010. Familial cases and a potential new genotype were observed. The patients' symptoms were mainly headache (68.9%) and cough (36.1%). Our findings suggest that T. whipplei is a cause of epidemic fever in Senegal.

Vitamin D Status and Bone Mineral Density in Female Collegiate Dancers and Cheerleaders

INTRODUCTION: An athlete’s bone mineral density reflects their cumulative history of energy availability, physical activity, genetic predisposition for bone health, and menstrual status, as well as nutritional, behavioral, and environmental factors. PURPOSE: To determine if bone mineral density (BMD) and nutritional factors in bone health are different in two groups of female athletes who have comparable body size/weight requirements, but who engage in qualitatively different training regimens. METHODS: Participants were female collegiate athletes who were members of the UNLV Dance team (n=10) or Cheer team (n=9), ages 18-22. Participants vitamin D status was assessed by obtaining a finger prick sample of blood (<1 ml). BMD for full body, spine and dual femur was assessed by dual energy X-ray absorptiometry (DXA). A calcium and vitamin D intake questionnaire was also completed. RESULTS: There was no significant difference between the groups for total body BMD (1.23 g/cm2 dance vs 1.22 g/cm2 cheer, p=0.70), spine BMD (1.39 g/cm2 dance vs 1.36 g/cm2 cheer, p=0.72) or dual femur BMD (1.20 g/cm2 dance vs 1.11 g/cm2, p=0.23). Age matched z-scores for total body BMD were also not significantly different (1.46±1.23 dance vs 0.83±0.52 cheer, p=0.19). However there was a significant difference between age-matched z-scores of the dance team vs. non-athlete female controls (1.46±1.23 dance vs 0.19±1.22 control, p=0.033). Serum vitamin D status was found to be insufficient (10-29 ng/mL) in 74% of the athletes (27 ± 4 ng/mL dance and 25 ± 8 ng/mL cheer). Daily calcium intake was 504 ± 723 mg for dance and 531 ± 236 mg for cheer versus the RDA of 1,000mg/day. Daily vitamin D intake was 256 ± 335 IU for dance and 228 ± 145 IU for cheer versus the RDA of 600 IU/day. CONCLUSION: BMD was not significantly different between the low impact dance team and high impact cheer team. These results suggest that the type of activity (low impact dance vs. high impact cheerleading) was not as important for BMD as participating in 20+ hours a week of physical activity. Although the low levels of calcium and serum vitamin D are of concern, the amount of physical activity in these athletes could have counteracted the negative effects of these nutrient insufficiencies on their bone health.

Pilot Study for Assessing Moderate to Long‐Term Outcomes of the Expanded Food and Nutrition Education Program (EFNEP)

Objectivesdetermine (1) the best communication channel for contacting EFNEP adult graduates; (2) moderate to long‐term (6 or 12 month) self‐reported behavior data; and (3) graduates willingness to provide objective data (BMI, blood pressure).MethodsGraduates were randomly assigned to be contacted by traditional mail, email, text, or phone call. Upon contact, graduates completed EFNEP's standard behavior checklist as they had completed at pre and post intervention – via web link, pencil and paper, or phone interview, and indicated willingness to provide objective data.ResultsResponse rates by communications channel ranged from 4 to 32%; phone call or text from the educator were above 30%. At 6 or 12 months post‐graduation, the score on the 3 behavior checklist scales (nutrition, food resource management, food safety) were all significantly better than the pretest and equal to the posttest scores, suggesting that positive dietary changes were maintained. Respondents “might” or “would” allow collection of BMI (70%), blood pressure (70%), finger prick (55%) or urine sample (60%).ConclusionsThis pilot study provides initial evidence that behavior changes reported at the end of EFNEP interventions are maintained at 6 or 12 months. Graduates willingness to provide objective data will enable EFNEP to strengthen outcome measures and confirm self‐report data to build the evidence base for the program. Using educators who have a relationship with graduates appears to offer the best way to recruit them.Support or Funding InformationUnited States Department of Agriculture's National Institute of Food and Agriculture Regional Nutrition Education Centers of Excellence Initiative

Analysis of ochratoxin A in dried blood spots - Correlation between venous and finger-prick blood, the influence of hematocrit and spotted volume.

