Let's take a look at what constitutes vaccine-related disease by assessing these cases using the widely acknowledged reference for yellow fever vaccine related disease, the Brighton Collaboration Criteria (Viscerotropic
disease: Case definition and guidelines for collection, analysis, and presentation of immunization safety data, Vaccine 2012 July 13; 30(33): 5038-5058.
tropica, has been implicated in occasional cases of recidivans or viscerotropic
NDV's also differ in the severity and type of the anomalies they cause, and various pathotypes, based on pathogenicity in poultry and the patterns around the protease cleavage site of fusion protein (F), have been defined in poultry: viscerotropic
velogenic, neurotropic velogenic, mesogenic, lentogenic or respiratory, and asymptomatic (Alexander and Senne, 2008).
The velogenic strains (neurotrophic or viscerotropic
) are highly fatal and therefore demonstrate the severest clinical form of the disease, causing haemorrhagic gastroenteritis, pneumonia, and/or encephalitis [20, 21].
Newcastle disease virus (NDV) can be grouped into five pathotypes with respect to tissue tropism and clinical signs, that is to say, (a) viscerotropic
velogenic pathotype and (b) neurotropic velogenic pathotype.
These histopathological aspects differ from those that have been described in the Old World for cutaneous lesions caused by other viscerotropic
species, such as Leishmania (L.) donovani and Leishmania (L.) infantum [8,9].
YF-VAAE symptoms can overlap those of YF disease (9).
Difference in viral antigens distribution between wild type and vaccine-associated viscerotropic
yellow fever fatal cases.
These patients should not undergo yellow fever vaccination, as there is a risk of developing a serious adverse event, specifically yellow fever vaccine-associated viscerotropic
disease, which is a systemic disease associated with multi-organ failure and death.
A comparison of the onset of protection induced by Newcastle disease virus strain B1 and a fowl poxvirus recombinant Newcastle disease vaccine to a viscerotropic
velogenic Newcastle disease virus challenge.
Results revealed that geometric mean titer values assessed up to 6 (log2) or above, provided excellent protection to chickens when challenged with viscerotropic
velogenic form of Newcastle Disease Virus (vvNDV).
It covers the following: laws and regulations for backyard poultry in the US, common breeds, basic housing and management, husbandry and management, nutrition, and parasitic diseases; physical examination, anatomy, physiology, biosecurity and zoonotic diseases, avian influenza and viscerotropic
velogenic (exotic) Newcastle disease, simple and complex surgeries, and respiratory, musculoskeletal, reproductive, gastrointestinal, hepatic, and cardiovascular diseases; and diagnostics, laboratory sampling and interpretation, medication use, and vaccination.