This article needs more reliable medical references for verification or relies too heavily on primary sources .(February 2023) |
Avian orthoavulavirus 1 | |
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Avian orthoavulavirus 1 (stained in brown) in the conjunctiva of a chicken | |
Virus classification | |
(unranked): | Virus |
Realm: | Riboviria |
Kingdom: | Orthornavirae |
Phylum: | Negarnaviricota |
Class: | Monjiviricetes |
Order: | Mononegavirales |
Family: | Paramyxoviridae |
Genus: | Orthoavulavirus |
Species: | Avian orthoavulavirus 1 |
Virulent Newcastle disease (VND), formerly exotic Newcastle disease, [1] is a contagious viral avian disease affecting many domestic and wild bird species; it is transmissible to humans. [2] Though it can infect humans, most cases are non-symptomatic; rarely it can cause a mild fever and influenza-like symptoms and/or conjunctivitis in humans. Its effects are most notable in domestic poultry due to their high susceptibility and the potential for severe impacts of an epizootic on the poultry industries. It is endemic to many countries. No treatment for VND is known, but the use of prophylactic vaccines [3] and sanitary measures reduces the likelihood of outbreaks.
The disease is caused by Newcastle disease virus (NDV), an avulavirus. Strains of Newcastle disease virus have been used to treat cancer in humans, since the virus appears to preferentially infect and kill cancerous cells. Strains of Newcastle disease virus have also been used to create viral vector vaccine candidates against Ebola and Covid-19. [4] [5]
Newcastle disease was first identified in Java, Indonesia, in 1926, and in Newcastle upon Tyne, England, in 1927. However, it may have been prevalent as early as 1898, when a disease wiped out all the domestic fowl in northwest Scotland. [6]
The policy of slaughter ceased in England and Wales on 31 March 1963, except for the peracute form of Newcastle disease and for fowl plague. In Scotland the slaughter policy continued for all types of fowl pest. [7]
Interest in the use of NDV as an anticancer agent has arisen from the ability of NDV to selectively kill human tumour cells with limited toxicity to normal cells. [8] [9]
Since May 2018, California Department of Food and Agriculture staff and the United States Department of Agriculture have been working on eliminating VND in South California and more than 400 birds have been confirmed to have VND. [10] [11] On February 27, 2019, the California state veterinarian, Annette Jones, increased the quarantine area in Southern California and on March 15, 2019 and April 5, 2019, cases of VND in Northern California and Arizona respectively. [12]
The causal agent, Newcastle disease virus (NDV), is a variant of avian orthoavulavirus 1, a negative-sense, single-stranded RNA virus. NDV belongs to the subfamily Avulavirinae , which infect birds. Transmission occurs by exposure to faecal and other excretions from infected birds, and through contact with contaminated food, water, equipment, and clothing.
NDV strains can be categorised as velogenic (highly virulent), mesogenic (intermediate virulence), or lentogenic (nonvirulent). Velogenic strains produce severe nervous and respiratory signs, spread rapidly, and cause up to 90% mortality. Mesogenic strains cause coughing, affect egg quality and production, and result in up to 10% mortality. Lentogenic strains produce mild signs with negligible mortality.
NDV is spread primarily through direct contact between healthy birds and the bodily discharges of infected birds. The disease is transmitted through infected birds' droppings and secretions from the nose, mouth, and eyes. NDV spreads rapidly among birds kept in confinement, such as commercially raised chickens.
High concentrations of the NDV are found in birds' bodily discharges; therefore, the disease can be spread easily by mechanical means. Virus-bearing material can be picked up on shoes and clothing and carried from an infected flock to a healthy one.
NDV can survive for several weeks in a warm and humid environment on birds' feathers, manure, and other materials. It can survive indefinitely in frozen material. However, the virus is destroyed rapidly by dehydration and by the ultraviolet rays in sunlight. Smuggled pet birds, especially Amazon parrots from Latin America, pose a great risk of introducing NDV into the US. Amazon parrots are carriers of the disease, but do not show symptoms, and are capable of shedding NDV for more than 400 days.
Signs of infection with NDV vary greatly depending on factors such as the strain of virus and the health, age and species of the host.
The incubation period for the disease ranges from 2 to 15 days. [13] An infected bird may exhibit several signs, including respiratory signs (gasping, coughing), nervous signs (depression, inappetence, muscular tremors, drooping wings, twisting of head and neck, circling, complete paralysis), swelling of the tissues around the eyes and neck, greenish, watery diarrhoea, misshapen, rough- or thin-shelled eggs and reduced egg production.
