Comparison of the Fluorescent Antibody Test and Direct Microscopic
Examination for Rabies Diagnosis at the National Veterinary Research
Institute, Vom, Nigeria.
One hundred and eighty-nine (189) dog brain samples submitted to the
National Veterinary Research Institute, Vom, Nigeria for rabies
diagnosis were assayed by the Direct Microscopic Examination (DME) for
Negri bodies, the Fluorescent Antibody Test (FAT) for rabies antigens,
and the Mouse Inoculation Test (MIT). The MIT was used as a
confirmatory test. There were 12(12.5%) false negative and 6(6.7%)
false positive results with DME, while there was 2(1.7%) false negative
and 2(1.7%) false positive with FAT. The FAT was more sensitive
(98.26%) than the DME (87.5%), and also more specific, 97.29% and
93.55% respectively. The FAT predicted positive and negative results
more accurately than the DME. Positive predictive value of FAT was
98.26% compared with 93.33% of DME, and the negative predictive value
of FAT was 97.29% compared with DME’s 87.88%. The pre-test
probability of rabies in Vom was 60.8%. This finding shows that FAT is
a sensitive and reliable rabies diagnostic test than DME and its
continued use is recommended in Nigeria whenever is feasible. The DME
is still useful as a screening test, and the MIT must be used to
confirm both FAT and DM