An evaluation of oral-fluid collection devices for the determination of rubella antibody status in a rural Ethiopian community

We compared 3 different oral-fluid collection devices to assess their suita bility for use in community studies of rubella antibody. Of 58 individuals enrolled from 13 households from a southern Ethiopian village, 38 provided a blood sample and oral fluids by the 3 devices: 2 proprietary, Omni-SAL an d OraSure, and a third a polystyrene sponge swab (Sponge). The Sponge swab, used like a toothbrush, was most acceptable to survey staff and to partici pants of all ages, although it proved ill-adapted for fluid extraction. The other devices more often caused participant discomfort or anxiety, particu larly in the young. Statistical comparison of rubella-specific immunoglobul in (Ig) G in oral fluid, measured by antibody-capture radioimmunoassay, and in serum, by indirect enzyme-linked immunosorbent assay, showed no clear d ifferences between the devices in oral-fluid performance. Specificity range was 75-100% and sensitivity 73-85%, relative to serum. Specific-antibody l evels declined with increasing age, with concomitant decreases in sensitivi ty, as previously documented. The relationship between specific IgG and tot al IgG in oral fluid differed by device. Specific IgG levels were highly co rrelated between paired samples using the Sponge device. We consider the Sp onge device to be the most suitable for community survey work, although the extraction method requires improvement. Further work is needed to improve the sensitivity of antibody status determination in adults.