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Chin C.D.,Columbia University | Laksanasopin T.,Columbia University | Cheung Y.K.,Columbia University | Steinmiller D.,Claros Diagnostics | And 15 more authors.
Nature Medicine | Year: 2011

One of the great challenges in science and engineering today is to develop technologies to improve the health of people in the poorest regions of the world. Here we integrated new procedures for manufacturing, fluid handling and signal detection in microfluidics into a single, easy-to-use point-of-care (POC) assay that faithfully replicates all steps of ELISA, at a lower total material cost. We performed this 'mChip' assay in Rwanda on hundreds of locally collected human samples. The chip had excellent performance in the diagnosis of HIV using only 1 Î 1/4l of unprocessed whole blood and an ability to simultaneously diagnose HIV and syphilis with sensitivities and specificities that rival those of reference benchtop assays. Unlike most current rapid tests, the mChip test does not require user interpretation of the signal. Overall, we demonstrate an integrated strategy for miniaturizing complex laboratory assays using microfluidics and nanoparticles to enable POC diagnostics and early detection of infectious diseases in remote settings. © 2011 Nature America, Inc. All rights reserved.

Chin C.D.,Columbia University | Cheung Y.K.,Columbia University | Laksanasopin T.,Columbia University | Modena M.M.,Columbia University | And 16 more authors.
Clinical Chemistry | Year: 2013

Background: Collection of epidemiological data and care of patients are hampered by lack of access to laboratory diagnostic equipment and patients' health records in resource-limited settings. We engineered a low-cost mobile device that combines cell-phone and satellite communication technologies with fluid miniaturization techniques for performing all essential ELISA functions. Methods: We assessed the device's ability to perform HIV serodiagnostic testing in Rwanda and synchronize results in real time with electronic health records. We tested serum, plasma, and whole blood samples collected in Rwanda and on a commercially available sample panel made of mixed antibody titers. Results: HIV testing on 167 Rwandan patients evaluated for HIV, viral hepatitis, and sexually transmitted infections yielded diagnostic sensitivity and specificity of 100% and 99%, respectively. Testing on 40 Rwandan whole-blood samples-using 1 μL of sample per patient-resulted in diagnostic sensitivity and specificity of 100% and 100%. The mobile device also successfully transmitted all whole-blood test results from a Rwandan clinic to a medical records database stored on the cloud. For all samples in the commercial panel, the device produced results in agreement with a leading ELISA test, including detection of weakly positive samples that were missed by existing rapid tests. The device operated autonomously with minimal user input, produced each result 10 times faster than benchtop ELISA, and consumed as little power as a mobile phone. Conclusions: A low-cost mobile device can perform a blood-based HIV serodiagnostic test with laboratorylevel accuracy and real-time synchronization of patient health record data. Copyright © 2012 American Association for Clinical Chemistry.

Mugo N.R.,University of Nairobi | Mugo N.R.,University of Washington | Heffron R.,University of Washington | Donnell D.,Fred Hutchinson Cancer Research Center | And 10 more authors.
AIDS | Year: 2011