We report the improvement of a method for the detection of ochratoxin A (OTA) and its thermal degradation product 2'R-ochratoxin A in dried blood spots (DBS) by high performance liquid chromatographic (HPLC) tandem mass spectrometry (MS/MS). The DBS technique was advanced for the analysis of these two compounds in DBS with unknown amounts of blood as well as varying hematocrit values. Furthermore the comparability of venous vs. capillary blood was investigated. Human whole blood samples were spotted, dried, and extracted with a solvent consisting of acetone, acetonitrile and water for analysis by HPLC-MS/MS. Quantification was carried out by stable isotope labelled internal standards. Blood samples of volunteers (n=50) were used to further optimize and simplify the procedure. Ochratoxin A and 2'R-ochratoxin A concentrations found in the entire spots (approx. 100 μL blood) were compared with punched DBS discs of 8.8mm size containing approximately 20 μL blood. As a result the amounts of both toxins in a punched 8.8mm disc correlate well with the entire DBS. Also the use of capillary blood from finger-pricks versus venous blood was evaluated. The analyte levels correlate as well indicating that the less invasive finger-prick sampling gives also reliable results. The influence of hematocrit was investigated in a range of 25-55% according to the hematocrit in the used real blood samples (34-46% hematocrit). However no significant hematocrit effect was observed for the utilized real blood samples. Moreover different blood volumes were spotted and punched as a minimal spot size is usually recommended for accurate analysis. In this experiment finger-prick samples typically consist of about 90 μL blood. Therefore spots of 75, 100 and 125 μL blood were prepared and analyzed. Similar to the hematocrit effect, no considerable influence was observed.

Widespread distribution of Plasmodium vivax malaria in Mauritania on the interface of the Maghreb and West Africa.

BackgroundPlasmodium vivax is very rarely seen in West Africa, although specific detection methods are not widely applied in the region, and it is now considered to be absent from North Africa. However, this parasite species has recently been reported to account for most malaria cases in Nouakchott, the capital of Mauritania, which is a large country at the interface of sub-Saharan West Africa and the Maghreb region in northwest Africa.MethodsTo determine the distribution of malaria parasite species throughout Mauritania, malaria cases were sampled in 2012 and 2013 from health facilities in 12 different areas. These sampling sites were located in eight major administrative regions of the country, within different parts of the Sahara and Sahel zones. Blood spots from finger-prick samples of malaria cases were processed to identify parasite DNA by species-specific PCR.ResultsOut of 472 malaria cases examined, 163 (34.5 %) had P. vivax alone, 296 (62.7 %) Plasmodium falciparum alone, and 13 (2.8 %) had mixed P. falciparum and P. vivax infection. All cases were negative for Plasmodium malariae and Plasmodium ovale. The parasite species distribution showed a broad spectrum, P. vivax being detected at six of the different sites, in five of the country’s major administrative regions (Tiris Zemmour, Tagant, Brakna, Assaba, and the capital Nouakchott). Most cases in Nouakchott were due to P. vivax, although proportions vary significantly among different health facilities in the city. In the northern town of Zouérat, all cases were due to P. vivax, whereas almost all cases in the south of the country were due to P. falciparum. All P. vivax cases tested were Duffy blood group positive.ConclusionsIt is important that P. vivax is recognized to be a widespread cause of malaria in Mauritania, occurring in diverse regions. This should be noted by the World Health Organization, as it has significant implications for diagnosis, treatment and control of malaria in the northwestern part of Africa.

The BD FACSPresto Point of Care CD4 Test Accurately Enumerates CD4+ T Cell Counts

ObjectiveCurrently 50% of ART eligible patients are not yet receiving life-saving antiretroviral therapy (ART). Financial constraints do not allow most developing countries to adopt a universal test and offer ART strategy. Decentralizing CD4+ T cell testing may, therefore, provide greater access to testing, ART, and better patient management. We evaluated the technical performance of a new point-of-care CD4+ T cell technology, the BD FACSPresto, in a field methods comparison study.Methods264 HIV-positive patients were consecutively enrolled and included in the study. The BD FACSPresto POC CD4+ T cell technology was placed in two rural health care facilities and operated by health care facility staff. We compared paired finger-prick and venous samples using the BD FACSPresto and several existing reference technologies, respectively.ResultsThe BD FACSPresto had a mean bias of 67.29 cells/ul and an r2 of 0.9203 compared to the BD FACSCalibur. At ART eligibility thresholds of 350 and 500 cells/ul, the sensitivity to define treatment eligibility were 81.5% and 77.2% and the specificities were 98.9% and 100%, respectively. Similar results were observed when the BD FACSPresto was compared to the BD FACSCount and Alere Pima. The coefficient of variation (CV) was less than 7% for both the BD FACSCalibur and BD FACSPresto. CD4+ T cell testing by nurses using the BD FACSPresto at rural health care facilities showed high technical similarity to test results generated by laboratory technicians using the BD FACSPresto in a high functioning laboratory.ConclusionsThe BD FACSPresto performed favorably in the laboratory setting compared to the conventional reference standard technologies; however, the lower sensitivities indicated that up to 20% of patients tested in the field in need of treatment would be missed. The BD FACSPresto is a technology that can allow for greater decentralization and wider access to CD4+ T cell testing and ART.