In acute cases, the death is very sudden, and, in the beginning of the outbreak, the remaining birds do not seem to be sick. In flocks with good immunity, however, the signs (respiratory and digestive) are mild and progressive, and are followed after seven days by nervous symptoms, especially twisted heads.[ citation needed ]
Petechiae in the proventriculus and on the submucosae of the gizzard are typical; also, severe enteritis of the duodenum occurs. The lesions are scarce in hyperacute cases (first day of outbreak).
Enzyme-linked immunosorbent assay, polymerase chain reaction, and sequence technology tests have been developed.
For routine isolation of NDV from chickens, turkeys, and other birds, samples are obtained by swabbing the trachea and the cloaca. Cotton swabs can be used. The virus can also be isolated from the lungs, brain, spleen, liver, and kidneys.
Prior to shipping, samples should be stored at 4 °C (refrigerator). Samples must be shipped in a padded envelope or box. Samples may be sent by regular mail, but overnight is recommended. [14]
Any animals showing symptoms of Newcastle disease should be isolated immediately. New birds should also be vaccinated before being introduced to a flock. An inactivated viral vaccine is available, as well as various combination vaccines. [3] [15] [16] A thermotolerant vaccine is available for controlling Newcastle disease in underdeveloped countries. [17] Schiappacasse et al 2020 demonstrates successful, complete inactivation of the virus in a space using a nonthermal plasma generator. [18]
Though the oncolytic effect of NDV was already documented in the 1950s, later advances in research into using viruses in cancer therapy came with the advent of reverse genetics technologies. [19] Later on it was Csatary LK and his colleagues to document anti-cancer effects in patients with brain gliomas. [20] [21]
One of the main issues using NDV would be the host/patient immune response against the virus itself, which prior to the time of the reverse genetics technology, decreased the potential applicability of NDV as a cancer treatment. [19] [22]
As of 2018 [update] there had been several clinical studies into the use of NDV for cancer treatment, but the research quality was low and the outcomes inconclusive. [23]
Influenza A virus (IAV) is the only species of the genus Alphainfluenzavirus of the virus family Orthomyxoviridae. It is a pathogen with strains that infect birds and some mammals, as well as causing seasonal flu in humans. Mammals in which different strains of IAV circulate with sustained transmission are bats, pigs, horses and dogs; other mammals can occasionally become infected.
Avian influenza, also known as avian flu or bird flu, is a disease caused by the influenza A virus, which primarily affects birds but can sometimes affect mammals including humans. Wild aquatic birds are the primary host of the influenza A virus, which is enzootic in many bird populations.
Influenza A virus subtype H5N1 (A/H5N1) is a subtype of the influenza A virus, which causes influenza (flu), predominantly in birds. It is enzootic in many bird populations, and also panzootic. A/H5N1 virus can also infect mammals that have been exposed to infected birds; in these cases, symptoms are frequently severe or fatal.
Swine influenza is an infection caused by any of several types of swine influenza viruses. Swine influenza virus (SIV) or swine-origin influenza virus (S-OIV) refers to any strain of the influenza family of viruses that is endemic in pigs. As of 2009, identified SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H2N1, H3N1, H3N2, and H2N3.
Infectious bursal disease (IBD), also known as Gumboro disease, infectious bursitis, and infectious avian nephrosis, is a highly contagious disease of young chickens and turkeys caused by infectious bursal disease virus (IBDV), characterized by immunosuppression and mortality generally at 3 to 6 weeks of age. The disease was first discovered in Gumboro, Delaware in 1962. It is economically important to the poultry industry worldwide due to increased susceptibility to other diseases and negative interference with effective vaccination. In recent years, very virulent strains of IBDV (vvIBDV), causing severe mortality in chicken, have emerged in Europe, Latin America, South-East Asia, Africa, and the Middle East. Infection is via the oro-fecal route, with affected birds excreting high levels of the virus for approximately 2 weeks after infection. The disease is easily spread from infected chickens to healthy chickens through food, water, and physical contact.
Marek's disease is a highly contagious viral neoplastic disease in chickens. It is named after József Marek, a Hungarian veterinarian who described it in 1907. Marek's disease is caused by an alphaherpesvirus known as "Marek's disease virus" (MDV) or Gallid alphaherpesvirus 2 (GaHV-2). The disease is characterized by the presence of T cell lymphoma as well as infiltration of nerves and organs by lymphocytes. Viruses related to MDV appear to be benign and can be used as vaccine strains to prevent Marek's disease. For example, the related herpesvirus found in turkeys (HVT), causes no apparent disease in the birds, and continues to be used as a vaccine strain for prevention of Marek's disease.
