Studies are difficult in areas lacking modern facilities due to the inability to reliably collect, store, and ship samples. Thus, we sought to evaluate the use of a dry plasma collection device for seroepidemiology studies. Plasma was obtained by fingerstick using a commercial dry plasma collection device (Chemcard Plasma Collection Device) and serum (venipuncture) from individuals in Kazakhstan. Plasma samples were air dried for 15 min and then stored desiccated in foil zip-lock pouches at 4 to 6°C and subsequently shipped to the United States by air at ambient temperature. Serum samples remained frozen at ؊20°C until assayed. Helicobacter pylori status was determined by enzyme-linked immunosorbent assay (HM-CAP EIA) for the dry plasma and the serum samples. The results were concordant in 250 of the 289 cases (86.5%). In 25 cases (8.6%), the dry plasma samples gave indeterminate results and could not be retested because only one sample was collected. Five serum samples were positive, and the corresponding dry plasma samples were negative; one serum sample was negative, and the corresponding plasma sample was positive. The relative sensitivity and specificity of the Chemcard samples to serum were 97.6 and 97.9%, respectively, excluding those with indeterminate results. Repeated freeze-thawing had no adverse effect on the accuracy of the test. We found the dry plasma collection device to provide an accurate and practical alternative to serum when venipuncture may be difficult or inconvenient and sample storage and handling present difficulties, especially for seroepidemiologic studies in rural areas or developing countries and where freeze-thawing may be unavoidable.Helicobacter pylori is a major human pathogen that is etiologically linked to gastritis, peptic ulcer disease, gastric adenocarcinoma, and primary gastric B-cell lymphoma (1, 3). There is continued interest in the epidemiology of H. pylori infection in order to better characterize the prevalence of infection, as well as the natural history and mode of transmission of the infection (1, 3). One problem with obtaining specimens from developing countries, where the infection is most common, has been the ability to reliably collect, store, and assay serum or plasma samples (N. Broutet, G. Duperrex, B. Bergery, and F. Megraud, Letter, Lancet 354:1529-1530, 1999). The problems relating to storage and transport of these samples have often been the limiting factor in determining which questions can be addressed in seroepidemiologic studies, especially in areas lacking modern medical facilities. Shipment of frozen serum samples is expensive, requiring the use of dry ice and expedited shipping schedules, and requires compliance with national and international regulations governing the shipment of biohazardous materials. Delays are not uncommon and can result in compromised samples. A method that eliminated the need to store and ship frozen serum would therefore be welcome. We evaluated the feasibility of using a simple device that allows collection of dry plasma...
