Comparison of virus isolation, immunofluorescence and electron microscopy for the diagnosis of animal viruses.

Results of 539 virus-positive samples from animals during the past three years were analyzed to determine the sensitivity of three different techniques i.e. virus isolation (VI), direct immunofluorescence (DFA), and electron microscopy (EM). The results showed that most of the positive cases were diagnosed with the help of all three techniques, either alone or in different combinations. While VI and DFA were more effective for the detection of bovine viral diarrhea, pseudorabies and infectious bovine rhinotracheitis viruses, EM was more sensitive for the detection of rota- and coronaviruses. The need for selective use of these tests for rapid diagnosis and the role of different factors affecting the sensitivity of these tests are discussed.