Laboratory Differential Diagnosis of Vesicular Skin Rashes

Human vaccinia-like virus outbreaks in São Paulo and Goiás States, Brazil: virus detection, isolation and identification

“…Virus identification on CAM is done by observation of characteristic lesions (pocks) produced on it. Direct electron microscopy (DEM) is the quickest method available for viral diagnosis as the virus particles can be detected in less than 30 minutes 4,7,15,21,24,38 . Serological methods as neutralization and hemagglutination inhibition tests can also be used 24 .…”

Laboratory diagnosis of smallpox: role of the Virus Reference Laboratory, Colindale, 1947–70

“…It stemmed from the application of the pioneering work by Downie (1943Downie ( , 1946Downie ( , 1947 on laboratory diagnosis in smallpox, in which he combined the serological vaccinia-variola group reaction (Craigie & Wishart, 1936) with viral culture on the chorioallantoic membrane of the developing chick embryo (Downie, 1939;Irons et al 1941 (Dumbell & Nizamuddin, 1959) which would provide an answer on vaccinia-variola within 1-2 h though it was less useful for chickenpox. The value of electron microscopy in demonstrating the presence of poxviruses or other viruses, established by Peters, Nielson & Bayer (1962) and Nagington & Macrae (1965), was extensively confirmed (Cruickshank, Bedson & Watson, 1966) (Macrae et al 1969). From that time its most effective use was in the differential diagnosis of vesicular skin rashes, particularly for distinguishing the herpesvirus particles of chickenpox.…”

Diagnostic Virology Using Electron Microscopic Techniques

“…Although smallpox has been eradicated other diagnostic problems remain for solution by electron microscopy. Compared with virus isolation and gel precipitin tests electron microscopy was conspicuously effective in diagnosis of varicella zoster virus infections (Cruickshank et Macrae et al, 1969). Orf virus grows only with difficulty and electron microscopy is the only practical diagnostic method; similarly, laboratory diagnosis of molluscum contagiosum is possible only by electron microscopy.…”

“…Human monkeypox infections were diagnosed by electron microscopy and in some cases other laboratory tests were negative (Breman et al, 1980). Negative stain IEM is not useful in this diagnostic situation because of the small sample size and because other laboratory tests can be more simply used to give precise identification (Macrae et al, 1969). Compared with virus isolation and gel precipitin tests electron microscopy was conspicuously effective in diagnosis of varicella zoster virus infections (Cruickshank et Macrae et al, 1969).…”