An influenza pandemic is an epidemic of an influenza virus that spreads across a large region and infects a large proportion of the population. There have been six major influenza epidemics in the last 140 years, with the 1918 flu pandemic being the most severe; this is estimated to have been responsible for the deaths of 50–100 million people. The 2009 swine flu pandemic resulted in under 300,000 deaths and is considered relatively mild. These pandemics occur irregularly.
Singapore has taken a series of measures against avian influenza and the potential threat of a pandemic.
Transmission and infection of H5N1 from infected avian sources to humans has been a concern since the first documented case of human infection in 1997, due to the global spread of H5N1 that constitutes a pandemic threat.
The genetic structure of H5N1, a highly pathogenic avian influenza virus, is characterized by a segmented RNA genome consisting of eight gene segments that encode for various viral proteins essential for replication, host adaptation, and immune evasion.
Aujeszky's disease, usually called pseudorabies in the United States, is a viral disease in swine that is endemic in most parts of the world. It is caused by Suid herpesvirus 1 (SuHV-1). Aujeszky's disease is considered to be the most economically important viral disease of swine in areas where classical swine fever has been eradicated. Other mammals, such as cattle, sheep, goats, cats, dogs, and raccoons, are also susceptible. The disease is usually fatal in these animal species.
Feline calicivirus (FCV) is a virus of the family Caliciviridae that causes disease in cats. It is one of the two important viral causes of respiratory infection in cats, the other being Felid alphaherpesvirus 1. FCV can be isolated from about 50% of cats with upper respiratory infections. Cheetahs are the other species of the family Felidae known to become infected naturally.
Canarypox virus (CNPV) is an Avipoxvirus and etiologic agent of canarypox, a disease of wild and captive birds that can cause significant losses. Canarypox can enter human cells, but it cannot survive and multiply in human cells. There is a live viral vaccine available which may have beneficial properties against human cancer when used as a mammalian expression vector.. Furthermore, the Poximune C vaccine does offer direct protection against CNPV in susceptible birds.
Fujian flu refers to flu caused by either a Fujian human flu strain of the H3N2 subtype of the Influenza A virus or a Fujian bird flu strain of the H5N1 subtype of the Influenza A virus. These strains are named after Fujian, a coastal province in Southeast China.
H5N1 influenza virus is a type of influenza A virus which mostly infects birds. H5N1 flu is a concern due to the its global spread that may constitute a pandemic threat. The yardstick for human mortality from H5N1 is the case-fatality rate (CFR); the ratio of the number of confirmed human deaths resulting from infection of H5N1 to the number of those confirmed cases of infection with the virus. For example, if there are 100 confirmed cases of a disease and 50 die as a consequence, then the CFR is 50%. The case fatality rate does not take into account cases of a disease which are unconfirmed or undiagnosed, perhaps because symptoms were mild and unremarkable or because of a lack of diagnostic facilities. The Infection Fatality Rate (IFR) is adjusted to allow for undiagnosed cases.
A panzootic is an epizootic that spreads across a large region, or even worldwide. The equivalent in human populations is called a pandemic.
Influenza, commonly known as the flu, is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin one to four days after exposure to the virus and last for about two to eight days. Diarrhea and vomiting can occur, particularly in children. Influenza may progress to pneumonia from the virus or a subsequent bacterial infection. Other complications include acute respiratory distress syndrome, meningitis, encephalitis, and worsening of pre-existing health problems such as asthma and cardiovascular disease.
In animals, rabies is a viral zoonotic neuro-invasive disease which causes inflammation in the brain and is usually fatal. Rabies, caused by the rabies virus, primarily infects mammals. In the laboratory it has been found that birds can be infected, as well as cell cultures from birds, reptiles and insects. The brains of animals with rabies deteriorate. As a result, they tend to behave bizarrely and often aggressively, increasing the chances that they will bite another animal or a person and transmit the disease.
The pandemic H1N1/09 virus is a swine origin influenza A virus subtype H1N1 strain that was responsible for the 2009 swine flu pandemic. This strain is often called swine flu by the public media due to the prevailing belief that it originated in pigs. The virus is believed to have originated around September 2008 in central Mexico.
Influenza A virus subtype H7N9 (A/H7N9) is a subtype of the influenza A virus, which causes influenza (flu), predominantly in birds. It is enzootic in many bird populations. The virus can spread rapidly through poultry flocks and among wild birds; it can also infect humans that have been exposed to infected birds.