Immunohistochemical study of human rabies

Abstract

Rabies is a communicable disease that is almost always fatal. In its classic form, rabies is well recognized, but cases presenting with a paralytic illness mimic Landre's Guillain-Barre syndrome and in such cases the diagnosis remains in doubt. This problem is further compounded when the history of dogbite is not forthcoming. At autopsy rabies can be diagnosed by subjecting fresh tissue to virologic investigations or examining formalin-fixed paraffin-embedded tissue sections for the presence of characteristic inclusions; that is, the Negri bodies. However, these inclusions are not present in all cases. Hence, the need arises for a better method for diagnosis. The present study utilized immunohistochemistry as a diagnostic tool using both monoclonal and polyclonal antirabies antibodies in 20 cases of rabies encephalomyelitis. The diagnosis of rabies could be confirmed in 17 cases (85%) based on neuropathologic findings alone. In contrast, immunohistochemistry yielded positive results in all cases. Moreover, the amount of rabies viral antigen was much more abundant than could be expected from the histopathologic findings. Thus immunohistochemistry is a rapid, safe, sensitive and specific technique for the diagnosis of rabies.

Rabies Prevalence in Migratory Tree-Bats in Alberta and the Influence of Roosting Ecology and Sampling Method on Reported Prevalence of Rabies in Bats

“…We also recognize that there may be temporal differences in rabies prevalence when estimates from half a century ago are compared with contemporary estimates. Many early diagnostic reports in the 1950s and 1960s were based on the presence of Negri bodies to confirm RABV, but it is now well recognized that Negri bodies may not always be observed in rabid animals (Jogai et al, 2000). With the increased sensitivity of the fluorescent antibody test for rabies diagnostics, it is possible that estimates of prevalence would be slightly higher than older reports.…”

Ocorrência de raiva em ovinos no Rio Grande do Sul

“…Essa região (tronco encefálico) foi selecionada para IHQ por ser a área de eleição para testes de marcação antigênica em bovinos (Bingham & van der Merwe 2002). A técnica de IHQ mostrou ser específica e sensível para a confirmação do diagnóstico e vem sendo usada como ferramenta adicional no diagnóstico de raiva em humanos e animais, principalmente em casos onde há somente meningoencefalite não-supurativa, sem CN, em casos em que as técnicas de IFD e ICC resultam negativas e na realização de estudos retrospectivos de material emblocado em parafina (Jogai et al 2000, Vural et al 2001, Arslan et al 2004, Pierezan et al 2007). Nos neurônios marcados positivamente eram observados antígenos virais distribuídos como finos grâ-nulos dispersos pelo citoplasma ou em densos agregados circulares de 3-10 μm de diâmetro.…”

Rabies Meningoencephalomyelitis presenting as Guillain Barré Syndrome

“…6,7 Multiple factors are responsible for this phenomenon. Firstly, diagnosis of rabies is not clinically suspected particularly in paralytic type where patients present with ascending paralysis (Guillain-Barre syndrome like picture) and therefore the history of dog bite is not specifically elicited at the time of clinical examination.…”

“…6,15 Unsuccessful immunization attempts were thought to be a predisposing factor for paralytic rabies, but this proposition was not supported by facts. In some series, only 4/18 and in others 1/3 patients had received postexposure vaccination.…”