title: Serodiagnosis of western equine encephalitis virus infections: relationships of antibody titer and test to observed onset of clinical illness.
abstract: Sera from horses and human beings with clinically diagnosed western equine encephalitis (WEE) virus infections were tested for hemagglutination-inhibition (HI), complement-fixation (CF), and neutralizing (N) antibody to WEE virus. These tests confirmed infection in 43.8% (HI), 56.3% (CF), and 80.4% (N) of horses and 54.5% (HI), 59.1% (CF), and 77.3% (N) of human beings. Use of the N test as an adjunct to the HI and CF tests increased the likelihood of serologic confirmation to 91.7%. In both horses and human beings, N antibody increased steeply at the end of the 1st week after onset. The results suggested that the presence of a high HI, CF, and/or N antibody titer in a single serum obtained from horses during the acute phase of illness caused by WEE virus can be used as presumptive evidence for infection with this virus.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis*; D004667:Encephalitis Virus, Western Equine / Q000276:immunology*; D004683:Encephalomyelitis, Equine / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D006734:Horse Diseases / Q000175:diagnosis* / Q000276:immunology; D006736:Horses; D006801:Humans; D013997:Time Factors
chemical_list: D000914:Antibodies, Viral