Testing for the specific viral cause can be done but has little effect on management and thus is not routinely recommended. RSV testing by direct immunofluorescence testing on nasopharyngeal aspirate had a sensitivity of 61% and specificity of 89%. Identification of those who are RSV-positive can help for disease surveillance, grouping ("cohorting") people together in hospital wards to prevent cross infection, predicting whether the disease course has peaked yet, and reducing the need for other diagnostic procedures (by providing confidence that a cause has been identified). Identification of the virus may help reduce the use of antibiotics.