Newcastle Disease (ND), also termed avian pneumoencephalitis or Ranikhet disease, is a highly contagious viral infection that affects virtually all bird species with a mortality rate of up to 90% depending on the viral strain. Humans in direct contact with affected birds can pick up the causative avian paramyxovirus-1. Infected humans may show mild symptoms of conjunctivitis or periocular inflammation which resolve spontaneously within a few days. No treatment is required in humans. Humans cannot pick up the virus from eating poultry products.
Newcastle Disease (ND) is a bird disease affecting numerous domestic and wild avian species. ND is caused by an infection with the avian paramyxovirus-1, a single-strand non-segmented RNA virus. Depending on its epidemic capacities, one can distinguish five subtypes: asymptomatic enteric strain, lentogenic strain, mesogenic strain, viscerotropic velogenic strain, and neurotropic velogenic strain .
It can be passed on to humans . While the symptoms in humans are very mild and essentially harmless, ND is fatal in birds with up to 90% probability. Humans may suffer from mild, spontaneously resolving conjunctivitis or eyelid edema for up to 14 days. The main role of humans as viral carriers lies in the possible contamination of remote healthy poultry populations . The virus can be picked up when humans are in direct contact with infected birds or their feces. Viral contamination easily spreads to farm equipment and work clothes. Poultry workers, vaccinators, and laboratory workers face an increased contamination risk.
In birds, ND can manifest with a variety of features. Most frequent avian manifestations are a tremor, paralysis, opisthotonos, greenish diarrhea, loss of appetite, twisted necks, clonic spasms, apathy, fever, coughing, dyspnea, and sneezing . Outbreaks can be managed with the reestablishment of high hygiene standards in affected poultry farms and prophylactic bird vaccination . Every single suspicion of an avian ND outbreak must be reported to public authorities.
If a patient presents with mild unexplained conjunctivitis and is in regular contact with affected birds, public authorities should be immediately informed about a potential ND outbreak. The causative RNA virus can be detected with enzyme-linked immunosorbent assay (ELISA) , reverse-transcriptase polymerase chain reaction (RT-PCR), or plaque neutralization test   . RT-PCR is often favored because of its unsurpassed specificity.
If the virus has been detected, the patient working with susceptible animals should be advised to decontaminate all equipment (tools, cars) and clothes that may have picked up the virus. Human symptoms of ND do not require particular medical attention since they resolve spontaneously. Ingestion of poultry products does not trigger an infection in humans .
Notably, paramyxovirus-1 has recently been presented as a potential oncolytic agent in humans and mammals in general .