BACKGROUND: Physiologic and behavioral changes during pregnancy may alter HIV-1 susceptibility and infectiousness. Prospective studies exploring pregnancy and HIV-1 acquisition risk in women have found inconsistent results. No study has explored the effect of pregnancy on HIV-1 transmission risk from HIV-1-infected women to male partners. METHODS: In a prospective study of African HIV-1-serodiscordant couples, we evaluated the relationship between pregnancy and the risk of HIV-1 acquisition among women and HIV-1 transmission from women to men. RESULTS: Three thousand three hundred and twenty-one HIV-1-serodiscordant couples were enrolled, 1085 (32.7%) with HIV-1 susceptible female partners and 2236 (67.3%) with susceptible male partners. HIV-1 incidence in women was 7.35 versus 3.01 per 100person-years during pregnant and nonpregnant periods [hazard ratio 2.34, 95% confidence interval (CI) 1.33-4.09]. This effect was attenuated and not statistically significant after adjusting for sexual behavior and other confounding factors (adjusted hazard ratio 1.71, 95% CI 0.93-3.12). HIV-1 incidence in male partners of infected women was 3.46 versus 1.58 per 100person-years when their partners were pregnant versus not pregnant (hazard ratio 2.31, 95% CI 1.22-4.39). This effect was not attenuated in adjusted analysis (adjusted hazard ratio 2.47, 95% CI 1.26-4.85). CONCLUSION: HIV-1 risk increased two-fold during pregnancy. Elevated risk of HIV-1 acquisition in pregnant women appeared in part to be explained by behavioral and other factors. This is the first study to show that pregnancy increased the risk of female-to-male HIV-1 transmission, which may reflect biological changes of pregnancy that could increase HIV-1 infectiousness. © 2011 Wolters Kluwer Health | Lippincott Williams &Wilkins.

Lambdin B.H.,Pangaea Global AIDS Foundation | Kanweka W.,Us Agency For International Development | Inambao M.,Zambia Emory HIV Research Project | Mwananyanda L.,Mothers2mothers | And 6 more authors.
Health Affairs | Year: 2011

Couples in sub-Saharan Africa are the largest group in the world at risk for HIV infection. Couples counseling and testing programs have been shown to reduce HIV transmission, but such programs remain rare in Africa. Before couples counseling and testing can become the norm, it is essential to increase demand for the services. We evaluated the effectiveness of several promotional strategies during a two-year program in Kitwe and Ndola, Zambia. The program attracted more than 7,600 couples through the use of radio broadcasts, billboards, and other strategies. The most effective recruiting technique was the use of local residents trained as "influence agents" to reach out to friends, neighbors, and others in their sphere of influence. © 2011 Project HOPE-The People-to-People Health Foundation, Inc.

Baeten J.M.,University of Washington | Donnell D.,Fred Hutchinson Cancer Research Center | Kapiga S.H.,London School of Hygiene and Tropical Medicine | Kapiga S.H.,Kilimanjaro Christian Medical Center | And 6 more authors.
AIDS | Year: 2010

Objective: Male circumcision reduces female-to-male HIV-1 transmission risk by approximately 60%. Data assessing the effect of circumcision on male-to-female HIV-1 transmission are conflicting, with one observational study among HIV-1-serodiscordant couples showing reduced transmission but a randomized trial suggesting no short-term benefit of circumcision. DESIGN/Methods: Data collected as part of a prospective study among African HIV-1-serodiscordant couples were analyzed for the relationship between circumcision status of HIV-1-seropositive men and risk of HIV-1 acquisition among their female partners. Circumcision status was determined by physical examination. Cox proportional hazards analysis was used. Results: A total of 1096 HIV-1-serodiscordant couples in which the male partner was HIV-1-infected were followed for a median of 18 months; 374 (34%) male partners were circumcised. Sixty-four female partners seroconverted to HIV-1 (incidence 3.8 per 100 person-years). Circumcision of the male partner was associated with a nonstatistically significant approximately 40% lower risk of HIV-1 acquisition by the female partner (hazard ratio 0.62, 95% confidence interval 0.35-1.10, P = 0.10). The magnitude of this effect was similar when restricted to the subset of HIV-1 transmission events confirmed by viral sequencing to have occurred within the partnership (n = 50, hazard ratio 0.57, P = 0.11), after adjustment for male partner plasma HIV-1 concentrations (hazard ratio 0.60, P = 0.13), and when excluding follow-up time for male partners who initiated antiretroviral therapy (hazard ratio 0.53, P = 0.07). Conclusion: Among HIV-1-serodiscordant couples in which the HIV-1-seropositive partner was male, we observed no increased risk and potentially decreased risk from circumcision on male-to-female transmission of HIV-1. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.

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